RFL 9300 RFL Electronics Inc.
October 20, 2004 7 - 13 (973) 334-3100
2. Connect a double-pole switch in the test current circuit.
This will provide a "timer-start" contact for trip time measurements. Use any spare trip
contact for "timer-stop," such as terminals 5-6 or 7-8 on TB-3.
3. Connect a dc circuit with 0.2-ampere loading in series with the TRIP 1 tripping contacts at each relay
(TB3-1 and TB3-2).
4. Gradually increase the test current.
At 0.5 ampere, the ground fault detectors will operate. At 0.75 ampere, the relays will
trip, with targets on G and TRIP-1.
At this point, the following conditions occur:
1. With 0.75 amperes at each terminal, the "arithmetic sum" (or differential cur-
rent) is 1.5 amperes. This satisfies the ground bias setting of 1.5 amperes.
2. Both local and remote ground fault detectors operate. This satisfies the fault
detector requirements for ground fault tripping.
3. The 93B PC module monitoring Phase A does not trip for two reasons:
a. There were no Phase A fault detector operations.
b. The phase bias setting is 3 amperes, which is well above the arithmetic
sum of 1.5 amperes.
5. Remove the test current. After externally interrupting the dc trip current, the relay targets may be reset
by pressing the RESET switch on the 93B DISPLAY module.
If the 0.2-Adc trip current remains for more than 500 ms, the message "ALARM 27" will
appear on the display. This means a breaker or auxiliary trip device is defective.
6. Repeat steps 4 and 5 with the breaker trip circuit unloaded.
The TRIP 1 indicator will not light because the dc trip current was never sensed.
7. Again starting from zero, gradually increase the current.
At 0.75 ampere, the relays will trip, and the G indicator on the 93B DISPLAY module will
light.
8. Continue to increase the current gradually.
At 1.5 amperes, several actions will occur:
a. The red SYS indicator on the 93B SV module will light.
b. The red ALARM indicator on the 93B PC module monitoring Phase A will light.
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