Voltage Measurement - janitza UMG511 Installation And Commissioning Manual

Voltage measurement

Three-phase 4 conductor system
The UMG511 can be used in a three-phase 4
conductor system (TN, TT networks) with an
earthed neutral wire. The bodies of the electri-
cal systems are earthed.
L1
417V/720V 50/60Hz
L2
L3
N
PE
V4 V1
System
Voltage measurement
earthing
UMG511
Fig. principle circuit diagram, UMG511 in the
TN network.
18
Installation
V2 V3 Vref
AC/DC
DC
Auxiliary energy
Three-phase 3 conductor system
The UMG511 is only restrictedly suitable for
use in IT networks because the measurement
voltage is measured against the housing po-
tential and the input impedance of the device
causes a leakage current against earth. The
leakage current can cause the insulation mon-
itoring in IT networks to respond.
The connect variations with voltage converter
are suitable for use in IT networks without any
restrictions.
L1
480V 50/60Hz
L2
L3
Impedance
V4 V1
System
earthing
Voltage measurement
UMG511
Fig. principle circuit diagram, UMG511 in the
IT network without N.
V2 V3
Vref
AC/DC
DC
Auxiliary energy