Ceramic fuse board out, RCDs in

The owners had been quoted for a home battery and been told, almost in passing, that the switchboard would need doing first. They rang us for a second opinion, half expecting to be told the same thing by someone else with something to sell.

The board was original to the 1979 house. Ceramic fuses with fuse wire, a main switch with a cracked bakelite handle, and nothing anywhere on it resembling a test button.

There was no fault to find. Everything in the house worked. What the board did not have was any residual current protection at all, which meant that in forty-six years nothing in that house had ever been protected against a person becoming part of the circuit.

Testing the existing circuits before quoting turned up one genuine surprise: the insulation resistance on the rear lighting circuit was well down, traced to a perished section of cable above the laundry where a previous roof leak had sat on it. That circuit was a fault waiting for a wet winter, and the old fuse would never have detected it.

The main earth was a stake driven beside the meter box with no visible bonding to the water service, which was also original and metallic.

• New surface-mount enclosure, weather-rated, replacing the recessed 1979 board
• RCBOs on all eleven final subcircuits — one device per circuit
• New main earth conductor, replacement earth stake and water service bonding
• Damaged section of rear lighting cable cut out and replaced above the laundry
• Six spare ways left free and pre-labelled for a battery, an EV charger and a future aircon
• Circuit schedule printed, laminated inside the door and emailed as a PDF

The house went from no residual current protection at all to a device on every circuit, and one genuinely dangerous cable came out of the roof on the way through.

The battery quote the owners were originally chasing is still on the table. When they go ahead with it, the board is ready and there is no second bill.