janitza UMG 512-Pro, User Manual And Technical Data

Page: 37 / 120

www.janitza.com
37
UMG 512-PRO
7.8.2 Example: Isolation of the residual
current transformers
A residual current transformer is used to mea-
sure on insulated mains wiring in a 300 V CAT III
network.
Provide basic insulation for 300 V CAT III for the
isolation of the network wiring and the isolation of
the residual current transformer.
ATTENTION
Transmission error and material damage due to
electrical malfunction.
With a cable length of more than 30 m, there is an
increased probability of transmission errors and
damage to the device due to atmospheric dis-
charge!
Use a shielded cable for the connection to the
residual current transformer inputs.
L1 L2 L3 N I1 I2 I3
L1
L2
L3
PEN
N
PE
UMG 512-PRO
M
3~
I5 I6 I4
Fig. Example UMG with residual current monitoring via measurement inputs I5/I6.
Residual current transformer
Residual
current
transformer
WARNING
Risk of injury due to electrical voltage!
The Profibus, RS-485, temperature measurement
input and residual current measurement input are
not galvanically isolated from each other.
It is therefore essential to note that dangerous
voltages at these inputs can have an effect on
the respective other connections.