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UMG 509-PRO
www.janitza.com
6.1
Three-phase 3-conductor systems
The device is only suitable to a limited extent for
use in IT networks since the measured voltage is
measured against the housing potential and the
input impedance of the device causes a leakage
current to ground. The leakage current can cause
the insulation monitoring in IT networks to be
triggered.
The connection variants with voltage transformers
are suitable without restriction for IT networks.
600 V 50/60 Hz
DC
AC/DC
L2
L3
Auxiliary supply
Voltage measurement
4M
4M
4M
4M
V1
V3
V2
4M
V4
Grounding
of the
system
Impedance
L1
UMG 509-PRO
Vref
Fig. Schematic diagram, UMG 509-PRO in an
IT network
without N
6.2
Three-phase 4-conductor systems
The device can be used in three-phase 4-con-
ductor systems (TN, TT network) with a grounded
neutral conductor. The components of the electri-
cal system are grounded.
The voltage measurement in the device is de-
signed for the overvoltage category 600 V CAT III
(rated surge voltage 6 kV).
Fig. Schematic diagram, UMG 509-PRO in a
TN network
PE
347V/600V 50/60Hz
L2
L3
N
L1
N
L1
240 V
50/60Hz
Grounding
of the
system
DC
AC/DC
Auxiliary supply
Voltage measurement
4M
4M
4M
4M
V1
V3
V2
Vref
4M
V4
UMG 509-PRO