User Manual

3UG458. insulation monitoring relay.
10.3 3UG4581 insulation monitoring relay
3UG4 / 3RR2 monitoring relays
Manual, 02/2013, NEB927043002000/RS-AA/002
211
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 210)" and in Chapter "Diagnostics (Page 215)".
Reset response and memory function
The device features an autoreset that resets output relay K1 to its original state after an fault
message and rectification of the fault that has occurred. As well as autoreset, the devices
can also be set to manual RESET by means of external switching.
The output relay (on 3UG4583: both output relays) remains dropped out if manual RESET is
active, and it only picks up again after actuation of the combined test/reset button, or
following activation of remote reset (terminals Y2-Y3) if the insulation resistance is greater
than the set threshold including hysteresis. Another method of resetting the device is by
switching the supply voltage off and on again, provided the fault is not stored in retentive
(non-volatile) memory.
Connection Y2-Y3 Reset options
<
<<
1) On the front (Test/Reset button)
2) Remote reset (remote button with NC function)
3) A1+ / A2- (switching the supply voltage off/on)
<
<
<
1) On the front (Test/Reset button)
2) A1+ / A2- (switching the supply voltage off/on)
<
<
<
1) Autoreset (factory setting)