16
UMG 508
Illu. Basic circuit diagram, UMG508 in the
TN-
network.
Voltage Measurement
Three-phase 4 conductor systems
The UMG508 can be used in three-phase 4 con-
ductor systems (TN, TT network) with a groun-
ded neutral wire. The bodies of the electrical
system are grounded.
Three-phase 3 conductor systems
The UMG508 is only suitable for use in IT net-
works with restrictions, because the measure-
ment voltage is measured against the housing
potential and the input impedance of the device
causes a leakage current against ground. The
leakage current can cause isolation monitoring
in IT networks to respond.
Connection variations with a voltage transfor-
mer are suitable for IT networks without any re-
strictions.
Illu. Basic circuit diagram, UMG508 in the IT net-
work without N.
600V 50/60Hz
DC
AC/DC
L2
L3
Auxiliary
power
Voltage measurement
4M
4M
4M
4M
V1
V3
V2
4M
V4
System
grounding
Impedance
L1
UMG508
Vref
PE
347V/600V 50/60Hz
L2
L3
N
L1
N
L1
240V
50/60Hz
System
grounding
DC
AC/DC
Auxiliary
power
Voltage measurement
4M
4M
4M
4M
V1
V3
V2
Vref
4M
V4
UMG508
