F20
Twin Earth Fault Indicator
© Nortech Management Ltd, United Kingdom
Page 6 of 16
The F20 requires the fault to be present for a minimum of 50ms, the operating
curve can be assumed to be close to definite time.
2.6
Test
A simple manual test of the F20 is achieved by pressing each of the TEST
buttons.
When pressed the associated LED will flash, however the output contacts will
not operate.
This simple test proves the processor, LED, test button and battery are
healthy. It does not test the integrity of the CT connections or output
contacts.
A primary injection into the CT arrangement is the best local test available.
Nortech supply a portable battery powered test set for this purpose.
