User Manual

3UG458. insulation monitoring relay.
10.4 3UG4582/3UG4583 insulation monitoring relays
3UG4 / 3RR2 monitoring relays
Manual, 02/2013, NEB927043002000/RS-AA/002
245
Application examples
The figure below shows monitoring for ground fault/insulation fault in the different load
circuits.
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① The voltage source is the secondary side of an isolating transformer that galvanically isolates the system and the
downstream circuit.
② The insulation resistance of this motor feeder is always monitored when the motor is switched off. If the motor
contactor drops out, the two NC contacts connect the measuring circuit with the motor cables.
③ The 3UG4582-1AW30 insulation monitoring relay permanently monitors the insulation resistance of the remaining
system with all connected loads.
④ Loads
Figure 10-12 Monitoring for ground fault/insulation fault with different load circuits
Note
The maximum cable length of the control cables is 50 m or 100 pF/m.