Hello, please can someone help.
I have a small (1KW) immersion heater on a boat in a small heating tank (20litres).
None of the immersion system is earthed because eathing the electrics on board messes up the electroysis with the metal that sits in the water (prop shaft, eathing shoe etc).
The immersion heater has recently had repairs to the terminals as they had corroded, as part of the repair they were strengthened with fibreglass resin around them.
After the repair the heater woked fine when in the tank in a testing environment (my back garden).
It has now been refitted back into the boat and is now tripping the RCD at the marina (I have an RCD at home which was OK when testing), If I take the heater out of the tank and sit it in a glass jug of water it works OK, screw it into the tank and the RCD trips, nothing else changes (wiring etc) the tank is not connected to any electical items at all.
I have measured the element it is around 38 ohms, between each terminal and the casing nut of the heater measure 2Meg ohms.
I cannot fathom why it is now tripping the RCD, any suggestions most welcome.
Thanks
I have a small (1KW) immersion heater on a boat in a small heating tank (20litres).
None of the immersion system is earthed because eathing the electrics on board messes up the electroysis with the metal that sits in the water (prop shaft, eathing shoe etc).
The immersion heater has recently had repairs to the terminals as they had corroded, as part of the repair they were strengthened with fibreglass resin around them.
After the repair the heater woked fine when in the tank in a testing environment (my back garden).
It has now been refitted back into the boat and is now tripping the RCD at the marina (I have an RCD at home which was OK when testing), If I take the heater out of the tank and sit it in a glass jug of water it works OK, screw it into the tank and the RCD trips, nothing else changes (wiring etc) the tank is not connected to any electical items at all.
I have measured the element it is around 38 ohms, between each terminal and the casing nut of the heater measure 2Meg ohms.
I cannot fathom why it is now tripping the RCD, any suggestions most welcome.
Thanks