Accessories
13.2 Accessories for 3UG4 monitoring relays
3UG4 / 3RR2 monitoring relays
Manual, 05/2016, NEB927043002000/RS-AC/004
333
13.2.5
3UL23 residual current transformers for 3UG4625 monitoring relays
Description
3UL23 residual current transformers detect fault currents in machines and systems.
Together with the residual current monitoring relay or the 3UF7510 SIMOCODE motor
management and control device ground-fault module, residual current monitoring and
ground-fault monitoring are possible. The 3UL23 residual current transformer is available in
six sizes with bushing opening diameters of ∅
35
mm, ∅
55
mm, ∅
80
mm, ∅
110 mm,
∅
140
mm, and ∅
210 mm.
13.2.5.1
General information
Various circuit types with resulting fault currents
The following table shows various circuit types and the resulting fault currents in the event of
a ground fault. Circuits 1 to 6 create pure AC fault currents or AC fault currents with a
pulsating direct fault current component. This type of fault current can be detected by type
A transformers in accordance with DIN VDE 0100-530, such as 3UL23 residual current
transformers.
Note
3UG4.25 residual current monitoring relays are only suitable for use with 3UL23 residual
current transformers.
