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WARNING DANGEROUS VOLTAGES, capable of causing death or serious injury, are present on the external terminals and inside the equipment. Use extreme caution and follow all safety rules when handling, testing or adjusting the equipment. However, these internal voltage levels are no greater than the voltages applied to the external terminals.
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PRODUCT CAUTIONS Before attempting any test, calibration, or maintenance procedure, personnel must be completely familiar with the particular circuitry of this unit, and have an adequate understanding of field effect devices. If a component is found to be defective, always follow replacement procedures carefully to that assure safety features are maintained.
Table of Contents TABLE OF CONTENTS LTC Transformer Control System Including Paralleling and Backup Control Introduction Figure 1 LTC Transformer Control System and Paralleling Components ....1 LTC Transformer Control Connections ................2 Figure 2 M-2001D Bottom View ................2 M‑0169A Auxiliary Current Transformer ................
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LTC Transformer Control Comprehensive System Manual Delta VAr Peer‑to‑Peer Paralleling (Cont.) Figure 15 TapTalk Peer to Peer Paralleling Enable Sympathy Manual Mode ..21 Overview of Sympathy Manual Operation ................ 22 Figure 16 Four Transformer Delta VAr Peer to Peer Sympathy Manual Example .. 22 Delta VAr Peer to Peer Paralleling –...
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Table of Contents Classic Paralleling (Cont.) Figure 32 Paralleling Scheme for Two Transformers Using Circulating Current or Delta VAr1 ................54 Figure 33 Paralleling Scheme for Three Transformers Using Circulating Current or Delta VAr1 ................55 Table 4 Adapter Panel/Control Connections For Circulating Current or Delta VAr1 Paralleling ...................
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Table of Contents Appendix D Advanced Circulating Current Paralleling Method (Cont.) Figure D-1 Basic Circuit for Three LTC Transformer Paralleling using the Circulating Current Method, including Circuit Breaker Auxiliary Switch Contacts ..................D–4 Figure D-2 Basic Circuit for Three LTC Transformer Paralleling using the Circulating Current Method, with Transformer #3 Out of Service ..
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LTC Transformer Control Comprehensive System Manual Appendix F Basic Considerations for the Application of LTC Transformers and Associated Controls Overview ..........................F–2 Considerations ........................F–2 Voltage Regulation Principles ..................F–2 Figure F-1 Typical System One-Line Diagram – Bus Regulation ......F–3 Figure F-1(B) Typical System One-Line Diagram – Feeder Regulation ....F–3 Factors Which Cause V to Change ................F–4 Objective #1: Hold the Bus Voltage (V...
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Introduction This Comprehensive System Manual compiles LTC Transformer Control and Paralleling information from several Beckwith Electric Application Guides, Instruction Books and Specifications. This manual also contains the essential information needed to implement any one of several Paralleling methods offered in the M‑2001 Series Tapchanger Control.
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Refer to Appendix B Appendix B for the following product Specification sheets for mechanical specs and additional product specific information: • M‑0169A Auxiliary Current Transformer • M‑0329B LTC Backup Control • M‑2026 and M‑2027 Backup Power Supply • M‑0115A Parallel Balancing Module • M‑0127A/M‑0170A AC Current Relay...
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual M‑0329B LTC BACKUP CONTROL M‑0329B LTC BACKUP CONTROL The M‑0329B Backup Control offers reliable voltage protection from both improperly set and malfunctioning Tapchanger controls. The most common voltage error in setting tapchanger controls occurs when values of Line Drop Compensation are set in the tapchanger control that result in unexpectedly high voltage at the transformer due to higher than anticipated load currents.
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Peer to Peer Paralleling Communications and Power Backup PEER TO PEER COMMUNICATIONS PEER TO PEER COMMUNICATIONS Peer to Peer paralleling (Delta VAr and Master/Follower) uses Ethernet to communicate information between the paralleled M‑2001Ds.
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Control House Computer running TapTalk S-2001D ® Communications Software Ethernet Switch* Yard Fiber recommended M-2001D M-2001D * = meets specifications above Figure 4 Isolated Network with Control House (no other traffic) Control House Computer running TapTalk S-2001D...
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual CONTROL POWER BACKUP CONTROL POWER BACKUP Control Power Backup Input Control Power Backup Input The optional Control Power Backup Input (two pin Molex connector on the top of control) sustains operation of the control in the event of a loss of AC input power to the control and serves as a backup of Fiber Optic communication loop‑through.
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Firmware Update Cautions with Peer to Peer Paralleling CAUTION: CAUTION: All M‑2001D controls in the Delta VAr Peer to Peer Paralleling scheme must have the same Firmware version same Firmware version installed for proper operation.
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Delta VAr Peer‑to‑Peer Paralleling The latest version of Delta VAr paralleling is the Peer‑to‑Peer version, (available only in the M‑2001D control), which reduces inter‑device wiring to primarily an Ethernet connection. To perform two‑transformer paralleling as shown in Figure 7, the control employs auxiliary breaker status contacts on the transformers'...
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual AC/DC Input M-2026 0.2 A P2-1 12 Vdc P2-5 M-0169A Back-Up Pwr In P2-6 M-2001D P2-4 P2-7 Blk R P2-2 Left Tie* P3-5 M-0329B Line Brkr* P2-16 P3-3 Blk L Right Tie* P2-8...
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Ethernet Switch SOURCE SOURCE PC with TapTalk As Req’d. AC/DC Input M-2026 M-0169A M-0169A M-0169A 0.2 A 0.2 A 0.2 A P2-4 P2-4 P2-1 P2-4 P2-1 P2-1 P2-2 P2-2 P2-2 12 Vdc...
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Table 1 Adapter Panel/Control Connections For Peer-To-Peer Paralleling (Delta VAr or Master/Follower)
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Control Network Map Determination Control Network Map Determination The Delta VAr Peer to Peer Paralleling settings for each control must meet the criteria described below based on the Bus Topology. It is recommended that the user create a Control Network Map of the proposed Delta VAr Peer to Peer Paralleling scheme similar to those presented in Figure 9 through...
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Ring Bus Ring Bus Figure 10 represents a Ring Bus with 8 transformers. LB1 through LB8 are Line Breakers and TB1‑2 through TB8‑1 are the Tie Breakers which take the transformer out of paralleling. As indicated in Figure Transformer 8 is connected to Transformer 1 through the Tie Breaker TB8‑1 which makes the single bus a special case of a ring bus.
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Double Bus High Side Bus M‑2001D M‑2001D M‑2001D M‑2001D M‑2001D M‑2001D M‑2001D M‑2001D Position 1 Position 2 Position 3 Position 4 Position 5 Position 6 Position 7 Position 8 Low Side Bus A DB1‑...
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Grouping Operation Algorithm (GOA) Grouping Operation Algorithm (GOA) This GOA determines the action that is taken by the control when it detects any Open Tie Breakers (Figure in the network. Each control individually monitors the status of the Tie Breakers (A2, A3 Auxiliary Inputs) connected to its section of the bus, and broadcasts to all the other controls these statuses via a GOOSE message.
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Paralleled – Paralleled – This is defined as two or more transformers directly connected to a common bus and sharing the load. These transformers must operate in a coordinated manner to regulate the common bus voltage, while minimizing circulating current between the transformers caused by a separation of tap positions.
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Double Bus Configuration Double Bus Configuration In a Double Bus configuration (Figure 14), these same Mode definitions also apply. However, there can only be a maximum of two paralleled groups, with a maximum of two Independent transformers, since there are only two buses.
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Parallel/Independent Switch Input Parallel/Independent Switch Input With the Parallel/Independent Switch input, the M‑2001D control may be placed into Independent Mode for testing, similar to the analog method. The local M‑2001D will go into Independent Mode and this status will be broadcast to all the other paralleled controls.
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Inputs Available for P2P Parallel/Independent Switch Example 1 Example 2 Input Settings Selections Tap Information Tap Information Input Contact (Settings in parentheses are Operational Pin # DISABLED KeepTrack 1N Modes pre-defi...
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual P2P Parallel or Independent Mode when No Input is Available P2P Parallel or Independent Mode when No Input is Available For cases where it is not possible to have a Parallel/Independent Switch Input, the front panel HMI of the M‑2001D may be used to select Parallel or Independent operation.
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual SYMPATHY MANUAL OPERATION WITH DELTA VAR PEER TO PEER SYMPATHY MANUAL OPERATION WITH DELTA VAR PEER TO PEER Application Overview Application Overview Sympathy Manual operation, when enabled, allows M‑2001D controls in a Delta VAr Peer to Peer Paralleling scheme to automatically go into Manual operation when any other paralleled control's Auto/Manual switch is placed into Manual operation.
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Overview of Sympathy Manual Operation Overview of Sympathy Manual Operation NOTE: NOTE: Sympathy Manual operation only applies to P2P Delta VAr paralleling. The Auto/Manual switch position of each paralleled control is broadcast, so that all paralleled controls know the position of the Auto/Manual switch of each control in the paralleling group.
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Control 2 Placed in Manual Operation Control 2 Placed in Manual Operation If the Auto/Manual switch of Control 2 Control 2 is placed in Manual Manual, it goes into Manual operation and broadcasts its Auto/Manual switch position to Controls 1/3/4 Controls 1/3/4.
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual DELTA VAR PEER TO PEER PARALLELING – CONTROL SETUP FROM TAPTALK DELTA VAR PEER TO PEER PARALLELING – CONTROL SETUP FROM TAPTALK TapTalk Setup/Configuration/Paralleling TapTalk Setup/Configuration/Paralleling The Delta VAr Peer to Peer settings for each control are available in the TapTalk Setup/Configuration Setup/Configuration screen (Figure 17).
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual • Number of Devices – The number of total devices that are in the paralleling scheme (2 to a maximum of 16 inclusive of the Initiator). • Paralleling Address (Control Network Map position 1 to X) •...
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual The line drop compensation settings R and X , in secondary voltage, can be calculated by multiplying the per unit resistance times the rated VT secondary voltage (typically VTs are selected to give a rated secondary voltage of 120 V).
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Discovered Paralleled Devices Discovered Paralleled Devices Each discovered control and its data is displayed on the Delta VAr Peer to Peer Configuration Tool dialog screen. The data is organized into control identifiers, read only statuses, and configurable (writable) settings. The control read only statuses are indicated by the color "gray", and configurable settings are identified by Bold Type.
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual DELTA VAR PEER TO PEER PARALLELING CONTROL SETUP FROM THE HMI DELTA VAR PEER TO PEER PARALLELING CONTROL SETUP FROM THE HMI It is highly recommended to setup the Paralleling scheme using TapTalk. However, the controls may be setup from the HMI of each paralleled control.
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual 10. Repeat the Configuration Steps for the remaining controls. The control with the highest address (the Initiator) must be setup last. CAUTION: CAUTION: After placing the Initiator control in the Delta VAr Peer to Peer Paralleling scheme the controls will not respond to any tapchange requests for 30 seconds.
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual • Delta VAr Limit Lockout – Delta VAr Limit Lockout – The Delta VAr Limit Lockout actuates when the calculated Delta VAr value is greater than the configured Delta VAr limit. This lockout will automatically clear when the calculated Delta VAr current value is less than the limit (Circulating Current Limit Reactive setting minus 4 mA).
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Communication Link Fail Lockout Alarm – Communication Link Fail Lockout Alarm – actuates when the ethernet cable is disconnected from the local control, or there is a hardware failure that affects communications. The local control will also display a message "P2P Comm Loss LO"...
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Figure 22 Peer to Peer Paralleling Configuration Tool Alarm Reset Example DELTA VAR PEER TO PEER PARALLELING CHECKOUT PROCEDURE DELTA VAR PEER TO PEER PARALLELING CHECKOUT PROCEDURE Two Transformer Verification Two Transformer Verification 1.
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual 11. If both transformers are not calling for a tap change operation, then manually increase the tap position difference between the transformers by raising Transformer 1, one tap and lowering Transformer 2 one tap until both controls are calling for the correct operation.
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual 28. Close the Low Side Breaker for Transformer 1 and verify that the DVAR current in all the transformers is at or near zero. 29. Raise or Lower either Transformer 1 or Transformer 2 by one tap to generate some DVAR current. The transformer with the higher voltage (typically the higher tap) will have the Lagging DVAR current and the other transformer will have the same magnitude but will Leading DVAR current.
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual 11. If all transformers are not calling for a tap change operation, then manually increase the tap position difference between the transformers by raising Transformer 1, one tap and lowering Transformers 2 and 3 one tap until all controls are calling for the correct operation.
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual If the load is not evenly distributed between the transformers, then the voltage on the transformer with the larger load may decrease and the control may call for a raise. The voltage on the transformer with the smaller load may increase and its control may call for a lower.
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual 43. Manually place the transformers to the same tap position (or the same difference as noted above). 44. Close the Low Side Breaker for Transformer 1 and verify that the DVAR current in all the transformers is at or near zero.
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual 58. Open the Low Side Breaker for Transformer 3 and verify that the controls are not calling for any tap change operations. The load current on Transformers 1 and 2 should have changed from one third to one half and Transformer 3 load should be at or near zero.
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Master/Follower Peer‑to‑Peer Paralleling The M‑2001D also provides the option for Master/Follower Peer‑to‑Peer Ethernet based paralleling. This is an update on a classic paralleling method that is based on the concept that identical transformers (Figure 23), driven from a common source, and maintained on the same tap will operate in an optimal manner in parallel.
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual AC/DC Input M-2026 0.2A 12 Vdc P2-1 P2-4 M-0169A Back-Up Pwr In P2-2 M-2001D Tap Pos. Sensing P2-7 Blk R System Left Tie* P3-5 M-0329B Line Brkr.* P2-16 P3-3 Blk L Right Tie*...
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Ethernet Switch SOURCE SOURCE PC with TapTalk As Req’d. AC/DC Input M-2026 M-0169A M-0169A M-0169A 0.2 A 0.2 A 0.2 A P2-4 P2-4 P2-1 P2-4 P2-1 P2-1 P2-2 P2-2 P2-2 12 Vdc...
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Master/Follower Peer to Peer Paralleling Application Master/Follower Peer to Peer Paralleling Application The Master/Follower Paralleling scheme employs the GOOSE messaging of the IEC 61850 protocol to provide peer to peer communications. The control can be placed in either the Master or Follower mode to achieve paralleling.
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual MASTER AND FOLLOWER CONTROL SETUP FROM TAPTALK MASTER AND FOLLOWER CONTROL SETUP FROM TAPTALK TapTalk Setup/Configuration/Paralleling TapTalk Setup/Configuration/Paralleling The Master/Follower settings for each control are available in the TapTalk Setup/Configuration Setup/Configuration screen (Figure 26).
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual 3. Select Paralleling Type to "Master/Follower" in the Paralleling section of the Configuration screen. 4. Select "None None" for the Master/Follower Configuration. The control will not be assigned as a Master until all controls in the Paralleling scheme have been configured.
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual • If the Master Band Status is not In‑Band: If the Master Band Status is not In‑Band: a. Adjust the Master tap position by initiating a tapchange as necessary to bring the Master Band Status "In‑Band"...
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Discovered Devices Discovered Devices Each discovered control and its data is displayed on the Master/Follower Configuration Tool screen. The data is organized into control identifiers, read only statuses, and configurable (writable) settings. NA indicates the data is not applicable.
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual 6. Press the Down arrow pushbutton, as necessary, until the "Paralleling Type" screen is displayed. Select the Paralleling Type "MASTER/FOLLOWER", then press the ENT ENT pushbutton. Paralleling Type MASTER/FOLLOWER 7.
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual 8. Drive the Follower Tap Position to match the Master Tap Position. 9. Repeat this procedure for each Follower in the Master/Follower scheme. 10. Determine the Master Master Band Status by navigating the Master HMI Master HMI menu to "Monitor/Status Monitor/Status": a.
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual MASTER/FOLLOWER LOCKOUTS AND ALARMS MASTER/FOLLOWER LOCKOUTS AND ALARMS Lockout Condition Lockout Condition Any lockout of the paralleling mode will initiate a Lockout alarm. Any lockout of the paralleling mode will initiate a Lockout alarm. There are two types of lockout conditions, Master Lockout and Follower Lockout.
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Figure 29 TapTalk Monitor/Master/Follower Alarm Messages Screen Clearing Master/Follower Paralleling Lockout/Alarms from TapTalk Clearing Master/Follower Paralleling Lockout/Alarms from TapTalk Master/Follower Paralleling Lockout/Alarms can be cleared/reset in TapTalk in two places. Individual control Lockout/Alarms can be reset from the Setup/Alarms screen and also from the Master/Follower Paralleling Configuration Tool.
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Independent Mode Operation Independent Mode Operation When the Remain in Block Automatic setting is ENABLED ENABLED, and the paralleling status changes to Independent Mode, due to a change in the Tie Breaker status (or any breaker status), the Master Control will be placed into Block Automatic Block Automatic mode and will not perform any automatic operations.
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Classic Paralleling CIRCULATING CURRENT PARALLELING CIRCULATING CURRENT PARALLELING Circulating current paralleling was originally developed using analog transformer controls. It is an active paralleling method, in that it continually strives to minimize circulating current between paralleled transformers. It utilizes 0.2 Ampere current loops in hard‑wired CT balancing circuits to bias transformer operating bandcenters to optimally share loads between transformers (See Figure...
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual TRANS 2 TRANS 1 From From M 0169A M 0169A LDC-CT LDC-CT M-2001D M-2001D (TRANS 1) (TRANS 2) CIRCULATING CURRENT M 0127A M 0127A 52-1a 52-2a (OPTIONAL) (OPTIONAL) 52-1b 52-2b BALANCE CURRENT...
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual 0.2 A M‑0127A P2‑1 M‑0169A P2‑5 ret. P2‑6 M‑2001D P2‑7 Auto Blk R Motor P2‑4 M‑0329B Power P2‑16 Input ret. P2‑2 Blk L P2‑8 P2‑3 Force Lower M‑0115A Adapter Panel Mtr.
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual 0.2 A M‑0127A P2‑1 52‑1a P2‑5 M‑0169A P2‑6 P2‑7 M‑2001D Auto Motor Blk R P2‑4 Power Input M‑0329B P2‑16 Blk L P2‑8 P2‑2 P2‑3 Force Lower M‑0115A Adapter Panel Tie 1a Neutral Tie 1a...
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Table 4 Adapter Panel/Control Connections For Circulating Current or Delta VAr1 Paralleling...
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual M-0169A Continues on next diagram 0.2A M-0127A AC CURRENT RELAY Auxiliary Current Transformer M-0115A PARALLEL BALANCING MODULE LTC Transformer Control TB‑1 M-2067B VOLTAGE INPUT (POLARITY) Adapter Panel LOAD CURRENT (RETURN) [90] NEUTRAL...
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual M-0169A Continued from previous diagram M-0127A 0.2A AC CURRENT RELAY Auxiliary Current Transformer M-0115A PARALLEL BALANCING MODULE LTC Transformer Control TB‑1 M-2067B VOLTAGE INPUT (POLARITY) Adapter Panel LOAD CURRENT (RETURN) [90] NEUTRAL...
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual CIRCULATING CURRENT AND DELTA VAR1 CONFIGURATION CIRCULATING CURRENT AND DELTA VAR1 CONFIGURATION Paralleling by the Circulating Current method or the Delta VAr1 method involves a configuration in which each M‑2001 Series Tapchanger Control is used with a Beckwith Electric M‑0115A Parallel Balancing Module.
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual M‑0115A PARALLEL BALANCING MODULE M‑0115A PARALLEL BALANCING MODULE Background Background When LTC transformers are connected in parallel, a control scheme is necessary to assure that the tap positions of all paralleled transformers remain at or near the same tap position. If tap positions are not maintained at or near the same position, reactive current will circulate between the transformers, wasting energy and overheating the transformers, possibly causing damage.
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual M‑0127A/M‑0170A AC CURRENT RELAY M‑0127A/M‑0170A AC CURRENT RELAY Application Application The M‑0127A, 10‑100 mA AC Overcurrent Relay is a recommended addition to the Circulating Current or Delta VAr1 Paralleling configurations. Its purpose is to monitor the current in the circulating loop between transformers, and interrupt Motor Power to its monitored transformer, should the circulating current exceed a predetermined value.
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual 7. Set Transformer #1 Line Drop Compensation F (Forward) Resistance to 24. The control should call for a Raise. (If the control calls for a Lower, then the polarity of the line current coming into the control is reversed, and must be corrected before continuing the test.) 8.
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual 37. Open the transformer breaker on Transformer #2 (52‑2). CAUTION: CAUTION: Transformer #1 is now supplying all the load, its voltage may drop. 38. Verify that Transformer #1 is not affected and the circulating current on the control is zero. 39.
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual 13. Set Transformer #3 Line Drop Compensation F (Forward) Resistance to 0. 14. Set Transformer #1, #2 and #3 Parallel Balancing Modules (M‑0115As) to the PARALLEL PARALLEL position 15.
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual 32. Manually return Transformer #2 back to the same tap. CAUTION: CAUTION: If the loads are not evenly balanced between the transformers then the voltage on the transformer with the larger load may decrease and the control may call for a Raise and the transformer with the smaller load may increase and the control may call for a Lower.
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual DELTA VAR1 PARALLELING CHECKOUT PROCEDURE DELTA VAR1 PARALLELING CHECKOUT PROCEDURE Two Transformer Verification Two Transformer Verification NOTE: NOTE: There must be a load on the transformer to perform this test. ...
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual 18. Manually return Transformer #2 and Transformer #1 back to the original tap. Neither control should call for a Raise or Lower. CAUTION: CAUTION: If loads are not evenly balanced between the two transformers, then the voltage on the transformer with the larger load may decrease and the control may call for a Raise.
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Delta VAr2 Paralleling If only two transformers are considered for Paralleling, and Line Drop Compensation is NOT required, Delta VAr2 Paralleling (available in the M‑2001C Base‑T and Comprehensive, and the M‑2001D) should be considered.
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual 0.2 A P2‑1 P2‑5 M‑0169A P2‑6 M‑2001D P2‑4 P2‑7 Blk R P2‑2 M‑0329B P2‑15 P2‑16 Blk L P2‑8 P2‑3 52‑ 52‑ P2‑3 Force Lower Adapter Panel Neutral Motor Pwr. In Mtr.
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Table 6 Adapter Panel/Control Connections for Delta VAr2 Paralleling...
LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Delta VAr2 Paralleling and Delta VAr2 Paralleling + KeepTrack™ Delta VAr2 Paralleling and Delta VAr2 Paralleling + KeepTrack™ The theoretical basis for the Delta VAr2 Method of paralleling is that paralleled transformers are meant to SHARE the VAr load (as well as the KW load) of the load bus.
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Exclusively for the Delta VAr2 method, there are three functions activated and set in the Configuration menu for proper operation: Sensitivity Sensitivity, Circulating Current Limit (Reactive) Circulating Current Limit (Reactive), and Input Ratio (Load/parallel) Input Ratio (Load/parallel).
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual Delta VAr2 Paralleling Setup from TapTalk S‑2001D Delta VAr2 Paralleling Setup from TapTalk S‑2001D NOTE: NOTE: This procedure requires Level 2 Access. 1. Select Setup/Configuration Setup/Configuration from the TapTalk toolbar. TapTalk will display the Configuration screen. 2.
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LTC Transformer Control Comprehensive System Manual LTC Transformer Control Comprehensive System Manual This Page Left Intentionally Blank...
LTC Transformer Control Comprehensive System Manual APPLICATION CONSIDERATIONS Interposing Motor Drive Relay, Buzz, Chatter, and Lock-Up Some installations of the M-2001 series Tapchanger Control may experience interposing relay buzzing, chatter (severe buzzing), or in extreme cases, lock-up and runaway tap changer operation. This is due to the Interposing Motor Drive relays in the LTC drive circuitry of the Tap Changer. Trends in manufacturing have resulted in the use of smaller relays, such as the "ice cube"...
Appendix A For 240 Vac Coil Interposing Relays Resistor Power Minimum Shunt I Value Dissipation Wattage 15 KΩ 16 mA 3.84 W 10 W 12 KΩ 20 mA 4.80 W 10 W 10 KΩ 24 mA 5.76 W 12.5 W 9.1 KΩ 26.4 mA 6.33 W 12.5 W 8.2 KΩ...
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LTC Transformer Control Comprehensive System Manual Voltage Sensing Fuse 1/4 A Voltage Input Voltage Input (Polarity) (Polarity) Load Current Load Current (Return) (Return) See NOTE below Neutral Neutral Load Current Load Current (Polarity) (Polarity) Circulating Current Circulating Current (Return) (Polarity) Circulating Current Circulating Current (Polarity) (Return) Tapchanger Raise Tapchanger Raise Output Output M-0127A Motor Power Input Motor Auxiliary Voltage See Note Voltage Reduction Tapchanger Lower Output Step #2 Input Contact "Wetting" Non-Sequential Operation/ Supply +12 Vdc Auto Tapchange Inhibit Input Operation Counter Voltage Reduction Step #1 Input...
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Appendix A M-2001 M-2131 TAPCHANGER ADAPTER PANEL CONTROL FUNCTIONS VOLTAGE IN FUNCTIONS FUSE (1/4 A) VOLTAGE INPUT NEUTRAL LINE CURRENT 1.0 A (RETURN) LINE CURRENT LINE CURRENT 1.0 A (POLARITY) TO M-0115A /0.2 A CIRCULATING CURRENT TO M-0115A /0.2 A LINE CURRENT 2.0 A M-0127A (RETURN) INPUT MOTOR AUXILIARY...
LTC Transformer Control Comprehensive System Manual M-2067B Main Terminal Block CB 1 Potential Transformer J1-Red 0.1 A ACVM Ground J2-Blk Ground A15F Aux CT B-0945 Circulating Current for Paralleling Circulating Current for Paralleling Manual Raise Raise CB 2 Auto 20 A Motor Supply (Hot) Jumper "A" see Note Lower Manual Lower Spare To Motor ■ NOTE: Unit is supplied with one end of Jumper Spare Varistor "A" connected to the Auto/Manual...
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Appendix A NOTE: TB1 Terminal Positions are M-2220 illustrated in numerical order. See Note below. M-2001 Voltage Input Voltage In Voltage Input (Polarity) Fuse (1/4 A) (Polarity) Load Current Neutral (Return) Line Current Neutral Return P2-1 Load Current Line Current 5.0 A (Polarity) (Polarity) Circulating Current Line Current 1.0 A (Polarity) (Polarity) P2-3 Circulating Current Line Current 0.2 A (Return) (Polarity) Circulating Current 0.2 A...
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LTC Transformer Control Comprehensive System Manual M-2230 M-2001 Voltage Input Voltage In Voltage Input (Polarity) Fuse (1/4 A) (Polarity) Load Current Neutral (Return) Line Current Neutral Return P2-1 Load Current Line Current 5.0 A (Polarity) (Polarity) Circulating Current Line Current 1.0 A (Polarity) (Polarity) P2-3 Circulating Current Line Current 0.2 A (Return) (Polarity) Circulating Current 0.2 A Tapchanger Raise Output (Polarity) Circulating Current 0.2 A Motor Power Input (Return) Voltage Reduction Lower...
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Appendix A (Front Panel Inputs) Test M-2001 Terminal Meter External Fuse 3 A Power Voltage Input Non-Sequential / Auto (Polarity) Tapchange Inhibit Input Load Current Voltage Reduction (Return) Step #2 Input Circulating Neutral Current (Return) Load Current Circulating (Polarity) Current (Polarity) Circulating Current Tapchanger Raise (Polarity) Output Circulating Current Tapchanger Lower (Return) Output Tapchanger Raise Voltage Reduction Output Step #1 Input Motor Power Input Neutral Voltage Reduction Motor Power 120/ Motor Power Step #2 Input...
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LTC Transformer Control Comprehensive System Manual See Note below NOTE: If the M-0127A is used, remove Jumper and connect output contact. Also, remove J15. Figure A-7 M-2278 Adapter Panel External Connections A–10...
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Appendix A Non-Sequential / Auto Tapchange Inhibit Input Voltage Reduction Step #2 Input Alarm Contacts from M-0329B, when M-0329B is purchased with unit Circulating Current (Return) Circulating Current (Polarity) Voltage Reduction Step #2 Contact Tapchanger Raise Output Voltage Reduction Step #1 Contact Tapchanger Lower Output Non-Sequential / Auto Tapchange Inhibit Input Voltage Reduction Step #1 Input +12 Vdc Wetting Supply Neutral Motor Power 120/ 240 Vac Supply Regulated Voltage (120 Vac) Neutral Light Drag Hands Reset Operations Counter Input Line Current (Polarity) Line Current Motor Pwr In (Return) (120 V) Operations Motor Power Return Counter Switch...
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LTC Transformer Control Comprehensive System Manual Test (Front Panel Inputs) M-2001 Terminal Meter Voltage Fuse 3 A Voltage Input Non-Sequential / Auto (Polarity) Tapchange Inhibit Input Load Current Voltage Reduction (Return) Step #2 Input Circulating Neutral Current (Return) Load Current Circulating (Polarity) Current (Polarity) Circulating Current Tapchanger Raise (Polarity) Output Circulating Current Tapchanger Lower (Return) Output Tapchanger Raise Voltage Reduction Output Step #1 Input Motor Power Input Neutral Voltage Reduction...
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Appendix A Cam Switch Connection (Non-Sequential) Ground TM-F NOTE: Must be connected to potential xfmr ground externally. 20 K Voltmeter MS2-F 52 AX Potential Xfmr Polarity Lower Pot. Xfmr MS1-A4 Polarity Raise PTT-1 TM-D M-2067 M-0127A Line Current "90" Return Common TM-H PTT-2...
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LTC Transformer Control Comprehensive System Manual Test (Front Panel Inputs) M-2001 Terminal Meter Voltage Fuse 3 A Voltage Input Non-Sequential / Auto Tapchange Inhibit Input (Polarity) Load Current Voltage Reduction (Return) Step #2 Input Circulating Neutral Current (Return) Load Current Circulating (Polarity) Current (Polarity) Circulating Current Tapchanger Raise (Polarity) Output Circulating Current Tapchanger Lower (Return) Output Tapchanger Raise Voltage Reduction Output Step #1 Input Motor Power Input Neutral Voltage Reduction...
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Appendix A M‑2326 Application Guide Attach the female end of the 4-position shorting plug to the male end that is mounted on the M-2326 flange. Using a cable tie, secure the 8-position shorting plug to the wiring harness. Attach the M-2326 wiring harness to the existing terminal block.
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LTC Transformer Control Comprehensive System Manual NOTE: If the M-0127A is used, remove Jumper and connect output contact. Figure A-13 M-2339 Adapter Panel External Connections A–16...
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Appendix A Test (Front Panel Inputs) M-2001 Terminal Voltage Meter Motor Fuse 3 A Pwr In Voltage Input Non-Sequential / Auto (Polarity) Tapchange Inhibit Input Load Current Voltage Reduction (Return) Step #2 Input Circulating Neutral Current (Return) Load Current Circulating (Polarity) Current (Polarity) Circulating Current Tapchanger Raise (Polarity) Output Circulating Current Tapchanger Lower (Return) Output Tapchanger Raise Voltage Reduction Output Step #1 Input Motor Power Input Neutral Voltage Reduction Motor Power 120/ Motor Power...
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LTC Transformer Control Comprehensive System Manual MCGRAW‑EDISON CABINET TERMINALS TB1‑14 0.2 A Input for Ammeter M‑0169‑3 0.2 A Return Output for Ammeter M‑0169A‑2 5A Polarity M‑0169A‑4 0.2 A Polarity M‑0169A‑1 5 / 8.66 A Return M‑0169A‑5 8.66 A Polarity TB1‑8 Ground TB1‑10 Regulated Voltage...
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Appendix A NOTE: If the M-0127A is used, remove Jumper and connect output contact. Figure A-16 M-2379D Adapter Panel External Connections A–19...
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Appendix B Paralleling Equipment Specifications This Appendix contains the following product Specification sheets that provide mechanical specs and additional product specific information: • M‑0169A Auxiliary Current Transformer • M‑0329B LTC Backup Control • M‑2026 Backup Power Supply • M-2027 Backup Power Supply •...
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CONTROLS Auxiliary Current Transformer Units M‑0121 M‑0169A M‑0121 For use with Beckwith Electric Tapchanger Controls when there is no additional burden present. M‑0169A For use in higher burden current circuits, such as those found in paralleling schemes. Output is protected against overvoltage.
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M‑0120/M‑0169 Specification Line Current, used for Line Drop Compensation, is provided by an Auxiliary Current Transformer. The current transformer drops the line current to a 0.2 A full scale rating. The M 0121 or M 0169A can be used for CTs with a 5 A secondary.
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CONTROLS LTC Backup Control M‑0329B • Prevents a defective LTC tapchanger control from running the voltage outside the upper or lower limits • Prevents the line drop compensator from raising the voltage too high under full or overload conditions • Fully transient protected and operates within ±1% voltage accuracy over a temperature range of -40°...
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M‑0329B Backup Control – Specification Introduction The M‑0329B Backup Control offers reliable voltage protection from both improperly set and malfunctioning Tapchanger controls. The most common voltage error in setting tapchanger controls occurs when values of Line Drop Compensation are set in the tapchanger control that result in unexpectedly high voltage at the transformer due to higher than anticipated load currents.
M‑0329B Backup Control – Specification Front Panel Controls BANDWIDTH VOLTS: An accurately calibrated dial adjusts the bandwidth between Block Raise and Block Lower from 6 V to 24 V for 120 Vac. BANDCENTER VOLTS: An accurately calibrated dial adjusts the Bandcenter from 100 V rms to 140 V rms which allows the M‑0329B to operate with most transformer controls.
M‑0329B Backup Control – Specification Installation The mounting and outline dimensions are shown in Figure 2, and the external connections in Figure The M‑0329B can be connected as a two‑terminal device, by paralleling the Power Input (TB1‑1 to TB1‑2) and the Voltage (Sensing) Input (TB1‑3 to TB1‑4).
M‑0329B Backup Control – Specification External Connections The M‑0329B LTC Backup Control is listed to UL Standards for Safety by Underwriters Laboratories Inc. (UL). To fulfill the UL requirements, terminal block connections must be made with No. 16 AWG wire inserted in an AMP #51864‑1 (or equivalent) connector.
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M‑0329B Backup Control – Specification Application The M‑0329B can be used in many applications not related to LTC backup for a very accurate overvoltage and/or undervoltage relay. The Block Raise (BLK R) and the Block Lower (BLK L) outputs can be used as overvoltage and undervoltage outputs, respectively.
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M‑0329B Backup Control – Specification Adjustment Accurately calibrated dials, labeled BANDCENTER and BANDWIDTH, set the Block Raise and Block Lower voltage levels. The dials on the M‑0329B cover are calibrated in volts for use with 120 Vac nominal voltage. The following equations will assist the user in choosing the correct setpoints for the M‑0329B: = the Upper Voltage Limit (Block Raise) desired = the Lower Voltage Limit (Block Lower) desired The Base Voltage is 120 Vac...
M‑0329B Backup Control – Specification Test Procedure Test Setup Make the electrical connections as required in Figure 7. The functional indicator lamps are suggested to facilitate testing and can be eliminated if other methods are used. Equipment Required A stable 60 Hz source with fixed 120 V rms and proper load regulation so that the amplitude does not change more than 0.05 V rms when the relays are energized or the functional indicator lamps are on.
M‑0329B Backup Control – Specification Procedure for Determining Voltage Bandcenter When checking the voltage BANDCENTER settings, the exact voltage where the BLOCK RAISE/LOWER and LOWER LEDs light should be recorded. The voltage level Bandcenter is calculated as the average of these voltages: The voltage at which the BLOCK RAISE/LOWER and LOWER LEDs, and the functional indicators shown in Figure 7...
M‑0329B Backup Control – Specification Fixed Alarm Time Delay Test 23. Set the BANDCENTER control to 120 V rms. 24. Set the BANDWIDTH control to 6 V. 25. Decrease the input voltage until the BLOCK RAISE/LOWER LED lights. Using a stopwatch, measure the time required for the ALARM relay to de‑energize.
M‑0329B Backup Control – Specification Disposal and Recycling Disposal of E-Waste for Beckwith Electric Products The customer shall be responsible for and bear the cost of ensuring all governmental regulations within their jurisdiction are followed when disposing or recycling electronic equipment removed from a fixed installation. Equipment may also be shipped back to Beckwith Electric for recycling or disposal.
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CONTROLS AC/DC to DC Backup Power Supply M‑2026 • Maintains the M-2001C/D or M-6200 energized during power outages to maintain the continuity of the communications loop • Accepts AC and/or DC power input (50 or 60 Hz) from station auxiliary supply over the following ranges: 21 to 32V DC 42 to 60V DC...
M‑2026 AC/DC to DC Backup Power Supply – Specification Inputs (AC and/or DC) 21 to 32 Vdc 42 to 60 Vdc 105 to 145 V AC/DC Burden of less than 8 VA Bipolar Fuse protection (1.5 A) Reverse polarity protection for a dc input Transient protected Output +12 Vdc regulated (±...
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M‑2026 AC/DC to DC Backup Power Supply – Specification GND CHASSIS GND CHASSIS DRAIN DRAIN The B-1021 and B-0920 +12V +12V +12V +12V harnesses include the J2/P2 12 Vdc from Beckwith Electric Adapter. P2 connects to M-2026 or M-2027 Backup M-2001C/D controls that utilize B-1021 Harness Power Supplies...
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CONTROLS AC to DC Backup Power Supply M‑2027 • Maintains the M-2001C/D or M-6200 energized during power outages to maintain the continuity of the communications loop • Accepts power input from station auxiliary supply over a range of 105 Vac to 140 Vac (50 or 60 Hz) •...
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M‑2027 AC to DC Backup Power Supply – Specification Input 105 Vac to 140 Vac at 50Hz/60Hz Burden of less than 2 VA Fuse protected (1.5 A) Transient protected Output +12 Vdc nominal @ 1 amp Fuse protected (1.5 A) Transient protected Transient Protection Surge Withstand Capability:...
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M‑2027 AC to DC Backup Power Supply – Specification GND CHASSIS GND CHASSIS DRAIN DRAIN The B-1021 and B-0920 +12V +12V +12V +12V harnesses include the J2/P2 12 Vdc from Beckwith Electric Adapter. P2 connects to M-2026 or M-2027 Backup M-2001C/D controls that utilize B-1021 Harness Power Supplies...
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CONTROLS Parallel Balancing Module M‑0115A Provides all components that are required for paralleling LTC Transformers using the Circulating Current Method...
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M‑0115A Parallel Balancing Module – Specification The M‑0115A Parallel Balancing Module includes all the components that must be added to load tapchanging (LTC) transformers to permit them to operate in parallel, using the circulating current method. The transformer controls must have a 0.2 A input for load and circulating current. Through the use of a circulating current sensitivity adjustment, the M‑0115A avoids the problems of hunting (caused by too much sensitivity), or permitting the transformers to be several steps apart (caused by too little sensitivity).
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M‑0115A Parallel Balancing Module – Specification Application The Beckwith Electric Compre hensive System Manual "LTC Transformer Control System including Paralleling and Backup Control", is available on www.BeckwithElectric.com, or by request. This manual includes an overview of typical system setup and connections, necessary components, and the information necessary to implement a paralleling scheme using the M‑0115A in the Circulating Current paralleling method.
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M‑0115A Parallel Balancing Module – Specification 4-1/2" 4-1/2" 11.43 cm 11.43 cm 4-1/4" 4-1/4" 10.79 cm 10.79 cm MORE SENSITIVE LESS SENSITIVE 10" 1-1/8" 25.4 cm 2.86 cm Figure 2 M-0115A Outline and Mounting Dimensions –5–...
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M‑0115A Parallel Balancing Module – Specification Brown Blue Less Sensitive Green Yellow 43P2 More Sensitive Black 43P4 Normally Tied to 5 43P1 43P3 43P Parallel - Independent switch shown in “P” position. 43S Sensitivity Switch Figure 3 M-0115A Schematic –6–...
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M‑0115A Parallel Balancing Module – Specification Trademarks All brand or product names referenced in this document may be trademarks or registered trademarks of their respective holders. Specification subject to change without notice. Beckwith Electric has approved only the English version of this document.
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TAPCHANGER CONTROLS AC Current Relay M‑0127A/M‑0170A • M‑0127A: 0.01 to 0.1 Amps • M‑0170A: 0.2 to 0.4 Amps • M‑0127A intended for use in 0.2 A circulating current circuit of paralleled LTC transformers to guard against damaging excessive circulating current •...
M‑0127A/M‑0170A AC Current Relay – Specification M‑0127A Application The M‑0127A AC Current Relay is primarily designed as a recommended addition to the Circulating Current or Delta VAr1 Paralleling configurations used with LTC Transformers. Its purpose is to monitor the current in the circulating loop between transformers, and interrupt Motor Power to its monitored transformer, should the circulating current exceed a predetermined value.
M‑0127A/M‑0170A AC Current Relay – Specification For very short times, the surge current limit is shown in Table Time Duration: Non-Repetitive Surge: Cycles, 60 Hz Amps Table 2 Output Surge Current Limit Inputs • All solid–state design, transient protected. • Two terminal input, transformer isolated from the output. •...
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M‑0127A/M‑0170A AC Current Relay – Specification Figure 1 AC Current Relay Circuit Figure 2 M‑0127A & M‑0170A Mounting Cutout Dimensions Figure 3 M‑0127A & M‑0170A Outline Dimensions –4–...
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M‑0127A/M‑0170A AC Current Relay – Specification Test Procedure Equipment Required • AC current supply capable of supplying 500 mA. • Digital voltmeter, Fluke model 8000A DMM or equivalent. • Light bulb. • 120 Vac source. • AC milliammeter. Test Setup Make the connections to the AC Current Relay as shown in Figure M–0127A/M–0170A...
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M‑0127A/M‑0170A AC Current Relay – Specification M-0170A Input 2.11 3.22 3.20 2.19 3.16 3.10 2.26 2.23 2.67 Table 4 M‑0170A Typical Voltages Calibration Refer to Figure 5 Simplified Component Location. NOTE: Always calibrate the unit at the point where the relay trips during an increasing current. When the relay trips, the RELAY TRIPPED lamp on the front panel will light.
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M‑0127A/M‑0170A AC Current Relay – Specification Figure 5 Simplified Component Location TRADEMARKS All brand or product names referenced in this document may be trademarks or registered trademarks of their respective holders. Specification subject to change without notice. Beckwith Electric has approved only the English version of this document.
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Appendix C Introduction to Circulating Current and Delta VAr1 Paralleling Methods NOTE: REPLACES Beckwith Electric Application Note #11. C.1 Overview ........................C–2 C.2 Application .......................C–2 Defining the Problem ....................C–2 Conditions When Transformer Tap Positions Are Not Identical ......C–3 Parallel Balancer ......................C–6 A Fundamental CT Principle ..................C–6 Basic Parallel Balancer Requirements ..............C–6 C.3 Using Line Drop Compensation ................C–8 C.4 Parallel/Independent Operation ................
LTC Transformer Control Comprehensive System Manual C.1 Overview The circuits used for proper operation of two LTC transformers in parallel are not complex, but may be intimidating when only the complete circuit is shown, without adequate explanation of the principles involved and the purpose of each component.
Appendix C If the transformers are identical and operating on the same tap position, then with circuit breakers 52‑1 and 52‑2, and bus tie breaker 24 closed, the total secondary bus load will divide equally between the transformers. In this system example, no provision has been made for the special requirements of parallel operation. Each LTC will operate independently according to the command of the independent controls.
LTC Transformer Control Comprehensive System Manual In this instance, the voltage difference between the two transformer secondaries will drive a circulating current which is limited only by the impedance of the two transformers. Since the transformer voltage change per tap is typically 5/8% (.00625 pu) the driving voltage for the current is: 13,800 .00625 ×...
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Appendix C 3. The summation of the load and circulating currents is: Transformer #1: = Load Current + Circulating Current = 334 ‑ j251 ‑ j70 = 334 ‑ j321 = 463∠ ‑ 44° Transformer #2: = Load Current ‑ Circulating Current = 334 ‑...
LTC Transformer Control Comprehensive System Manual PARALLEL BALANCER One component, a parallel balancer, is essential to the proper operation of the system. It is the function of the parallel balancer, such as Beckwith Electric's M‑0115A Parallel Balancing Module, to "separate" the unequal (or unbalanced) portion of the current in each transformer.
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Appendix C By tracing the path of this unbalanced current, observe that the direction of the current (the polarity) is opposite in the two controls. This polarity difference is the foundation for a positive or negative bias being applied to the control to run the tapchangers. Figure C‑6, I represents the desired balanced components of the current.
LTC Transformer Control Comprehensive System Manual C.3 Using Line Drop Compensation Another level of complexity in the circuit is required to accommodate Line Drop Compensation (LDC). The special situation when the transformers are intended for use in parallel, but one is taken out of service, must be taken into account.
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Appendix C 35 A 500 A 52-1 1000: 0.2 A .1000 .0070 90 Relay .0070 .0070 LOADS .0070 K1-1 1000 K2-1 .1000 Balancer #1 35 A 500 A 52-2 1000: 0.2 A .1000 .0070 90 Relay .0070 .0070 K1-2 K2-2 .1000 Balancer #2 Figure C-7 Circuit for LTC Transformer Paralleling by Circulating Current Method,...
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LTC Transformer Control Comprehensive System Manual 1000 52-1 1000: 0.2 A .2000 .2000 90 Relay .2000 LOADS .2000 K1-1 .2000 1000 .1000 .1000 .1000 K2-1 .1000 52-2a .1000 52-2b 52-2 1000: 0.2 A Open 90 Relay K1-2 .1000 K2-2 .1000 Figure C-8 Circuit for LTC Transformer Paralleling by Circulating Current Method –...
Appendix C C.4 Parallel/Independent Operation The circuit developed thus far assumes that only two transformers are involved, and that they will always be operated in parallel with each other. However, one transformer may occasionally be removed from service and the other must continue to operate independently. In this condition, the circulating current paths must be removed from the control and the parallel balancer of the out‑of‑service transformer.
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LTC Transformer Control Comprehensive System Manual 52-1 90 Relay 52-1a LDC Motor LOADS 120 V Motor Power 52-1b 52-2b 52-2 52-2a 90 Relay LDC Motor 120 V Motor Power Figure C-9 Circuit for LTC Transformer Paralleling by Circulating Current Method, including Circuit Breaker Auxiliary Switch Contacts C.5 CT Correction and Circulating Current Limit Two additional components complete this two transformer paralleling circuit: an auxiliary CT, and a current...
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Appendix C AC Current Relay – When the circulating current becomes too great, it is often required that additional tap change operations are inhibited. This is based on the assumption that the circulating current is high because the transformers are already too many steps apart due to some malfunction, and a further digression of the tap positions should be prevented.
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Appendix D Advanced Circulating Current Paralleling Method NOTE: REPLACES Beckwith Electric Application Note #13. D.1 Overview ........................D–2 D.2 Application .......................D–2 Three Or More Identical Transformers In Parallel ..........D–2 Three Identical Transformers In Service with an Evenly Distributed Load ....D–2 Two Out of Three Transformers In Service with an Evenly Distributed Load ..D–3 Three Transformers In Service with a Load Bus Tie Opened ........D–3 Complete Circuit with Auxiliary CT and AC Current Relay ........D–3 Unequal Transformers In Parallel ................D–8...
LTC Transformer Control Comprehensive System Manual D.1 Overview Paralleling of LTC transformers by the Circulating Current Method may involve systems that are much more complex than the basic scheme of two identical transformers operating in parallel, as defined in Appendix C. While most systems are covered by that definition, there are also installations with the following: • More than two transformers • Transformers which are very different in their electrical characteristics...
Appendix D Two Out of Three Transformers In Service with an Evenly Distributed Load Figure D‑2 illustrates the "a" and "b" contacts when circuit breaker 52‑3 is open (Transformer #3 is out of service), where the load is unchanged and the reactive (circulating) current in T1 remains 35 A. The Parallel Balancer associated with T3 is removed from the circuit, except for the Line Drop Compensation current.
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LTC Transformer Control Comprehensive System Manual 500A 52-1 1000:0.2A .1000 .0070 52-1a .0070 90 Relay LOADS LDC Motor .1000 24-1 .1000 24-1b 24-1b 35 A 24-1a 52-1b 24-1a 17.5A 500A Source 52-2 1000:0.2A TOTAL LOAD .0035 .1000 1500 A .1000 17.5 A 1.0 PF 52-2a...
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Appendix D 750A 52-1 1000:0.2A .1500 .0070 .0070 52-1a 90 Relay LDC Motor LOADS .1000 24-1 .1000 24-1b .0500 24-1b 24-1a 52-1b 24-1a TOTAL LOAD 1500 A 750A Source 1.0 PF 52-2 1000:0.2A .1500 .0070 52-2a .0070 .0070 90 Relay LDC Motor 52-2b .1000...
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Appendix D 1000:5.0 A 52-1 5.0A 120 V 0.2A Motor Power 52-1a 90 Relay LOADS LDC Motor 24-1 24-1b 24-1b 24-1a 52-1b 24-1a 1000:5.0 A Source 52-2 5.0A 120 V 0.2A Motor Power 52-2a 90 Relay LDC Motor 52-2b 24-2 24-2b 24-2a 52-3b...
LTC Transformer Control Comprehensive System Manual UNEQUAL TRANSFORMERS IN PARALLEL Basic Requirements Before attempting to operate two LTC transformers in parallel, it must first be established that the transformers exhibit essentially the same voltage ratio and identical line phasing; otherwise, paralleling is not possible. 1.
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Appendix D The problem is that both transformers are rated for 12 MVA, but the circuit impedances define a system where T2 will be loaded to only one‑half that of T1. Therefore, when T1 is fully loaded, T2 is loaded at only 50%;...
LTC Transformer Control Comprehensive System Manual Paralleling Transformers of Unequal kVA Rating or Impedance Keeping in mind the previous conclusion, it is also common that there may be two transformers, of different manufacture or age, which have significantly different kVA or impedance nameplate ratings. The objective is to load them in parallel in order to avoid the capital expenditure of a new transformer.
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Appendix D Accomplishing this requires knowledge of the configuration of the current transformers (CTs) monitoring the load current. Examples of possible CT/ VT configurations are presented in Section D.3 Instrument Transformer Configuration. Presuming the VTs and CTs used in each transformer are compatible, it is necessary to scale the CT input of the LTC control on T2, so that its base is 1.43 times that of T1.
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LTC Transformer Control Comprehensive System Manual While this system will result in the transformers being loaded in the ratio of their usable capacity, it does not properly account for a circulating current due to unequal tap position. As illustrated in Figure D‑11, a presumed 40 A circulating current results in different CT secondary current in T1 and T2.
Appendix D Paralleling Systems with an Intermediate Load Tap There are instances where the system to be paralleled involves an intermediate load tap. This is illustrated Figure D‑13. In this instance, the upper path is transformers T11 and T12 in series, and in parallel with another transformer, T2.
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LTC Transformer Control Comprehensive System Manual Where Z is a fictitious impedance included to simulate the drop of Z . Now, the circuit can be further simplified as illustrated in Figure D‑15, where the upper path series impedance consists of the impedances of transformers T11 and T12 plus the new Z .
Appendix D D.3 Instrument Transformer Configuration Many configurations are possible to connect Voltage Transformers (VTs) and Current Transformers (CTs) that serve as the input sources to the LTC control. The application under consideration involves different power transformer designs of different manufacture. Therefore, it is likely the instrument transformers are not configured identically on the two power transformers.
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LTC Transformer Control Comprehensive System Manual a. One VT, one CT on same phase SYSTEM VOLTAGE CURRENT b. One VT connected line-line, two CT's on same phase as VT CURRENT SYSTEM VOLTAGE –I –I –V –V c. One VT, two CT's on phase not used for VT CURRENT SYSTEM VOLTAGE...
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Appendix E Advanced Delta VAr Paralleling Methods NOTE: REPLACES Beckwith Electric Application Note #24. E.1 Overview ........................E–2 E.2 Application ....................... E–2 Defining the Problem ....................E–2 Understanding the Conditions ................E–3 The Delta VAr Methods .................... E–3 E.3 Operational Comparisons ..................E–4 Common High &...
LTC Transformer Control Comprehensive System Manual E.1 Overview Appendix C "Introduction to Circulating Current and Delta VAr1 Paralleling Methods" builds a system and describes the operation for a basic application of two identical transformers operating in parallel. Appendix D "Advanced Circulating Current Paralleling Method" expands that definition to address installations that have more than two transformers or have mismatched transformers with different electrical characteristics (ratings or impedances).
Appendix E Tap Difference path LOADS Figure E-1 Substation Breaker Configuration Understanding the Conditions 1. A power transformer has a very high (25 to 50) X/R ratio. That is, power systems in general are reactive and the resistive effects of transformer impedances are negligible. 2.
LTC Transformer Control Comprehensive System Manual E.3 Operational Comparisons Common High & Low Side Busses As illustrated in Figure E‑1, all breakers (A through D) are closed. All considerations previously examined in Appendix C and D are applicable. Changes in circulating current are a function of mismatched tap position operations.
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Appendix E Power Factor Paralleling Method: • If the intersystem flow was VArs, the power factor method would block the operation of the appropriate tapchanger to attempt to minimize the difference in power factor. This would result in operation at different tap positions for the transformers, which would cause equal VAr flow in the transformers.
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Appendix F Basic Considerations for the Application of LTC Transformers and Associated Controls NOTE: REPLACES Beckwith Electric Application Note #17. Overview ........................F–2 Considerations ....................... F–2 Voltage Regulation Principles ................F–2 Factors Which Cause V to Change ..............F–4 Objective #1: Hold the Bus Voltage (V ) at the Desired Level ......
LTC Transformer Control Comprehensive System Manual Overview This Appendix provides an overview of the fundamental topics related to the theory of voltage regulation, control equipment commonly used in conjunction with load tapchanging (LTC) transformers and step‑voltage regulators, and criteria for establishing the proper settings for this equipment. LTC Transformers and/or Step‑Voltage Regulators are used extensively throughout the utility and industrial complex.
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Appendix F substation Distribution 3Ф LTC Transformer Feeders ‑OR‑ Non LTC Transformer and 3Ф Regulator ‑OR‑ Non LTC Transformer and 3 – 1Ф Regulators Figure F-1 Typical System One-Line Diagram – Bus Regulation substation Feeder Regulators Non‑ LTC 1Ф Regulators on Transformer Distribution Feeders Figure F-1(A) Typical System One-Line Diagram –...
LTC Transformer Control Comprehensive System Manual Factors Which Cause V to Change An examination of Figure F‑1 reveals that there are four simple factors which when changed, will cause the voltage at the substation secondary bus to change. 1. Transmission system voltage 2.
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Appendix F Voltage Level This is the desired Voltage Level at the Bus. This is related in terms of the 120 V basis of the control. The setting used will generally be higher than 120 V (for example 124 V to 126 V) in recognition that there will be a voltage drop along the distribution feeders and a common criterion is to hold 114 V to 126 V at all loads.
LTC Transformer Control Comprehensive System Manual OBJECTIVE #2: HOLD THE LOAD VOLTAGE (V ) AT THE DESIRED LEVEL The real objective should be to hold the voltage at the load to a desired level. To accomplish this, controls include a provision to set Line Drop Compensation (LDC). This provides the control with the additional feature of modeling the impedance of the distribution feeder between the LTC and the load, to compensate for the voltage drop of the feeder.
Appendix F Figure F‑5, it is important to note that V and V will not usually be in phase with each other, the phasing being a function of the relative magnitudes of R and X and the magnitude and power factor angle (Ф) of the load current.
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LTC Transformer Control Comprehensive System Manual 3. The values above are calculated for one mile of feeder length. Multiply these values by the length of the feeder, in miles, for the total line resistance and reactance. Example: if the circuit is connected in wye, and the length is 1.1 miles: Z = 1.1 (r + jx) = 1.1 (0.385 + j0.598) = 0.424 + j0.658 ohms 4.
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Appendix F COPPER – HARD DRAWN Conductor 60 Hz Reactance Size Resistance (Ohms per conductor per mile at equivalent "D'') at 50° C 18" 24" 30" 36" 42" 48" 54" 60" 1000 0.0685 .449 .484 .511 .533 .552 .568 .583 .595 0.0888 .466...
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LTC Transformer Control Comprehensive System Manual Adjustment for Voltage/Current Phasing Errors in Single Phase Step-Voltage Regulators Connected in Delta Systems The calculations presented so far, presume that the signals from the VT and CT are in‑phase at unity power factor. This can always be accomplished with proper instrument transformer connections on three‑phase transformers and regulators, and will hold on single phase step‑voltage regulators connected in wye, or in single phase applications.
Appendix F Bus Voltage Conditions When Using Line Drop Compensation As stated, the Line Drop Compensation feature will hold a desired voltage at the load. It accomplishes this by recognizing that there will be a voltage drop between the bus and the load (Figure F‑5), and consequently will cause the voltage V...
LTC Transformer Control Comprehensive System Manual Comparison Voltage Profile, Non‑LDC vs LDC The following two figures, show the voltage profile of a line, to illustrate the benefit of use of Line Drop Compensation. In Figure F‑7 the voltage at the load is heavily influenced by the magnitude of the load current.
Appendix F Voltage Limit Override As illustrated, the use of Line Drop Compensation may cause the substation bus voltage to go too high if the load increases higher than anticipated, or if no provision is made to limit the magnitude of the bus voltage V The appropriate solution is to add an LTC Backup Control.
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LTC Transformer Control Comprehensive System Manual Figure F‑9 illustrates the Voltage/Time relationships and actions for an LTC Backup Control, when used in a system application as defined by the three previous examples in the "Bus Voltage Conditions When Using Line Drop Compensation" section. Using the three examples, the LTC Backup Control settings are: • Voltage Level = 120 V • Bandwidth = 12 V = ±6 V • Deadband = 2 V = 126 V to 128 V.
Appendix F Control Settings when the Feeder Includes Capacitors It is frequently the case that a distribution feeder will include power factor correction capacitors as well as step‑voltage regulators. Often, it is incorrectly assumed that the use of these capacitors will necessitate the use of the negative X setting of Line Drop Compensation.
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LTC Transformer Control Comprehensive System Manual LINE LENGTH Source Midpoint Load Figure F-11 Voltage Profile of Feeders for Three Possible Conditions The conclusion is that LDC R and LDC X should be established based on the same premise as that originally described in "Setting LTC Control LDC R and LDC X", without regard to the presence of any capacitors on the line.
Appendix F Regulators in Cascade Operation In the case of longer feeders, several regulators may be included at intervals of several miles in order to keep the voltage profile as desired. This condition requires the addition of a Time Delay, in order to assure optimum operation.
LTC Transformer Control Comprehensive System Manual Reverse Power Flow Operation Many regulators are equipped to recognize the reversal of power flow, and alter tapchanger action accordingly. Reverse Power Flow (RPF) operation in the classic sense, is applied to feeder regulators. Unfortunately, this approach has been improperly applied to systems with remote generation, in the mistaken belief that the classic solution will also work in this application.
Appendix F This reverse power operation is characterized by two very important points: 1. The transition was quick, accomplished in less time than that required for the control on Regulator B to have timed out. 2. At the completion of the switching, the system is again operating radially, though with Regulator B recognizing the power flow reversal.
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The Seller shall not be liable for any property The units described in this manual are covered by damages whatsoever or for any loss or damage U.S. Patents, with other patents pending. arising out of, connected with, or resulting from this Buyer shall hold harmless and indemnify the Seller, contract, or from the performance or breach thereof, its directors, officers, agents, and employees from...
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