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Electro-Voice 1252 manual

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Table of contents for the manual

  • Page 1

    Nexus 1 2 50 /1252 High P erformance SC ADA Monitor  Electro Industries/GaugeTech Installation & Operation Manual V ersion 1.2 5 Novem ber 13 , 200 6 Doc # E107706 V1. 25 1 800 Shames Drive Westbury, New Y ork 11590 T el: 516-334-0870  F ax: 516-338-4741 Sales@electroind.com  www.electroind.com “The Leader in W eb Accessed Power Moni[...]

  • Page 2

     Electro Industries/GaugeTech Doc # E107706 V1.2 5[...]

  • Page 3

    Nexus 1250/1252 Installation and Operation Manual Revision 1.2 5 Published by: Electro Industries/GaugeT ech 1800 Shames Drive W estbury , NY 1 1590 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, recording, or information storage or ret[...]

  • Page 4

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 ii Customer Service and Support Customer support is available 9:00 am to 4:30 pm, eastern standard time, Monday through Friday . Please have the model, serial number and a detailed problem description available. If the problem concerns a particular reading, please have all meter readings availab[...]

  • Page 5

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 iii About Electro Industries/GaugeTech Electro Industries/GaugeT ech was founded in 1973 by Dr . Samuel Kagan. Dr . Kagan’ s first innovation, an affordable, easy-to-use AC power meter , revolutionized the power -monitoring field. In the 1980s Dr . Kagan and his team at EIG developed a digital[...]

  • Page 6

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 iv[...]

  • Page 7

    Table of Contents Chapter 1: Three-Phase Power Measurement 1.1: Three-Phase System Configurations . . . . . . . . . . . . . . . . . . . . . 1-1 1.1.1: W ye Connnection . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 1.1.2: Delta Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3 1.1.3: Blondell’ s Theorem and Three[...]

  • Page 8

    Chapter 5: Communication W iring 5.1: Communication Overview . . . . . . . . . . . . . . . . . . . . . . . . . 5-1 5.2: RS-232 Connection-Nexus Meter to a Computer . . . . . . . . . . . . . . . 5-5 5.3: RS-485 Wiring Fundamentals (with R T Explanation) . . . . . . . . . . . . . . 5-5 5.4: RS-485 Connection- Nexus Meter to a Computer or PLC . . . . [...]

  • Page 9

    8.3: TOU Prior Season and Month . . . . . . . . . . . . . . . . . . . . . . . 8-2 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 V iewer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-7 12.8: Performance Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-8 Appendix A: T ransformer Loss Compensation Excel Spreadsheet with Examples A.1: Calculating V alues . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1 A.2: Excel Spreadsheet w[...]

  • Page 11

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 1-1 Chapt er 1 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 Elec[...]

  • Page 12

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 1-2 Fig 1.2: Phasor Diagram Showing Three-phase V oltages and Currents Q The phasor diagram shows the 120 o 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 [...]

  • Page 13

    1.1.2: Delta Connection Q 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. In this example of a delta service, three wires will transmit th[...]

  • Page 14

    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: Q If energy is supplied to any system of conductors through N wires, th[...]

  • 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 phas[...]

  • Page 16

    1.2: Power, Energy and Demand Q It is quite common to exchange power , ener gy and demand without differentiating between the three. Because this practice can lead to confusion, the differences between these three measurements will be discussed. Q Power is an instantaneous reading. The power reading provided by a meter is the present flow of watts.[...]

  • Page 17

    T able 1.2: Power and Energy Relationship Over T ime As in T able 1.2, the accumulated energy for the power load profile of Figure 1.7 is 14.92 kWh. Q Demand is also a time-based value. The demand is the average rate of ener gy use over time. The actual label for demand is kilowatt-hours/hour but this is normally reduced to kilowatts. This makes it[...]

  • Page 18

    Q 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 ener gy use in each interval typically falls between 50 and 70 kWh. However , during two intervals the ener gy rises sharply and peaks at 100 kWh in interval number 7. This peak of usage will result in setting [...]

  • Page 19

    Q The voltage (V) and the total current (I) can be combined to calculate the apparent power or V A. 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 . The quadrature current may be lagging the voltage (as shown in Fig[...]

  • Page 20

    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 T otal Power Factor will equal the Displacement [...]

  • Page 21

    Figure 1.1 1: Distorted Current W ave Q The distortion observed in Figure 1.1 1 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. These high[...]

  • Page 22

    Q Inductive and capacitive impedance are present in all power systems. W e are accustomed to thinking about these impedances as they perform at 60 Hz. However , these impedances are subject to frequency variation. X L = j ω L and X C = 1/j ω C At 60 Hz, ω = 377; but at 300 Hz (5 th harmonic) ω = 1,885. As frequency changes impedance changes and[...]

  • Page 23

    1.5: Power Quality Q 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 equ[...]

  • Page 24

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 1-14[...]

  • Page 25

    e Electro Industries/GaugeTech Doc # E107706 V1.25 2-1 Chapt er 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 [...]

  • Page 26

    e Electro Industries/GaugeTech Doc # E107706 V1.25 2-2 Q Nexus 1250/1252 Revenue Metering: • Delivers laboratory-grade 0.04% W att-hour accuracy in a field-mounted device. • Autocalibrates when there is a temperature change of more than 10 degrees centigrade. • Exceeds all ANSI C-12 and IEC 687 specifications. • Adjusts for transformer and [...]

  • Page 27

    e Electro Industries/GaugeTech Doc # E107706 V1.25 2-3 2.4: INP2 Internal Modem with Dial -I I n/Dial -O O ut Option 2.4.1: Hardware Overview Q 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 [...]

  • Page 28

    e Electro Industries/GaugeTech Doc # E107706 V1.25 2-4 2.5: Total Web Solutions Q The 10/100BaseT Ethernet Option (INP 100) is a fully customizable web server that uses XML to provide access to real time data via Internet Explorer . EIG’ s name for this dynamic system is T otal W eb Solutions. The system incorporates a highly programmable network[...]

  • Page 29

    e Electro Industries/GaugeTech Doc # E107706 V1.25 2-5 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: Communi[...]

  • Page 30

    e Electro Industries/GaugeTech Doc # E107706 V1.25 2-6 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 W ye and Delta services. Samples for Wy e : v an , v bn , v cn , i a , i b , i c , i n Samples for Delta :[...]

  • Page 31

    e Electro Industries/GaugeTech Doc # E107706 V1.25 2-7 Q Power (W atts) per phase: For Wy e : x = a, b, c Q Apparent Power (V A) per phase: For Wy e : x = a, b, c Q Reactive Power (V AR) per phase: For Wy e : x = a, b, c Q Power (W atts) T otal: For Wy e : For Delta : c b a T W W W W + + = n i v i v W n t C BC A AB T t t t t ∑ = • − • = 1 )[...]

  • Page 32

    e Electro Industries/GaugeTech Doc # E107706 V1.25 2-8 Q Reactive Power (V AR) T otal: For Wy e : For Delta : + Q Apparent Power (V A) T otal: For Wy e : For Delta : Q Power Factor (PF): For Wy e : x = A, B, C, T For Delta : x = T C B A T VA VA VA VA + + = 2 2 T T T VAR W VA + = x x x VA Watt PF = C B A T VAR VAR VAR VAR + + = 2 1 ) ( ) ( 2 ) ( ⎥[...]

  • Page 33

    e Electro Industries/GaugeTech Doc # E107706 V1.25 2-9 Q Phase Angles: Q % T otal Harmonic Distortion (%THD): For Wy e : 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 Q K Factor: x = I A , I B , I C Q W att hour (Wh): Q V AR hour (V ARh): ) ( cos 1 PF − = ∠ 1 127 2 2 ) ( x h x RMS RMS THD h ∑ = [...]

  • Page 34

    e Electro Industries/GaugeTech Doc # E107706 V1.25 2-10 2.7: 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 followi[...]

  • Page 35

    e Electro Industries/GaugeTech Doc # E107706 V1.25 2-11 Example: Using the previous settings of 3 five-minute intervals and a new setting of 120% prediction factor , the working of the Predictive W indow Demand could be described as follows: At 12:10, we have the average of the subintervals from 1 1:55-12:00, 12:00-12:05 and 12:05-12:10. In five mi[...]

  • Page 36

    e Electro Industries/GaugeTech Doc # E107706 V1.25 2-12 2.8: 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 capabil[...]

  • Page 37

    e Electro Industries/GaugeTech Doc # E107706 V1.25 2-13 2.9: Nexus 1250/1252 Meter Specifications Specification Nexus Meter Control Power Requirements Option D: 24V DC (-20%) – 48V DC (+20%) Option D2: 120V AC/DC (-20%) – 230V AC (+20%) Input V oltage Range 150 V olts Phase to Neutral (Standard; for use with PT s) 300 V olts Phase to Neutral (O[...]

  • Page 38

    e Electro Industries/GaugeTech Doc # E107706 V1.25 2-14 2.10: Nexus P40N, P41N, P43N LED External Display Specifications Specification Nexus P40N, P41N, P43N LED External Display Maximum Input V oltage 30V DC Minimum Input V oltage 7V DC Maximum Power Consumption 8 W atts Nominal Power Consumption Approximately 6 W atts Operating T emperature Range[...]

  • Page 39

    Chapt er 3 Hardware Installatio n 3.1: Mounting the Nexus 1250/1252 Meter Q 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 envir onment , such as in [...]

  • Page 40

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 3-2 Figure 3.2 2.35” (5.96cm) 3.40” (8.63cm) (MAX) Nexus Meter Mounting Diagram, Side View[...]

  • Page 41

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 3-3 3.2: Mounting the Nexus LED External Displays Q The Nexus 1250/1252 LED Displays, Model # P40N, P41N and P43N, mount using a standard ANSI C39.1 drill plan. Q Secure the four mounting studs to the back of the panel with the supplied nuts. Q Six feet of RS-485 communication/power cable harnes[...]

  • Page 42

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 3-4 3.3: Mounting the Nexus P60N Touch Screen External Display Q The Nexus 1250/1252 P60N T ouch 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 consid[...]

  • Page 43

    Figure 3.6: Cutout for Nexus P60N T ouch Screen Display  Electro Industries/GaugeTech Doc # E107706 V1.2 5 3-5 Q T o bezel mount the P60N, cut an opening in the mounting panel. Follow above cutout dimensions. Q Carefully “drop in” the P60N with bezel and gasket attached. Q Fasten the unit securely with the four 6-32 hex nuts supplied.[...]

  • Page 44

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 3-6 3.4: Mounting the Nexus External I/O Modules Q 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 . Q If multiple I/O modules are connected together , as shown in Figure 3.4[...]

  • Page 45

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 3-7 Figure 3.9 Mounting Bracket (MBIO) Mounting Bracket (MBIO) 0.605” (1.53cm) 2x1.10” (2.79cm) Y 1.235” (3.13cm) 1.25” (3.17cm)+Y P er Module 3.41” (8.66cm) 2.20” (5.58cm) Nexus I/O Modules Mounting Diagram, Front V iew[...]

  • Page 46

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 3-8[...]

  • Page 47

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 4-1 Chapt er 4 Electrical Installation 4.1: Wiring the Monitored Inputs and Voltages Q Select a wiring diagram from Section 4.8 that best suits your application. W ire the Nexus 1250/1252 exactly as shown. For proper operation, the voltage connection must be maintained and must correspond to the[...]

  • Page 48

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 4-2 Q It is important to maintain the polarity of the CT circuit when connecting to the Nexus. If the polarity is reversed, the Nexus will not provide accurate readings. CT polarities are dependent upon correct connection of CT leads and the direction CT s are facing when clamped around the cond[...]

  • Page 49

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 4-3 Q Do not ground the unit through the negative of the DC supply . Separate grounding is required. Q Externally fuse the power supply with a 5 Amp fuse. 4.8: Wiring Diagrams Q Choose the diagram that best suits your application. Diagrams appear on the following pages. If the connection diagram[...]

  • Page 50

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 4-4 Figure 4.1: 4-Wire Wye, 3-Element Direct V oltage with 4 CT s 0.25 A INPUT[...]

  • Page 51

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 4-5 Figure 4.2: 4-Wire Wye, 3-Element with 3 PT s and 4 CT s INPUT 0.25A[...]

  • Page 52

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 4-6 Figure 4.3: 4-Wire Wye, 3-Element with 3 PT s and 3 CT s INPUT 0.25 A[...]

  • Page 53

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 4-7 Figure 4.4: 3-Wire, 2-Element Open Delta with 2 PT s and 3 CT s. 0.25 A[...]

  • Page 54

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 4-8 Figure 4.5: 3-Wire, 2-Element Open Delta with 2 PT s, 2 CT s. 0.25 A[...]

  • Page 55

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 4-9 Figure 4.6: 3-Wire, 2-Element Delta Direct V oltage with 3 CT s. 0.25 A INPUT[...]

  • Page 56

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 4-10 Figure 4.7: 3-Phase, 4-Wire Wye, 2.5 Element with 2 PT s, 3 CT s. 0.25 A INPUT[...]

  • Page 57

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 4-11 Figure 4.8: 4-Wire, 3-Element Grounded Delta with 4 CT s - G Option. 0.25 A INPUT[...]

  • Page 58

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 4-12[...]

  • Page 59

    Figure 5.1: Communication Overview e Electro Industries/GaugeTech Doc # E107706 V1.25 5-1 Chapt er 5 Communicat ion Wiring 5.1: Communication Overview  RS-232 communication is used to connect a single Nexus 1250/1252 Meter with another device, such as a computer , R TU or PLC. The link is viable for a distance up to 50 feet (15.2 m) and is avail[...]

  • Page 60

    e Electro Industries/GaugeTech Doc # E107706 V1.25 5-2  RJ-1 1 T elephone Line allows a Nexus Meter with the Internal Modem Option to communicate with a PC. No other hardware is necessary for this easy-to-use connection. The Nexus 1250/1252 Meter with the Internal Modem Option can connect via RS-485 to other Nexus Meters in local or remote sites[...]

  • Page 61

    e Electro Industries/GaugeTech Doc # E107706 V1.25 5-3  RJ-45 Network Connection allows a Nexus Meter with the Internal Network Option to communicate with multiple PC’ s concurrently . No other hardware is necessary for this easy-to-use connection. The Nexus Meter with the Internal Network Option can connect via RS-485 to other Nexus Meters in[...]

  • Page 62

    – – ++G A(+) B(-) S - V + A(+) B(-) S - V + +V - S B ( - ) A ( + ) +V - S B ( - ) A ( + ) +V - S B ( - ) A ( + ) +V- SB ( - ) A ( + ) 87 6 5 4 3 21C -+ Port 1 RS-232 or RS-485 (Set) RS-232 RS-485 Port 2 Normally Slave Modem/Ethernet Gateway High S peed Input s IRIG-B RS-485 Master Unicom or Modem Manager Nexus P40N External Display Nexus I/O Mo[...]

  • Page 63

    + V - S B(-) A(+) e Electro Industries/GaugeTech Doc # E107706 V1.25 5-5 Figure 5.5: Nexus Port 1—RS-232/RS-485 Communication Switch set for RS-232 communication RS-232 RS-485 5 4 3 2 1 9 8 7 6 RS-232 Port Pin #2=T ransmit Pin #3=Receive Pin #5=Ground RS-485 Port (see Section 5.3 for details) Nexus Meter Port 1 5.2: RS -2 2 32 Connection—Nexus [...]

  • Page 64

    e Electro Industries/GaugeTech Doc # E107706 V1.25 5-6 F or All RS -485 Connections:  Use a shielded twisted pair cable 22 A WG (0.33 mm 2 ) or larger , grounding the shield at one end only .  Establish point-to-point configurations for each device on a RS-485 bus: Connect (+) terminals to (+) terminals; connect (-) terminals to (-) terminals[...]

  • Page 65

     Electro Industries/GaugeTech Doc # E107706 V1.25 5-7 Incorrect Connection: “T” Figure 5.7: Incorrect “T” and “S t ar” T opologies Incorrect Connection: “Star ” “S t ar” Connection Incorrect! The three wires connected in a “S t ar” shape on both the (+) and (-) terminals will cause interference problems. RS-485 Ports RS-4[...]

  • Page 66

     Electro Industries/GaugeTech Doc # E107706 V1.25 5-8 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).  Y ou must use an RS-485 to [...]

  • Page 67

     Electro Industries/GaugeTech Doc # E107706 V1.25 5-9 5.7: RS -4 4 85 Connection—Nexus to an RS -4 4 85 Master (Unicom or Modem Manag er)  T o 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-4[...]

  • Page 68

     Electro Industries/GaugeTech Doc # E107706 V1.25 5-10 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. As shown in Figure 5.9, you connect the "RX-" and "TX-" termina[...]

  • Page 69

    Nexus P40N, P41N or P43N Display , Back View  Electro Industries/GaugeTech Doc # E107706 V1.25 5-11 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. T o use[...]

  • Page 70

     Electro Industries/GaugeTech Doc # E107706 V1.25 5-12 Nexus P60N Display , Back View (Det ail) To p Bottom 5.9: RS -4 4 85 Connection—Nexus Meter to the Nexus P60N External Display  T o connect the Nexus P60N T ouch Screen External Display , use the Stand Alone Interface Cable provided with the display . The cable is six (6) feet long with[...]

  • Page 71

     Electro Industries/GaugeTech Doc # E107706 V1.25 5-13 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 p[...]

  • Page 72

     Electro Industries/GaugeTech Doc # E107706 V1.25 5-14 5.11: RS -4 4 85 Connection—Nexus Meter to Nexus I/O Modules  Six feet of RS-485 cable harness is supplied. Insert one end of the cable into Port 4 of the Nexus 1250/1252 Meter .  Insert the other end of the cable into the I/O module’ s female RS-485 side port (see Figure 5.9). The[...]

  • Page 73

     Electro Industries/GaugeTech Doc # E107706 V1.25 5-15 5.12: Steps to Determine Power Needed • A vailable power for All Ports of the Nexus 1250/1252 is 12 V A. • Refer to the table below to determine the V A Ratings for I/O modules and displays. • Add together the V A Ratings for I/Os and Displays in use. • Compare A vailable Power to Po[...]

  • Page 74

     Electro Industries/GaugeTech Doc # E107706 V1.25 5-16 Figure 5.14: Linking Multiple Nexus Devices in Series Nexus RS-485 Port Nexus RS-485 Port RS-485 to RS-232 Converter (RS-485 Master) + V - S B(-) A(+) + V - S B(-) A(+) GND TX- RX- TX+ RX+ R Up to 31 Nexus 1250/1252 Meters Maximum 5.14: Linking Multiple Nexus Devices in Series  Y ou may c[...]

  • Page 75

     Electro Industries/GaugeTech Doc # E107706 V1.25 5-17 Nexus Nexus Nexus Nexus Nexus Nexus Nexus Nexus Nexus Nexus Maximum 31 Nexus 1250/1252 Meters, RS-485 Maximum 31 Nexus Meters, RS-485 Maximum 31 Repeaters Figure 5.15: Networking Groups of Nexus Meters 5.15: Networking Groups of Nexus Meters  Y ou may connect up to 31 Nexus 1250/1252 Mete[...]

  • Page 76

     Electro Industries/GaugeTech Doc # E107706 V1.25 5-18 T elephone Line Remote Modem NULL Modem Adapter (Required if 232/485 Converter does not support DTE/DCE reconfigura tion) RS- Originate Modem RS-232 to RS-485 Converter (Modem Manager Recommended) Nexus 1250/1252 Meter PC at office Figure 5.16: Remote Connections—RS-232/RS-485 PSTN (Public[...]

  • Page 77

     Electro Industries/GaugeTech Doc # E107706 V1.25 5-19  Use RJ-1 1 T elephone Lines when devices are at great distances. Connections are simple, requiring no additional hardware. RJ-1 1 RS-485 Figure 5.17: Remote Connections with Internal Modem Option PC Originate Modem (or Internal to PC) Daisy Chain  Standard T elephone wall to phone cab[...]

  • Page 78

     Electro Industries/GaugeTech Doc # E107706 V1.25 5-20  Or , use RJ-45 Network Connection when devices are at great distances. Connections are simple, requiring no additional hardware. MODBUS/TCP over Ethernet 10/100BaseT or 10BaseT RJ-45 Network Daisy Chain MODBUS/R TU RS-485 Figure 5.18: Remote Connections with Internal Network Option[...]

  • Page 79

     Electro Industries/GaugeTech Doc # E107706 V1.25 5-21 5.17: Remote Communication—RS -2 2 32  EIG r ecommends using RS-485 wiring with a Modem Manager . See section 5.13.  For RS-232 communication, use Port 1. Set the selector switch under the port to RS-232 (Fig. 5.3).  Use an RS-232 serial extension cable connected to the 9-pin fema[...]

  • Page 80

     Electro Industries/GaugeTech Doc # E107706 V1.25 5-22 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 Manag[...]

  • Page 81

     Electro Industries/GaugeTech Doc # E107706 V1.25 5-23 5.20: Selected Modem Strings Modem S tring/Setting Cardinal modem: A T&FE0F8&K0N0S37=9 Zoom/Faxmodem VFX V .32BIS(14.4K): A T&F0&K0S0=1&W0&Y0 Zoom/Faxmodem 56Kx Dual Mode: A T&F0&K0&C0S0=1&W0&Y0 USRobotics Sportster 33.6 Faxmodem: A T&F0&N6[...]

  • Page 82

     Electro Industries/GaugeTech Doc #: E107706 V1.25 5-24 5.22: Five Modes of Time Synchronization  The Nexus meter offers up to five modes of T ime Synchronization, depending on options selected at the time of ordering. 1. Internal Crystal: The Default T ime Constant is an Internal Crystal. The crystal is accurate to approximately 1 minute per[...]

  • Page 83

     Electro Industries/GaugeTech Doc # E107706 V1.25 5-25 + + - Nexus IRIG-B Port 5.23: IRIG -B 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 ge[...]

  • Page 84

     Electro Industries/GaugeTech Doc #: E107706 V1.25 5-26[...]

  • Page 85

    Chapt er 6 Using the Nexus External Displays 6.1: Overview Q 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 T ouch Screen Display , which provides easy access to Nexus 1250/12[...]

  • Page 86

    6.2.1: Connect Multiple Displays Q 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 V A. Each P40N, P41N or P43N requires 3.3 V A (maximum 3.8 V A). The Master Display (P40N) is the master in communication. The Amp, Power and Nexus devices are slaves in[...]

  • Page 87

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 6-3 6.3: Dynamic Readings Mode Q 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 th[...]

  • Page 88

    • Maximum Quadrant 1 T otal PF • Minimum Quadrant 1 T otal PF • Maximum Quadrant 2 T otal PF • Minimum Quadrant 2 T otal PF • Maximum Quadrant 3 T otal PF • Minimum Quadrant 3 T otal PF • Maximum Quadrant 4 T otal PF • Minimum Quadrant 4 T otal PF Q Group 6: Deliver ed Energy (Use the LEFT/RIGHT arrows to access the following readin[...]

  • Page 89

    1 Second V olts AN,BN,CN Maximum V olts AN,BN,CN Maximum V olts AB,BC,CA Minimum V olts AB,BC,CA Minimum V olts AN,BN,CN %THD V olts AN,BN,CN Max %THD V olts AN,BN,CN Min %THD V olts AN,BN,CN Return to First Reading Return to First Reading Return to First Reading Return to First Reading Return to First Reading Return to First Reading Return to Firs[...]

  • Page 90

    6.5: Nexus Information Mode Q 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. Q Group 1: Device T ime • Meter T ime Q Group 2: Communication Settings (Use the LEFT/RIGHT arrows t[...]

  • Page 91

    Meter T ime Display Primary/Secondary CT Ratio PT Ratio Serial # Display , Serial # Monitor Boot Display , DSP , Comm Run-time Display , DSP , Comm G r o u p s Readings Return To First Reading Return To First Reading 6.6: Navigational Map of Nexus Information Mode Q Use UP/DOWN arrows to scroll between groups. Q Use LEFT/RIGHT arrows to scroll betw[...]

  • Page 92

    6.7: Display Features Mode Q 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. Q Group 1: Reset Max/Min • Note : If the password protection feature has been enabled with the Communic[...]

  • Page 93

    Reset Max/Min Reset Energy Communication Protocol Baud Rate/Address EIG Use Only EIG Use Only Display Scroll On/Off G r o u p s 6.8: Navigational Map of Display Features Mode Q Use UP/DOWN arrows to scroll between groups.  Electro Industries/GaugeTech Doc # E107706 V1.2 5 6-9 Lamp T est[...]

  • Page 94

    6.9: Nexus P60N Touch Screen External Display Q The P60N T ouch Screen External Display is ready to use upon power-up. T ouching the “buttons” at the top of the screen will take you to the Groups of Readings listed below . W ith the “buttons” at the bottom of the screen, you can use the touch screen to review Limits and review and/or change[...]

  • Page 95

    Q VOL TS: V oltage Readings Details • Real T ime V olts AN/BN/CN/AB/BC/CA • Maximum V olts AN/BN/CN/AB/BC/CA • Minimum V olts AN/BN/CN/AB/BC/CA T ouch PH-N or PH-PH to view details of Phase-to-Neutral or Phase-to-Phase Readings. Q VOL TS: V oltage Readings PH-N • V olts AN/BN/CN T ouch BACK to return to the V olts main screen. Q VOL TS: V o[...]

  • Page 96

    Q AMPS: Current Readings A-B-C • Real T ime Current A/B/C T ouch BACK to view the Amps main screen. Q REAL TIME POWER: Real T ime Power Readings Details • Instant W att/V AR/V A/PF • A verage W att/V AR/V A/PF • Predicted W att/V AR/V A T ouch the DEMAND button to go to the Demand Power screen (shown below) Q DEMAND POWER: Demand Power Read[...]

  • Page 97

    Q TOU: Accumulations • -W atthr Quadrant 2+Quadrant 3 (Primary) • +V Ahr Quadrant 2 (Primary) • +V ARhr Quadrant 2 (Primary) • +V Ahr Quadrant 3 (Primary) • -V ARhr Quadrant 3 (Primary) • +W atthr Quadrant 1+Quadrant 4 (Primary) • +V Ahr Quadrants 1 & 4 (Primary) • -V ARhr Quadrant 4 (Primary) T ouch DEMAND to view Register Dema[...]

  • Page 98

    Q FLICKER - LONG TERM: • V olts A/B/C • Max V olts A/B/C • Min V olts A/B/C T ouch INST or LONG TERM to view other Flicker screens. ST AR T or STOP will appear , depending on Status. Q LIMITS: Limit S tatus Current Limits Settings for Nexus Meters, ID 1 - 32. For each ID number , the T ype of Reading, V alue, Status (In or Out of Limit) and S[...]

  • Page 99

    Q 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 . Q REAL TIME TRENDING ANAL YSIS: Select Channel by touching the CHANNEL button. The Channel Selector screen (shown below) appears. Select a Channel and touch O[...]

  • Page 100

    Q LOG ST A TUS: Logging S tatistics An Overview of the Logs for the Primary Meter . The Number of Records and Memory Used are listed for each log. Q RESET : Meter Reset Commands. W ARNING! RESETS cause data to be lost. T ouch the window for the Reset you want to perform. Don’t Reset changes to Reset. T ouch RESET NOW button. OK will appear . T ou[...]

  • Page 101

    Q NEXUS POR T SETTINGS : Port 1 (Baud and Protocol selected). Port 2 (Baud and Protocol selected). Port 3 (Baud and Protocol selected). Port 4 (Baud and Protocol selected). Q NEXUS ST A TUS : Device T ype: Nexus 1252 Serial Number (10 digit number) Comm State: Healthy or Unhealthy Nv Ram: 4 MB DSP S tate: Healthy or Unhealthy Protection: Password E[...]

  • Page 102

    6.10: Navigational Map for P60N Touch Screen External Display  Electro Industries/GaugeTech Doc # E107706 V1.2 5 6-18[...]

  • Page 103

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 7-1 Chapt er 7 Transformer Loss Compensation 7.1: Introductio n Q 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,[...]

  • Page 104

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 7-2 Q A single meter cannot measure the losses in a transformer or transmission line directly . 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 compensat[...]

  • Page 105

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 7-3 • Performs Bidirectional Loss Compensation. • Requires no additional wiring; the compensation occurs internally . • Imposes no additional electrical burden when performing Loss Compensation. Q Loss Compensation is applied to 1 second per phase W att/V AR readings and, because of that, [...]

  • Page 106

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 7-4 7.2.1: Loss Compensation in Three Element Installations Q 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

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 7-5 7.2.1.1: Three Element Loss Compensation Worksheet Q T ransformer Data (from T ransformer Manufacturer’ s T est Sheet) 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 W atts to 1-Phase kW by [...]

  • Page 108

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 7-6 Q Meter/Installation Data 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). Q Base Conversion Factors For T ransformer V oltage, enter the P[...]

  • Page 109

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 7-7 Full-Load Loss W atts (kW) = 1-Phase Kw Load Loss = ______________ Full-Load Loss V A (kV A) = (%Impedance) * (1-Phase kV A Self-Cooled Rating) / 100 = (______________) * (________________) / 100 = _______________ kV A Full-Load Loss V AR (kV AR) = SQR T((Full-Load Loss kV A) 2 - (Full-Load [...]

  • Page 110

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 7-8 Q Calculate Load Loss V alues Enter “V alue at Meter Base” from Normalize Losses section. Enter “Meter Base kV A” from previous calculation. Calculate “% Loss at Meter Base” by dividing (V alue at Meter Base) by (Meter Base kV A) and multiplying by 100. Enter calculated % Loss W [...]

  • Page 111

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 8-1 Chapt er 8 Nexus Time -o o f -U U se 8.1: Introductio n Q A T ime-of-Use (T OU) usage structure takes into account the quantity of energy used and the time at which it was consumed. The Nexus 1250/1252 T OU function, available with the Communicator EXT software, is designed to accommodate a [...]

  • Page 112

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 8-2 8.3: TOU Prior Season and Month Q The Nexus 1250/1252 Monitor stores accumulations for the prior season and the prior month. When the end of a billing period is reached, the current season or month becomes stored as the prior . The registers are then cleared and accumulations resume, using t[...]

  • Page 113

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 9-1 Chapt er 9 Nexus External I/O Modules 9.1: Hardware Overview Q All Nexus External I/O modules have the following components: • • 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 Me[...]

  • Page 114

     Electro Industries/GaugeTech Doc E107706 V1.2 5 9-2 9.1.1: Port Overview Q 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 -1 1 mA and 4 -2 2 0mA) (0 -1 1 mA and 4 -2 2 0mA) Eight Anal[...]

  • Page 115

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 9-3 9.2: Installing Nexus External I/O Modules Q 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 modul[...]

  • Page 116

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 9-4 9.2.1: Power Source for I/O Modules Q 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. RS-485 communication is viable for up to 4[...]

  • Page 117

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 9-5 Mounting Bracket Communication ONL Y (A+, B - and Shield) Female RS -485 Side P ort LEDs Control P ower I/O P ort (Size and pin configuration vary) Reset Button 9.3: Using PSIO with Multiple I/O Modules 9.3.1: Steps for Attaching Multiple I/O Modules 1. Each I/O module in a group must be ass[...]

  • Page 118

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 9-6 NOTE: The PB1 can also be used for a Low V oltage 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. Attach the right Mounting Bracket to [...]

  • Page 119

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 9-7 9.5: Analog Transducer Signal Output Modules 9.5.1: Overview Q The Analog T ransducer Signal Output Modules (0±1mA or 4–20mA) are available in either a 4- or 8-channel configuration. Maximum registers per request, read or write, is 17 registers. Q Nexus 1250/1252 Unit supplies power for u[...]

  • Page 120

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 9-8 Q 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 Q 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. Both[...]

  • Page 121

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 9-9 Default Settings (Reset Button) 9.6: Analog Input Modules Analog Input Modules Specifications Model Numbers 8AI1: 8-Channel Analog Input, 0±1mA 8AI2: 8-Channel Analog Input, 0±20mA 8AI3: 8-Channel Analog Input, 0±5V dc 8AI4: 8-Channel Analog Input, 0±10V dc Accuracy 0.1% of Full Scale Sc[...]

  • Page 122

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 9-10 Q 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 Q In Normal Mode, the Input Module: 1. Reads and averages the A/D and adjusts values for process 2. 2. Calculates the percentage of Input V a[...]

  • Page 123

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 9-11 9.7: Digital Dry Contact Relay Output (Form C) Module Digital Dry Contact Relay Output (Form C) Module Specifications Model Number Communication Power Requirement Operating T emperature Maximum Load Impedance 4RO1: 4 Latching Relay Outputs RS-485, Modbus R TU Programmable Baud Rates: 4800, [...]

  • Page 124

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 9-12 9.7.2: Communication Q Maximum registers per request, read or write, is 4 registers.orm Q The device will operate with the following Default Parameters: Address 247 (F7H) Baud Rate 57600 Baud T ransmit Delay T ime 20 csec Q Some situations will cause the device to operate with the above Def[...]

  • Page 125

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 9-13 9.8: Digital Solid State Pulse Output (KYZ) Module Digital Solid S tate Pulse Output (KYZ) Module Specifications Model Number Communication Power Requirement Operating T emperature Memory Factory Settings Default Settings (Reset Button) 4PO1 RS-485, Modbus R TU Programmable Baud Rates: 4800[...]

  • Page 126

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 9-14 9.8.2: Communication Q Maximum registers per request, read or write, is 4 registers.orm Q The device will operate with the following Default Mode Parameters. See section 9.4.1 for details. Address 247 (F7H) Baud Rate 57600 Baud T ransmit Delay T ime 20 csec 9.8.3: Normal Mode Q Energy readi[...]

  • Page 127

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 9-15 9.9.1: Overview Q The Digital Status Input Module is used for either additional status detect or for accumulating pulses from external equipment, such as power meters, water meters, etc. Q Nexus 1250/1252 Unit supplies power for up to 4 connected Digital Status Input modules. See section 9.[...]

  • Page 128

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 9-16 9.9.3: Normal Mode Q The device is polling the inputs at 100Hz (once every 10 msec), debouncing the inputs and incrementing the T ransition Accumulators for each channel as appropriate. The inputs are represented by Channel 1 in the LSB through Channel 8 in the MSB of the low order byte of [...]

  • Page 129

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 10-1 Chapt er 10 Nexus Monitor with Internal Modem Option 10.1: Hardware Overview Q 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 [...]

  • Page 130

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 10-2 10.2: Hardware Connection Q Use RJ-1 1 S tandard T elephone Line to connect with an INP2 Option Nexus. The RJ-1 1 line is inserted into the RJ-1 1 Port on the face of the Nexus 1250/1252 with Internal Modem Option. The connection using RJ-1 1 into the Nexus is virtually unlimited, since it [...]

  • Page 131

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 11-1 Chapt er 11 Nexus Meter with Internal Network Option 11.1: Hardware Overview Q 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 hardw[...]

  • Page 132

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 11-2 Q The Internal Network Option of the Nexus Meter is an extremely versatile communications tool. · Adheres to IEEE 802.3 ethernet standard using TCP/IP . · Utilizes simple and inexpensive 10/100BaseT wiring and connections. · Plugs right into your network using built-in RJ-45 jack. · Pro[...]

  • Page 133

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 11-3 11.2: Hardware Connection Q 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. Q Set the IP Address using the following steps: (Refer to Section 3.5 of the Communicat[...]

  • Page 134

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 11-4[...]

  • Page 135

    Chapt er 12 Flic ker 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 ef fects of flicker are headaches, irritability and sometimes epilepsy . IEC 61000-4-15 and former IEC 868 describe the methods used to dete[...]

  • 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. • Short T erm Flicker Evaluation An output of 1.00 fr[...]

  • Page 137

    Measurement Pr ocedur e 1. Original Signal with amplitude variations. 2. Square demodulator . 3. W eighted filter . 4. Low pass filter 1 st order . 5. Statistical computing. Q Data available Pst, Pst Max, Pst Min values for long term recording Plt, Plt Max, Plt Min values for long term recording Figure 12.1: Simulation of Eye Brain Response 12.3: S[...]

  • Page 138

    • 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 [...]

  • 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 S tart of Flicker is also equivalent to a Reset in that the PST and PL T are restarted and the Max/Min V alues are cleared. Stop corresponds to the time when Flicker is turned of f[...]

  • Page 140

    Q Short T erm Readings Click on the Short T erm tab to access the screen containing three groups of Pst readings. Pst Readings Displayed • Current Pst values for V a, Vb and Vc and the time of computation. • Current Pst Max values for V a, Vb and Vc since the last reset and the time of the last reset. • Current Pst Min values for V a, Vb and [...]

  • Page 141

    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 . Pst, Pst Max, Pst Min, Plt, Plt Max, Plt Min, Start/Reset and S top times are all recorded. All values can be down- loaded to the Log V iewer where they are[...]

  • Page 142

    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. If the wrong frequency is chosen (e.g. 50Hz selection for a system operating at [...]

  • Page 143

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 A-1 Appen dix A Transformer Loss Compensation Excel Spreadsheet with Example s A.1: Calculating Values Q T ransformer Loss Compensation is discussed in Chapter 7 of this manual. V alues for three element installations can be calculated in two ways: • Click the TLC Calculator button on the T ra[...]

  • Page 144

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 A-2[...]

  • Page 145

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 A-3[...]

  • Page 146

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 A-4[...]

  • Page 147

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 A-5[...]

  • Page 148

     Electro Industries/GaugeTech Doc # E107706 V1.2 5 A-6[...]

  • Page 149

    e Electro Industries/Gauge Tech Doc # E107706 V1.2 5 Glossary-1 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)[...]

  • Page 150

    e Electro Industries/Gauge Tech Doc # E107706 V1.2 5 Glossary-2 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 v[...]

  • Page 151

    e Electro Industries/Gauge Tech Doc # E107706 V1.2 5 Glossary-3 Flicker: 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. IEC 61000-4-15 and former IEC 868 describe the methods used to determine flicker severity. Form: Wiring and Hookup [...]

  • Page 152

    e Electro Industries/Gauge Tech Doc # E107706 V1.2 5 Glossary-4 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 [...]

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    e Electro Industries/Gauge Tech Doc # E107706 V1.2 5 Glossary-5 Register: An entry or record that stores a small amount of data. Register Rollover: A point at which a Register reaches its maximum value and rolls over to zero. Reset: Logs are cleared or new (or default) values are sent to counters or timers. Rolling Window The Rolling (Sliding) Wind[...]

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    e Electro Industries/Gauge Tech Doc # E107706 V1.2 5 Glossary-6 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 Qua[...]