Emergency callout: three-phase main switch fault in Double Bay
- When
- October 2026
- Where
- Double Bay
- Service
- Electrical faults
The problem: The three-phase isolator on a sub-board upstairs, which controls the oven and power circuits, was not working properly.
What Peter did:
- Tested the 32 A three-phase main switch in the main switch room, on its supply side and its load side
- Supply side: 415 volts between every pair of phases, as it should be
- Load side: 415 volts between two of the phases, but 240 volts across the other two pairs, where 415 should be
- Found no continuity through the main switch on the third phase (the blue cable)
The result: The fault was in the main switch downstairs, not the sub-board upstairs. The fix is to replace it with a new 32 A three-phase main switch from a reputable brand.
My recommendation, folks, is to stay with the reputable brands.
