The device monitors the ungrounded power system insulation
in resistance in accordance with the following timing diagram which
represents the default settings:
||An insulation decrease is detected on the system. The insulation
resistance drops below the preventive insulation alarm threshold.
The preventive insulation alarm relay switches and the preventive
insulation alarm indicator light lights up.
||An insulation fault is detected on the system.
||Once T (insulation alarm delay) has elapsed, the device switches
to the insulation alarm state. The insulation alarm relay switches
and the insulation alarm indicator LED turns ON.
||Press the button to acknowledge the
insulation alarm. Both the insulation alarm relay and the preventive
insulation alarm relay revert back to their initial state. Depending
on the setup of the I/Os, the preventive insulation alarm relay and
the insulation alarm relay may or may not revert back to their initial
states. The timing diagram represents the case when the I/Os are set
up to acknowledge the relays. See Relay Mode for more information on relay modes. See Relay Acknowledgement for more information on relay acknowledgement.
||The insulation fault is corrected. The alarm LED turns off.
The device reverts to normal status.
NOTE: If you don't acknowledge the insulation alarm state,
and the insulation rises again above the insulation alarm threshold,
then the insulation fault is recorded as transient.