3-16 L60 LINE PHASE COMPARISON SYSTEM – INSTRUCTION MANUALWIRING CHAPTER 3: INSTALLATION3Table 3-2: Power supply LED on moduleFigure 3-15: Control power connectionWhen using an SH power supply module, after disconnecting power and powering up again, some measured valuesdisplayed can change from that last displayed. This is because there is not enough time for the compact flash to storedata. Upon power up the last stored value displays.3.3.4 CT/VT modulesThe CT and VT inputs are analog current transformer and voltage transformer signals used to monitor AC power lines. TheUR-series relays support 1 A and 5 A CTs.A CT/VT module can have current or voltage inputs on channels 1 through 4 inclusive, or channels 5 through 8 inclusive.Channels 1 and 5 are intended for connection to phase A, and are labelled as such in the relay. Likewise, channels 2 and 6are intended for connection to phase B, and channels 3 and 7 are intended for connection to phase C.Channels 4 and 8 are intended for connection to a single-phase source. For voltage inputs, these channels are labelled asauxiliary voltage (VX). For current inputs, these channels are intended for connection to a CT between system neutral andground, and are labelled as ground current (IG).To connect to the module, size 12 American Wire Gauge (AWG) is used commonly; the maximum size is 10 AWG.LED indication Power supplyContinuous on OKOn/off cycling FailureOff Failure or no powerWhen using a L60 with a HardFiber system, before powering off the L60, save data in the compact flash memoryusing Commands > Relay Maintenance > Save Non-Volatile Data. When not saved or the relay loses power, up tothe last two minutes of data is not saved to the compact flash memory.Verify that the connection made to the relay terminals for nominal current of 1 A or 5 A matches thesecondary rating of the connected CTs. Unmatched CTs can result in equipment damage orinadequate protection.
