Toshiba GRT100 Series, Instruction Manual

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6.5.1.4 High-set overcurrent element HOC
Operating current value
The testing circuit is shown in Figure 6.5.1.
The output signal numbers of the HOC elements are as follows:
Element Signal number
HOC-A 41
HOC-B 42
HOC-C 43

Press 4 (= Logic circuit) on the "Test" sub-menu screen to display the "Logic circuit"
screen.

Enter a signal number 41 to observe the HOC-A output at monitoring jack A and press the
ENTER
key.

Apply a test current to A-phase current terminals and change the magnitude of the current
applied and measure the value at which the element operates.
Check that the measured value is within 7% of the following value.
Operating value = (CT secondary rated current)

(kh setting)
Operating time
The testing circuit is shown in Figure 6.5.4.

Set a test current to 2 times of HOC operating current (= CT secondary rated current

kh
setting)

Apply the test current and measure the operating time.

Check that the operating time is 25 ms or less.