I-Gard GCHK-100, Instruction Manual

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I-GARD GCHK-100 Instruction Manual
6
Control transformers may be connected to the LINE side of the protective breaker through protective fuses
or any other reliable source of power. Failsafe operation cannot be achieved with LOAD side connection
since the breaker would trip before the GCHK-100 had energized the TRIP relay thus preventing closure.
Furthermore, indication would be defeated when the breaker tripped and the power removed.
Current Sensors
There are no restrictions on the location of the ZSCS sensor, No.14 unshielded wire may be used to
connect the SEC terminals of the T type sensor to the 1000 Terminal and SENSOR ground as shown in
Figure 6.1 connection diagram. For other sensor types, the 600 or 40 Terminal would be used depending on
the ratio of the chosen sensor.
All phases supplied to the trailing cable must pass through the window of the ZSCS, which must be sized
accordingly. I-Gard sensors range from 2in. to 9in. in diameter. Neither the ground conductor, nor the pilot
ground conductors pass through the sensor; otherwise the ground fault detection would be disabled.
Figure 6.1 Connection Diagram shows the Shunt Trip coil of the protective circuit breaker connected to the NO
contacts of the GCHK-100 relay. This is the non-failsafe connection. The NC contacts of the Form Z relay are not
used in this case, but would be required in case of failsafe mode of operation.
GC G
GCHK-ZT
X0 X1
ZSCS
TRIPCOIL
UNIT SUBSTATION
TRAILING CABLE
CONTROL POWER
5VA AC OR 5W DC
110-240VAC / DC
TO OTHER
GCHK-100
RELAYS
TO MODBUS
NETWORK
OPTIONAL
mGARD-SYM
INDICATOR
AUXILARY
RELAYS
OPTIONAL
GCHK-DRI
REMOTE
INDICATOR
GCHK-100
GROUND
CHECK
RELAY
MOBILE
EQUIPMENT
FAULT GND
RELAY CHECK