Electro Industries 1252 Installation And Operation Manual
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Electro Industries 1252 Installation And Operation Manual

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Nexus
1250 /1252
High Performance SCADA Monitor
Installation & Operation Manual
Version 1.25
November 13, 2006
Doc # E107706 V1.25
Electro Industries/GaugeTech
1800 Shames Drive
Westbury, New York 11590
Tel: 516-334-0870
Fax: 516-338-4741
Sales@electroind.com
www.electroind.com
"The Leader in Web Accessed Power Monitoring and Control"

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  • Page 1 Nexus 1250 /1252 High Performance SCADA Monitor Installation & Operation Manual Version 1.25 November 13, 2006 Doc # E107706 V1.25 Electro Industries/GaugeTech 1800 Shames Drive Westbury, New York 11590 Tel: 516-334-0870 Fax: 516-338-4741 Sales@electroind.com www.electroind.com “The Leader in Web Accessed Power Monitoring and Control”...
  • Page 2 Electro Industries/GaugeTech Doc # E107706 V1.25...
  • Page 3 Nexus 1250/1252 Installation and Operation Manual Revision 1.25 Published by: Electro Industries/GaugeTech 1800 Shames Drive Westbury, NY 11590 All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical,...

  • Page 4: Limitation Of Warranty

    This warranty does not apply to defects resulting from unauthorized modification, misuse, or use for any reason other than electrical power monitoring. Nexus 1250/1252 is not a user-serviceable product. OUR PRODUCTS ARE NOT TO BE USED FOR PRIMARY OVER-CURRENT PROTECTION. ANY PROTECTION FEATURE IN OUR PRODUCTS IS TO BE USED FOR ALARM OR SECONDARY PROTECTION ONLY.
  • Page 5 Today, with the Nexus 1250/1252,1262/1272 and the Shark, EIG is a leader in the development and production of power monitoring products. All EIG products are designed, manufactured, tested and calibrated at our facility in Westbury, New York.
  • Page 6 Electro Industries/GaugeTech Doc # E107706 V1.25...

  • Page 7: Table Of Contents

    Chapter 3: Hardware Installation 3.1: Mounting the Nexus 1259/1252 Meter ....3-1 3.2: Mounting the Nexus P40N, P41N, P43N External Displays ... 3-3 3.3: Mounting the Nexus P60N Touch Screen External Display .
  • Page 8 ....... 7-1 7.2: Nexus 1250/1252 Transformer Loss Compensation 7.2.1: Loss Compensation in Three Element Installations ....7-4 7.2.1.1: Three Element Loss Compensation Worksheet .
  • Page 9 8.3: TOU Prior Season and Month 8.4: Updating, Retrieving and Replacing TOU Calendars ....8-2 8.5: Daylight Savings and Demand ..... . . 8-2 Chapter 9: Nexus External I/O Modules 9.1: Hardware Overview .
  • Page 10 12.7: Log Viewer ......12-7 12.8: Performance Notes ......12-8 Appendix A: Transformer Loss Compensation Excel Spreadsheet with Examples A.1: Calculating Values .

  • Page 11: Three-Phase System Configurations

    Three-P P hase Power Measurement This introduction to three-phase power and power measurement is intended to provide only a brief overview of the subject. The professional meter engineer or meter technician should refer to more advanced documents such as the EEI Handbook for Electricity Metering and the application standards for more in-depth and technical coverage of the subject.
  • Page 12 Three-phase voltages and currents are usually represented with a phasor diagram. A phasor diagram for the typical connected voltages and currents is shown in Figure 1.2. Fig 1.2: Phasor Diagram Showing Three-phase Voltages and Currents The phasor diagram shows the 120 phase voltage in a balanced three-phase wye system is 1.732 times the phase-to-neutral voltage.

  • Page 13: 2: Delta Connection

    1.1.2: Delta Connection Delta connected services may be fed with either three wires or four wires. In a three-phase delta service the load windings are connected from phase-to-phase rather than from phase-to-ground. Figure 1.3 shows the physical load connections for a delta service. Phase C Phase A Phase B...

  • Page 14: 3: Blondell's Theorem And Three Phase Measurement

    Fig 1.5: Phasor Diagram Showing Three-phase, Four-wire Delta Connected System 1.1.3: Blondell’s Theorem and Three Phase Measurement In 1893 an engineer and mathematician named Andre E. Blondell set forth the first scientific basis for poly phase metering. His theorem states: If energy is supplied to any system of conductors through N wires, the total power in the system is given by the algebraic sum of the readings of N wattmeters so arranged that each of the N wires contains one current coil, the corresponding potential coil being connected between that wire and...
  • Page 15 single three-phase reading. Some digital meters calculate the individual phase power values one phase at a time. This means the meter samples the voltage and current on one phase and calculates a power value. Then it samples the second phase and calculates the power for the second phase. Finally, it samples the third phase and calculates that phase power.

  • Page 16: Power, Energy And Demand

    1.2: Power, Energy and Demand It is quite common to exchange power, energy and demand without differentiating between the three. Because this practice can lead to confusion, the differences between these three measurements will be discussed. Power is an instantaneous reading. The power reading provided by a meter is the present flow of watts.
  • Page 17 Time Interval Power (kW) (Minute) Table 1.2: Power and Energy Relationship Over Time As in Table 1.2, the accumulated energy for the power load profile of Figure 1.7 is 14.92 kWh. Demand is also a time-based value. The demand is the average rate of energy use over time. The actual label for demand is kilowatt-hours/hour but this is normally reduced to kilowatts.

  • Page 18: Reactive Energy And Power Factor

    Figure 1.8 shows another example of energy and demand. In this case, each bar represents the energy consumed in a 15-minute interval. The energy use in each interval typically falls between 50 and 70 kWh. However, during two intervals the energy rises sharply and peaks at 100 kWh in interval number 7.
  • Page 19 Angle θ Figure 1.9: Voltage and Complex The voltage (V) and the total current (I) can be combined to calculate the apparent power or VA. The voltage and the in-phase current (IR) are combined to produce the real power or watts. The volt- age and the quadrature current (IX) are combined to calculate the reactive power.

  • Page 20: Harmonic Distortion

    result, it does not include the impact of harmonic distortion. Displacement power factor is calculated using the following equation: Displacement PF = cos θ, where θ is the angle between the voltage and the current (see Fig. 1.9). In applications where the voltage and current are not distorted, the Total Power Factor will equal the Displacement Power Factor.
  • Page 21 Total A Phase Current with Harmonics 1500 1000 -500 -1000 -1500 Figure 1.11: Distorted Current Wave The distortion observed in Figure 1.11 can be modeled as the sum of several sinusoidal waveforms of frequencies that are multiples of the fundamental 60 Hz frequency. This modeling is performed by mathematically disassembling the distorted waveform into a collection of higher frequency waveforms.
  • Page 22 Inductive and capacitive impedance are present in all power systems. We are accustomed to thinking about these impedances as they perform at 60 Hz. However, these impedances are subject to frequency variation. = jωL = 1/jωC At 60 Hz, ω = 377; but at 300 Hz (5 changes and system impedance characteristics that are normal at 60 Hz may behave entirely different in presence of higher order harmonic waveforms.

  • Page 23: Power Quality

    1.5: Power Quality Power quality can mean several different things. The terms "power quality" and "power quality problem" have been applied to all types of conditions. A simple definition of "power quality problem" is any voltage, current or frequency deviation that results in mis-operation or failure of customer equipment or systems.
  • Page 24 Electro Industries/GaugeTech 1-14 Doc # E107706 V1.25...

  • Page 25: Chapter 2: Nexus Overview

    2.1: The Nexus System Electro Industries’ Nexus 1250/1252 combines high-end revenue metering with sophisticated power quality analysis. Its advanced monitoring capabilities provide detailed and precise pictures of any metered point within a distribution network. The P60N, P40N, P41N and P43N displays are detailed in Chapter 6.

  • Page 26: Dnp V3.00 Level 1 And Level 2

    For complete details, download the appropriate DNP User Manual from our website www.electroind.com. 2.3: Flicker Nexus 1252 provides Flicker Evaluation in Instantaneous, Short Term and Long Term Forms. For a detailed explanation of Flicker, see Chapter 12 of this manual. Electro Industries/GaugeTech...

  • Page 27: Inp2 Internal Modem With Dial-In/Dial-Out Option

    2.4: INP2 Internal Modem with Dial-I I n/Dial-O O ut Option 2.4.1: Hardware Overview The INP2 Option for the Nexus 1250/1252 meter provides a direct connection to a standard tele- phone line. No additional hardware is required to establish a communication connection between the meter and a remote computer.

  • Page 28: Total Web Solutions

    NOTE: Nexus meters with the INP10 Option do not support Total Web Solutions. 2.5.1: Hardware Overview The Nexus 1250/1252 with the 10/100BaseT Ethernet Option (INP 100) has all the components of the standard Nexus 1250/1252 PLUS the capability of connection to a network through an Ethernet LAN or through the Internet via Modbus TCP, HTTP, SMTP, FTP and/or DHCP.
  • Page 29 2. If you are going to use DHCP, click the Advanced Settings Button: Click the tab at the top of the DHCP screen. Click Enable. DHCP will automatically enter the IP Address and some or all of the Interface Settings. Click OK at the bottom of the screen to return to the Device Profile: Communication Ports screen.

  • Page 30: Measurements And Calculations

    2.6: Measurements and Calculations The Nexus 1250/1252 Meter measures many different power parameters. The following is a list of the formulas used to conduct calculations with samples for Wye and Delta services. Samples for Wye: v an , v bn , v cn , i a , i b , i c , i n...
  • Page 31 Power (Watts) per phase: For Wye: x = a, b, c ∑ • Apparent Power (VA) per phase: For Wye: x = a, b, c • Reactive Power (VAR) per phase: For Wye: x = a, b, c − Power (Watts) Total: For Wye: For Delta: ∑...
  • Page 32 Reactive Power (VAR) Total: For Wye: For Delta: • • Apparent Power (VA) Total: For Wye: For Delta: Power Factor (PF): For Wye: x = A, B, C, T For Delta: x = T Watt PF = Electro Industries/GaugeTech ⎡ ⎤...
  • Page 33 Phase Angles: − ∠ % Total Harmonic Distortion (%THD): For Wye: x = V AN , V BN , V CN , I A , I B , I C For Delta: x = I A , I B , I C , V AB , V BC , V CA ∑...

  • Page 34: Demand Integrators

    Peak demand, expressed in kilowatts (kW), is the highest level of demand recorded during a set period of time, called the interval. The Nexus 1250/1252 supports the following most popular conventions for averaging demand and peak demand: Thermal Demand, Block Window Demand, Rolling Window Demand and Predictive Window Demand.
  • Page 35 Example: Using the previous settings of 3 five-minute intervals and a new setting of 120% prediction factor, the working of the Predictive Window Demand could be described as follows: At 12:10, we have the average of the subintervals from 11:55-12:00, 12:00-12:05 and 12:05-12:10. In five minutes (12:15), we will have an average of the subintervals 12:00-12:05 and 12:05-12:10 (which we know) and 12:10-12:15 (which we do not yet know).

  • Page 36: Nexus External I/O Modules (Optional)

    The following multiple analog or digital I/O modules mount externally to the Nexus 1250/1252 Monitor. The Nexus 1250/1252 Monitor supports up to four I/O modules using internal power. Use the additional power supply, EIG PSIO, to extend I/O capability. See section 3.4 for mounting diagrams. See Chapter 9 for details on installation and usage of the Nexus External I/O Modules.

  • Page 37: Nexus 1250/1252 Meter Specifications

    2.9: Nexus 1250/1252 Meter Specifications Specification Control Power Requirements Input Voltage Range Input Current Range Input Withstanding Capabilities Burden I/O Isolation Sensing Method Update Time Frequency Range Dimensions (HxWxL) Maximum Power Consumption Nominal Power Consumption Operating Temperature Auxiliary Output Power Voltage...

  • Page 38: Nexus P40N, P41N, P43N External Display Specifications

    2.10: Nexus P40N, P41N, P43N LED External Display Specifications Specification Maximum Input Voltage Minimum Input Voltage Maximum Power Consumption Nominal Power Consumption Operating Temperature Range Overall Dimensions (HxWxL) 2.11: Nexus P60N Touch Screen Display Specifications Specification Maximum Input Voltage Minimum Input Voltage Maximum Power Consumption Nominal Power Consumption Operating Temperature Range...

  • Page 39: Chapter 3: Hardware Installation

    3.1: Mounting the Nexus 1250/1252 Meter The Nexus 1250/1252 Meter is designed to mount against any firm, flat surface. Use a #10 screw in each of the four slots on the flange to ensure that the unit is installed securely. For safety reasons, mount the Meter in an enclosed and protected environment, such as in a switchgear cabinet.
  • Page 40 Nexus Meter Mounting Diagram, Side View 2.35” (5.96cm) 3.40” (8.63cm) (MAX) Figure 3.2 Electro Industries/GaugeTech Doc # E107706 V1.25...
  • Page 41 3.2: Mounting the Nexus LED External Displays The Nexus 1250/1252 LED Displays, Model # P40N, P41N and P43N, mount using a standard ANSI C39.1 drill plan. Secure the four mounting studs to the back of the panel with the supplied nuts.

  • Page 42: Mounting The Nexus P60N Touch Screen External Display

    Figure 3.4: Nexus P60N Touch Screen Display Mounting Diagram The Nexus 1250/1252 P60N Touch Screen Display mounts easily, using the diagrams above and on the next page. A bezel and a gasket are included with the P60N. Since the P60N employs an LCD display, the viewing angle must be considered when mounting.
  • Page 43 Figure 3.6: Cutout for Nexus P60N Touch Screen Display To bezel mount the P60N, cut an opening in the mounting panel. Follow above cutout dimensions. Carefully “drop in” the P60N with bezel and gasket attached. Fasten the unit securely with the four 6-32 hex nuts supplied. Electro Industries/GaugeTech Doc # E107706 V1.25...

  • Page 44: Mounting The Nexus External I/O Modules

    3.4: Mounting the Nexus External I/O Modules Secure the mounting brackets to the I/O using the screws supplied (#440 pan-head screws). Next, secure the brackets to a flat surface using a #8 screw with a lock washer. If multiple I/O modules are connected together, as shown in Figure 3.4, secure a mounting bracket to both ends of the group.
  • Page 45 Nexus I/O Modules Mounting Diagram, Front View Mounting Bracket (MBIO) Mounting Bracket (MBIO) 1.25” (3.17cm)+Y Per Module 2.20” (5.58cm) 3.41” (8.66cm) 2x1.10” (2.79cm) 0.605” (1.53cm) 1.235” (3.13cm) Figure 3.9 Electro Industries/GaugeTech Doc # E107706 V1.25...
  • Page 46 Electro Industries/GaugeTech Doc # E107706 V1.25...

  • Page 47: Chapter 4: Electrical Installation

    4.1: Wiring the Monitored Inputs and Voltages Select a wiring diagram from Section 4.8 that best suits your application. Wire the Nexus 1250/1252 exactly as shown. For proper operation, the voltage connection must be maintained and must correspond to the correct terminal. Program the CT and PT Ratios in the Device Profile section of the Communicator EXT software;...

  • Page 48: Isolating A Ct Connection Reversal

    CT Size (VA) 10.0 15.0 30.0 DO NOT leave the secondary of the CT open when primary current is flowing. This may cause high voltage, which will overheat the CT. If the CT is not connected, provide a shorting block on the secondary of the CT. It is important to maintain the polarity of the CT circuit when connecting to the Nexus.

  • Page 49: Wiring Diagrams

    Control Power 18-60 Volts DC 90-276 Volts AC/DC Do not ground the unit through the negative of the DC supply. Separate grounding is required. Externally fuse the power supply with a 5 Amp fuse. 4.8: Wiring Diagrams Choose the diagram that best suits your application. Diagrams appear on the following pages. If the connection diagram you need is not shown, contact EIG for a custom Connection diagram.
  • Page 50 0.25 A INPUT Figure 4.1: 4-Wire Wye, 3-Element Direct Voltage with 4 CTs Electro Industries/GaugeTech Doc # E107706 V1.25...
  • Page 51 0.25A INPUT Figure 4.2: 4-Wire Wye, 3-Element with 3 PTs and 4 CTs Electro Industries/GaugeTech Doc # E107706 V1.25...
  • Page 52 0.25 A INPUT Figure 4.3: 4-Wire Wye, 3-Element with 3 PTs and 3 CTs Electro Industries/GaugeTech Doc # E107706 V1.25...
  • Page 53 0.25 A Figure 4.4: 3-Wire, 2-Element Open Delta with 2 PTs and 3 CTs. Electro Industries/GaugeTech Doc # E107706 V1.25...
  • Page 54 0.25 A Figure 4.5: 3-Wire, 2-Element Open Delta with 2 PTs, 2 CTs. Electro Industries/GaugeTech Doc # E107706 V1.25...
  • Page 55 0.25 A INPUT Figure 4.6: 3-Wire, 2-Element Delta Direct Voltage with 3 CTs. Electro Industries/GaugeTech Doc # E107706 V1.25...
  • Page 56 0.25 A INPUT Figure 4.7: 3-Phase, 4-Wire Wye, 2.5 Element with 2 PTs, 3 CTs. Electro Industries/GaugeTech 4-10 Doc # E107706 V1.25...
  • Page 57 0.25 A INPUT Figure 4.8: 4-Wire, 3-Element Grounded Delta with 4 CTs - G Option. Electro Industries/GaugeTech 4-11 Doc # E107706 V1.25...
  • Page 58 Electro Industries/GaugeTech 4-12 Doc # E107706 V1.25...

  • Page 59: Communication Overview

    RTU or PLC. The link is viable for a distance up to 50 feet (15.2 m) and is available only through the Nexus 1250/1252 Meter’s Port 1. You must set the selector switch beneath the port to RS-232 (see Figure 5.3).
  • Page 60 The Nexus Meter with the Internal Modem Option has a unique label; Port 2 is labeled Modem Gateway. If you are going to use RS-485 to connect multiple Nexus 1250/1252 meters, you MUST use the Modem Gateway. For more details, see Chapter 10 of this manual.
  • Page 61 Nexus Meters in local or remote sites in a daisy chain configuration, as depicted below. The Nexus 1250/1252 Meter with the Internal Network Option has a unique label; Port 2 is labeled Ethernet Gateway. If you are going to use RS-485 to connect multiple Nexus meters via the net- work, you MUST use the Ethernet Gateway.
  • Page 62 I/O Modules and Display RS-232 Extension require power connections Cable to the +/- voltage terminals (1 to 1 wiring) (dashed lines). RS-485 Master Unicom or Modem Manager – – + + G R T= ~120 Ohms + V - S B(-) A(+) Port 1 RS-232 or RS-485 (Set)

  • Page 63: Rs-232 Connection-Nexus Meter To A Computer

    Voltage terminals for power connections: Use with Nexus I/O Modules and the Nexus Displays only. The Nexus 1250/1252 Meter supplies 17V DC through the +V- ter- minal connections. Note: Do not connect these pins to devices that receive power from another source—ie, a computer—or to devices that do not require power to operate.
  • Page 64 RS-485 communication allows multiple devices to communicate on a bus. The Nexus 1250/1252 Ports 1 to 4 are RS-485 terminals, viable for a distance of up to 4000 feet (1219 m). (Nexus’ Port 1 can be switched between RS-232 and RS-485.) Below is a detail of a 2-wire RS-485 port.
  • Page 65 Incorrect Connection: “T” “Tee” Connection Incorrect! The three wires connected in a “T” shape on both the (+) and (-) terminals will cause interfer- ence problems. RS-485 Port Incorrect Connection: “Star” “Star” Connection Incorrect! The three wires connected in a “Star”...

  • Page 66: Rs-485 Connection- Nexus Meter To A Computer Or Plc

    5.4: RS-4 4 85 Connection—Nexus Meter to a Computer or PLC Use any Port on the Nexus 1250/1252. If you use Port 1, set the selector switch beneath the port to RS-485 (see Figure 5.3). The link using RS-485 is viable for up to 4000 feet (1219 meters).

  • Page 67: Rs-485 Connection- Nexus To An Rs-485 Master (Unicom Or Modem Manager)

    5.7: RS-4 4 85 Connection—Nexus to an RS-4 4 85 Master (Unicom or Modem Manager) To establish communication between a Nexus Meter and any RS-485 master, such as EIG’s Unicom 2500, Modem Manager or other RS-232–485 converter, use a shielded, twisted pair cable. Use an RS-485 port (Ports 1–4) on the Nexus Meter.
  • Page 68 Figure 5.9: Detail of “Jumpers” Figure 5.8: Unicom 2500 with Connections The Unicom 2500 can be configured for either 4-wire or 2-wire RS-485 connections. Since the Nexus uses a 2-wire connection, you need to add jumper wires to convert the Unicom 2500 to the 2-wire configuration.
  • Page 69 5.8: RS-4 4 85 Connection—Nexus Meter to the Nexus P40N External Display Insert one end of the supplied RS-485 cable into Port 3 of the Nexus 1250/1252 Meter. Port 3 is factory-set to match the Nexus Display’s baud rate of 9600. To use a port other than Port 3, you must set the port’s baud rate to 9600 using the Communicator EXT software (see the Communicator EXT...
  • Page 70 The cable is six (6) feet long with 20 AWG conductors (see detail below). Insert one end of the supplied cable into Port 3 of the Nexus 1250/1252 Meter. Port 3 is factory-set to match the Nexus Display’s baud rate of 9600. To use a port other than Port 3, you must set the port’s baud rate to 9600 using the Communicator EXT software (see the...

  • Page 71: Communication Ports On The Nexus I/O Modules

    5.10: Communication Ports on the Nexus I/O Modules Female RS-485 Side Port: use to connect to another module’s female RS-485 side port. Male RS-485 Side Port: use to connect to the Nexus Meter’s Port 4 (see section 5.8) or to connect to another module’s male RS-485 side port.

  • Page 72: Rs-485 Connection-Nexus Meter To Nexus I/O Modules

    RS-485 port. Connect the shield to the shield (S) terminal. The (S) terminal on the Nexus 1250/ 1252 is used to reference the Nexus port to the same potential as the source. It is not an earth ground connection. You must also connect the shield to earth-ground at one point.

  • Page 73: Steps To Determine Power Needed

    5.12: Steps to Determine Power Needed • Available power for All Ports of the Nexus 1250/1252 is 12 VA. • Refer to the table below to determine the VA Ratings for I/O modules and displays. • Add together the VA Ratings for I/Os and Displays in use.

  • Page 74: Linking Multiple Nexus Devices In Series

    5.14: Linking Multiple Nexus Devices in Series You may connect a total of 31 Nexus 1250/1252 Meters in series on a single bus using RS-485. The cable length may not exceed 4000 feet (1219 meters). Before assembling the bus, each Nexus Meter must be assigned a unique address;...

  • Page 75: Networking Groups Of Nexus Meters

    5.15: Networking Groups of Nexus Meters You may connect up to 31 Nexus 1250/1252 Meters on the same RS-485 bus. Each one must be assigned a unique address; see the Communicator EXT User Manual. Use an RS-485 repeater to network several links of instruments.

  • Page 76: Remote Communication Overview

    PSTN (Public Remote Switched Modem Telephone Network) Telephone Line Remote Modem NULL Modem Adapter tion) Doc # E107706 V1.25 Nexus 1250/1252 Meter RS-232 NULL Modem Adapter or Null Cable Required Nexus 1250/1252 Meter RS-232 to RS-485 Converter (Modem Manager Recommended) 5-18...
  • Page 77 Standard Telephone wall to phone cabling can be used. This cabling is widely available in many lengths with RJ-11 plugs on each end. Plug one end into the Nexus 1250/1252 and the other end into the wall jack. Electro Industries/GaugeTech...
  • Page 78 Or, use RJ-45 Network Connection when devices are at great distances. Connections are simple, requiring no additional hardware. RS-485 MODBUS/RTU 10/100BaseT or 10BaseT RJ-45 MODBUS/TCP over Ethernet Daisy Chain Network Figure 5.18: Remote Connections with Internal Network Option Electro Industries/GaugeTech 5-20 Doc # E107706 V1.25...
  • Page 79 5.18: Remote Communication—RS-4 4 85 Use any Port on the Nexus 1250/1252. If you use Port 1, set the selector switch beneath the port to RS-485 (see Figure 5.3). The link using RS-485 is viable for up to 4000 feet (1219 meters).

  • Page 80: Programming Modems For Remote Communication

    5.19: Programming Modems for Remote Communication When a modem speaks to most RS-485 or RS-232-based devices, it must be programmed for the communication to work. This task is often quite complicated because modems are quirky when talking to remote devices. If you are not using a Modem Manager device, you must set the following strings to communicate with the remote Nexus Meter(s).

  • Page 81: Selected Modem Strings

    5.20: Selected Modem Strings Modem Cardinal modem: Zoom/Faxmodem VFX V.32BIS(14.4K): Zoom/Faxmodem 56Kx Dual Mode: USRobotics Sportster 33.6 Faxmodem: DIP switch setting: USRobotics Sportster 56K Faxmodem: DIP switch setting: 5.21: High Speed Inputs Connection The Nexus High Speed Inputs can be used in many ways: Attach the KYZ HS Outputs from other meters for totalizing.

  • Page 82: Five Modes Of Time Synchronization

    5.22: Five Modes of Time Synchronization The Nexus meter offers up to five modes of Time Synchronization, depending on options selected at the time of ordering. 1. Internal Crystal: The Default Time Constant is an Internal Crystal. The crystal is accurate to approximately 1 minute per month.

  • Page 83: Irig-B Connections

    IRIG-B is a standard time code format that synchronizes event timestamping to within 1 millisecond. An IRIG-B signal-generating device connected to the GPS satellite system will synchronize Nexus 1250/1252 Meters located at different geographic locations. Nexus utilizes an UNMODULATED signal from a satelite-controlled clock (such as Arbiter 1093B). For details on installation, refer to the User’s Manual for the satellite-controlled clock in use.
  • Page 84 Electro Industries/GaugeTech 5-26 Doc #: E107706 V1.25...

  • Page 85: Chapter 6: Using The Nexus External Displays

    Using the Nexus External Displays 6.1: Overview Electro Industries offers four external displays for use with the Nexus 1250/1252. The P40N, P41N and P43N are LED displays that provide easy-to-use access to the information stored in the Nexus 1250/1252. The P60N is our Touch Screen Display, which provides easy access to Nexus 1250/1252 readings and information combined with a graphical touch screen presentation.

  • Page 86: 1: Connect Multiple Displays

    6.2.1: Connect Multiple Displays One cable (housing two-wire RS-485 and two-wire power wires plus shield) is used to connect the displays. One port of the Nexus meter supports 12 VA. Each P40N, P41N or P43N requires 3.3 VA (maximum 3.8 VA). The Master Display (P40N) is the master in communication. The Amp, Power and Nexus devices are slaves in communication.

  • Page 87: Dynamic Readings Mode

    6.3: Dynamic Readings Mode The External Display puts itself in the Dynamic Readings Mode upon power-up. Use the MODE button to access the Dynamic Readings from other Modes. Use the UP/DOWN arrows to navigate from Group to Group within this Mode. See section 6.4 for a navigational map of the Dynamic Readings Mode.
  • Page 88 • Maximum Quadrant 1 Total PF • Minimum Quadrant 1 Total PF • Maximum Quadrant 2 Total PF • Minimum Quadrant 2 Total PF • Maximum Quadrant 3 Total PF • Minimum Quadrant 3 Total PF • Maximum Quadrant 4 Total PF •...

  • Page 89: Navigational Map Of Dynamic Readings Mode

    6.4: Navigational Map of Dynamic Readings Mode Use LEFT/RIGHT arrow keys to navigate Readings Use UP/DOWN arrows to scroll between groups. 1 Second Volts Maximum Volts AN,BN,CN AN,BN,CN 1 Second Volts Maximum Volts AB,BC,CA AB,BC,CA 1 Second Minimum Maximum IA,IB,IC IA,IB,IC IA,IB,IC +Max kWatt,...

  • Page 90: Nexus Information Mode

    6.5: Nexus Information Mode Use the MODE button to access the Nexus Information Mode from other Modes. Use the UP/DOWN arrows to navigate from Group to Group within this Mode. See section 6.6 for a navigational map of the Nexus Information Mode. Group 1: Device Time •...

  • Page 91: Navigational Map Of Nexus Information Mode

    6.6: Navigational Map of Nexus Information Mode Use UP/DOWN arrows to scroll between groups. Use LEFT/RIGHT arrows to scroll between readings. Readings Meter Time Comm Comm Settings Settings Port 2 Port 1 PT Ratio CT Ratio First Reading Display Primary/Secondary Run-time Boot Display, Serial...

  • Page 92: Display Features Mode

    6.7: Display Features Mode Use the MODE button to access the Display Features Mode from other Modes. Use the UP/DOWN arrows to navigate from Group to Group within this Mode. See section 6.8 for a navigational map of the Display Features mode. Group 1: Reset Max/Min •...

  • Page 93: Navigational Map Of Display Features Mode

    6.8: Navigational Map of Display Features Mode Use UP/DOWN arrows to scroll between groups. Reset Max/Min Reset Energy Baud Rate/Address Communication Protocol EIG Use Only EIG Use Only Lamp Test Display Scroll On/Off Electro Industries/GaugeTech Doc # E107706 V1.25...

  • Page 94: Nexus P60N Touch Screen External Display

    6.9: Nexus P60N Touch Screen External Display The P60N Touch Screen External Display is ready to use upon power-up. Touching the “buttons” at the top of the screen will take you to the Groups of Readings listed below. With the “buttons” at the bottom of the screen, you can use the touch screen to review Limits and review and/or change Settings on the Display and the Nexus Meter.
  • Page 95 VOLTS: Voltage Readings Details • Real Time Volts AN/BN/CN/AB/BC/CA • Maximum Volts AN/BN/CN/AB/BC/CA • Minimum Volts AN/BN/CN/AB/BC/CA Touch PH-N or PH-PH to view details of Phase-to-Neutral or Phase-to-Phase Readings. VOLTS: Voltage Readings PH-N • Volts AN/BN/CN Touch BACK to return to the Volts main screen. VOLTS: Voltage Readings PH-PH •...
  • Page 96 AMPS: Current Readings A-B-C • Real Time Current A/B/C Touch BACK to view the Amps main screen. REAL TIME POWER: Real Time Power Readings Details • Instant Watt/VAR/VA/PF • Average Watt/VAR/VA/PF • Predicted Watt/VAR/VA Touch the DEMAND button to go to the Demand Power screen (shown below) DEMAND POWER: Demand Power Readings Details...
  • Page 97 TOU: Accumulations • -Watthr Quadrant 2+Quadrant 3 (Primary) • +VAhr Quadrant 2 (Primary) • +VARhr Quadrant 2 (Primary) • +VAhr Quadrant 3 (Primary) • -VARhr Quadrant 3 (Primary) • +Watthr Quadrant 1+Quadrant 4 (Primary) • +VAhr Quadrants 1 & 4 (Primary) •...
  • Page 98 FLICKER - LONG TERM: • Volts A/B/C • Max Volts A/B/C • Min Volts A/B/C Touch INST or LONG TERM to view other Flicker screens. START or STOP will appear, depending on Status. LIMITS: Limit Status Current Limits Settings for Nexus Meters, ID 1 - 32. For each ID number, the Type of Reading, Value, Status (In or Out of Limit) and Setting is shown.
  • Page 99 SPECTRUM: Harmonic Spectrum Analysis. Select a Channel by touching the CHANNEL button. Graphs and readings appear for the selected channel. Zoom In or Out for detail by touching IN or OUT. REAL TIME TRENDING ANALYSIS: Select Channel by touching the CHANNEL button.
  • Page 100 LOG STATUS: Logging Statistics An Overview of the Logs for the Primary Meter. The Number of Records and Memory Used are listed for each log. RESET: Meter Reset Commands. WARNING! RESETS cause data to be lost. Touch the window for the Reset you want to perform. Don’t Reset changes to Reset.
  • Page 101 Port 2 (Baud and Protocol selected). Port 3 (Baud and Protocol selected). Port 4 (Baud and Protocol selected). NEXUS STATUS: Device Type: Nexus 1252 Serial Number (10 digit number) Comm State: Healthy or Unhealthy Nv Ram: 4 MB DSP State: Healthy or Unhealthy...

  • Page 102: Navigational Map For P60N Touch Screen External Display

    6.10: Navigational Map for P60N Touch Screen External Display Electro Industries/GaugeTech 6-18 Doc # E107706 V1.25...

  • Page 103: Chapter 7: Transformer Loss Compensation

    Transformer Loss Compensation 7.1: Introduction The Edison Electric Institute’s Handbook for Electricity Metering, Ninth Edition defines Loss Compensation as: A means for correcting the reading of a meter when the metering point and point of service are physically separated, resulting in measurable losses including I transformers and iron-core losses.
  • Page 104 Line loss compensation is calculated in the meter using the same terms but the percent values are calculated by a different methodology as described in a subsequent section below. Nexus 1250/1252 Transformer Loss Compensation: • Performs calculations on each phase of the meter for every measurement taken. Unbalanced loads are accurately handled.

  • Page 105: Nexus 1250/1252 Transformer Loss Compensation

    KYZ Output of Energy Accumulations. NOTE: Loss Compensation is disabled when the meter is placed in Test Mode. 7.2: Nexus 1250/1252 Transformer Loss Compensation The Nexus meter provides compensation for active and reactive power quantities by performing the numerical calculations using factors derived by clicking the TLC Calculator button on the Transformer Loss screen of the Device Profile or by manually figuring values in section 7.2.1,...

  • Page 106: 1: Loss Compensation In Three Element Installations

    7.2.1: Loss Compensation in Three Element Installations Loss compensation is based on the loss and impedance values provided on the transformer manufacturer’s test report. A typical test report will include at least the following information: • Manufacturer • Unit Serial Number •...

  • Page 107: 1: Three Element Loss Compensation Worksheet

    7.2.1.1: Three Element Loss Compensation Worksheet Company Date Trf Manf Calculation by Transformer Data (from Transformer Manufacturer’s Test Sheet) Winding Voltage HV - High Xv - Low YV - Tertiary Value 3-Phase No-Load Loss Load Loss Enter 3-Phase or 1-Phase values. If 3-Phase values are entered, calculate 1-Phase values by dividing 3-Phase values by three.
  • Page 108 Meter/Installation Data Instrument Transformers Potential Transformer Current Transformer Power Multiplier [(PT Multiplier) times (CT Multiplier)] Enter the Numerator and Denominator for each instrument transformer. For example, a PT with a ratio of 7200/120 has a numerator or 7200, a denominator or 120 and a multiplier of 60 ( 7200/120 = 60/1). Meter Secondary Voltage (volts) Meter Secondary Current (amps) Base Conversion Factors...
  • Page 109 Full-Load Loss Watts (kW) = 1-Phase Kw Load Loss = ______________ Full-Load Loss VA (kVA) = (%Impedance) * (1-Phase kVA Self-Cooled Rating) / 100 = (______________) * (________________) / 100 = _______________ kVA Full-Load Loss VAR (kVAR) = SQRT((Full-Load Loss kVA) = SQRT((_________________) = SQRT((__________________) - (_________________)) = SQRT (_________________)
  • Page 110 Calculate Load Loss Values Value at Meter Quantity Base No-Load Loss kW No-Load Loss kVAR Load Loss kW Load Loss kVAR Enter “Value at Meter Base” from Normalize Losses section. Enter “Meter Base kVA” from previous calculation. Calculate “% Loss at Meter Base” by dividing (Value at Meter Base) by (Meter Base kVA) and multiplying by 100.

  • Page 111: Introduction

    EXT software, is designed to accommodate a variety of programmable rate structures. Nexus TOU accumulates data based on the time-scheme programmed into the Nexus Monitor. See the Communicator EXT User Manual for details on programming the Nexus 1250/1252 20 Year TOU calendar and retrieving TOU data.

  • Page 112: Tou Prior Season And Month

    Up to a maximum of twenty yearly calendars can be stored in the Nexus 1250/1252 Monitor at any given time. You may retrieve them one at a time; a new calendar can be stored while a current calendar is in use.

  • Page 113: Chapter 9: Nexus External I/O Modules

    Female RS-485 Side Port: use to connect to another module’s male RS-485 side port. • • Male RS-485 Side Port: use to connect to the Nexus 1250/1252 Meter’s Port 3 or 4 or to another module’s female RS-485 side port. See Figure 9.2 for wiring detail.

  • Page 114: 1: Port Overview

    9.1.1: Port Overview All Electro Industries I/O Modules have ports through which they interface with other devices. The port configurations are variations of the four types shown below. Four Analog Outputs (0-1 1 mA and 4-2 2 0mA) Eight Analog Inputs (0-1 1 mA, 0-2 2 0mA, 0-5 5 V dc , 0-1 1 0V dc ) or Eight Status Inputs...

  • Page 115: Installing Nexus External I/O Modules

    9.2: Installing Nexus External I/O Modules I/O modules must use the Nexus 1250/1252 Meter’s Port 3 or 4. Six feet of RS-485 cable harness is supplied. Attach one end of the cable to the port (connectors may not be supplied); insert the other end into the communication pins of the module’s Male RS-485 Side Port.

  • Page 116: 1: Power Source For I/O Modules

    9.2.1: Power Source for I/O Modules The Nexus 1250/1252 will supply power to a limited number (3) I/O MODULES. For more, you must use an external power source, such as the EIG PSIO (12V). Refer to sections 5.12 and 5.13 to Determine Power Needed.

  • Page 117: Using Psio With Multiple I/O Modules

    9.3: Using PSIO with Multiple I/O Modules LEDs Female RS-485 Side Port Reset Button I/O Port (Size and pin configuration vary) Figure 9.6: Using PSIO with Multiple I/O Modules NOTE: PSIO must be to the right of I/O Modules when viewing the side label (as shown). 9.3.1: Steps for Attaching Multiple I/O Modules 1.

  • Page 118: Factory Settings And Reset Button

    NOTE: The PB1 can also be used for a Low Voltage Power Supply. It must be mounted separately. 5. Once you have combined all the I/O modules together for the group, fasten tightly. This final tightening will lock the whole group together as a unit. 6.

  • Page 119: Analog Transducer Signal Output Modules

    8-channel configuration. Maximum registers per request, read or write, is 17 registers. Nexus 1250/1252 Unit supplies power for up to two connected Analog Output modules. See section 9.2 for power and communication details. Refer to sections 5.12 - 5.13 to determine if you must use an additonal power source, such as the EIG PSIO.

  • Page 120: 2: Normal Mode

    The Modbus Map for the Analog Output Module (and operating details) can be found in the Modbus Communicating I/O Modules Manual. 9.5.2: Normal Mode Normal Mode is the same for the 0-1mA and the 4-20mA Analog Output Modules except for the number of processes performed by the modules.

  • Page 121: Analog Input Modules

    Maximum registers per request, read or write, is 17 registers. Nexus 1250/1252 Unit supplies power for up to 4 connected Analog Input modules. See section 9.2 for power and communication details. Refer to sections 5.12 - 5.13 to determine if you must use an additonal power source, such as the EIG PSIO.

  • Page 122: 2: Normal Mode

    The Modbus Map for the Analog Output Module (and operating details) can be found in the Modbus Communicating I/O Modules Manual. 9.6.2: Normal Mode In Normal Mode, the Input Module: 1. Reads and averages the A/D and adjusts values for process 2. 2.

  • Page 123: Digital Dry Contact Relay Output (Form C) Module

    Communicator EXT software. See the Communicator EXT User Manual for details on programming limits. Nexus 1250/1252 Unit supplies power for up to 4 connected Relay Output modules. See section 9.2 for power and communication details. Refer to sections 5.12 - 5.13 to determine if you must use an additonal power source, such as the EIG PSIO.

  • Page 124: 2: Communication

    9.7.2: Communication Maximum registers per request, read or write, is 4 registers.orm The device will operate with the following Default Parameters: Address 247 (F7H) Baud Rate 57600 Baud Transmit Delay Time 20 csec Some situations will cause the device to operate with the above Default Parameters. See section 9.4.1 for details of Default Mode.

  • Page 125: Digital Solid State Pulse Output (Kyz) Module

    I/O Modules User Manual for details on programming the module. Nexus 1250/1252 Unit supplies power for up to 4 connected KYZ Pulse Output modules. See section 9.2 for power and communication details. Refer to sections 5.12 - 5.13 to determine if you must use an additonal power source, such as the EIG PSIO.

  • Page 126: 2: Communication

    9.8.2: Communication Maximum registers per request, read or write, is 4 registers.orm The device will operate with the following Default Mode Parameters. See section 9.4.1 for details. Address 247 (F7H) Baud Rate 57600 Baud Transmit Delay Time 20 csec 9.8.3: Normal Mode Energy readings are given to the device frequently.

  • Page 127: Digital Status Input Module

    Nexus 1250/1252 Unit supplies power for up to 4 connected Digital Status Input modules. See section 9.2 for power and communication details. Refer to sections 5.12 - 5.13 to determine if you must use an additonal power source, such as the EIG PSIO.

  • Page 128: 3: Normal Mode

    Other I/O Accessories PSIO: External Power Supply which is necessary if you are connecting more than 2 to 4 I/O modules to a Nexus 1250/1252 Meter. The number is determined by the type of I/O Module. MBIO: Bracket for surface-mounting I/O modules to any enclosure.

  • Page 129: Hardware Overview

    Nexus Monitor with Internal Modem Option 10.1: Hardware Overview The Nexus 1250/1252 Monitor with the INP2, Internal Modem Option, has all the components of the standard Nexus Monitor PLUS the cabability of connecting to a PC via standard phone line. No additional hardware is required to establish a virtually unlimited connection from a PC to a Nexus 1250/1252 with INP2, Internal Modem Option.

  • Page 130: Hardware Connection

    Use RJ-11 Standard Telephone Line to connect with an INP2 Option Nexus. The RJ-11 line is inserted into the RJ-11 Port on the face of the Nexus 1250/1252 with Internal Modem Option. The connection using RJ-11 into the Nexus is virtually unlimited, since it utilizes a PSTN (Public Switched Telephone Network).

  • Page 131: Hardware Overview

    Nexus Meter with Internal Network Option 11.1: Hardware Overview The Nexus 1250/1252 Meter with the Internal Network Option has all the components of the standard Nexus Meter PLUS the cabability of connecting to a multiple PC’s via Modbus/TCP over Ethernet. Additional hardware is not required to establish a connection from a network to a Nexus with Internal Network Option.
  • Page 132 · Communicates using the industry standard Modbus/TCP protocol. With the Internal Network Option, the standard Port 2 on the Nexus 1250/1252 becomes a “gateway” to allow additional Nexus Meters access via the LAN. Simply connect a daisy chain of Nexus Meters together via RS-485, each with its own device address and using the same baud rates.

  • Page 133: Hardware Connection

    11.2: Hardware Connection Use Standard RJ-45 10/100BaseT cable to connect with the Nexus 1250/1252. The RJ-45 line is inserted into the RJ-45 Port on the face of the Nexus with Internal Network Option. Set the IP Address using the following steps: (Refer to Section 3.5 of the Communicator EXT User Manual for more details).
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  • Page 135: Chapter 12: Flicker

    12.1: Overview Flicker is the sensation that is experienced by the human visual system when it is subjected to changes occurring in the illumination intensity of light sources. The primary effects of flicker are headaches, irritability and sometimes epilepsy. IEC 61000-4-15 and former IEC 868 describe the methods used to determine flicker severity. This phenomenon is strictly related to the sensitivity and the reaction of individuals.
  • Page 136 • Instantaneous Flicker Evaluation An output of 1.00 from Block 4 corresponds to the Reference Human Flicker Perceptibility Threshold for 50% of the population. This value is measured in Perceptibility Units (PU) and is labeled Pinst. This ia a real time value and it is continuously updated. •...

  • Page 137: Setup

    Measurement Procedure 1. Original Signal with amplitude variations. 2. Square demodulator. 3. Weighted filter. 4. Low pass filter 1 order. 5. Statistical computing. Data available Pst, Pst Max, Pst Min values for long term recording Plt, Plt Max, Plt Min values for long term recording Simulation Of Eye Brain Response Block 1 Block 2...

  • Page 138: Software - User Interface

    • Select a Pst time range from 1 to 10 minutes. The standard measurement period is nominally 10 minutes. • Select a Plt time range from 1 to 240 minutes. The standard measurement is nominally 12 Pst periods (120 minutes). Plt time must always be equal to or great than and a multiple of Pst time. This is reflected in the selections available to the user.
  • Page 139 Time Start/Reset is the time when Flicker was started or reset. A Reset of Flicker causes the Max/Min values to be cleared and restarts the Flicker Pst and Plt timers. A Start of Flicker is also equivalent to a Reset in that the PST and PLT are restarted and the Max/Min Values are cleared. Stop corresponds to the time when Flicker is turned off.
  • Page 140 Short Term Readings Click on the Short Term tab to access the screen containing three groups of Pst readings. Pst Readings Displayed • Current Pst values for Va, Vb and Vc and the time of computation. • Current Pst Max values for Va, Vb and Vc since the last reset and the time of the last reset. •...

  • Page 141: Logging

    12.5: Logging The Nexus is capable of logging Flicker values in an independent log. When Flicker is on, entries are made into the log in accordance with the times that associated values occur. Min, Plt, Plt Max, Plt Min, Start/Reset and Stop times are all recorded. All values can be down- loaded to the Log Viewer where they are available for graphing or export to another program, such as Excel.

  • Page 142: Performance Notes

    12.8: Performance Notes Pst and Plt average time are synchronized to the clock (e.g. for a 10 minute average, the times will occur at 0, 10, 20, etc.). The actual time of the first average can be less than the selected period to allow for initial clock synchronization.

  • Page 143: Appendix A Transformer Loss Compensation Excel Spreadsheet With Examples

    Transformer Loss Compensation Excel Spreadsheet A.1: Calculating Values Transformer Loss Compensation is discussed in Chapter 7 of this manual. Values for three element installations can be calculated in two ways: • Click the TLC Calculator button on the Transformer Loss screen of the Nexus Device Profile. The TLC Calculator button activates an Excel Spreadsheet, ONLY if you have MS Excel installed on your computer.
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  • Page 149: Glossary Glossary

    0.1 Second Values: These values are the RMS values of the indicated quantity as calculated after approximately 50 milliseconds (3 cycles) of sampling. 1 Second Values: These values are the RMS values of the indicated quantity as calculated after one second (60 cycles) of sampling. Alarm: An event or condition in a meter that can cause a trigger or call-back to occur.
  • Page 150 DNP 3.0: A robust, non-proprietary protocol based on existing open standards. DNP 3.0 is used to operate between various systems in electric and other utility industries and SCADA networks. Nexus 1250 supports Level 1; Nexus 1252 supports Level 2. EEPROM: Nonvolatile memory.
  • Page 151 Measuring values of the fundamental current and voltage and percent of the fundamental. Heartbeat Pulse: Energy indicator on the face of the Nexus 1250/1252; pulses are generated per the programmed K e value. Infrared Test Pulse: Energy indicator located on the upper left side of the face of the Nexus 1260 /1270 meter;...
  • Page 152 Modbus ASCII: Alternate version of the Modbus protocol that utilizes a different data transfer format. This version is not dependent upon strict timing, as is the RTU version. This is the best choice for telecommunications applications (via modems). Modbus RTU: The most common form of Modbus protocol.
  • Page 153 100 feet. Communications speed is typically in the range of 1200 bits per second to 57,600 bits per second. RS-232 connection can be accomplished using Port 1 of the Nexus 1250/1252 or the Optical Port on the face of the Nexus 1260/1270.
  • Page 154 Time Stamp: A stored representation of the time of an event. Time Stamp can include year, month, day, hour, minute and second and Daylight Savings Time indication. TOU: Time of Use. Voltage Imbalance: The ratio of the voltage on a phase to the average voltage on all phases. Voltage Quality Event: An instance of abnormal voltage on a phase.

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