Hi All,
A friend has a smallholding with a small woden bungalow and has asked me to fix a problem with his water heater / electrics. Firstly, a little background (a little hazy as i've got most of it second hand)....
He used to have some kind of immersion heater which fed all the water in the bungalow inc a shower and he also had a full size cooker. The bungalow is fed from approx 100 metres of (I think 3 core) cable buried in the ground which is fed from a meter cupboard up the track.
All was "well" until a few years ago when someone (the supply company??) fitted an RCD (100ma I think, time delayed maybe (it's a soft of S shaped switch which you turn clockwisw to set) in the meter cupboard.
At that point, he had to have the imersion heater and the cooker removed (no more hot shower) as they kept tripping the RCD. The immersion was replaced with some sort of under sink stored water heater, and the cooker with a kind of "son of baby Belling (2 solid rings and a very small oven)
All has been sort of well-ish for a few years, but he has suffered from nuicance trips on a regular basis, usually either when he's tucked up in bed, or else off site (and has to talk someone through where to find the meter cupboard, how to reset the trip).
Back to our story, the water heater is now tripping the RCD. I cecked with him whether this behaviour started when he tried to get it going at the start of the season and he said yes. I am inclined to think that the element in the water heater has absorbed some moisture, and if this could be "driven off" all would be well. It has been suggested here before that in a domestic 16th edition type setting, you could temporarily connect the heater up to a non RcD supply to do just that. but how to proceed in this particular setting?
One thought is to take a butchish generator up there and run the heater on that for a while (how long might be long enough?) I suppose the other option might be to try and isolate it's earth connection and exposed metalwork from and then run it from the existing supply?
How would I check that the earth leakage is in fact minimal before trying any of the above?
Anyone any other ideas?
TIA
Chris