3 HARDWARE
3.2 WIRING
The CT/VT module may be ordered with a standard ground current input that is the same as the phase current inputs (Type
8A) or with a sensitive ground input (Type 8B) which is 10 times more sensitive (see the Technical Specifications section for
more details). Each AC current input has an isolating transformer and an automatic shorting mechanism that shorts the
input when the module is withdrawn from the chassis. There are no internal ground connections on the current inputs. Cur-
rent transformers with 1 to 50000 A primaries and 1 A or 5 A secondaries may be used.
CT connections for both ABC and ACB phase rotations are identical as shown in the Typical Wiring Diagram.
The exact placement of a Zero Sequence CT so that ground fault current will be detected is shown below. Twisted pair
cabling on the zero sequence CT is recommended.
3
Figure 3–10: ZERO-SEQUENCE CORE BALANCE CT INSTALLATION
b) VT INPUTS
The phase voltage channels are used for most metering and protection purposes. The auxiliary voltage channel is used as
input for the Synchrocheck and Volts/Hertz features.
VOLTAGE INPUTS
CURRENT INPUTS
8A / 8B
827831A8-X5.CDR
CURRENT INPUTS
8C / 8D
827831A8-X3.CDR
Figure 3–11: CT/VT MODULE WIRING
Wherever a tilde "~" symbol appears, substitute with the Slot Position of the module.
NOTE
GE Multilin
T60 Transformer Management Relay
3-9