GE MVAX 12 User Manual

R8010RB
Service Manual
Page 8/24 MVAX
Apply 75% of the relay’s lower voltage of the voltage rating range. Check that the relay
operates satisfactorily and that the flag indication can be reset. Reduce the voltage slowly
until the relay drops-off. Check that this occurs between 25% to 40% of the lower voltage
rating, as indicated below:
V rating range 24/27 30/34 48/54 110/125 220/250
75% of lower (V) 18 22.5 36 82.5 165
25-40% of lower (V) 6 – 9.6 7.5 – 12 12 – 19.2 27.5 – 44 55 – 88
Replace all links and fuses. Check that the relay operates and manually reset the flag. With
alarm circuits operational, temporarily remove a trip supply fuse. Check that the appropriate
alarms are initiated. Replace the fuse and reset the relay flag.
2.7.3 MVAX 21 only
The following tests assume trip and alarm supply battery voltages are equal to the maximum
voltage of the rel
ay’s voltage rating range. For other voltages within the relays normal
voltage rating range, tolerance bands for other measured supply voltages should be altered
pro-rata.
A table (Table 1) of acceptable tolerances for each test is given below.
Measure the trip supply and alarm supply voltages immediately prior to the tests
and note.
Test 1
With the circuit breaker open, check that no voltage appea
rs across terminals 13 and 14 of
the relay. Check that the voltage appearing across terminals 21(+) and 28 comply with that
given in Table 1 (alarm supply) and that the front relay, RL1, has operated. Reset its flag.
Test 2
With the circuit breaker closed, check that the front relay re
mains operated. Measure the
voltage across terminals 13(+) and 14. Ensure that it complies with Table 1
(Trip supply).
Test 3
With the circuit breaker closed, apply a temporary sho
rt circuit across the external resistor
R
EXT
2* of the trip supply circuit. Ensure the CB does not trip. Remove the short circuit and
re-apply it across terminals 13 and 14 of the relay. Check that RL1 drops-off to initiate
alarm circuits and that RL1 flag indication is given. Ensure the CB does not trip. Remove
the short circuit and reset the flag/alarms.
*Note: Where 2 resistors are used in series for R
EXT
2, a temporary short
circuit should be applied across each resistor in turn.
Test 4
With the circuit breaker closed, operate, or simulate operation of the associated trip relay.
Note that the CB
trips but ensure that RL1 of the MVAX does not operate.
RL1 and RL2 units are slugged on drop-off to prevent mal-operation during the transition
period.

GE MVAX 12 Specifications

General

Brand	GE
Model	MVAX 12
Category	Relays
Language	English