Nexus 1250 Installation & Operation Manual
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Nexus 1250 Installation & Operation Manual

Power meter and power quality recorder
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  • Page 2 This page intentionally left blank.
  • Page 3 ® Nexus 1250/1252 Meter Installation and Operation Manual Version 1.39 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, including photocopying, record-...
  • Page 4 This page intentionally left blank. Electro Industries/GaugeTech Electro Industries/GaugeTech E107706 The Leader In Power Monitoring and Smart Grid Solutions The Leader In Power Monitoring and Smart Grid Solutions...

  • Page 5: Product Warranty

    This warranty does not apply to defects resulting from unauthorized modification, ® misuse, or use for any reason other than electrical power monitoring. The Nexus 1250/1252 meter is not a user-serviceable product. THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABIL- ITY OR FITNESS FOR A PARTICULAR PURPOSE.

  • Page 6: Disclaimer

    Use of Product for Protection 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. Statement of Calibration Our instruments are inspected and tested in accordance with specifications published by Electro Industries/GaugeTech.
  • Page 7 This symbol indicates the field wiring terminal that must be connected to earth ground before operating the meter, which protects against electrical shock in case of a fault condition. Ce symbole indique que la borne de pose des canalisations in-situ qui doit être branchée dans la mise à...
  • Page 8 This page intentionally left blank. Electro Industries/GaugeTech Electro Industries/GaugeTech E107706 The Leader In Power Monitoring and Smart Grid Solutions The Leader In Power Monitoring and Smart Grid Solutions...

  • Page 9: Table Of Contents

    2-12 2.8: Nexus® External I/O Modules (Optional) 2-15 2.9: Nexus® 1250/1252 Meter Specifications 2-17 2.10: Nexus® P40N+, P41N+, P43N+ LED External Display Specifications 2-18 2.11: Upgrading the Nexus® 1252 Meter’s V-Switch 2-19 3: Hardware Installation 3.1: Mounting the Nexus® 1250/1252 Meter 3.2: Mounting the Nexus®...
  • Page 10 5.3.1: RS485 Connection 5.3.2: Connection to an RS485 Master (Unicom or Modem Manager) 5.3.3: Using the Unicom 2500 5.3.4: RS485 Connection to the Nexus® P40N+ External Display 5.4: RJ11 (Telephone Line) Connection—Nexus® Meter with Internal Modem Option (INP2) to a PC 5-10 5.5: RJ45 Connection—Nexus®...
  • Page 11 12: Flicker and Analysis 12-1 12.1: Overview 12-1 12.2: Theory of Operation 12-1 12.2.1: Summary 12-3 12.3: Flicker Setting (Nexus® 1250 meter and 1252 V-1) 12-4 12.4: Flicker Polling Screen 12-6 12.5: Logging 12-10 12.6: Polling through a Communication Port 12-10 12.7: Log Viewer...
  • Page 12 Table of Contents 13: Substation 19-inch Rack Mount Assembly (Nexus® 1252 Meter) 13-1 13.1: Overview 13-1 13.2: Features 13-1 13.3: Options 13-2 13.4: Dimensions 13-2 13.5: Installation 13-2 13.6: Wiring 13-3 13.7: Ordering Information 13-3 Glossary GL-1 Electro Industries/GaugeTech E107706...

  • Page 13: 1:Three-Phase Power Measurement

    1: Three-Phase Power Measurement 1:Three-Phase 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 14 1: Three-Phase Power Measurement Phase 3 Phase 1 Phase 2 Figure 1.1: Three-phase Wye Winding The three voltages are separated by 120 electrically. Under balanced load conditions the currents are also separated by 120 . However, unbalanced loads and other conditions can cause the currents to depart from the ideal 120 separation.
  • Page 15 1: Three-Phase Power Measurement The phasor diagram shows the 120 angular separation between the phase voltages. The phase-to-phase voltage in a balanced three-phase wye system is 1.732 times the phase-to-neutral voltage. The center point of the wye is tied together and is typically grounded.

  • Page 16: 2: Delta Connection

    1: Three-Phase Power Measurement 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.
  • Page 17 1: Three-Phase Power Measurement Figure 1.4: Phasor Diagram, Three-Phase Voltages and Currents, Delta-Connected Another common delta connection is the four-wire, grounded delta used for lighting loads. In this connection the center point of one winding is grounded. On a 120/240 volt, four-wire, grounded delta service the phase-to-ground voltage would be 120 volts on two phases and 208 volts on the third phase.

  • Page 18: 3: Blondell's Theorem And Three-Phase Measurement

    1: Three-Phase Power Measurement 1.1.3: Blondel’s Theorem and Three Phase Measurement In 1893 an engineer and mathematician named Andre E. Blondel set forth the first scientific basis for polyphase 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 some common point.
  • Page 19 1: Three-Phase Power Measurement age and current and calculates the single-phase power for each phase. The meter then sums the three phase powers to a 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.

  • Page 20: Power, Energy And Demand

    1: Three-Phase Power Measurement If we measure the currents in wires A, B and C, we then know the current in wire N by Kirchhoff's Law and it is not necessary to measure it. This fact leads us to the conclu- sion of Blondel's Theorem- that we only need to measure the power in three of the four wires if they are connected by a common node.
  • Page 21 1: Three-Phase Power Measurement in the graph will represent the power load for the one-minute increment of time. In real life the power value moves almost constantly. The data from Figure 1.7 is reproduced in Table 2 to illustrate the calculation of energy.
  • Page 22 1: Three-Phase Power Measurement Time Accumulated Power Energy Interval Energy (kW) (kWh) (minute) (kWh) 0.50 0.50 0.83 1.33 0.67 2.00 0.92 2.92 1.00 3.92 1.00 4.92 1.17 6.09 1.17 7.26 1.00 8.26 1.17 9.43 1.33 10.76 0.83 12.42 0.83 12.42 1.17 13.59 1.33...
  • Page 23 1: Three-Phase Power Measurement 59.68 kWh. The same process is applied to calculate the 15-minute demand value. The demand value associated with the example load is 59.68 kWh/hr or 59.68 kWd. Note that the peak instantaneous value of power is 80 kW, significantly more than the demand value.

  • Page 24: Reactive Energy And Power Factor

    1: Three-Phase Power Measurement 1.3: Reactive Energy and Power Factor The real power and energy measurements discussed in the previous section relate to the quantities that are most used in electrical systems. But it is often not sufficient to only measure real power and energy. Reactive power is a critical component of the total power picture because almost all real-life applications have an impact on reactive power.
  • Page 25 1: Three-Phase Power Measurement leads the voltage the load is requiring real power (watts) but is delivering reactive power (VARs) back into the system; that is VARs are flowing in the opposite direction of the real power flow. Reactive power (VARs) is required in all power systems. Any equipment that uses magnetization to operate requires VARs.

  • Page 26: Harmonic Distortion

    1: Three-Phase Power Measurement where 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. But if harmonic distortion is present, the two power factors will not be equal.
  • Page 27 1: Three-Phase Power Measurement 1500 1000 –500 –1000 –1500 Figure 1.11: Distorted Current Waveform The distortion observed in Figure 1.11 can be modeled as the sum of several sinusoi- dal 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 28 1: Three-Phase Power Measurement The waveforms shown in Figure 1.12 are not smoothed but do provide an indication of the impact of combining multiple harmonic frequencies together. When harmonics are present it is important to remember that these quantities are operating at higher frequencies.

  • Page 29: Power Quality

    1: Three-Phase Power Measurement picture of the voltage or current waveform for viewing and harmonic analysis. Typi- cally a waveform capture will be one or two cycles in duration and can be viewed as the actual waveform, as a spectral view of the harmonic content, or a tabular view showing the magnitude and phase shift of each harmonic value.
  • Page 30 1: Three-Phase Power Measurement In his book Power Quality Primer, Barry Kennedy provided information on different types of power quality problems. Some of that information is summarized in Table 1.3. Cause Disturbance Type Source Impulse transient Transient voltage disturbance, Lightning sub-cycle duration Electrostatic discharge Load switching...

  • Page 31: 2: Meter Overview

    The Nexus® meter with Internal Modem (or Network) Option connects to a PC via standard phone line (or Modbus TCP/IP) and a daisy chain of Nexus® meters via an RS485 connection. See Chapters 10 and 11 for details.

  • Page 32: Dnp V.3.00 Level 1 And

    • Built-in PLC functionality • High speed updates for Control 2.2: DNP V.3.00 Level 1 and 2 NOTE: Nexus® 1250 supports DNP V3.00 Level 1; Nexus® 1252 supports DNP V3.00 Level 2. DNP Level 2 Features: • Up to 136 measurement (64 Binary Inputs, 8 Binary Counters, 64 Analog Inputs) can be mapped to DNP Static Points (over 3000) in the customizable DNP Point Map.

  • Page 33: Flicker

    The following sections describe the optional INP2 Internal Modem. 2.4.1: Hardware Overview The INP2 Option for the Nexus® 1250/1252 meter provides a direct connection to a standard telephone line. No additional hardware is required to establish a communica- tion connection between the meter and a remote computer. The RJ11 Jack is on the face of the meter.

  • Page 34: 2: Dial-In Function

    Each card can be programmed to perform an extensive array of monitoring functions. The INP200 system is much faster than the 10BaseT Ethernet Option. NOTE: Nexus® meters with the INP10 Option do not support Total Web Solutions. Electro Industries/GaugeTech...

  • Page 35: 1: Hardware Overview

    Ethernet (1252 only) protocols 2.5.2: Hardware Connection Use Standard RJ45 10/100BaseT cable to connect with the Nexus® meter. The RJ45 line is inserted into the RJ45 Port on the face of a Nexus® meter with the INP200 Ethernet Option. 2.5.3: Software Overview To make the software connection, follow these steps: 1.

  • Page 36: 4: Network Settings

    2: Meter Overview 2.5.4: Network Settings Configure the Network Settings using the following steps (refer to the Communicator 4.0 and MeterManager EXT Software User Manual for more details). 1. From the Communicator EXT application‘s Main screen, click Profile to open the Device Profile screen.
  • Page 37 2: Meter Overview 6. Default web pages with an extensive array of readings come with the meter. The content of the pages can be customized using FTP Client. Follow these steps: a. Click the Advanced Settings button in the Communications Settings screen. b.

  • Page 38: Measurements And Calculations

    2: Meter Overview 2.6: Measurements and Calculations The Nexus® 1250/1252 meter measures many different power parameters. Following is a list of the formulas used to perform calculations with samples for Wye and Delta services. Samples for Wye: v Samples for Delta: v...
  • Page 39 2: Meter Overview For Delta: xy = ab, bc, ca xy t Power (Watts) per phase: N = number of samples 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 Active Power (Watts) Total: N = number of samples...
  • Page 40 2: Meter Overview For Delta: ab t bc t Reactive Power (VAR) Total: N = number of samples For Wye: For Delta: ⎡ ⎤ ⎡ ⎤ ∑ ∑ • • ⎢ ⎥ ⎢ ⎥ ab t bc t ⎢ ⎥ ⎢...
  • Page 41 2: Meter Overview Power Factor (PF): For Wye: x = a,b,c,T For Delta: x = T Phase Angles: x = a, b, c % Total Harmonic Distortion (%THD): For Wye: x = v For Delta: x = i K Factor: x = i h RMS KFactor Electro Industries/GaugeTech...

  • Page 42: Demand Integrators

    Power utilities take into account both energy consumption and peak demand when billing customers. 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: Block Window Demand, Rolling Window Demand, Thermal Demand, and Predictive Window Demand.
  • Page 43 The pointer remains at peak level until a subsequent increase in demand moves it again, or until it is manually reset. The Nexus® 1250/1252 mimics traditional meters to provide Thermal Demand readings.
  • Page 44 2: Meter Overview 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 subinter- vals 12:00-12:05 and 12:05-12:10 (which we know) and 12:10-12:15 (which we do not yet know).

  • Page 45: Nexus® External I/O Modules (Optional)

    The following multiple analog or digital I/O modules mount externally to the Nexus® 1250/1252 meter. The Nexus® 1250/1252 meter supplies 12VA to its ports. You may need to use additional power supplies, such as EIG’s 12V PSIO, to extend I/O capabil- ity.
  • Page 46 2: Meter Overview Digital Dry Contact Relay Outputs • 4RO1: 4 Relay Outputs 10 Amps, 125V AC, 30V DC, Form C Digital Solid State Pulse Outputs • 4PO1: 4 Solid State Pulse Outputs, Form A KYZ pulses Digital Inputs • 8DI1: 8 Digital status inputs Wet/Dry Auto Detect, up to 300V AC/DC Other I/O Accessories •...

  • Page 47: Nexus® 1250/1252 Meter Specifications

    2: Meter Overview 2.9: Nexus ® 1250/1252 Meter Specifications UL Measurement Category - Category III Rated Altitude - 2,000 Meters Maximum ® Specification Nexus meter Control Power Requirement Option D: 24VDC (-20%) to 48 VDC (+20%) Option D2: 120V AC/DC (-20%) to 230VAC (+20%) Connection Screws’...

  • Page 48: Nexus P40N+, P41N+, P43N+ Led External Display Specifications

    1252) EN50160/IEC 61000-4-30 PQ Analysis Evaluation per IEC 61000-4-30* IRIG-B Port Impedance 8mA@5V * EN50160/EN61000-4-30 PQ Analysis is only available for a Nexus® 1252 meter with V- Switch™ key 2. 2.10: Nexus ® P40N+, P41N+, P43N+ LED External Display Specifications...

  • Page 49: Upgrading The Nexus® 1252 Meter's V-Switch

    Enter the upgrade key provided by EIG. f. Click OK. The V-Switch key is enabled and the meter is reset. NOTE: The Nexus® 1250 meter does not have a V-Switch key upgrade. Electro Industries/GaugeTech Doc# E107706...
  • Page 50 2: Meter Overview This page intentionally left blank. Electro Industries/GaugeTech Doc# E107706 2 - 20 Electro Industries/GaugeTech The Leader In Power Monitoring and Smart Grid Solutions The Leader In Power Monitoring and Smart Grid Solutions...

  • Page 51: 3: Hardware Installation

    ® 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 52 1.25-inch (3.17cm) diameter hole in the back for the cable harness. See Chapter 5 for communication and power supply details. The cable harness brings power to the display from the Nexus® 1250/1252 meter, which supplies 15–20V DC. The P40N+ (or P41N+ or P43N+) can draw up to 500mA in display test mode.
  • Page 53 3: Hardware Installation 4.38” Sq. (11.12 cm) NOTE: The P40N is not intended for new applications. .75” (1.91 1.438” Sq. (3.65 cm) P40N Front Dimensions P40N Side Dimensions P40N+ Display Figure 3.3: Legacy P40N and P40N+ Dimensions Electro Industries/GaugeTech Electro Industries/GaugeTech E107706 3 - 3 The Leader In Power Monitoring and Smart Grid Solutions...
  • Page 54 3: Hardware Installation 3.375”/8.572cm 1.688”/ 4.287cm 4x 0.200”/ 0.508cm 3.375”/ 8.572cm 04.00”/10.16cm Figure 3.4: ANSI C39.1 Drill Plan for P40N/P40N+ Display Electro Industries/GaugeTech Electro Industries/GaugeTech E107706 3 - 4 The Leader In Power Monitoring and Smart Grid Solutions The Leader In Power Monitoring and Smart Grid Solutions...

  • Page 55: Mounting The Nexus External I/O Modules

    If multiple I/O modules are connected together, as shown in Figure 3.5, secure a mounting bracket to both ends of the group. One Nexus® will supply power for a number of I/O modules. See Sections 5.6.2 to see if you need to use an additional power supply, such as the EIG PSIO.
  • Page 56 3: Hardware Installation Mounting Brackets (MBIO) Female RS485 Side Port I/O Port (Size and Pin Male RS485 Configuration Vary) Side Port Figure 3.6: I/O Module Communication Ports and Mounting Brackets Mounting Bracket Mounting Bracket 6.879”/13.088cm 3.437”/8.729cm 2.200”/5.588cm 1.100”/2.54cm .618”/1.570cm 1.301”/3.305cm Figure 3.7: I/O Modules Mounting Diagram Front View Electro Industries/GaugeTech Electro Industries/GaugeTech...

  • Page 57: 4: Electrical Installation

    This chapter provides electrical installation information for the Nexus® 1250/1252 meter. 4.1: Considerations When Installing Meters Installation of the Nexus® 1250/1252 meter must be performed only by qualified personnel who follow standard safety precautions during all procedures. Those personnel should have appropriate training and experi- ence with high voltage devices.
  • Page 58 The CTs shall be Approved or Certified and rated for the current of the meter used. L’installation des compteurs de Nexus 1250/1252 doit être effectuée seulement par un personnel qualifié qui suit les normes relatives aux précautions de sécurité...
  • Page 59 4: Electrical Installation endommagements de transformateur de courant si l'unité Nexus 1250/1252 doit être enlevée du service. Un côté du transformateur de courant doit être mis à terre. NOTE: Les entrées actuelles doivent seulement être branchées dans le transforma- teur externe actuel par l'installateur. Le transformateur de courant doit être approuvé...
  • Page 60 4: Electrical Installation NOTE: IF THE EQUIPMENT IS USED IN A MANNER NOT SPECI- FIED BY THE MANUFACTURER, THE PROTECTION PROVIDED BY THE EQUIPMENT MAY BE IMPAIRED. NOTE: THERE IS NO REQUIRED PREVENTIVE MAINTENANCE OR INSPECTION NECESSARY FOR SAFETY. HOWEVER, ANY REPAIR OR MAINTENANCE SHOULD BE PERFORMED BY THE FACTORY.

  • Page 61: Wiring The Monitored Inputs And Voltages

    (see Section 4.9). The Nexus® 1250/1252 meter can handle a maximum voltage of 150V phase to neu- tral and 300V phase to phase. Potential Transformers (PTs) are required for higher voltages with the standard rating.
  • Page 62 It is important to maintain the polarity of the CT circuit when connecting to the Nexus® 1250/1252 meter. If the polarity is reversed, the meter will not provide accurate readings. CT polarities are dependent upon correct connection of CT leads and the direction CTs are facing when clamped around the conductors.

  • Page 63: Isolating A Ct Connection Reversal

    Manual for instructions). The current should be 30 degrees off the phase-to-phase voltage. 4.8: Instrument Power Connections The Nexus® 1250/1252 meter requires a separate power source. To use AC power: 1. Connect the line supply wire to the L+ terminal 2.

  • Page 64: Wiring Diagrams

    • Use at least 14 Gauge supply wire for the power supply and ground connections. NOTE ON CORRECT METER FUNCTIONING: The Nexus® 1250/1252 meter has a Heartbeat LED, located on the top, right side of the meter face. When the meter is functioning correctly, the red LED pulse toggles on and off (blinks) 5 times per second.
  • Page 65 4: Electrical Installation Table 3: Figure # Description 4-Wire Wye, 3-Element Direct Voltage with 4 CTs 4-Wire Wye, 3-Element with 3 PTs and 4 CTs 4-Wire Wye, 3-Element with 3 PTs and 3 CTs 3-Wire, 2-Element Open Delta with 2 PTs and 3 CTs 3-Wire, 2-Element Open Delta with 2 PTs and 2 CTs 3-Wire, 2-Element Delta Direct Voltage with 3 CTs 3-Phase, 4-Wire Wye, 2.5 Element with 2 PTs and 3 CTs...
  • Page 66 4: Electrical Installation LINE SHORTING SWITCH OR TEST BLOCK FUSES Vref Vaux AUXILIARY VOLTAGE POWER SUPPLY (DEPENDENT ON EQUIPPED SUPPLY OPTION) LOAD Figure 4.2: 4-Wire Wye, 3-Element Direct Voltage with 4 CTs Electro Industries/GaugeTech E107706 4- 10 The Leader In Power Monitoring and Smart Grid Solutions...
  • Page 67 4: Electrical Installation LINE SHORTING SWITCH OR TEST BLOCK FUSES Vref Vaux AUXILIARY VOLTAGE POWER SUPPLY (DEPENDENT ON EQUIPPED SUPPLY OPTION) LOAD Figure 4.3: 4-Wire Wye, 3-Element with 3 PTs and 4 CTs Electro Industries/GaugeTech E107706 4- 11 The Leader In Power Monitoring and Smart Grid Solutions...
  • Page 68 4: Electrical Installation LINE SHORTING SWITCH OR TEST BLOCK FUSES Vref Vaux AUXILIARY VOLTAGE POWER SUPPLY (DEPENDENT ON EQUIPPED SUPPLY OPTION) LOAD Figure 4.4: 4-Wire Wye, 3-Element with 3 PTs and 3 CTs Electro Industries/GaugeTech E107706 4- 12 The Leader In Power Monitoring and Smart Grid Solutions...
  • Page 69 4: Electrical Installation LINE A B C SHORTING SWITCH OR TEST BLOCK FUSES POWER SUPPLY (DEPENDENT ON EQUIPPED SUPPLY OPTION) LOAD Figure 4.5: 3-Wire, 2-Element Open Delta with 2 PTs and 3 CTs Electro Industries/GaugeTech E107706 4- 13 The Leader In Power Monitoring and Smart Grid Solutions...
  • Page 70 4: Electrical Installation LINE A B C SHORTING SWITCH OR TEST BLOCK FUSES POWER SUPPLY (DEPENDENT ON EQUIPPED SUPPLY OPTION) Figure 4.6: 3-Wire, 2-Element Open Delta with 2 PTs and 2 CTs Electro Industries/GaugeTech E107706 4- 14 The Leader In Power Monitoring and Smart Grid Solutions...
  • Page 71 4: Electrical Installation LINE SHORTING SWITCH OR TEST BLOCK FUSES POWER SUPPLY (DEPENDENT ON EQUIPPED SUPPLY OPTION) LOAD Figure 4.7: 3-Wire, 2-Element Delta Direct Voltage with 3 CTs Electro Industries/GaugeTech E107706 4- 15 The Leader In Power Monitoring and Smart Grid Solutions...
  • Page 72 4: Electrical Installation LINE SHORTING SWITCH OR TEST BLOCK FUSES Vref Vaux AUXILIARY VOLTAGE POWER SUPPLY (DEPENDENT ON EQUIPPED SUPPLY OPTION) LOAD Figure 4.8: 3-Phase, 4-Wire, 2.5 Element with 2 PTs and 3 CTs Electro Industries/GaugeTech E107706 4- 16 The Leader In Power Monitoring and Smart Grid Solutions...
  • Page 73 4: Electrical Installation LINE SHORTING SWITCH OR TEST BLOCK FUSES Vref Vaux AUXILIARY VOLTAGE POWER SUPPLY (DEPENDENT ON EQUIPPED SUPPLY OPTION) LOAD Figure 4.9: 4-Wire, 3-Element Grounded Delta with 4 CTs - G Option Electro Industries/GaugeTech E107706 4- 17 The Leader In Power Monitoring and Smart Grid Solutions...

  • Page 74: Extended Surge Protection For Substation Instrumentation

    4: Electrical Installation 4.10: Extended Surge Protection for Substation Instrumentation EIG offers a surge protector for applications with harsh electrical conditions. The surge protector is EI-MSB10-400 and it can be ordered from EIG’s webstore: www.electroind.com/store. The EI-MSB10-400 surge protector is designed to protect sensitive equipment from the damaging effects of lightning strikes and/or industrial switching surges in single phase AC networks up to 320VAC (L-N / L-G), and DC networks up to 400 VDC.

  • Page 75: 5: Communication Wiring

    RS485 communication allows multiple Nexus® meters to communicate with another device at a local or remote site. The I/O modules and the Nexus® displays use RS485 to communicate with the Nexus® meter. All RS485 links are viable for a distance of up to 4000 feet (1220 meters).
  • Page 76 Network Option (INP200) to communicate with multiple PC’s simultaneously. No other hardware is necessary for this easy-to-use connection. In a Nexus® meter with INP200, Port 2 becomes a Gateway for connecting multiple Nexus® meters using RS485. See Chapter 11 for INP200 details.
  • Page 77 • I/O Modules and External Displays require power connections to the +/- Voltage terminals (dashed lines). • For all communications: S=Shield. This connection is used to reference the Nexus® meter’s port to the same potential as the source. It is not an earth-ground connec- tion.

  • Page 78: Rs232 Connection (Port 1)

    RS485 communication allows multiple devices to communicate on a bus. The Nexus® 1250/1252 meter’s Ports 1 to 4 are RS485 terminals, viable for a distance of up to 4000 feet (1219 meters). (Port 1 can be switched between RS232 and RS485.) The following figure shows wiring detail of a 2-wire RS485 port.
  • Page 79 • +/- (Two-wire, RS485 communication terminals): connect the + terminal of the Nexus® meter’s port to the + terminal of the device; connect the - terminal of the Nexus® meter’s port to the - terminal of the device. NOTES on RS485 Communication: •...
  • Page 80 5: Communication Wiring • Avoid both “star” and “tee” connections (see Figure 5.6). No more than two cables should be connected at any one point on an RS485 network, whether the connec- tions are for devices, converters or terminal strips. •...

  • Page 81: 1: Rs485 Connection

    5: Communication Wiring 5.3.1: RS485 Connection • Use any Port on the Nexus® 1250/1252 meter. If you use Port 1, set the selector switch beneath the port to RS485. • The link using RS485 is viable for up to 4000 feet (1219 meters).

  • Page 82: 3: Using The Unicom 2500

    5.3.3: Using the Unicom 2500 The Unicom 2500 provides RS485/RS232 conversion. In doing so it allows the Nexus® 1250/1252 meter to communicate with a PC or other device. See the Unicom 2500 Installation and Operation Manual for additional information. You can order the Unicom 2500 from EIG’s webstore: www.electroind.com/store.

  • Page 83: 4: Rs485 Connection To The Nexus® P40N+ External Display

    Insert one end of the supplied RS485 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...

  • Page 84: Rj11 (Telephone Line) Connection-Nexus® Meter With Internal Modem Option (Inp2) To A Pc

    • Female RS485 Side Port: use to connect to another module’s female RS485 side port. • Male RS485 Side Port: use to connect to the Nexus® meter’s Port 3 or Port 4, or to connect to another module’s male RS485 side port.

  • Page 85: 1: Rs485 Connection-Nexus® Meter To Nexus® I/O Modules

    4000 feet (1219 meters). However, if your cable length exceeds 200 feet, use the remote power supply and: 1. Connect the + and - terminals on the Nexus® meter to the + and - terminals of the female RS485 port. Connect the shield to the shield (S) terminal. The (S) terminal on the Nexus®...
  • Page 86 5: Communication Wiring Table 1: I/O Module Factory Settings and VA Ratings Model# Module Address VA Rating 1mAON4 0-1mA, 4 Analog 2.7VA Outputs 1mAON8 0-1mA, 8 Analog 3.2VA Outputs 20mAON4 4-20mA, 4 Analog 5.0VA Outputs 20mAON8 4-20mA, 8 Analog 8.5VA Outputs 8AI1 0-1mA, 8 Analog...

  • Page 87: Linking Multiple Nexus® Meters In Series

    P43N+ 5.7: Linking Multiple Nexus® Meters in Series You may connect a total of 31 Nexus® meters in series on a single bus using RS485. The cable length may not exceed 4000 feet (1219 meters). Before assembling the bus, each Nexus® meter must be assigned a unique address. See Chapter 13 in the Communicator EXT 4.0 and MeterManager EXT Software User Manual for instruc-...

  • Page 88: Remote Communication Overview

    • You must use a Null Modem or Null Cable between the Nexus® meter and the remote modem when using RS232. A Null Modem enables two DCE devices to communicate. The figure below details how a null modem reconfigures the RS232 pins.

  • Page 89: 2: Remote Communication-Rs485

    4.0 and MeterManager EXT Software User Manual for further details. 5.8.2: Remote Communication-RS485 Use any Port on the Nexus® 1250/1252 meter. If you use Port 1, set the selector switch beneath the port to RS485. The link using RS485 is viable for up to 4000 feet (1219 meters).
  • Page 90 • Set modem to auto answer on n rings. This sets the remote modem to answer the call after n rings. • Set modem to ignore DTR Signal. This is necessary for the Nexus® meter, to insure connection with originate modem.

  • Page 91: 1: Selected Modem Strings

    Up Up Down Down Up Up Up Down 5.9: High Speed Inputs Connection The Nexus® 1250/1252 meter’s built-in High Speed Inputs can be used in many ways: • Attach the KYZ HS Outputs from other meters for totalizing. • Attach relaying contacts for breaker status or initiated logging.

  • Page 92: Irig-B Connections

    Connection Connect the (+) terminal of the Nexus® meter to the (+) terminal of the signal gen- erating device; connect the (-) terminal of the Nexus® meter to the (-) terminal of the signal generating device.
  • Page 93 2 Months of the actual date). This provides the right year for the clock (GPS does not supply the year). 3. Connect the (+) terminal of the Nexus® meter to the (+) terminal of the signal generating device; connect the (-) terminal of the Nexus® meter to the (-) terminal of the signal generating device.

  • Page 94: Time Synchronization Alternatives

    4.0 and MeterManager EXT Software User Manual for details.) IRIG-B • All Nexus® 1250/1252 meters are equipped to use IRIG-B for time synchroniza- tion. • If IRIG-B is connected, this form of time synchronization takes precedence over the internal clock. If the GPS Signal is lost, the internal clock takes over time keeping at the precise moment the signal is lost.
  • Page 95 5: Communication Wiring • Script & Scheduler: Time stamps retrieved logs and data • MV90: Can synchronize time on retrievals in the form of a Time Stamp. Refer to the Communicator EXT 4.0 and MeterManager EXT Software User Manual (HHF Converter) for more MV-90 details.
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  • Page 97: 6: Using The External Displays

    P40N+ display also features a USB port for direct data download. Plug one of the Nexus® external displays into Port 3 or 4 of the meter, using the cable supplied with the display. The displays operate at 9600 baud. Port 3 is already factory-set to 9600 baud (see Chapter 5 for communication details).
  • Page 98 To use the USB, follow these instructions: 1. Use the Nexus® Series Product CD, shipped with your meter, to install the Communicator EXT software and the driver for the P40N+ USB port.
  • Page 99 6: Using the External Displays c. To install Communicator EXT 4.0 software and the driver for the P40N+: i. Click Software>Communicator EXT Software to install the software. ii. Click Software>USB Driver to install the driver. 2. Connect the USB cable from your PC to the port: using a USA-A Male to USB-B Male cable, attach the USB-A connector to the PC and attach the USB-B connector to the...
  • Page 100 6: Using the External Displays 3. Once the USB cable is connected to the P40N+, the display clears and the message “USB in Use” scrolls at the bottom of the display. Additionally, the USB LED icon lights up when the USB connection is being used. You connect to the USB port using Communicator EXT software the same way you connect to a meter with the software.
  • Page 101 6: Using the External Displays e. Click the plus sign next to Ports (COM & LPT). The COM ports are displayed. Note the COM number for the USB Serial Port. This is the number you will use to connect to the P40N+ through Communicator EXT software.

  • Page 102: 1: Connect Multiple Displays

    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. Therefore, the Master display (P40N+) should be at the end of the daisy-chained units as shown in Figure 6.2.

  • Page 103: Dynamic Readings Mode

    6: Using the External Displays • Use the MODE button to scroll between modes. • Use the UP/DOWN arrows to scroll from group to group within each mode. • Use the LEFT/RIGHT arrows to scroll from reading to reading within each group. Use the Communicator EXT software to Flash Update the P40N/P40N+ external display.
  • Page 104 6: Using the External Displays Group 3: Current (Use the Left/Right arrows to access the following readings, in order.) • Current A/B/C • Maximum Current • Minimum Current • Current %THD • Current Maximum %THD • Current Minimum %THD • Current Calculated N/Measured N •...
  • Page 105 6: Using the External Displays • 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 106 6: Using the External Displays • kI2t A • kI2t B • kI2t C • kV2t A • kV2t B • kV2t C Group 9: Phase Angles (Use the Left/Right arrows to access the following readings, in order.) • Phase Angle Van/bn/cn •...

  • Page 107: Navigation Map Of Dynamic Readings Mode

    6: Using the External Displays 6.4: Navigation Map of Dynamic Readings Mode • Use Left/Right arrow keys to navigate Readings • Use Up/Down arrows to scroll between groups. Max %THD Min %THD Return to 1 Second Volts Maximum Volts Minimum Volts %THD Volts Volts Volts...

  • Page 108: Nexus® Information Mode

    6: Using the External Displays 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 Navigation map of the Nexus® Information Mode.

  • Page 109: Navigation Map Of Nexus® Information Mode

    6: Using the External Displays • Run Time External Display/Run Time DSP/RunTime Comm • Boot External Display/Boot DSP/Boot Comm • Serial Number External Display; Serial Number Nexus® Monitor 6.6: Navigation Map of Nexus ® Information Mode • Use Left/Right arrow keys to navigate Readings Use Up/Down arrows to scroll between groups.

  • Page 110: Display Features Mode

    6: Using the External Displays 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 Navigation map of the Display Features mode. Group 1: Reset Max/Min Press Enter to reset the Max and Min values.
  • Page 111 6: Using the External Displays Press Enter to conduct an LED test. Group 8: Display Scroll ON/OFF Press Enter to turn the scroll feature on or off. When the scroll feature is on, the P40N+ external display scrolls through the first reading of each group in the Dynamic Readings mode.

  • Page 112: Navigation Map Of Display Features Mode

    6: Using the External Displays 6.8: Navigation Map of Display Features Mode Use Up/Down arrows to scroll between groups. Reset Max/Min Reset Energy Baud Rate/Address Communication Protocol Lamp Test Display Scroll On/Off Electro Industries/GaugeTech Electro Industries/GaugeTech E107706 6 - 16 The Leader In Power Monitoring and Smart Grid Solutions The Leader In Power Monitoring and Smart Grid Solutions...

  • Page 113: 7: Transformer Loss Compensation

    7: Transformer Loss Compensation 7: 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 I2R losses in conductors and transformers and iron-core losses.
  • Page 114 It can, however, include computational corrections to calculate the losses and add or subtract those losses to the power flow measured at the meter location. This is the method used for loss compensation in the Nexus® meter. Refer to Appen- dix A in the Communicator EXT 4.0 and MeterManager EXT Software User Manual...
  • Page 115 Nexus® Meter Transformer Loss Compensation: • Performs calculations on each phase of the meter for every measurement taken. Unbalanced loads are accurately handled.

  • Page 116: Nexus® 1250/1252 Meter's Transformer Loss Compensation

    NOTE: Loss Compensation is disabled when the meter is placed in Test Mode. 7.2: Nexus® 1250/1252 Meter's Transformer Loss Compensation The Nexus® meter provides compensation for active and reactive power quantities by performing numerical calculations. The factors used in these calculations are derived either: •...

  • Page 117: 1: Loss Compensation In Three Element Installations

    7: Transformer Loss Compensation base voltage and current and taking into account the number of elements used in the metering installation. For three-element meters, the installation must be normalized to the phase-to-neutral voltage and the phase current; in two-element meters the installation must be normalized to the phase-to-phase voltage and the phase current.

  • Page 118: 1: Three-Element Loss Compensation Worksheet

    • Current Transformer Ratio (CTR) • Meter Base Voltage • Meter Base Current This section is limited to application of Nexus® meters to three-element metering installations. As a result, we know that: • Number of metering elements = 3 • Meter Base Voltage = 120 Volts •...
  • Page 119 7: Transformer Loss Compensation Table 3: Value Watts Loss 3-Phase 1-Phase 1-Phase kW 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. Convert 1-Phase Loss Watts to 1-Phase kW by dividing 1-Phase Loss Watts by 1000.
  • Page 120 7: Transformer Loss Compensation Meter/Installation Data Table 7: Instrument Transformers Numerator Denominator Multiplier Potential Transformers Current Transformers Power Multiplier [(PT Multiplier) x (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).
  • Page 121 7: Transformer Loss Compensation Load Loss at Transformer No-Load Loss Watts (kW) = 1-Phase kW No-Load Loss = ______________ No-Load Loss VA (kVA) = (%Exciting Current) * (1-Phase kVA Self-Cooled Rating) / 100 = (______________) * (________________) / 100 = _______________ kVA No-Load Loss VAR (kVAR) = SQRT((No-Load Loss kVA)2 - (No-Load Loss kW)2) = SQRT((_________________)2 - (________________)2) = SQRT((__________________) - (_________________))
  • Page 122 7: Transformer Loss Compensation Normalize Losses to Meter Base Table 10: Quantity Value M/T Factor M/T Factor M/T Factor Value at Trf Value w/Exp Base Meter Base No-Load Loss kW No-Load Loss kVAR Load Loss Load Loss kVAR Enter Value at Transformer Base for each quantity from calculations above. Enter Meter/Trf Factor value from Base Conversion Factor calculations above.
  • Page 123 Calculate "% Loss at Meter Base" by dividing (Value at Meter Base) by (Meter Base kVA) and multiplying by 100. Enter calculated % Loss Watts values into the Nexus® meter using Communicator software. Refer to Appendix A in the Communicator EXT 4.0 and MeterMan-...
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  • Page 125: 8: Time-Of-Use Function

    8.1: Introduction A Time-of-Use (TOU) usage structure takes into account the quantity of energy used and the time at which it was consumed. The Nexus® 1250/1252 meter's TOU func- tion, available with the Communicator EXT software, is designed to accommodate a variety of programmable rate structures.

  • Page 126: Tou Prior Season And Month

    Up to a maximum of twenty yearly calendars can be stored in the Nexus® meter 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 127: Daylight Savings And Demand

    8: Time-of-Use Function crossed, the second calendar, if present, is used. To retain continuity, you have up to one year to replace the old calendar with one for the following year. 8.5: Daylight Savings and Demand To enable Daylight Savings Time for the meter: from the Device Profile menu click General Settings>Time Settings.
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  • Page 129: 9: External I/O Modules

    • Female RS485 Side Port: use to connect to another module’s male RS485 side port. • Male RS485 Side Port: use to connect to the Nexus® 1250/1252 Meter’s Port 3 or 4 or to another module’s female RS485 side port.

  • Page 130: 1: Port Overview

    9: External I/O Modules 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 Eight Analog Outputs (0-1mA and 4-20mA) (0-1mA and 4-20mA) 0-1mA 0-1mA...

  • Page 131: I/O Module Installation

    See sections 3.3 and 5.6 for installation instructions for the external I/O Modules. 9.2.1: Power Source for I/O Modules The Nexus® 1250/1252 can supply power to a limited number of I/O Modules and external displays. For more modules, you must use an external power source, such as the EIG PSIO (12V).

  • Page 132: Using The Psio With Multiple I/O Modules

    9: External I/O Modules Power In N(-) L(+) DANGER Power Supply PSIO Max Power: 12 VA Input Voltage: 12-60V DC 90-240V AC/DC Output Voltage: 12V DC ElectroIndustries/GaugeTech www.electroind.com POWER + POWER - Figure 9.4: PSIO Side and Top Labels (Labels are Red and White) 9.3: Using the PSIO with Multiple I/O Modules LEDs Communication...

  • Page 133: 1: Steps For Attaching Multiple I/O Modules

    9: External I/O Modules 9.3.1: Steps for Attaching Multiple I/O Modules 1. Each I/O module in a group must be assigned a unique address. See the Communicator EXT 4.0 and MeterManager EXT Software User Manual for details on configuring and programming the I/O Modules. 2.
  • Page 134 9: External I/O Modules 10. If not mounting on a DIN rail, mount the group of modules on a secure, flat surface. This procedure will insure that all modules stay connected securely. 11.The MBIO mounting brackets kit comes with 2 DIN rail mounting clips and an 8mm screw and lock washer for each clip.

  • Page 135: Factory Settings And Reset Button

    Figure 9.7: Detail of DIN Rail Mounting Clip 9.4: Factory Settings and Reset Button Factory Settings: All Nexus® I/O Modules are shipped with a preset address and a baud rate of 57600. See following sections for I/O Module addresses. Reset Button: If there is a communication problem or if you are unsure of a module’s address and...

  • Page 136: Analog Transducer Signal Output Modules

    4- or 8-channel configuration. Maximum registers per request, read or write, is 17 registers. The Nexus® 1250/1252 meter supplies power for up to two connected Analog Output modules. See Section 9.2 for power and communication details. Refer to Section 5.6.2 to determine if you must use an additional power source, such as EIG’s PSIO.

  • Page 137: 2: Normal Mode

    9: External I/O Modules All outputs share a single common point. This is also an isolated connection (from ground). 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 138: Analog Input Modules

    The Analog Input Modules (0±1mA, 0±20mA, 0±5Vdc and 0±10Vdc) are available in 8-channel format. Maximum registers per request, read or write, is 17 registers. The Nexus® 1250/1252 meter supplies power for up to 4 connected Analog Input modules. See Section 9.2 for power and communication details. Refer to Section 5.6.2 to determine if you must use an additional power source, such as EIG’s PSIO.

  • Page 139: 2: Normal Mode

    9: External I/O Modules 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 140: Digital Dry Contact Relay Output (Form C) Module

    4.0 and MeterManager EXT Software User Manual for details on programming limits. The Nexus® 1250/1252 meter supplies power for up to 4 connected Relay Output modules. See Section 9.2 for power and communication details. Refer to Section 5.6.2 to determine if you must use an additional power source, such as EIG’s PSIO.

  • Page 141: 2: Communication

    9: External I/O Modules The Modbus Map for the Analog Output Module (and operating details) can be found in the Modbus Communicating I/O Modules Manual. Each latching relay will hold its state in the event of a power loss. 9.7.2: Communication Maximum registers per request, read or write, is 4 registers.

  • Page 142: Digital Solid State Pulse Output (Kyz) Module

    VA-hours. See the Modbus Communicating I/O Modules User Manual for details on programming the module. The Nexus® 1250/1252 meter supplies power for up to 4 connected KYZ Pulse Output modules. See Section 9.2 for power and communication details. Refer to Section 5.6.2 to determine if you must use an additional power source, such as EIG’s PSIO.

  • Page 143: 2: Communication

    9: External I/O Modules The Modbus Map for the KYZ Pulse Output Module (and operating details) can be found in the Modbus Communicating I/O Modules Manual. NC = Normally Closed; NO = Normally Open; C = Common. 9.8.2: Communication Maximum registers per request, read or write, is 4 registers. The device will operate with the following Default Mode Parameters.
  • Page 144 9: External I/O Modules 2. The second process occurs in the main loop and attempts to decrement the Resid- ual by the Programmed Energy/Pulse Value. If the Residual is greater than the Pro- grammed Energy/Pulse Value and the Pending Pulses Value for that channel has not reached the maximum limit, then Residual is decremented appropriately and the Pending Pulses is incremented by two, signifying two more transitions and one more pulse.

  • Page 145: Digital Status Input Module

    The Digital Status Input Module is used either for additional status detect or for accu- mulating pulses from external equipment, such as power meters, water meters, etc. The Nexus® 1250/1252 meter supplies power for up to 4 connected Digital Status Input modules. See Section 9.2 for power and communication details. Refer to Section 5.6.2 to determine if you must use an additional power source, such as EIG’s...

  • Page 146: 2: Communication

    9: External I/O Modules 9.9.2: Communication Maximum registers per request, read or write, is 4 registers. The device will operate with the following Default Mode Parameters. See Section 9.4 for details. Address: 247 (F7H) Baud Rate: 57600 Baud Transmit Delay Time: 20 msec 9.9.3: Normal Mode The device polls the inputs at 100Hz (once every 10 msec), debouncing the inputs...

  • Page 147: 10: Meter With Internal Modem Option (Inp2)

    Use RJ11 Standard Telephone Line to connect with the Nexus® 1250/1252 meter. Insert the RJ11 line into the RJ11 Port on the face of a Nexus® meter with the Inter- nal Modem Option. The RJ11 connection is virtually unlimited, since it utilizes a PSTN (Public Switched Telephone Network).

  • Page 148: Dial-In Function

    • Is any other log approaching a full condition? • Has the Modem Password failed? • Has communication with the Nexus® meter failed? If any of the monitored events exist, the modem automatically initiates a call to a specified location to make a report or perform some other function. For log full condi-...
  • Page 149 10: Meter with Internal Modem Option tions, the meter automatically downloads the log(s) that are nearing the full state. The modem can be programmed to call two different numbers to make the required reports: Primary and Backup. The modem can be programmed with an ASCII string for identification purposes. If this string is present, the modem plays the string to the host computer upon connec- tion to identify the meter to the host software.
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  • Page 151: 11: Meter With Internal Network Option (Inp200)

    (INP200) 11.1: Hardware Overview The Nexus® 1250/1252 meter with the Internal Network Option (INP200) has all the components of the standard Nexus® meter, plus giving you the capability of connect- ing to multiple PC’s via Modbus/TCP over the Ethernet and providing a DNP LAN/WAN connection.

  • Page 152: Network Connection

    11.2: Network Connection Use Standard RJ45 10/100BaseT cable to connect with the Nexus® meter. Insert the RJ45 line into the RJ45 Port on the face of a Nexus® 1250/1252 meter with the Inter- nal Network Option. Set the IP Address using the following steps: (Refer to Section 13.1.5 of the Commu- nicator EXT 4.0 and MeterManager EXT Software User Manual for more detailed...
  • Page 153 Ethernet Gateway as a Master and an RS485 connection to any port on the remote Nexus. The Address of the remote Nexus® meter must be something other than “1.” “1” is reserved for the meter connected to the network via RJ45.
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  • Page 155: 12: Flicker And Analysis

    It can only be studied on a statistical basis by setting up suitable experiments among people. The Nexus® 1250/1252 meter with V-1 (base configuration) offers Flicker monitoring and analysis. The Nexus® 1252 meter with V-2 has EN50160/IEC61000-4-30 Power Quality Compliance analysis for Flicker and other power quality measurements. (Refer to the V-Switch™...
  • Page 156 12: Flicker and Analysis tion consists of a .05 Hz Low High Pass filter and a 6 Pole Butterworth Low Pass filter located at 35 Hz. The second filter is a weighting filter that simulates the response of the human visual system to sinusoidal voltage fluctuations of a coiled filament, gas-filled lamp (60 W - 230 V).

  • Page 157: 1: Summary

    12: Flicker and Analysis P(3s) = (P(2.2) + P(3) + P(4))/3 P(10s) = (P(6) + P(8) + P(10) + P(13) + P(17))/5 P(50s) = (P(30) + P(50) + P(80))/3 The .3-second memory time constant in the Flicker meter ensures that P(0.1) can- not change abruptly and no smoothing is needed for this percentile.

  • Page 158: Flicker Setting (Nexus® 1250 Meter And 1252 V-1)

    12.3: Flicker Setting (Nexus® 1250 meter and 1252 V-1) You must set up several parameters to properly configure Flicker. NOTE: If your Nexus® 1252 meter has V-Switch key 2, see Section 12.9 for instruc- tions on configuring EN50160/IEC61000-4-30 Power Quality Compliance analysis, including Flicker.
  • Page 159 12: Flicker and Analysis 2. From the Device Profile screen, double-click Power Quality and Alarm Settings>EN50160/IEC61000-4-30 Flicker. You will see the screen shown below. • Select the Frequency of operation. 50 Hz is the approved frequency according to Flicker standards. A 60 Hz implementation is available and can be selected. Remember the voltage is normalized.

  • Page 160: Flicker Polling Screen

    12: Flicker and Analysis 12.4: Flicker Polling Screen 1. From the Communicator EXT application’s Title bar, select Real-Time Poll>Power Quality and Alarms>Flicker. You will see the screen shown below. Main screen: This section describes the Main Screen functions. These functions are found on the left side of the screen.
  • Page 161 12: Flicker and Analysis Status • This screen indicates the current status: Active = On; Stopped = Off. Frequency • Base is the operating frequency (50 or 60 Hz) selected in the EN50160 Flicker screen (see Section 12.3). • Current is the real-time frequency measurement of the applied voltage. Base Voltage •...
  • Page 162 12: Flicker and Analysis Short Term Readings Click on the Short Term tab to access a screen containing three groups of Pst readings (shown below). Pst readings displayed: • Current Pst values for Va, Vb and Vc and the time of computation •...
  • Page 163 12: Flicker and Analysis Long Term Readings 1. Click on the Long Term tab to access a screen containing three groups of Plt readings (shown below). Plt readings displayed: • Current Plt values for Va, Vb and Vc and the time of computation •...

  • Page 164: Logging

    12: Flicker and Analysis 12.5: Logging The Nexus® 1250/1252 meter 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. Pst, Pst Max, Pst Min, Plt, Plt Max, Plt Min, Start/Reset and Stop times are all recorded.

  • Page 165: Performance Notes

    12: Flicker and Analysis 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 166: En50160/Iec61000-4-30 Power Quality Compliance Analysis

    12: Flicker and Analysis 12.9: EN50160/IEC61000-4-30 Power Quality Compliance Analysis (Nexus® 1252 meter with V-2) If your Nexus® 1252 meter is equipped with V-Switch™ key 2, you have access to the EN50160/IEC61000-4-30 PQ Compliance analysis function, as well as to Flicker measurement.
  • Page 167 12: Flicker and Analysis 3. The Nexus® 1252 meter with V-2 can use Historical Log 2 to record the results of Flicker testing: you will see the top screen if EN50160/IEC61000-4-30 logging has not been selected for the meter; you will see the bottom screen if it has already been selected.

  • Page 168: 2: En50160/Iec61000-4-30 Analysis

    12: Flicker and Analysis 12.9.2: EN50160/IEC61000-4-30 Analysis NOTE: A full week of logging is necessary before an EN50160/IEC61000-4-30 analysis can be created. 1. From the Communicator EXT application toolbar, click Logs>Retrieve Logs from Device(s) or click the Retrieve Logs icon. You will see the screen shown below.
  • Page 169 12: Flicker and Analysis 6. The Log Viewer opens. 7. Your meter is displayed next to Meter 1. If you want to view EN 50160/IEC 61000- 4-30 information for a specific time range, e.g., for the last month only, click the Time Range button and select the range you want.
  • Page 170 12: Flicker and Analysis 8. Click the EN50160 button. 9. The screen that is displayed (example shown above) lists all of the weeks for which data has been collected, within the date range specified in the Log Viewer’s Main screen. Information provided includes: •...

  • Page 171: 13: Substation 19-Inch Rack Mount Assembly (Nexus 1252 Meter)

    ® 13.1: Overview The Nexus® 1252 meter can be ordered in a 19-inch rack mount assembly for use in modern substation control apparatus. The assembly houses the Nexus® 1252 meter, a Test switch, and three LED displays. The assembly is pre-wired and pre-labeled for easy installation.

  • Page 172: Options

    • P41N+: An LED Amps display which is a slave display. • P43N+: An LED Power display which is a slave display. 13.4: Dimensions The dimensions for the Nexus® 1252 rack assembly are: • Length: 19 inches/482.6mm • Height: 7 inches/177.8 mm (4 Rack units) •...

  • Page 173: Wiring

    Please follow the Nexus® 1252 meter wiring diagrams concerning proper connections (see Section 4.9). 13.7: Ordering Information The rack assembly ordering code is 4RU3DSP. It is placed at the end of the Nexus® 1252 meter order, for example: 1252-A-120-D-60-V1-X-X-4RU3DSP which translates to a Nexus® 1252 meter with Advanced memory, 120 Input Voltage...
  • Page 174 13: Substation Rack Mount Assembly Test Switch Displays connected to meter’s Port 3 Port 1 Serial Connection going to front of the unit Figure 13.3: Back of Rack Assembly CURRENT CURRENT CURRENT DC SUPPLY AØ AØ BØ BØ CØ CØ –...

  • Page 175: Glossary

    Glossary Glossary 0.2 Second Values: These values are the RMS values of the indicated quantity as calculated after approximately 200 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.
  • Page 176 Glossary Average (Power): When applied to power values (Watts, VARs, VA), the average is a calculated value that corresponds to the thermal average over a specified time interval. The interval is specified by the user in the meter profile. The interval is typically 15 minutes. So, the Average Watts is the thermal average of Watts over the previous 15-minute interval.
  • Page 177 Glossary Byte: A group of 8 binary digits processed as a unit by a computer (or device) and used especially to represent an alphanumeric character. CBEMA Curve: A voltage quality curve established originally by the Computer Business Equipment Manufacturers Association. The CBEMA Curve defines voltage disturbances that could cause malfunction or damage in microprocessor devices.
  • Page 178 Glossary accumulated total of the maximum demands. Demand: The average value of power or a similar quantity over a specified period of time. Demand Interval: A specified time over which demand is calculated. Display: User-configurable visual indication of data in a meter.
  • Page 179 Harmonics: 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 meter; pulses are generated per the programmed Ke value. I2T Threshold: Data will not accumulate until current reaches programmed level.
  • Page 180 NVRAM: Nonvolatile Random Access Memory: able to keep the stored values in memory even during the loss of circuit or control power. High speed NVRAM is used in the Nexus® meter to gather Electro Industries/GaugeTech E107706 GL- 6 The Leader In Power Monitoring and Smart Grid Solutions...
  • Page 181 Glossary measured information and to insure that no information is lost. Optical Port: A port that facilitates infrared communication with a meter. Using an ANSI C12.13 Type II magnetic optical communications coupler and an RS232 cable from the coupler to a PC, the meter can be programmed with Communicator EXT software.
  • Page 182 Glossary Quadrant (Programmable Values and ® Factors on the Nexus meter:) Watt and VAR flow is typically represented using an X-Y coordinate system. The four corners of the X-Y plane are referred to as quadrants. Most power applications label the right hand corner as the first quadrant and number the remaining quadrants in a counter-clockwise rotation.
  • Page 183 Communications speed is typically in the range of 1200 bits per second to 57,600 bits per second. RS232 connection can be accomplished using Port 1 of the Nexus® 1250/1252 meter. RS485: A type of serial network connection that connects two or more devices to enable communication between the devices.
  • Page 184 For example, a 3% THD indicates that the magnitude of all harmonic distortion measured equals 3% of the magnitude of the fundamental 60Hz quantity. The %THD displayed is calculated by your Nexus® meter. ------------------------------------------------------ Time Stamp: A stored representation of the time of an event.
  • Page 185 Glossary TOU: Time of Use. Uncompensated Power: VA, Watt and VAR readings not adjusted by Transformer Loss Compensation. V2T Threshold: Data will stop accumulating when voltage falls below programmed level. Voltage Imbalance: The ratio of the voltage on a phase to the average voltage on all phases.
  • Page 186 Glossary Voltage, Vaux This is the fourth voltage input measured from between the Vaux and Vref inputs. This input can be scaled to any value. However, the actual input voltage to the meter should be of the same magnitude as the voltages applied to the Va, Vb and Vc terminals.

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