3UG458. insulation monitoring relay
9.3 3UG4581 insulation monitoring relay
3UG4 / 3RR2 monitoring relays
220
Manual, 05/2016, NEB927043002000/RS-AC/004
Monitoring
The system to be monitored is connected to terminal L (connection to phase or N conductor).
The ground potential is connected to terminal
.
The devices work according to the closed-circuit principle NC.
After applying the rated control and supply voltage, the insulation monitoring relay goes
through an internal test that checks the proper functioning of the operational device. The test
encompasses an internal test of the device at hardware and firmware level, as well as
system diagnostics with calculation of the first measured value of the insulation resistance. If
there are no internal device faults or external faults on completion of this test, output relay K1
picks up. This test can take several seconds depending on individual system properties.
If the measured value undershoots the set threshold, output relay K1 drops out. If the
measured value overshoots the threshold including hysteresis, output relay K1 picks up (if
autoreset is active). All operating statuses of the insulation monitoring relay are displayed via
three LEDs.
Note
If the continuously present rated system voltage is greater than 240 V, a minimum gap of 10
mm must be maintained to the next device.
You will find the switching states of the output relay below in the section "Functions
(Page 219)" and in Chapter "Diagnostics (Page 226)".