- Reaction score
- 131
Just tried this method and it still trips the RCBO in the main DBI've always overcome this problem by testing the second RCD using the test probes across its load-side line and supply-side neutral. The tester doesn't care whether the test current returns to earth or neutral, it should still perform a valid test on that RCD provided only the line goes through it. But because the test current returns via the the first RCD's neutral, that sees the tester as a legitimate load and shouldn't trip.