GE Multilin B90 Low Impedance Bus Differential System 3-113 HARDWARE 3.2 WIRING3Figure 3–11: CONTROL POWER CONNECTIONThe optional Ethernet switch shown in the connection diagram above is not available for the B90 device.3.2.4 CT AND VT MODULESInformation on the CT and VT modules for the B90 relay is shown below.Verify that the connection made to the relay nominal current of 1 A or 5 A matches the sec-ondary rating of the connected CTs. Unmatched CTs may result in equipment damage or inad-equate protection.Each AC current input has an isolating transformer and an automatic shorting mechanism that shorts the input when themodule is withdrawn from the chassis. There are no internal ground connections on the current inputs. Current transform-ers with 1 to 50000 A primaries and 1 A or 5 A secondaries may be used.Each B90 voltage input is intended for monitoring a single-phase voltage. The may include phase voltages or neutral volt-age from the open-delta VT.All CT and VT modules are available with enhanced diagnostics. These modules can automatically detect CT/VT hardwarefailure and take the relay out of service.Substitute the tilde “~” symbol with the slot position of the module in the following figure.AC or DC NOTE:14 gauge strandedwire with suitabledisconnect devicesis recommended.Heavy copper conductoror braided wireSwitchgearground bus UR-seriesprotection systemFILTER SURGE– +LOW+HIGHB8b B8a B6a B6b B5bCONTROLPOWER827759AA.CDR—+OPTIONALETHERNET SWITCHAC or DCGNDNOTENOTICENOTE
