Siemens 7UT51 Instruction Manual
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Siemens 7UT51 Instruction Manual

Siemens 7UT51 Instruction Manual

Protective relay
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7 UT 51
Protective Relay
V3
Differential Protection for Transformers, Generators, Motors, and Busses
Instruction Manual
Document No. PRIM-2330C

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Summary of Contents for Siemens 7UT51

  • Page 1 7 UT 51 Protective Relay Differential Protection for Transformers, Generators, Motors, and Busses Instruction Manual Document No. PRIM-2330C...
  • Page 2 The sales contract contains the entire obligation of Siemens Energy & Automation, Inc. The warranty contained in the contract between parties is the sole warranty of Siemens Energy & Automation, Inc. Any statements contained herein do not create new warranties or modify the existing warranty.

  • Page 3: Table Of Contents

    Contents 7UT51 v3 Contents Introduction............................ 11 Using This Manual ............................11 Definitions of Terms ............................ 11 Description of Relay........................13 Overview..............................13 Features ..............................13 2.2.1 Protection Overview ........................... 13 2.2.2 Differential Protection (87T/87HS, 87M/G, 87B)..................14 2.2.3 Overcurrent Protection (50/51, 50HS) ......................14 2.2.4...
  • Page 4 Contents 7UT51 v3 Transformer Differential Protection (87T and 87HS)..............39 Method of Operation...........................39 4.1.1 Matching Currents ............................39 4.1.2 Handling Non-Ideal Behavior........................41 Describing the Transformer ........................43 4.2.1 Type of Transformer ...........................44 4.2.2 Normal Operational Status ......................... 44 4.2.3 System Frequency............................44 4.2.4...
  • Page 5 Contents 7UT51 v3 Trip Characteristic............................71 5.4.1 Trip Characteristic Settings......................... 72 Through-Fault Restraint..........................74 Blocking by Frequency Variance ........................ 74 Time Delays..............................75 Events and Actions ............................. 75 Bus Differential Protection (87B) ....................79 Method of Operation ........................... 79 Describing the Protected Bus ........................79 6.2.1...
  • Page 6 Contents 7UT51 v3 8.4.2 Inverse Time Element (51) ........................101 Reset Time Delay .............................101 Overcurrent Protection during Manual Close of Breaker ................102 Events and Actions...........................106 Thermal Overload Protection (49-1, 49-2) ................. 107 Method of Operation..........................107 Normal Operational Status ........................108 Pickup Characteristic and Warning Levels ....................108...
  • Page 7 Contents 7UT51 v3 13 Binary-Signal Inputs, Signal Contacts, Trip Contacts, and LED Indicators......123 13.1 Overview..............................123 13.2 Binary-Signal Inputs ..........................126 13.3 Signal Output Contacts..........................127 13.3.1 Programmable Signal Contacts ........................ 127 13.4 LED Targets.............................. 128 13.5 Trip (Command) Contacts ........................129 13.6...
  • Page 8 Contents 7UT51 v3 14.11 Use of Multiple Parameter Sets........................ 151 14.12 Setting Date & Time..........................152 15 Operation Using a Personal Computer ..................153 15.1 Overview..............................153 15.2 Programming the Relay..........................154 15.3 Parameter Menu ............................154 15.3.1 Configuration Menu ..........................154 15.3.2 Marshalling Menu .............................156 15.3.3 Settings Menu Example for Transformer Protection.................
  • Page 9 18.8.3 Measured Current Tests – Address Block 4100 ..................206 18.8.4 Waveform Capture during Test Fault Record – Address 4900 ..............207 18.9 Installation of 7UT51 Relay in Existing Circuit ..................208 18.9.1 Output Connections ..........................208 18.10 Testing for In-Service Setting Changes ....................208 18.11...
  • Page 10 Contents 7UT51 v3 PRIM-2330C...

  • Page 11: Introduction

    I/O devices. This manual assumes the operator is using the 7UT51 relay’s operator panel to program, maintain, and Matching Factors – (see Section 4.1.1 on page 39 operate the relay;...
  • Page 12 30°. See Table 4.1 and Table 4.2 for list of vector groups. WinDIGSI – Windows based, Siemens software that will enable the user to perform all settings and data requisition with a PC through the relay’s communication port.

  • Page 13: Description Of Relay

    • Restraint of differential protection when a In addition to the differential protection (87T/87HS, through-fault causes CT saturation. 87M/G, or 87B), the 7UT51 relay provides current-model based thermal overload protection • Zero sequence current elimination (7UT512 or (49-1 and 49-2) for two selected windings. High-set 7UT513) or correction (7UT513 only).

  • Page 14: Differential Protection (87T/87Hs, 87M/G, 87B)

    Differential protection for transformers can be further Pow er Bloc k ed complicated by transformation ratios and phase shift. The 7UT51 relay will automatically accommodate 87 H S these factors based on the system settings, relay configuration settings, and protection settings programmed into the relay.

  • Page 15: Thermal Overload Protection (49-1, 49-2)

    7UT513. load shedding. 2.2.7 Metering 2.2.5 Ground Differential The 7UT51 relay provides access to measured data, Protection (87N) which can be displayed on the front display or via the ® communications port to a PC running WinDIGSI . The...

  • Page 16: Commissioning Data

    7UT51 v3 2.2.8 Commissioning Data 2.2.10 Configuration & Analysis Software (WinDIGSI ® The 7UT51 can be placed in test mode to aid in commissioning the transformer and protection system. • Windows-Based Graphical User Interface • Restraint Values • Menu-Driven for Settings, Configuration, Metering, Log Interrogation, &...

  • Page 17: Construction

    Description of Relay 7UT51 v3 2.2.13 Construction 7 U T 5 1 G B 1 1 - • Compact Case for Flush Mounting Application • Screw Terminals: #10 Current, #8 Voltage Two windings Three windings, or two windings • Drawout Case...

  • Page 18: Protection Functions Available At 60Hz

    Description of Relay 7UT51 v3 Protection Functions Available At 60Hz Table 2.1 lists the protection functions 7UT513 that are available for the 7UT513 and 3 87T 3 87B 2 50/51 7UT512 at 60Hz. Note: The choice of frequency affects the availability the auxiliary protection functions.
  • Page 19 Description of Relay 7UT51 v3 DC Supply Power Rated supply voltage (specified when relay is ordered) 24/48 Vdc 60/110/125 Vdc 220/250 Vdc Permissible voltage range 19 to 56 Vdc 48 to 144 Vdc 176 to 288 Vdc ≤ 12% at rated voltage Superimposed a.c.

  • Page 20: Phase Differential Protection Of A Transformer (87T And 87Hs)

    Description of Relay 7UT51 v3 Phase Differential Protection of a Transformer (87T and 87HS) Settings Operational status Active, inactive, or block contacts; can be temporarily changed using binary signal inputs Minimum differential current required for pickup (87T) 0.15 to 2.00 times I (0.01 steps)

  • Page 21: Phase Differential Protection Of A Transformer (87T And 87Hs)

    Description of Relay 7UT51 v3 Phase Differential Protection of a Transformer (87T and 87HS) Settings Operational status Active, inactive, or block contacts; can be temporarily changed using binary signal inputs Minimum differential current required for pickup (87T) 0.15 to 2.00 times I (0.01 steps)

  • Page 22: Phase Differential Protection Of A Generator Or Motor (87G/M)

    Description of Relay 7UT51 v3 Phase Differential Protection of a Generator or Motor (87G/M) Settings Operational status Active, inactive, or block contacts; can be temporarily changed using binary signal inputs Minimum differential current required for pickup 0.05 to 2.00 times I (steps 0.01)

  • Page 23: Phase Differential Protection Of A Bus (87B)

    Description of Relay 7UT51 v3 Phase Differential Protection of a Bus (87B) Settings Operational status Active, inactive, or block contacts; can be temporarily changed using binary signal inputs Minimum differential current required for pickup (87B) 0.30 to 2.50 times I (steps 0.01)

  • Page 24: Ground Differential Protection (87N) (Optional With 7Ut513)

    Description of Relay 7UT51 v3 2.10 Ground Differential Protection (87N) (Optional with 7UT513) Settings Operational status Active, inactive, or block contacts; choice can be temporarily changed using binary signal inputs Minimum differential current required for pickup (87N) 0.05 to 2.00 times I (step 0.01)

  • Page 25: Overcurrent Protection (50/51 And 50Hs)

    Description of Relay 7UT51 v3 2.11 Overcurrent Protection (50/51 and 50HS) Settings Operational status Active, inactive, or block contacts; choice can be temporarily changed using binary signal inputs 50HS Minimum current required for pickup 0.10 to 30.00 times I n (0.01steps) 0.00 to 32.00 s, (0.01s steps) or ∞...

  • Page 26: Thermal Overload Protection (49-1 And 49-2)

    Description of Relay 7UT51 v3 2.12 Thermal Overload Protection (49 1 and 49 Settings Operational status Active, inactive, or block contacts; choice can be temporarily changed using binary signal inputs Maximum Continuous Overload Current k factor (Imax/In) 0.10 to 4.00 (0.01 steps) τ...

  • Page 27: Tank Leakage Protection (64T)

    Description of Relay 7UT51 v3 2.13 Tank Leakage Protection (64T) Measuring Principle Measurement of the leakage current from the isolated tank to ground. Settings Ground leakage current pickup (dependent on connection) 10mA to 1000mA (1mA steps) Sensitive CT B 0.10 to 10.00 In (0.01In steps) Insensitive CTA 0.00 to 60.00 s or ∞...
  • Page 28 30 days per year. Condensation is not permitted! Note: Siemens recommends that all units be installed such that they are not subjected to direct sunlight, nor to large temperature fluctuations which may result in condensation.
  • Page 29 Description of Relay 7UT51 v3 Vibration and Shock when In Service Standards IEC 255 21 and IEC 68 Vibration sinusoidal 10 Hz to 60 Hz; ± 0.035 mm amplitude; IEC 255 1, class 1 IEC 68 60 Hz to 150 Hz; 0.5 g acceleration...
  • Page 30 Description of Relay 7UT51 v3 PRIM-2330C...

  • Page 31: Application Examples

    In addition, the 7UT513 mode can provide a choice of overcurrent backup, ground differential, or tank leakage current protection. Typical 7UT51 applications are illustrated in the figures and descriptions which follow. These by no means exhaust the range of possible applications, but do demonstrate the relay's flexibility and some common ways of applying it.
  • Page 32 Application Examples 7UT51 v3 Figure 3.3 Winding Transformer Protection using the Ground Differential Protection Element Figure 3.2 Three Winding Transformer Protection with The 7UT513 model can be used for a unique Overcurrent Backup for Tertiary Load application involving paired transformers in the same yard or facility.

  • Page 33: Reactor Protection

    Application Examples 7UT51 v3 Figure 3.4 Parallel Transformers using Cross Connected Overcurrent Backup Protection Reactor Protection The ground differential element of a model 7UT513 can protect a reactor in at least two different ways. Figure 3.5 shows a reactor bank made up of three single-phase reactors with CTs available at the breaker and one CT available in the grounded neutral.

  • Page 34: Motor And Generator Protection

    Protection applications, the independently configurable trip contacts provide flexible tripping schemes. A 7UT51 relay can protect a single motor or generator as shown in Figure 3.7), or a system comprised of a generator and main power transformer connected as a unit (as shown in Figure 3.8).

  • Page 35: Bus Protection

    Application Examples 7UT51 v3 Bus Protection Because of the very high fault currents associated with 7U T 513 bus faults, primary bus protection is normally other 49-1 implemented with a high-impedance type differential relays. However, when fault currents are of lower...
  • Page 36 Application Examples 7UT51 v3 7UT513 7UT513 Bus 1 Bus 2 Radial Bus Differential Protection Including Bus Tie Breaker for Two Bus Distribution System Figure 3.9 A typical radial transformer and feeder breaker Ground differential protection could also be combination is illustrated in Figure 3.10. A 7UT513 is...
  • Page 37 Application Examples 7UT51 v3 Figure 3.10 Differential Protection for Radial Distribution Transformer and Bus Configuration, Feeder Breakers Excluded Figure 3.11 Differential Protection for Radial Distribution Transformer and Bus Configuration, Feeder Breakers Included PRIM-2330C...
  • Page 38 Application Examples 7UT51 v3 PRIM-2330C...

  • Page 39: Transformer Differential Protection (87T And 87Hs)

    Transformer Differential Protection (87T and 87HS) 7UT51 v3 Transformer Differential Protection (87T and 87HS) The transformer differential protection functions (87T The relay computes the matched-current (I’) values and 87HS) provide high speed, secure primary according the following matrix equation: protection for faults within a transformer. The trip characteristic is configurable;...
  • Page 40 Transformer Protection The following factors are available: Figure 4.1 Classic Phase Shift Correction k CT 1 = current processed by 7UT51 current through the relay terminals No Delta-Wye CT connection is necessary. Phase-shift correction is done internally. for Side 1 of the protected object and similar for the...

  • Page 41: Handling Non-Ideal Behavior

    Transformer Differential Protection (87T and 87HS) 7UT51 v3 k_CT_n: Matching Factor for Winding n In_CT_Wn: Nominal CT Current of Winding n In_Tr_Wn: Nominal Transformer Current 7UT512 for Winding n. In_Relay: Nominal Current of the Relay=5A In_Tr_Wn_sec Nominal Current of the Transformer...
  • Page 42 Transformer Differential Protection (87T and 87HS) 7UT51 v3 The relay performs a Fourier analysis of the differential current using numerical filters optimized for transient behavior. Hence, no additional restraining measures are necessary. Prim ary 3A 1 3A 2 2A 1...

  • Page 43: Describing The Transformer

    Transformer Differential Protection (87T and 87HS) 7UT51 v3 Prim ary 3 A 2 3 A 1 2 A 2 2 A 1 1 A 2 1 A 1 3 B 2 3 B 1 2 B 1 2 B 2...

  • Page 44: Type Of Transformer

    Transformer Differential Protection (87T and 87HS) 7UT51 v3 4.2.1 Type of Transformer Note that the default setting is OFF. Without correct parameter settings the relay may show unexpected reactions which include false tripping. The relay uses different addresses and algorithms for different types of protected objects.

  • Page 45: Rated Phase-To-Phase Voltage

    Transformer Differential Protection (87T and 87HS) 7UT51 v3 4.2.4 Rated Phase Phase Note that for FOA transformers, choosing the lowest rating will provide the most sensitive protection; Voltage however, there is a possibility the relay will be continuously “picked up” if the load approaches the...
  • Page 46 Transformer Differential Protection (87T and 87HS) 7UT51 v3 Group Type Symbol Winding Wiring Elimination Correction Without Delta Reference Winding 0° 30° 60° 90° 120° 150° 180° 210° 240° 270° 300° Dd10 330° Dy11 Vector Group Options and Zero Sequence Current Handling Options for a Delta Reference Winding Table 4.1...
  • Page 47 Transformer Differential Protection (87T and 87HS) 7UT51 v3 Group Type Symbol Winding Wiring Elimination Correction Without Reference Winding 0° 30° 60° 90° 120° 150° 180° 210° 240° 270° 300° Yy10 330° Yd11 Table 4.2 Vector Group Options and Zero Sequence Current Handling Options for a Wye Reference Winding...

  • Page 48: Describing The Ct Scheme

    (more than the factor 4), interposing transformers are recommended. Since the current inputs in the 7UT51 are galvanically isolated from each other, the interposing transformers may be designed as auto-transformers. This better...

  • Page 49: Orientation Of Cts

    Transformer Differential Protection (87T and 87HS) 7UT51 v3 The ratio of the interposing transformers is chosen which results in a current transformer ratio of: such that the winding with the lower rating (usually the tertiary winding of the transformer) is roughly matched...

  • Page 50: Zero-Sequence Current Elimination Vs. Correction Mathematical Illustration

    Transformer Differential Protection (87T and 87HS) 7UT51 v3 The settings in Addresses 1106, 1126, and 1146 tell 4.3.6 Zero Sequence Current the relay how to process the zero sequence current of Elimination vs. Correction each winding. These addresses only affect the...
  • Page 51 Transformer Differential Protection (87T and 87HS) 7UT51 v3 Io-Correction - Refer to Figure 4.6. And Section 4.3.5 External Single Phase to Ground Fault, on page 49 Io-Elimination Refer to Figure 4.7 I* = Normalized Current Delta-Winding Wye-Winding Wye-Winding: I0-Correction Currents: Currents: ∠...
  • Page 52 Transformer Differential Protection (87T and 87HS) 7UT51 v3 External Single Phase to Ground Fault, Io-Correction Refer to Figure 4.7 Delta-Winding Wye-Winding Currents: Currents: ∠ ∠ − ∠ ∠ − ∠ ∠ − External Phase to Ground Fault Figure 4.7 Wye-Winding Currents after I0-Correction: ∠...
  • Page 53 Transformer Differential Protection (87T and 87HS) 7UT51 v3 Internal Single Phase to Ground Fault with Io-Elimination Refer to Figure 4.8 Wye-Winding Delta-Winding Currents: Currents: ∠ − ∠ − ∠ ∠ Figure 4.8 Internal Single Phase to Ground Fault − Wye-Winding Currents after I0-Elimination: −...

  • Page 54: Using A Ground Or Neutral Current Ct

    Transformer Differential Protection (87T and 87HS) 7UT51 v3 Internal Single Phase to Ground Fault with 4.3.7 Using a Ground or Neutral Io-Correction Current CT Refer to Figure 4.8 If the protection application includes measuring one or two ground currents (or neutral currents), relay model...

  • Page 55: Trip Characteristic

    Transformer Differential Protection (87T and 87HS) 7UT51 v3 As for the ground-current inputs, the relay must know The differential current, I , is a scalar quantity that is diff the rated nominal primary current and orientation of the absolute value of the amplitude of the vector sum the CT(s) measuring ground or neutral currents.

  • Page 56: Minimum 87T Trip Threshold

    Transformer Differential Protection (87T and 87HS) 7UT51 v3 • If there is a short circuit within the protected 4.4.1 Minimum 87T Trip transformer with current entering from only one Threshold ′ = side, , so: Constant error currents, such as magnetizing currents, = ′...

  • Page 57: Lower Slope Of Pickup Characteristic

    Transformer Differential Protection (87T and 87HS) 7UT51 v3 The 87HS pickup level should be set as low as enable the 87HS function to trip for a fault on a possible, but not so low that it will trip in the event of transformer terminal.

  • Page 58: Upper Slope Of Pickup Characteristic

    Transformer Differential Protection (87T and 87HS) 7UT51 v3 The default value (a slope of 0.25) should be sufficient Through Fault Restraint for regulating ranges up to 20%. If the transformer has a larger regulated range, or there are in-zone loads CT saturation caused by a high-current internal fault (e.g., auxiliary transformers), then the slope must be...

  • Page 59: Second-Harmonic Restraint

    Transformer Differential Protection (87T and 87HS) 7UT51 v3 Second Harmonic if desired, the relay can be configured to have the inrush restraint of any phase “crossblock” the Restraint differential protection of all three phases for a specified duration. The choice and duration are set in Address 1612.

  • Page 60: Higher-Harmonic Restraint

    Transformer Differential Protection (87T and 87HS) 7UT51 v3 Higher Harmonic that phase will not be blocked; however, when appropriate, the relay can be configured to have the Restraint higher-order harmonic restraint of any phase “crossblock” the differential protection of all three phases for a configurable duration.

  • Page 61: Blocking By Frequency Variance

    Transformer Differential Protection (87T and 87HS) 7UT51 v3 Time Delays $GGUHVV If an 87T pickup occurs, and the 87T function is not ,GLII PD[ Q ,Q GHIDXOW being restrained, the function will immediately trip unless a time delay has been set in Address 1625. If...

  • Page 62: Events And Actions

    Transformer Differential Protection (87T and 87HS) 7UT51 v3 4.10 Events and Actions that will appear when viewing logs on the front panel LCD display. In the “Oper” column, a letter “C” or “G” indicates that the “Coming” and/or “Going” events are Figure 4.13 shows the logic of these events.
  • Page 63 Transformer Differential Protection (87T and 87HS) 7UT51 v3 Transformer Differential Protection (87T and/or 87HS) LCD Abbreviation Event Oper Fault In/Out Occurrence Restraint If the 87T/87HS function is in pickup, harmonic restraint 87Blk HarmPhA 5641 87Blk HarmPhB 5642 conditions (inrush and/or overexcitation) are reported separately...
  • Page 64 Transformer Differential Protection (87T and 87HS) 7UT51 v3 Transformer Differential Protection (87T and/or 87HS) LCD Abbreviation Event Oper Fault In/Out Occurrence Configuration Errors Configuration Error (7UT513 only): Both ground current inputs Err 2 CT star 5711 are set to monitor the same winding (addresses 7806 and 7807).
  • Page 65 Transformer Differential Protection (87T and 87HS) 7UT51 v3 Figure 4.13 Tripping Logic of Transformer Differential Protection (87T and 87HS) PRIM-2330C...

  • Page 66: Single-Phase Transformers

    Transformer Differential Protection (87T and 87HS) 7UT51 v3 4.11 Single Phase Transformers Single-phase transformers can be designed with one If the common is grounded, the zero sequence current or two phases per winding; in the latter case, the must be eliminated. The current-matching matrix...

  • Page 67: Motor Or Generator Differential Protection (87M/G)

    Generator on detection that a through-fault is causing CT saturation. The algorithm responds to instantaneous The 7UT51 relay provides differential protection for current measurements, and so can often detect a motors and generators with either longitudinal short circuit in less than one cycle.

  • Page 68: Type Of Protected Object

    Motor or Generator Differential Protection (87M/G) 7UT51 v3 5.2.1 Type of Protected Object 1701 87 STATUS Operational status of differential protection (87M/G) The relay uses different settings and algorithms for when the protected object is a motor or generator. different types of protected objects. Address 7801...

  • Page 69: Describing The Ct Scheme

    Motor or Generator Differential Protection (87M/G) 7UT51 v3 Describing the CT This section describes the associated settings. Scheme 5.3.1 CT Orientation 1203 VA M/G In normal operation, the current has the same Rated apparent power of the motor or magnitude and phase on both sides of the motor or generator generator.
  • Page 70 Motor or Generator Differential Protection (87M/G) 7UT51 v3 Prim ary A B C 3 A2 3 A1 2 A1 2 A2 1 A2 1 A1 3 B2 3 B1 2 B1 2 B2 1 B2 1 B1 Secondary 7 U T 51 R e la y Figure 5.1...

  • Page 71: Nominal Primary Rating Of Cts

    Motor or Generator Differential Protection (87M/G) 7UT51 v3 5.3.2 Nominal Primary Rating As described in Section 5.1 on page 67, the non-ideal behavior of a real system may result in a differential of CTs current when in fact no fault exists within the protected transformer.

  • Page 72: Trip Characteristic Settings

    Motor or Generator Differential Protection (87M/G) 7UT51 v3 The differential protection function uses the transformer protection) since differential currents, due instantaneous values of I and I to plot the to tap-changers and matching errors, are not diff rest location of the “operating point” on the trip expected;...
  • Page 73 Motor or Generator Differential Protection (87M/G) 7UT51 v3 ′ I ′ I 7UT51 = ′ + ′ diff = ′ + ′ rest Operate Area Non-Operate Area Through-Fault Restraint Area ( slope = 1/2 of 1706, left edge = 1718,...

  • Page 74: Through-Fault Restraint

    Motor or Generator Differential Protection (87M/G) 7UT51 v3 Through Fault Restraint Blocking by Frequency Variance CT saturation caused by a high-current internal fault (or by long system time constants) affects the If the system frequency varies too far from the rated...

  • Page 75: Time Delays

    Motor or Generator Differential Protection (87M/G) 7UT51 v3 Time Delays Events and Actions If an 87M/G pickup occurs, the 87M/G function will Table 5.1 describes the events that control and are immediately trip unless a corresponding time delay generated by the 87M/G function. They are listed in has been set in Address 1725.
  • Page 76 Motor or Generator Differential Protection (87M/G) 7UT51 v3 Motor or Generator Differential Protection (87M/G) Occurrence LCD Abbreviation Event Oper Fault In/Out Time Delay Before Trip If an 87M/G pickup occurs, the corresponding 87Diff Pickup 5621 time delay before trip timer will start (see Section 5.7 on page 75).
  • Page 77 Motor or Generator Differential Protection (87M/G) 7UT51 v3 Tripping Logic of Generator or Motor Differential Protection (One Measuring System) Scheme Figure 5.5 PRIM-2330C...
  • Page 78 Motor or Generator Differential Protection (87M/G) 7UT51 v3 PRIM-2330C...

  • Page 79: Bus Differential Protection (87B)

    (see Section 6.5 on page 85). If the 7UT51 relay is used as differential protection for busses, all currents are referred to the nominal current of the protected bus. This data is set during device configuration.

  • Page 80: System Frequency

    Bus Differential Protection (87B) 7UT51 v3 The relay can protect a three-phase bus with two If, during configuration, more functions have been branches (7UT512 or 7UT513) or three branches selected than the device is able to process, the relays (7UT513 only). The protected zone is defined by the will give a corresponding message after configuration location of the CTs (see Figure 6.1 and Figure 6.2).

  • Page 81: Describing The Ct Scheme

    Bus Differential Protection (87B) 7UT51 v3 Describing the CT 6.3.2 Nominal Secondary Rating of CTs Scheme The relay is manufactured with either 1A or 5A current Unlike electromechanical relays, numerical relays do inputs. The choice should match the rated nominal...
  • Page 82 Bus Differential Protection (87B) 7UT51 v3 Branch 1 7UT51 Relay Branch 2 Figure 6.1 Typical CT Wiring for a Bus with Two Branches Branch 1 Branch 3 a’ b’ c’ 7UT513 Branch 2 Figure 6.2 Typical CT Wiring for a Bus with Three Branches...

  • Page 83: Trip Characteristic

    Bus Differential Protection (87B) 7UT51 v3 Trip Characteristic • During normal operation, or if there is a fault ′ = − ′ outside of the protected zone, , so: As shown in Figure 6.1, Figure 6.2, and Figure 6.3, CTs measure the currents flowing into and out of the = ′...

  • Page 84: Trip Characteristic Settings

    Bus Differential Protection (87B) 7UT51 v3 The 87T or 87HS function will pickup if either (1) the The lower sloped-segment of the trip characteristic operating point of any phase moves above 85% of the (Slope 1) deals with a differential current resulting from...

  • Page 85: Through-Fault Restraint

    Bus Differential Protection (87B) 7UT51 v3 Figure 6.3 Differential Protection Characteristic for a Bus Through Fault Restraint current to the restraining current is less than 0.9 (that is, the operating point moves up to within 90% of the line on Figure 6.3), which would indicate an...

  • Page 86: Ct Circuit Monitoring

    Bus Differential Protection (87B) 7UT51 v3 CT Circuit Monitoring Time Delays The differential currents of each phase are If an 87B pickup occurs, the 87B function will continuously monitored on a low level. If a differential immediately trip unless a time delay has been set in current flows (during normal load conditions) that Address 1825.
  • Page 87 Bus Differential Protection (87B) 7UT51 v3 Bus Differential Protection (87B) Occurrence LCD Abbreviation Event Oper Fault In/Out Change in Operational Status When the operational status of the 87B function changes, a 87Diff OFF 5615 87Diff BLOCK 5616 going event for the old status occurs followed by a coming...
  • Page 88 Bus Differential Protection (87B) 7UT51 v3 Bus Differential Protection (87B) Occurrence LCD Abbreviation Event Oper Fault In/Out Trip and Reset Any 87B trip event will also cause event 5671 to occur. With the 87Diff GenTrip 5671 default marshalling, event 5671 will actuate all the trip contacts, signal contact 2, and (as for the general trip of any protection function) signal contact 1.
  • Page 89 Bus Differential Protection (87B) 7UT51 v3 Figure 6.4 Tripping Logic of Bus Differential Protection PRIM-2330C...
  • Page 90 Bus Differential Protection (87B) 7UT51 v3 PRIM-2330C...

  • Page 91: Ground Differential Protection (87N)

    Ground Differential Protection (87N) 7UT51 v3 Ground Differential Protection (87N) The 7UT513 relay can be ordered with a ground differential protection function (87N) to protect power transformers, shunt reactors, neutral grounding transformers, or rotating machines with a common point that is connected to an earth ground.

  • Page 92: Calculated Quantities

    Ground Differential Protection (87N) 7UT51 v3 − ∑ π − sin( (7.5) Two calculated current vectors, , are the major components of the algorithm: (7.6) (7.7) Both quantities are calculated using the Fourier-analysis algorithm described in equation 7.3, equation 7.4, and equation 7.5.

  • Page 93: Trip Decision

    Ground Differential Protection (87N) 7UT51 v3 Trip Decision 1 . 2 In theory, an external fault can be easily recognized 1 . 0 since the calculated quantities I * and I ** will have BLOCK equal magnitudes and a phase angle difference of ϕ = 0 .

  • Page 94: Second Harmonic Restraint

    Ground Differential Protection (87N) 7UT51 v3 Since only the ratio of I * to I ** is of interest, one can Compare Figure 7.4, Figure 7.5, and Figure 7.6 to see imagine graphing I as a three-dimensional surface how, as the ratio of I...

  • Page 95: Normal Operational Status

    Ground Differential Protection (87N) 7UT51 v3 Normal Operational Pickup Level and Limit Status Angle Like the other protection functions, the ground The critical limit angle (Address 1904) determines the differential function (87N) can be set either to exist or restraint of the protection. It indicates at which phase not exist.

  • Page 96: Harmonic Restraint

    Ground Differential Protection (87N) 7UT51 v3 Harmonic Restraint Time Delays Harmonic restraint of the 87N function during If an 87N pickup occurs, the function will immediately transformer energization can be turned off or on trip unless a time delay has been set in Address 1925.
  • Page 97 Ground Differential Protection (87N) 7UT51 v3 Ground Differential Protection (87N) Occurrence LCD Abbreviation Event Oper Fault In/Out Change in Operational Status When the operational status of the 87N function changes, a RGFOFF 5811 RGF ACTIVE 5813 going event for the old status occurs followed by a coming...
  • Page 98 Ground Differential Protection (87N) 7UT51 v3 PRIM-2330C...

  • Page 99: Time Overcurrent Protection (50Hs And 50/51)

    Time Overcurrent Protection (50HS and 50/51) 7UT51 v3 Time Overcurrent Protection (50HS and 50/51) As a backup to the differential protection, the relay A binary input can be used to signal the relay that a provides time overcurrent protection that includes a manual close is occurring;...

  • Page 100: High-Set Element (50Hs)

    Time Overcurrent Protection (50HS and 50/51) 7UT51 v3 High Set Element Overcurrent Element (50HS) (50 or 51) The high-set overcurrent element (50HS) has its own The overcurrent element can have either a pickup threshold level (Address 2103) and time delay definite-time (50) time delay or an inverse-time (51) (Address 2104).

  • Page 101: Definite Time Element (50)

    Time Overcurrent Protection (50HS and 50/51) 7UT51 v3 8.4.1 Definite Time Element (50) delay until trip. Finally, Address 2116 determines if the value used as the measured current contains only the fundamental component (without harmonics) or is the If DEFINITE TIME is selected in Address 2111, the...

  • Page 102: Overcurrent Protection During Manual Close Of Breaker

    Time Overcurrent Protection (50HS and 50/51) 7UT51 v3 Reset Time Delay Overcurrent Protection during Manual Close of To ensure that the time between a trip and reset lasts Breaker long enough for the circuit breaker to operate, the trip state can be prolonged by a reset time delay (Address 2118).
  • Page 103 Time Overcurrent Protection (50HS and 50/51) 7UT51 v3 Multiples of Pickup Current ( I/I p 1000 1000 1000 1000 Multiples of Pickup Current ( I/I p Time Overcurrent Characteristic Curves for 0.054196 + 0.09328 × TD 0.02 Moderately I/I p 7UT51 ≤...
  • Page 104 Time Overcurrent Protection (50HS and 50/51) 7UT51 v3 Multiples of Pickup Current ( I/I p 1000 1000 1000 1000 Multiples of Pickup Current ( I/I p Time Overcurrent Characteristic Curves for 19.138 + 0.48258 × TD Very I/I p 7UT51 ≤...
  • Page 105 Time Overcurrent Protection (50HS and 50/51) 7UT51 v3 Multiples of Pickup Current ( I/I p 1000 1000 1000 1000 Multiples of Pickup Current ( I/I p Time Overcurrent Characteristic Curves for 28.2785 + 0.12173 × TD Extremely I/I p 7UT51 ≤...

  • Page 106: Events And Actions

    Time Overcurrent Protection (50HS and 50/51) 7UT51 v3 Events and Actions Table describes the events that control and are indicates that the “Coming” and/or “Going” events are generated by the 50/51 and 50HS functions. They are logged in the Operational Log, while if in the “Fault”...

  • Page 107: Thermal Overload Protection (49-1, 49-2)

    Each 7UT51 relay has two independent 49 model expressed as the following differential equation: protection elements, which are called 49-1 and 49-2.

  • Page 108: Normal Operational Status

    Thermal Overload Protection (49-1, 49-2) 7UT51 v3 Normal Operational Pickup Characteristic Status and Warning Levels The thermal overload elements (49-1, 49-2) can be 9.3.1 Maximum Continuous Non-Existent/Disabled, or a choice is made as to Overload Current which side (or winding) is to be monitored. A common practice is to monitor the lowest rated winding.

  • Page 109: Warning Alarm Levels

    Thermal Overload Protection (49-1, 49-2) 7UT51 v3 Example: If the short-time overload capacity is stated For example, if k is 1.1, then 1/k is 83%, so Q warn for a duration of 1 s, then that short-term should be more than 83% (the allowed continuous current is inserted into the above formula.
  • Page 110 Thermal Overload Protection (49-1, 49-2) 7UT51 v3 load load --------- - --------- - ⁄ ⁄ ⎛ ⎞ ⎛ ⎞ – 0.90 load load τ × τ × ⎜ ⎟ ⎜ ⎟ ---------------------------------------- ------------------------------------------------------- ⎝ ⎠ ⎝ ⎠ ⁄ ⁄ –...

  • Page 111: Logical Events And Actions

    Thermal Overload Protection (49-1, 49-2) 7UT51 v3 Logical Events and Actions Table describes the events that control and are indicates that the “Coming” and/or “Going” events are generated by the 49-1 and 49-2functions. They are logged in the Operational Log, while if in the “Fault”...
  • Page 112 Thermal Overload Protection (49-1, 49-2) 7UT51 v3 Thermal Overload Protection (49 1 and 49 2) Occurrence LCD Abbreviation Event Oper Fault In/Out Trip The thermal overload protection will trip if and when ALL the >49 O/L1 TRIP 1571 >49 O/L2 TRIP...

  • Page 113: Tank Leakage Protection (64T)

    Tank Leakage Protection (64T) 7UT51 v3 Tank Leakage Protection (64T) A 7UT513 relay can ordered with a tank-leakage Tank leakage protection (64T) operates like an protection element (64T). The element can either overcurrent element using one of the following two...

  • Page 114: Pickup And Dropout Levels

    Tank Leakage Protection (64T) 7UT51 v3 Once the tank-leakage element exists, it can be The measured current value compared to the pickup configured. Its normal operational status is set in level can be either the true rms current, or only the Address 2701.

  • Page 115: Time Delays

    Tank Leakage Protection (64T) 7UT51 v3 10.4 Time Delays If a trip occurs, the contacts and LEDs marshalled to the event will remain activated until the measured tank-leakage current drops below the dropout level set If a 64T pickup occurs, the element will immediately in Address 2709.
  • Page 116 Tank Leakage Protection (64T) 7UT51 v3 Tank Leakage Protection (64T) Occurrence LCD Abbreviation Event Oper Fault In/Out Time Delay Before Trip If a pickup occurs, the time delay (set in Address 2725) starts. If Tank T start 5916 this setting is zero, this event never occurs. Any outputs marshalled to this event will remain energized until the time delay expires.

  • Page 117: Protecting An Additional Device Or Equipment

    Protecting an Additional Device or Equipment 7UT51 v3 Protecting an Additional Device or Equipment A 7UT513 relay has three sets of phase-current inputs 1402 In CT that enable it to protect an object with three windings Rated nominal primary current of the CTs monitoring or branches.
  • Page 118 Protecting an Additional Device or Equipment 7UT51 v3 PRIM-2330C...

  • Page 119: Protection Self-Monitoring

    Protection Self-Monitoring 7UT51 v3 Protection Self Monitoring The relay has self-monitoring features that monitor the 12.2.2 Change of Parameter Set relay hardware, relay software, DC supply power, and the CT circuitry. If self-monitoring determines that the When changing which parameter set is active, or...

  • Page 120: Processor

    When If the relay detects a problem of the analog/digital (A/ using the 7UT51 as protection for a single-phase D) converters, event 145C occurs and the relay is not transformer, both parameters should be set to the ready.

  • Page 121: Current Summation

    Protection Self-Monitoring 7UT51 v3 The relay detects non-symmetric currents if the ratio of the magnitude of I to the magnitude of I smaller than a setting value, “SYM. Fact. I” (setting 2904): < SYM.Fact.I (12.1) When all the phase currents are small, they may be...

  • Page 122: Events And Actions

    Protection Self-Monitoring 7UT51 v3 12.5 Events and Actions This table describes the events that control and are letter “C” or “G” indicates that the “Coming” and/or generated by the self-monitoring features of the relay. “Going” events are logged in the Operational Log, They are listed in numerical order by their event while if in the “Fault”...

  • Page 123: Binary-Signal Inputs, Signal Contacts, Trip Contacts, And Led Indicators

    Overview The logical annunciation functions can be used in multiple. For example, one annunciation function can The 7UT51 can be programmed (or mashalled) to trigger several signal relays, several trip relays, allow external signal contact inputs to function within additionally be indicated by LEDs, and be controlled the relay, and to cause internal functions to activate by a binary input unit.
  • Page 124 Binary-Signal Inputs, Signal Contacts, Trip Contacts, and LED Indicators 7UT51 v3 Signal Contacts „ Each signal contact is controlled Event 1 by up to 20 events. Event 2 For example: Event 20 „ 0141 Failure of internal 24V power supply „...
  • Page 125 Binary-Signal Inputs, Signal Contacts, Trip Contacts, and LED Indicators 7UT51 v3 Trip Contacts „ Each signal contact is controlled Event 1 Event 2 by up to 20 events. For example: Event 20 „ 0511 General Trip of the Relay „...

  • Page 126: Binary-Signal Inputs

    Binary-Signal Inputs, Signal Contacts, Trip Contacts, and LED Indicators 7UT51 v3 13.2 Binary Signal Inputs Binary-signal inputs (also called discrete inputs, input The input functions will have no effect if the contacts, or binary inputs) enable the relay to respond...

  • Page 127: Signal Output Contacts

    Binary-Signal Inputs, Signal Contacts, Trip Contacts, and LED Indicators 7UT51 v3 Event Effect of Input Signal Abbreviation >BU50HS BLK 2306 Block 50HS stage of backup O/C >BU50/51 BLK 2307 Block 50/51 stage of backup O/C >Ext1 BLOCK 4523 External Trip 1 signal (received through another signal input) will be blocked, will be blocked from causing a trip ( ), or will be issued by a signal to this discrete input ( ).

  • Page 128: Led Targets

    Binary-Signal Inputs, Signal Contacts, Trip Contacts, and LED Indicators 7UT51 v3 Relay Code Function(s) Description Relay 4 Failure 24V Relay failure Failure 15V Failure 5V Failure 0V Failure I/O 1 Failure I/O 1 Relay 5 51 Device Operative Relay 6...

  • Page 129: Trip (Command) Contacts

    Binary-Signal Inputs, Signal Contacts, Trip Contacts, and LED Indicators 7UT51 v3 Code Function(s) Description LED 5 24V Failure Relay failure 15V Failure 5V Failure Offset Fail I/O 1 Failure i/O 2 Failure LED 6 95 SetChg in Prog Setting change in progress...
  • Page 130 Binary-Signal Inputs, Signal Contacts, Trip Contacts, and LED Indicators 7UT51 v3 LCD Message Code Event that will activate the trip relay >Buchh. Trip >Tripping stage from Buchholz protection >Buchh. Tank >Tank supervision from Buchholz protection Relay Pick Relay Pick Trip...

  • Page 131: Processing External Trip Commands

    Up to two desired trip signals from external protection or supervision units can be incorporated into the processing of 7UT51. the signals are coupled as If a pickup occurs, the function will immediately trip “External signals” via binary-signal inputs. Like the...

  • Page 132: Numerical Listing Of User Definable Trip And Signal Functions

    Binary-Signal Inputs, Signal Contacts, Trip Contacts, and LED Indicators 7UT51 v3 13.7 Numerical Listing of User Definable Trip and Signal Functions The events listed below are the marshalling Note: Annunciations with a leading “>” sign are possibilities for signal contact inputs, signal contact identical with those for binary inputs and signal outputs, trip contact outputs, and LEDs.
  • Page 133 Binary-Signal Inputs, Signal Contacts, Trip Contacts, and LED Indicators 7UT51 v3 Event LCD Abbreviation Description 1553 >49 O/L1 BLK Block thermal O/L protection 1 1554 >49 O/L1 EVNT Event only from thermal O/L prot. 1 1555 >49 O/L1 BLK Block trip of thermal O/L prot. 1...
  • Page 134 Binary-Signal Inputs, Signal Contacts, Trip Contacts, and LED Indicators 7UT51 v3 Event LCD Abbreviation Description 4543 >Ext2 BLOCK BLOCK external trip 2 4545 >Ext2 blkTRIP BLOCK trip signal of external trip 2 4546 >Ext2 TRIP External trip 2 4551 Ext2 OFF...
  • Page 135 Binary-Signal Inputs, Signal Contacts, Trip Contacts, and LED Indicators 7UT51 v3 Event LCD Abbreviation Description 5903 >Tank BLOCK Block transformer tank protect 5905 >Tank blkTrip Block transformer tank protect trip signal 5911 Tank OFF Transformer tank protection switched OFF 5912...
  • Page 136 Binary-Signal Inputs, Signal Contacts, Trip Contacts, and LED Indicators 7UT51 v3 PRIM-2330C...

  • Page 137: Operation Using The Front Panel Controls

    As a result, lowercase characters are used operated remotely by connecting the relay to a PC for the subscripts in the display. For example, I running WinDIGSI software provided by Siemens (see becomes In. In this manual, most of the specific Chapter 15).

  • Page 138: Relay Nameplate

    Operation Using the Front Panel Controls 7UT51 v3 14.1.4 Relay Nameplate The relay nameplate identifies specific data about your relay such as rated current, DC supply voltage, relay model number, and serial number. Pow er LED In dic ates relay is in service...

  • Page 139: Led Indicators

    Operation Using the Front Panel Controls 7UT51 v3 P ow e r LE D In dicate s re lay is in se rvice A lp han um eric D isp la y Power (G reen ) Blocked 7 U T...

  • Page 140: Custom Led Labels

    Operation Using the Front Panel Controls 7UT51 v3 14.1.6 Custom LED Labels Passw ord P ass A ccesses th e relay p assw ord fu nction. Each relay provides you space to label its LEDs based w ord on how you program them. Labels for the preset annunciations are provided with the relay.

  • Page 141: Scrolling To An Address

    Operation Using the Front Panel Controls 7UT51 v3 14.2.2 Scrolling to an Address 14.3.1 Entering Password Mode If you are not sure of the number of the Address you To prevent inadvertent changes to the relay want to view or change, or if you want to scroll to...

  • Page 142: Changing An Entered Value

    Operation Using the Front Panel Controls 7UT51 v3 4. If a correct password has been entered, the LCD cancel the change and keep the existing displays a confirmation message that the value. password has been accepted: 4. If you wish, change other values or choices in other addresses.

  • Page 143: Using Multiple Settings Groups

    Operation Using the Front Panel Controls 7UT51 v3 4. To change the existing option, press the No key 14.4.2 Changing the Group in Use until the option you want is displayed. by the Relay 5. Press F and to exit the submenu.

  • Page 144: Copying A Group's Contents

    Operation Using the Front Panel Controls 7UT51 v3 Change-over of the Active Parameter Set via 14.4.3 Copying a Group’s Binary Inputs Contents If change-over of parameter sets is intended to be carried out via binary inputs, the following should be...

  • Page 145: Operational/Event Log And Fault Logs

    Operation Using the Front Panel Controls 7UT51 v3 14.5 Operational/Event Log For each event, the data and time of the event are displayed on the top line, while the event type and and Fault Logs coming/going code is displayed on the bottom line. For...

  • Page 146: Clearing A Log

    Operation Using the Front Panel Controls 7UT51 v3 14.5.2 Clearing a Log 14.6 Measured Values Follow these steps to reset the Event Log and/or Fault Metered values are system data collected and Logs: calculated by the relay. The relay can display metered values on the front panel LCD, or export them to a 1.

  • Page 147: Capturing Waveform Data

    Operation Using the Front Panel Controls 7UT51 v3 14.7 Capturing Waveform Data 5700 Operational Metered Values 5900 Thermal Overload Protection Calculated Values Metered values are stored in these address. They are updated every 1 – 5 seconds. LCD Abbreviation Address...
  • Page 148 7490 SYS LENGTH Specification of length each fault record exported out either of the relay’s serial ports. This setting only applies to older data communication networks using the Siemens LSA protocol, and has no effect on networks using the VDEW/ZVEI protocol.

  • Page 149: Address Blocks

    Operation Using the Front Panel Controls 7UT51 v3 14.8 Address Blocks Each relay setting is assigned to an Address number that must be accessed to display or to change the setting. Address numbers are grouped into blocks according to their function. The main Address blocks are listed below.
  • Page 150 Operation Using the Front Panel Controls 7UT51 v3 Block Function (LCD Text) Description EVENT DATA Data available about events (faults) (5100 5900) 5000 EVENT LOG Event (fault) log 5100 LAST FAULT Data of the most recent event (fault) including time stamp and applicable alarms...

  • Page 151: General Configuration

    Operation Using the Front Panel Controls 7UT51 v3 14.9 General Configuration 7107 LINE1 FAULT 7108 LINE2 FAULT Information shown on line 1 (top line) and line 2 (bottom Operating the relay and configuring its settings is done line) of LCD after a network disturbance until a reset...

  • Page 152: Setting Date & Time

    Operation Using the Front Panel Controls 7UT51 v3 14.12 Setting Date & Time The date and time can be set as long as the real-time clock is operational. This is done by changing the setting in Address 8100. The password is required to change the setting.

  • Page 153: Operation Using A Personal Computer

    The Windows-based software allows the user to All the settings and data of the 7UT51 relay are configure a relay for various types of protection. It also available to a PC connected to the communications allows the user to retrieve and analyze event data.

  • Page 154: Programming The Relay

    Response Time Programming of the relay with a PC and WinDIGSI software is straight forward since it is Windows based; Delete device files however, consult the Siemens WinDIGSI User’s Transmit with/without saving Manual for detailed instruction if necessary. Modify baud rate...
  • Page 155 PC and depending on the model ordered, another • 7235 PROGviaREAR system interface for connection of a central control and storage unit, for example Siemens LSA 678. Choice of whether relay will allow Communication via these interfaces requires some configuration via the rear data port (on the configured settings: identification of the relay, back of the relay case).

  • Page 156: Marshalling Menu

    Operation Using a Personal Computer 7UT51 v3 • Address 7831 – State of external trip function 2 • Address 6310 – Configuration of LED 10 • Address 6311 – Configuration of LED 11 • Address 7885 – Select settings group •...
  • Page 157 Operation Using a Personal Computer 7UT51 v3 • Address 1124 – Rated primary current of • Address 1610 – 87-State of 2nd harmonic Winding 2 CT restraint • Address 1125 – Star-point formation of • Address 1611 – 87-2nd harmonic content in the...
  • Page 158 Operation Using a Personal Computer 7UT51 v3 PRIM-2330C...

  • Page 159: Bench Testing

    One source that can provide 120 Hz, 180 Hz, This chapter describes procedures for bench testing a 240 Hz, and 300 Hz current 7UT51 relay, such as for acceptance tests or testing of Both sources can be individually or applied settings. A 7UT51 has many protective...

  • Page 160: Important Notes For This Procedure

    CURRENT operation of the relays and targets based on the RATING CURRENT RATING settings for the particular 7UT51 being tested. I ≤ 20 AMPS 20AMPS < I ≤ 100 AMPS 5 AMPS Verification of the programming of trip relays and signals relays is especially important during I ≤...
  • Page 161 A primary and phase a secondary. When performing testing other than three-phase Address Description Value testing for the 7UT51 relay and protecting a 1103, Trans. Winding 45,000 transformer with a 30 degrees phase shift, keep in 1123 1 &...

  • Page 162: Ideal Through-Fault Test

    Bench Testing 7UT51 v3 16.3.1 Ideal Through Fault Test Connect Test Equipment Connect the test equipment and the relay as shown in When performing two-source testing, the sources can Figure 16.3. The currents I and I must be 180° apart be set to create an ideal through-fault condition, in (±1°) to simulate a through-fault condition.

  • Page 163: Validate Metering

    Bench Testing 7UT51 v3 16.3.2 Validate Metering To read these values using WinDIGSI, begin communication with the relay, then: Testing the metering of numerical relays is the 1. Click Test in the menu bar. quickest method of determining if a relay is no longer functioning or that it is incorrectly connected.

  • Page 164: Three-Winding Transformer Differential Protection (7Ut513 Only)

    Bench Testing 7UT51 v3 6. Click Close to close the Test Results dialog box. 16.3.3 Three Winding Transformer Differential Protection 7. Click Close to close the Commissioning Tests (7UT513 Only) window. 8. Select “4800 Commissioning Tests Stop”. A 7UT513 relay, protecting three winding transformers, can be adequately tested by considering 9.

  • Page 165: Testing The Differential Element 87T

    Bench Testing 7UT51 v3 16.3.4 Testing the Differential Ramp up the single-phase current (60 Hz) slowly from 0 A and stop when Trip Contact 1 closes. Ramp the Element 87T single-phase current down slowly, from the trip value, and stop when Trip Contact 1 opens.

  • Page 166: Testing Differential Setting Of High-Set Element 87Hs

    Bench Testing 7UT51 v3 Testing of Other Phases 1. Set 87 Delay, Address 1625, to infinite seconds. With the current source still connected to the CT If testing of the High Set differential element is desired, input, switch the single-phase current from 0 A to...

  • Page 167: Testing Harmonic Restraint

    Bench Testing 7UT51 v3 16.3.6 Testing Harmonic Restraint 7. Enable both sources simultaneously. The relay should restrain. Connect the relay as shown in Figure 16.8. 8. Turn Off both sources. 9. Slightly adjusting the Source 2 current magnitude while the currents are off, until the minimum Source 2 current magnitude for restraint is found.
  • Page 168 5. The display should approximately read: “IA= setting). 20.0%” for the 1.0A current injected. Connect the test set to the 7UT51 as shown in 6. Go to Address “4801 STOP TEST - FINISH?” Figure 16.10 7. Press the Yes key to end the Commissioning Tests.
  • Page 169 Bench Testing 7UT51 v3 3. Execute the function “4101 Measuring and RGF protection is based on detecting a zero sequence indication of current values”. source (such as a ground-fault or insulation degrading to a ground-fault) in the zone defined by the location of 4.
  • Page 170 Bench Testing 7UT51 v3 To read these values from the relay front display: 1. Go to Address “4181 Test RGF - Measuring?” 2. Press the Yes key. ”IPhA= xxx” will be displayed. This is PhA current on the winding assigned to RGF protection in percentage of 5A.

  • Page 171: Branch Point Differential Protection Testing

    Bench Testing 7UT51 v3 IL1 should display the current you are 16.5 Branch Point applying to the relay’s phase A input in % of 5 Differential Protection Testing “Io*-Io**=” displays the angle between the calculated 3Io (sum of phases) and the 3Io For testing the differential protection, this function input.

  • Page 172: Testing The High-Set Overcurrent Stage

    Bench Testing 7UT51 v3 16.6.1 Testing the High It must be noted that the set times are pure delay times, operating times of the measurement functions Overcurrent Stage are not included. Testing can be performed with single-phase, 16.6.3 Testing the Inverse Time two-phase or three-phase test current.

  • Page 173: Thermal Overload Protection Testing

    Test currents larger than four (4) time In or 15A (Sensitive input) may overload and damage the relay if The same 7UT51 connections can be used for all of applied continuously. the 49 tests. Figure 16.13 shows the connections for Observe a cooling down period! the following example.

  • Page 174: Warning, Overload Current: Address 2405 (49-1) And 2505 (49-2)

    = 49k factor, Address 2402 X I Address 2405 (49 1) and NsecWx 2505 (49 Connect the 7UT51 using the example and the accompanying Figure 16.13. The timer is not needed Let a = 49k factor, Address 2402 X I (for 49-1) Objsec for this test.

  • Page 175: Warning, Temperature: Addresses 2404, 2403 And 2402

    Turning off the current before the trip saves time in of the winding or object. Therefore, prior testing or reading the LCD. loading of the 7UT51 will make the test results below unpredictable unless the temperature rise is forced to 8. Record the value from the timer.

  • Page 176: Tripping: Addresses 2402 And 2403 (49-1), 2502 And 2503 (49-2)

    “49 O/L1 PU Θ” or “49 O/L2 PU Θ”. LED 3 and Signal Relay 2 should not reset immediately after the 49-2 Tripping current is off. The 7UT51 will calculate the Follow steps 1-10 for 49-1 tripping except use temperature as still being above the alarm point, until Address 2501 in steps 1 and 4, Address 2502 in step a cool-down period occurs.

  • Page 177: Tank Leakage Protection Testing (If Available)

    For testing the tank leakage protection, this function supervisory units can be connected into the must be parameterized as operative, On or Block Trip processing of the 7UT51 via binary inputs. Like the Rel in Address 2701. internal signals, they can be annunciated, delayed and transmitted to the trip matrix.

  • Page 178: Putting The Relay Into Operation

    Bench Testing 7UT51 v3 16.10 Putting The Relay Into Operation All setting values should be checked and returned to in Progress. After erasure the relay the required settings. Particularly check that all acknowledges “Successful.” desired protection functions have been programmed in the configuration parameters (Address Block 7800) •...

  • Page 179: Installation And Servicing

    7UT51 relays are completely tested at the factory prior to shipment and are designed so that no special testing, calibration, or maintenance is required. To install a 7UT51 relay, you must be familiar with all applicable safety regulations from ANSI, IEC, NEC, and other pertinent standards.

  • Page 180: Removing And Inserting The Relay Modules

    Installation and Servicing 7UT51 v3 17.3 Removing and Inserting the Relay Modules A 7UT512 relay consists of a relay module that is inserted into the relay case and secured by the relay cover (see Figure 17.2). A 7UT513 has a larger case that holds two modules: a main module and a smaller Hazardous voltage or current.

  • Page 181: Mounting The Relay Case

    Installation and Servicing 7UT51 v3 17.4 Mounting the Relay Case The procedure for mounting the relay case is as follows: 1. Cut and drill the mounting panel to the dimensions shown in Figure 17.6 (for the 7UT512 relay) or Figure 17.7 (for the 7UT513 relay).
  • Page 182 Installation and Servicing 7UT51 v3 Connecting the Ground Strap Figure 17.5 Dimensions of Case and Panel Cutout for a 7UT512 Relay Figure 17.6 PRIM-2330C...

  • Page 183: Wiring

    Installation and Servicing 7UT51 v3 Figure 17.7 Dimensions of Case and Panel Cutout for a 7UT513 Relay 17.5 Wiring Figure 17.8 Screw Terminals & Ring Lugs Terminal Block Detail PRIM-2330C...

  • Page 184: Connection Diagrams

    Installation and Servicing 7UT51 v3 17.5.1 Connection Diagrams Figure 17.9 Connection Diagram for 7UT513 PRIM-2330C...
  • Page 185 Installation and Servicing 7UT51 v3 Figure 17.10 Terminal Locations for 7UT512 PRIM-2330C...
  • Page 186 Installation and Servicing 7UT51 v3 Figure 17.11 Connection Diagram for 7UT512 PRIM-2330C...
  • Page 187 Installation and Servicing 7UT51 v3 Figure 17.12 Terminal Locations on Back of 7UT513 PRIM-2330C...

  • Page 188: Checking Connections

    Installation and Servicing 7UT51 v3 17.6 Checking Connections Make sure the circuit breaker for the DC supply is Check through the tripping circuits to the circuit open. breakers. Check the continuity of all the current transformer Check through the control wiring to and from other circuits against the plant and connection diagrams: devices.

  • Page 189: Installing Or Replacing The Battery

    Installation and Servicing 7UT51 v3 17.8 Installing or Replacing the Battery While the relay’s settings are stored in non-volatile RAM memory, the event logs and captured waveform data are not. In addition, the internal clock requires continuous power. To provide power during any power failure, the relay has a backup battery.
  • Page 190 Installation and Servicing 7UT51 v3 Main Module (7UT512 and 7UT513): Auxiliary Module: Figure 17.15 Locations of Jumpers for Setting Rated Nominal Current of Current Inputs (Production Series /JH or Earlier). PRIM-2330C...
  • Page 191 Installation and Servicing 7UT51 v3 Main Module (7UT512 and 7UT513): Auxiliary Module (7UT513 only): Figure 17.16 Locations of Jumpers for Setting Rated Nominal Current of Current Inputs (Production Series /KK or Later). PRIM-2330C...

  • Page 192: Changing The Rated Voltage Of The Binary-Signal Inputs

    Installation and Servicing 7UT51 v3 17.10 Changing the Rated Voltage of the Binary Signal Inputs A binary-signal input is actuated by applying a control 1. Remove the module(s) from the relay case as voltage across its two terminals. When delivered from described in Section XREF.
  • Page 193 Installation and Servicing 7UT51 v3 Component side of the left pcb Figure 17.18 Jumper Locations for Setting Rated Voltage of Binary Signal Inputs 1 and 2 (Production Series /KK or Later) Figure 17.19 Jumper Locations for Setting Rated Voltage of Binary...

  • Page 194: Changing The Normal Signal Position Of The Fiberoptic Data Port

    Installation and Servicing 7UT51 v3 17.11 Changing the Normal Signal Position of the Fiberoptic Data Port If the relay was ordered with a fiberoptic rear data port, 1. Remove the main module from the relay case as the normal signal position is factory preset to be “Light described in section XREF.

  • Page 195: Field Testing And Commissioning

    Ensure that current inputs are wired with an A-B-C This chapter describes commissioning a 7UT51 relay, phase rotation. Ensure that settings match those including procedures to verify correct operation and prepared by a qualified protective relaying engineer.

  • Page 196: Energizing The Relay

    Field Testing and Commissioning 7UT51 v3 18.1.2 Energizing the Relay Stored indications on the front plate should be reset by pressing the “Target Reset” on the front so that from then on, only real faults are indicated. From that Before energizing the relay, it must be installed for at...

  • Page 197: Check Matching Factors

    Since external matching transformers have been Buchholz protection must remain operative as backup eliminated and since the digital protection unit 7UT51 protection. offers a number of commissioning aids, commissioning can be performed quickly and without The test arrangement varies depending on the external instruments.

  • Page 198: Symmetrical Current Tests, Address Block 4100

    Field Testing and Commissioning 7UT51 v3 18.3 Symmetrical Current On branch points, a low-voltage test source can be used. Alternatively, load current test is possible. Tests, Backup protection must be in service if current tests are only possible under voltage.

  • Page 199: Tests Related To All Applications

    Field Testing and Commissioning 7UT51 v3 The symbols for the side or winding of the protected measured angle is outside of this tolerance range, the object are W1, W2, W3*, WA*, WB* or I1, I2, I3, IA, IB. display shows “inval” The angle differences are The symbols for the phase reference are Ia, Ib, Ic or defined for clockwise phase rotation.
  • Page 200 Field Testing and Commissioning 7UT51 v3 The polarities of the through flowing currents are bridges are on the lower voltage side. If defined to be equal. When currents of equal phase measurement is carried out from the lower flow through the protected object, the angle difference voltage side, the angle must be: 360°...

  • Page 201: Tests Related To Protected Objects With Three Terminals

    Section 18.3.1 on page 199. If this If the 7UT51 is configured for a protected object with parameter is changed, the complete tests two sides, the symmetrical current tests are thus concerning Side 1 against Side 2 would have to completed.

  • Page 202: Preparation For Zero Sequence Current Tests

    Field Testing and Commissioning 7UT51 v3 If the phase angles are correct, the differential and 18.4.1 Zero Sequence Tests – stabilizing currents can be checked in Address 4161. If Address Block 4100 considerable differential currents occur, recheck the concerned parameters as is Sections 18.3.1. If these...

  • Page 203: Current Test For Restricted Ground Fault Protection, Address Block 41

    Field Testing and Commissioning 7UT51 v3 If considerable deviations occur, recheck the If the differential current corresponds to 1/3 of the test corresponding parameters and correct them where current, the star-point current correction is not necessary: effective. If the differential current corresponds to 2/3 of the test current, the star-point current has wrong •...
  • Page 204 Field Testing and Commissioning 7UT51 v3 Measured Values of the Restricted Ground Fault Before the tests are terminated, the differential and Protection stabilizing currents are checked. When assessing the currents, note that the differential and stabilizing The current Io* and Io** are referred to the rated relay values are referred to the rated current of the current and correspond to the values Io’...

  • Page 205: Leaving Test Operation, Address Block 4800

    If the coupling of external functions for alarm and/or After verifying all tripping from the lockout (86) through trip processing is used in 7UT51, then one or more of the test blades, all external tripping of the 86 relay is these functions must be configured as EXISTENT in performed.

  • Page 206: Energizing The Protected Object

    Field Testing and Commissioning 7UT51 v3 18.8 Energizing the 18.8.3 Measured Current Tests – Address Block 4100 Protected Object All current circuits were checked in the previous tests; Place test switch in the operating position. however the use may want to perform the measured current test again under normal operating conditions.

  • Page 207: Waveform Capture During Test Fault Record - Address 4900

    Field Testing and Commissioning 7UT51 v3 18.8.4 Waveform Capture during The data storage parameters can be programmed in Address Block 7400. Data storage can also be Test Fault Record – initiated via a discrete input or by the operator via the Address 4900 front panel of the relay or a PC.

  • Page 208: Installation Of 7Ut51 Relay In Existing Circuit

    Relay in Existing Circuit Note: Since the relay is installed in an energized circuit, operational checks of each output The installation of the Siemens 7UT51 relay in an cannot be performed; however, all outputs from energized circuit can be perform without disturbing the the relay are checked prior to installation and existing system.

  • Page 209: Putting The Relay Into Operation

    Field Testing and Commissioning 7UT51 v3 18.11 Putting the Relay into 8203 Deletes the fault annunciation buffer storage -using WinDIGSI, deleting the Operation operational buffer is found under: Control/ Resetting Stored Data / 8202 - Reset event log / or / 8203 – Reset Trip All setting values should be checked again, in case they were altered during the tests.
  • Page 210 Field Testing and Commissioning 7UT51 v3 PRIM-2330C...

  • Page 211: Maintenance And Servicing

    Maintenance and Servicing 7UT51 v3 Maintenance and Servicing The 7UT51 relays has measurement and signal 19.1 Troubleshooting Tips processing circuits that are fully solid state and, therefore, completely maintenance-free. However, If the relay indicates a defect but none of the...

  • Page 212: When To Return A Relay

    Maintenance and Servicing 7UT51 v3 If the protective device indicates a defect, the following 19.3 When to Return a Relay procedure is suggested: If you cannot correct a problem with the relay using If none of the LEDs on the front plate of the module is...

  • Page 213: Settings Record

    Settings Record 7UT51 v3 Settings Record This 7UT51 (version 3) settings worksheet enables Before configuring the device, copy this form and easy recording of 7UT51 parameter settings when enter the device identification number as well as the configuring the relay. The settings are listed in date of configuration.
  • Page 214 Settings Record 7UT51 v3 Options or Addr LCD Line 1 Setting Setting Setting Setting Default WinDIGSI Description Group A Group B Group C Group D Range and Unit CT2 GND Towards transformer 1128 Towards ground Ground point formation of wind. 2...
  • Page 215 Settings Record 7UT51 v3 Options or Addr LCD Line 1 Setting Setting Setting Setting Default WinDIGSI Description Group A Group B Group C Group D Range and Unit 1400 ADDITIONAL PROTECTED OBJECT DATA In VIRT OB 100000 A 2000 1401...
  • Page 216 Settings Record 7UT51 v3 Options or Addr LCD Line 1 Setting Setting Setting Setting Default WinDIGSI Description Group A Group B Group C Group D Range and Unit 60.00 s or ∞ 87HS DELAY 0.00 0.00 1626 Op time of high set diff.
  • Page 217 Settings Record 7UT51 v3 Options or Addr LCD Line 1 Setting Setting Setting Setting Default WinDIGSI Description Group A Group B Group C Group D Range and Unit RESTRICTED GROUND FAULT PROTECTION DATA 1900 Password level = 2 RGF STATUS...
  • Page 218 Settings Record 7UT51 v3 Options or Addr LCD Line 1 Setting Setting Setting Setting Default WinDIGSI Description Group A Group B Group C Group D Range and Unit M/C MODE P Inactive 50HS IOC w/o Phase overcurrent stage effective: Manual...
  • Page 219 Settings Record 7UT51 v3 Options or Addr LCD Line 1 Setting Setting Setting Setting Default WinDIGSI Description Group A Group B Group C Group D Range and Unit 60.00 s or ∞ Tdly TANK 0.00 0.00 2725 Operating time delay of tank protection...
  • Page 220 Settings Record 7UT51 v3 Addr LCD Line 1 Index Setting Index Setting DISCRETE 0391 >Warning stage from Buchholz INPUT 4 prot. HI 6104 DISCRETE 0392 >Tripping stage from Buchholz INPUT 5 prot. HI 6105 SIGNAL RELAYS 6200 Password level = 3 Up to 20 functions per signal relay.
  • Page 221 Settings Record 7UT51 v3 Addr LCD Line 1 Index Setting Index Setting SIGNAL RELAY 8 001 5821 Restricted ground fault: General TRIP 6208 SIGNAL RELAY 9 001 5921 Transformer tank prot.: General TRIP 6209 SIGNAL RELAY 0391 Warning stage from Buchholz...
  • Page 222 Settings Record 7UT51 v3 Addr LCD Line 1 Index Setting Index Setting LED 6 0095 Setting change in progress nm 6306 LED 7 5821 Restricted ground fault: General TRIP m 6307 LED 8 5921 Transformer tank prot.: General TRIP m...
  • Page 223 Settings Record 7UT51 v3 Addr LCD Line 1 Index Setting Index Setting TRIP RELAYS 6400 Password level = 3 TRIP RELAY 1 5691 87 Diff protection: Trip 1571 49 TRIP by thermal O/L protection 1 5692 87HS Diff protection: Trip...
  • Page 224 Settings Record 7UT51 v3 Options or LCD Line 1 Addr Default Setting WinDIGSI Description Range and Unit LOCAL USER INTERFACE 7100 Password level = 3, except password level = 4 to set addresses 7151 to 7154 LANGUAGE German 7101 English...
  • Page 225 Settings Record 7UT51 v3 Options or LCD Line 1 Addr Default Setting WinDIGSI Description Range and Unit REAR PARITY VDEW/WinDIGSI/LSA 7226 NO PARITY,2 STOP Parity and stop bits for the rear port NO PARITY,1 STOP PROGviaREAR 7235 Programming via the rear port...
  • Page 226 Settings Record 7UT51 v3 Options or LCD Line 1 Addr Default Setting WinDIGSI Description Range and Unit 49 Therml2 NONEXISTENT Reference Side 1Side 2 Thermal overload protection 2 7825 Reference Side 2 Reference Side 3 Virtual object TANK PROT. NONEXISTENT...
  • Page 227 Address Reference 7UT51 v3 A Address Reference 1102 Vn WIND 1 ............45 1405 CT STARPT ........... 117 1103 VA WIND 1............45 1601 87 STATUS ............44 1104 In CT WIND1 (for winding 1)......48 1603 87 PICKUP ............56 1105 CT1 STARPT (for winding 1)......
  • Page 228 Address Reference 7UT51 v3 1832 87 MON DLY ........... 86 3002 T-DELAY ............131 1901 RGF STATUS ..........95 3003 T-RESET ............131 1904 CRIT.ANGLE ........... 95 3101 EXT1 STATUS ..........131 1910 HARMN RSTR..........96 3102 T-DELAY ............131 1912 I RGF max 2 .............
  • Page 229 Address Reference 7UT51 v3 6402 TRIP CONTACT 2 .......... 129 8104 DELTA TIME ........... 152 6403 TRIP CONTACT 3 .......... 129 8501 ACTIVE GRP ..........143 6404 TRIP CONTACT 4 .......... 129 8503 SELECT GRP ..........143 6405 TRIP CONTACT 5 .......... 129 8510 COPY ORIG.SET ->SET A ......
  • Page 230 7UT51 v3 PRIM-2330C...
  • Page 232 Siemens Power Transmission & Distribution Distribution Automation Division PO Box 29503 Raleigh, NC 27626-0503 www.siemenstd.com Manual No. PRIM-2330C © 1999 Siemens Power Transmission & Distribution Printed in USA 0699 1K-HP SIEMENS is a registered trademark of Siemens AG.

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