I know this is an old chestnut, I've been googling !
This 70s house (live wires are red - not brown) has always been sensitive to tripping.
The old washer made it happen a lot. It was replaced with a great improvement. (I guessed there were leaky radio interference suppression capacitors from live and netral to ground causing this ???) An old iron made it happen a lot. It was sent to another house with no problem there.
Well, the problem seems to be back.
I've come up with an idea to help locate it and would be grateful for any comments.
The house uses a 63A / 30mA Crabtree RCCB with everything except lighting and immersion heater on the protected side.
This assumes an appliance problem. (I am reasonably electrically savvy.)
- I made up a 2m 13A extension cable with the earth lead disconnected in the plug.
- I *VERY CAREFULLY* connect appliances to the extension cable.
- I measure current using a multimeter between the opened earth lead and the earth pin in the plug.
Checking the washing machine, I measure 2mA. I'm going to work my way around everything. Obviously it will be more difficult on hard wired units, eg the cooker. I'll try to post measured values.
I understand that a 30mA breaker could trip at 50% x 30mA = 15mA, so several times 2mA can add up quickly to 15mA.
I hope it's an appliance fault as wiring leakage sounds a very painful and expensive fix.
Any comments or pointers to other tracing techniques.
I don't have a megger, but could easily do resistance checks with the multimeter.
I seem to recall while googling seeing a technique of (power off situation) strapping together the live and neutral, then measuring resistance to earth. This sounds promising and not too difficult.
Is there any way to test to see if the RCCB is too sensitive ?
Thanks in advance.
James