- 8 -
See graph(a), the measurement of operation value, return value, operation time
and return time is same as overrange, underrange relay
Graph(b
）
to current hold relay. Firstly turn T2 to relay rated voltage value,
switch on power, push set button, to make relay voltage coil joined into rated
voltage value. After relay operation, turn T4 to make J1 current same as rated
current value, then cut off voltage, regulate protection coil current (T4), the
minimum hold current of the relay is the minimum hold value. Operation time and
return time test refer to point5(2).
Differential relay (BCH—1type as example)
Item 4
、
9
、
10 test can be done without external device. Item 6 test can be done
when match with external voltage regulator and current generator. Others not
within the test scope of this instrument
1) Executive component operation voltage, operation current and return current
test, wire connection as following: