EM TEST
CNI 501 / CNI 503
Manual of operation
V 3.32
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5.3.
Connection of DC Equipment
For the connection of DC power supplies following connections are provided.
Polarity
3- Phase CNI
1- Phase CNI
+ Pole
L1
L
- Pole
N
N
As DC input the terminals L1 and N must be used. These two plugs are marked at the rear side of with an
additional plus or minus sign.
TEST ON Switch
The switching capacity of conventional AC contactors for DC application is limited. Therefore, the specification for
DC current and voltage are reduced compared to the AC specifications.
If the coupling network should have the same parameters for AC and DC, special mains switch must be installed,
for meet the DC specifications. This costly expansion requires a larger enclosure than the normal version.
Cost- economical coupling networks have no internal DC switches. In this case the user has already installed an
external dc switch, he can use for disconnect the dc supply in case of an emergency.
Coupling networks that require mandatory external DC contactor
The table on the right shows the coupling networks
that require an external power switch mandatory for
DC application.
Type
DC Parameter
CNI 503B7.4
CNI 503B9.2
1000V
32A
1000V
100A
