EC328 shorting out mains supply

I have just connected my Auto Sleepers Lancashire to the main supply at my home.
When I switched on the EC328, it tripped the main RCD in my house.
I tried again - same thing happened.
Has anybody else experienced this?
What is the solution?
Thanks
Dave

Check hook up cable

If the OP is an accurate description, it's not likely to be a problem with the hookup cable - that would normally cause the house RCD to trip as soon as the EHU cable is plugged in.

You should be able to pin the problem down a bit further as follows: Unplug EHU, turn off the RCD and all of the MCBs on the EC328 main panel, reconnect the EHU and check that the house RCD has not tripped. Now turn on the EC328's RCD, leaving all of the MCBs off. If it trips then, the problem is probably internal to the EC328. If it has not yet tripped, turn on each MCB and check for tripping. From this you can work out which circuit, and hence which group of appliances, is causing the problem.

Roopert wrote:If the OP is an accurate description, it's not likely to be a problem with the hookup cable - that would normally cause the house RCD to trip as soon as the EHU cable is plugged in.

You should be able to pin the problem down a bit further as follows: Unplug EHU, turn off the RCD and all of the MCBs on the EC328 main panel, reconnect the EHU and check that the house RCD has not tripped. Now turn on the EC328's RCD, leaving all of the MCBs off. If it trips then, the problem is probably internal to the EC328. If it has not yet tripped, turn on each MCB and check for tripping. From this you can work out which circuit, and hence which group of appliances, is causing the problem.

Thanks Roopert - I'll be out of the country for a few days, but I'll try your check when I get back. Cheers!

Weird!!! I came back from holiday, tried Roopert's suggestion, switched on the EC328's RCD and, one by one, the three MCBs. The problem has "gone away"! I can't imagine what was going on. Thank you Roopert for the tip.

I hate to be the pessimist here but... I suspect it will be back.

In my experience, the only situation where such an issue could be temporary is where you have very high humidity, and condensation forms around electrical connectors. It seems very rare.

The other main type of fault - which can appear to come and go - is where the insulation within a heating element starts to break down. This type of fault can lead to a level of earth leakage that is ~just~ on the trigger threshold of and RCD - so sometimes it will trip and sometimes it won't.

I've had that type of fault on an immersion heater (in a building, not a van) and that was quite hard to track down. In that instance, the heating element was changed and the symptoms went away.