Eaton Cooper Power Series Installation, Instruction And Service Manual

Also see for COOPER POWER SERIES: Installation and operation instructions Installation instructions Installation instructions Installation and operation instructions Operation instructions

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Eaton Cooper Power Series Installation, Instruction And Service Manual Manual pdf 23 page image

Control setupRatio correctionIt may be necessary to "ratio correct" the control voltagesfrom the regulator. Ratio correction is a fine adjustmentof the load side voltage signal to an approximate 120 voltbase. The adjustment is made using the ratio correctiontransformer (RCT). The magnitude of the voltage signalcoming to the control box is dependent upon the systemvoltage applied to the regulator and the regulators internalpotential transformer ratio. The application of the RCT allowsfor the fine adjustment of the incoming voltage as near aspossible to 120 volts. The CRA is designed to work with the120 volt signal from the load side of any regulator. The CL-7control does not require a fine adjustment to the source-sideor differential voltage signal, but instead uses the internal PTratio and software correction to determine the source sidevoltage.ote:N The CRA is shipped from the factory set for noratio correction. Examine the regulator nameplateto determine if ratio correction is required for yourapplication.If the regulator nameplate indicates that the load controlsignals at nominal system voltage are something other than120 volts, such as 115, 125, etc., it will be necessary toutilize the RCT located on the back panel of the CRA. SeeFigure 2. Ratio correction is achieved by applying the loadvoltage signals to the RCT autotransformer to adjust theoutput as near as possible to 120 volts. How much ratiocorrection required can be determined by using the internalPT ratio and system voltage and then determining therequired ratio of the RCT.Ratio correction and control programmingSource voltage control signal (when present)If the regulator is supplied with a source-side signal(Siemens green "U2"; GE #16AWG black 32; Eaton/McGraw-Edison white/black) the appropriate lead will be terminatedon the top of the V6 knife switch. Ratio correction isnot required, but the correct internal PT ratio must beentered into the control. The control must also be set up torecognize the signal sent from the PT.1. Determine the internal PT ratio by dividing the nominalsystem voltage by the control source voltage andentering this value at FC 44 (enter function code 44and then press the down arrow). On Eaton/McGraw-Edison regulators, the internal PT ratio can be readfrom the voltage chart.Example: If the regulator nameplate lists a controlsource voltage of 120 volts for a system voltage of 7620,the Internal PT Ratio will be 7620/120 = 63.5.2. The Vin PT Setting must be correctly set at FC 146.Select the correct setting as follows:• Select Vdiff without RCT2 when an internal differentialPT (IDPT) supplies the source-side voltage bymeasuring the voltage difference between the sourceand the load. This is standard for Eaton/McGraw-Edisonvoltage regulators.• Select Vin if the a source-side PT provides a voltagesignal measured between the source and source/load.This is standard on voltage regulator manufactured bySiemens and GE.Load control signal (always present)The regulator will be supplied with a load-side signal(Siemens blue "P2"; GE 20 orange/black or 21 orange or 22blue; Eaton/McGraw-Edison black). The appropriate lead willbe terminated on the top of the V1 knife switch. The RCTmust be set up correctly and the Overall PT Ratio must beset in the control.ote:N Some Siemens type A regulators may not beequipped with a load control signal. Eaton's controlwill not work on such devices.1. If the regulator nameplate identifies the load controlsignal as 120 volts for the system voltage used, no ratiocorrection is necessary. Determine the Overall PT ratioby dividing the nominal system voltage by the controlvoltage and enter this value at FC 44. This value is listedon Eaton/McGraw-Edison nameplates in the voltagechart for the appropriate system voltage.Example: If the regulator nameplate lists a controlvoltage of 120 volts for a system voltage of7620, the Overall PT Ratio will be 7620/120 =63.5.CAUTIONOver-voltage hazard. Equipment damage. Insure that thenominal PT voltage plus 10% does not exceed 140 Vac.In such a case, do not connect the source PT, but insteaduse the source-voltage calculation. A source-PT voltageabove 150 Vac will result in equipment damage. VR-T244.019CL-7 control replacement assembly installation instructions and service information MN225017EN October 2016