Power shower electrical shocks

[Dave]

I've recently refitted a Mira Event Power Shower after retiling the shower cubicle. I've also fitted a new shower head and hose of a metal type. The one originally supplied with the shower was plastic. Everything seemed to be fine for a week after the shower was put back into action but now there is a slight electrical shock when standing in the shower and touching the shower hose, and only when the shower pump is running. (I've now isolated the shower until it's resolved). Does anyone know if showers of this type should always be fitted with a plastic hose and shower head? The earth connection from the fused spur feeding the shower unit is connected but there is no way to cross bond the metal shower hose as the inlet and outlet connections for the water are all plastic.

[burbeck]

Hi Dave, good idea isolating the thing. my suggestions regarding the fault are: the earth wire to the shower has come loose somwhere along the line, visualy inspect all connections, inside the shower as well as the fused spur etc, followed bye an earth continuity test. or the shower has developed a earth leakage fault, an insulation test would be the thing here. it is possible that water has got to the inards, possibly missplaced gasket/seal? or possibly another appliance in the house with an earth leakage fault. no i dont want the work regards bob

[BigWallop]

You may need to bond from the mixer valve to the nearest metal pipework or main earth terminal in the fuse box. Because the pump is more likely using an induction motor, there will be leakage to earth through its casing, so this needs to be dealt with before the problem goes away.

Maybe that's why the shower had a rubber hose fitted and the plumber or sparks couldn't find anything nearby to bond on to.

[roger]

Dave writes

Sounds familiar. Check the voltage between E and N at the terminals where the mains comes into the unit. If it isn't between a small fraction of a volt and 3 volts, the earth lead to the shower is broken/not connected somewhere.

[burbeck]

hi, although i can see the thinking behind Rogers idea, it is incorrect, the earth terminal could be floating i.e not connected to anything and would/could show a low or zero voltage from N to E at the terminals. which would lead to the wrong asumption. further testing in this way would be also be dependent on the volt meter used. this could lead to a potentially dangerous condition, is esential that the earth is good on this unit. i refer you to my first post, which contains the correct way of sorting the problem, with regard to safety. regards bob