Eaton Cooper Power Series Installation, Operation And Maintenance 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, Operation And Maintenance Manual Manual pdf 131 page image

the other values are already available.On the control back panel, when no source or differentialPT are present, the connection that would be the input forone of these PTs if they were present is tied to the load-side PT input. When the load and source PT inputs are tiedand the values are the same, the control interprets that asmeaning that the calculation is required. If the inputs arenot tied when there is no source-side PT signal, the controlwill attempt to read the source-side voltage and will providean errant value. Often, this value will be in the range of 40volts. If the source-voltage value is displaying errantly andthere is no source PT, check to make sure the source andload PT inputs (terminals V7 and VS) are tied together.Reverse power operationMost voltage regulators are installed in circuits with well-defined power flow from source to load. However, somecircuits have interconnections or loops in which the directionof power flow through the regulator may change. Foroptimum utility system performance, a regulator installed onsuch a circuit should have the capability of detecting reversepower flow and of sensing and controlling the voltage,regardless of the power flow direction.The control has full reverse power capabilities. For fullyautomatic reverse operation, the source voltage mustbe available to the control. Refer to Section 6: ControlFeatures: Source-side voltage in this section of themanual.The control offers nine different response characteristics forforward and reverse power detection and operation. Thesecharacteristics are user-selectable by programming theReverse Sensing Mode (FC 56). The nine modes are LockedForward, Locked Reverse, Reverse Idle, Bi-directional,Neutral Idle, Co-generation, Reactive Bi-directional, BiasBi-directional, and Bias Co-generation.This section will separately explain each mode of operation.Since the control retains the reverse metered demandvalues separate from the forward metered values, themetering will also be explained for each mode.In determining power direction the control uses one of twomethods, depending upon the reverse sensing mode in useand the current level detected. In most cases, the controlsenses the real component of the current, then determinesthe current direction and magnitude in that direction.Power direction may also be determined using a test-tappingroutine under certain conditions when the "Bias" reversesensing modes are employed.When the conditions indicate power is flowing in reverse,the following parameters assume new values and the controloperation is affected accordingly:Load Voltage Now sensed from what was previouslythe source voltage supply.Source Voltage Now sensed from what was previouslythe load voltage supply.Load Current In the forward direction, the current isused directly as measured. In the reversedirection, the current is scaled to reflectthe ratio difference between the sourceand load side of the regulator, accordingto this formulaQ:Reverse Load Current =Load Voltage SupplyForwardLoadCurrentSourceVoltageSupplyQWhere source voltage supply and loadvoltage supply are in the reverse direction.Based upon the new metered reverse values, the kVA, kW,kvar, and % buck/boost are now calculated.Locked forward modeThe Lock Forward setting is intended for applications wherereverse power flow is not possible. When the control isset for Locked Forward, a measured voltage from the loadbushing is required, but a source voltage is not required.METERING: Always determined in the forward direction,regardless of power flow direction. If reverse power occurs,the metering functions remain on the normal load side ofthe regulator—no reverse demand readings will occur.125INSTALLATION, OPERATION, AND MAINTENANCE INSTRUCTIONS MN225003EN April 2018CL-7 Voltage Regulator Control