I-GARD Gemini Instruction Manual
6
3
OPERATION
Figure 5 Gemini Control Panel
Upon energizing the control panel only the green SYSTEM HEALTHY light will turn ON signifying that no ground
faults are on the system and the
Gemini
is receiving control voltage.
Verify the
Gemini
condition by pushing the TEST button and holding for the delay time set on the
GFR-RM.
This causes the
GFR-RM
to trip. The green light turns OFF, the red GROUND FAULT light turns ON and the fans
activate. This confirms that control voltage is available, the
GFR-RM
is functioning and the fans are operational.
Push the RESET button to restore the system to normal operational status. The red GROUND FAULT, RESISTOR
FAULT and TRIP lights will go OFF and the green SYSTEM HEALTHY light will turn ON, and the fans stop.
(The meter may indicate a slight leakage). The
Gemini
is now ready to monitor the distribution system.
When a ground fault occurs the potential between the system neutral and ground will increase causing the
meter to display the fault level which may be any value between 0 and 100% of 5A. This current is also being
monitored by the FAULT CURRENT ammeter. If the fault current magnitude is greater than the pick up setting
of the
GFR-RM
and the duration is greater than the time delay setting on the
GFR-RM
, the
GFR-RM
will trip,
changing the state of the GROUND FAULT TRIP contacts. The green SYSTEM HEALTHY light turns OFF and
the red GROUND FAULT and TRIP lights turn ON, and cooling fans activate.
By adjustment of the GFR-RM relay, the ground fault pickup level can be set from 5% to 50% of the 5A
let-through current. The time delay can be adjusted from 60mS to 3.15s.
T
his allows the
Gemini
settings to be
adjusted for the unique requirements of each system in order to avoid nuisance tripping.
Both ground fault pickup level and time delay are adjusted using the bank of Dipswitches located on the front
plate of the
GFR-RM
relay, which is located inside the
Gemini
enclosure. (Refer to I-Gard Manual IM-GFR-RM)
for complete details of this relay).
