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RCD testing in IT systems
RCD testing at locations with IT systems requires a special test procedure because the
Protective Earth connection is grounded locally and is not tied directly to the power system.
The test is conducted at the electrical panel using probes. Use the connection shown in
Figure 13 when performing RCD testing on IT electrical systems.
RCD
Mains Supply
PE (L2/Green)
L (L1/Red)
N (L3/Blue)
Figure 13. Connection for RCD Testing on IT Electrical Systems
The test current flows through the upper side of the RCD, into the L terminal, and returns
though the PE terminal.
Testing Phase Sequence
Figure 14. Phase Sequence Display/Switch and Terminal Settings
Use the connection shown in Figure 15 for a phase sequence test connection.
L1
L2
L3
PE (L2/Green)
L (L1/Red)
N (L3/Blue)
Figure 15. Phase Sequence Test Connection
