Testing of earth leakage circuit breakers

Residual current devices (RCDs) can be tested with our GLP2-ce Modular in two test steps for single-phase or in four test steps for three-phase RCDs.

1st test step: Test L1 by the RCD.
2nd test step: Test N by the RCD.
3rd test step: Test L2 by the RCD (only if the RCD is 3-phase).
4th test step: Test L3 by the RCD (only if the RCD is 3-phase).

The function test of the RCD is performed with the help of a load resistor.
During the test, it is first checked whether voltage is connected to the test object, i.e. whether the RCD is switched on. Then the GLP2-ce tester will run a current through the RCD until it switches off.

For testing each individual connection, the test current is gradually regulated upwards through the connection. It is checked at which current the RCD switches off.

If this tripping current is within a certain range, the test is OK (IO). However, if a minimum current value is undershot or a maximum current value is exceeded, the test is not in order (NIO).

Moreover, it is possible to determine the switch-off time of the ground fault current circuit breaker (RCD).

For this, the adjusted test current is passed through the RCD and the tripping time is detected. There are two modes:

The current is connected directly and the RCD may not switch off. (IO).
The current is connected immediately and the RCD must switch off within a certain time. (NIO).