Ah yes - enamel bath, fault somewhere, faulty protection, no supplementary bonding
Electricity in the bath
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Whippet - have you got RCD protection now?
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Wind up mega or impulse mag still dangerous what you are implying is some one is having some fun with their mum?
It would be nice to say electrician has looked at it so must be OK but when at college we were told the story on how an electrician wired up a boiler and found a lose green wire which he assumed was an earth so popped it back onto a multi spade earth connection.
However it turned out it was the normally closed contact of the on/off switch so with boiler switched on there was no problem only when switched off was there a direct contact line to earth. There was also a fault in not being any earth to 13A socket he had used which all came out in court after a death.
The point was made in court that making the mistake was understandable however not rectifying the mistake was not. The electrician had been called back to find what was giving the occupant the shock and had failed to find it. With boiler turned on there was no earth fault and he tested with it turned on.
The court said he should have tested the socket and this produced great discussion in the class as many said if you go to a house and fit a plug on a kettle you don't test the socket but lecturer said we should. He said if some one brings kettle into shop we just fit plug and PAT test kettle but in the home we should test socket.
I have looked for the case and failed so maybe a story the lecturer made up but the point is if we visit a house once we will do a quick test and do minimum amount of work and once we find something which may cause the problem we give up.
However when we are recalled to a home for same fault we then start looking far more into the odd faults which may cause the problem. Not longer do we just fit some earth bonding we start to test and ask ourselves how.
So I look at my bathroom and what metal is there! The plug hole is metal but waste is plastic so unlikely. Taps are metal but pipes again plastic so unlikely. Most likely if my bathroom would be the glass screens which have metal fixings screwed to the wall so may be cable in the wall has be hit by screws.
To test is a problem if the cable is for example from lights to switch in another room the fault would only exist when lights in other room were on. So like the lecturers story yes would be easy to miss.
As to cure there are many options. Bonding and RCD will likely cause an automatic disconnection should a fault be there but it has not removed the fault. Insulation tester may locate the fault as would removing metal fittings. Careful inquiry may also give some pointers.
However I would say no to fourth electrician call one of the others back. They are going to take it far more seriously second time around. With three electricians missing the problem clearly not an easy one to find and if I was one of the electricians and I was recalled I would be very worried and would be very careful not to miss a single trick.
When bath water is running through it a plastic pipe lined with bath water slime the pipe can provide a remarkably conductive path between metal fittings at the opposite ends.
The problem is that most electricians are installers and are not very experienced at finding obscure faults. It requires out of the box thinking and being able to accept that the impossible fault is possible.
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Perhaps not directly connected but I as a former (now retired) audio visual technician I was called to a factory that was having crackling problems intermittently on a microphone which was some distance from the amplifier. There was nothing wrong with the cable or the amplifier. I ran a temporary cable and the problem was still there. That proved the cable OK. I was stumped. As I was walking back to the office to report that I could not find any fault I noticed a flashing fluorescent fitting, switched it off and bingo, problem solved!!.
RF's offer is great. Nice spirit shown there.
Going back to the original post, there are two points (forgive me if I'm wrong) that seem relevant :
There is a metal bath touching the wall. The OP gets a shock not just from the bath, but from the tiles.
No mention is made of the type of shower - electric. power, gravity mixer?
No mention of the type of water heating, but comment on worse with CH on.
Here's a wild stab - which is not meant to replace logical investigation; it is just a mental exercise:
The problem is that the wall is live.
The electricians have bonded the pipes to the bath, but we have no idea about the earthing or the bonding to the shower pipe in the wall. As stated by Westie, a N-E fault could give the problem, so the cause could be a originate in 'the system' (CU/circuits/earthing/etc) or be from an electric shower or a pump, however, the clue that it is worse when the CH is on suggests that a fault on pump, boiler or valves is the likely origin, i.e. the problem does not lie in the bathroom.
Is this sound ? Please note I'd never in real life work that way, but does this make sense to the professionals out there?
Going back to the original post, there are two points (forgive me if I'm wrong) that seem relevant :
There is a metal bath touching the wall. The OP gets a shock not just from the bath, but from the tiles.
No mention is made of the type of shower - electric. power, gravity mixer?
No mention of the type of water heating, but comment on worse with CH on.
Here's a wild stab - which is not meant to replace logical investigation; it is just a mental exercise:
The problem is that the wall is live.
The electricians have bonded the pipes to the bath, but we have no idea about the earthing or the bonding to the shower pipe in the wall. As stated by Westie, a N-E fault could give the problem, so the cause could be a originate in 'the system' (CU/circuits/earthing/etc) or be from an electric shower or a pump, however, the clue that it is worse when the CH is on suggests that a fault on pump, boiler or valves is the likely origin, i.e. the problem does not lie in the bathroom.
Is this sound ? Please note I'd never in real life work that way, but does this make sense to the professionals out there?
There is no mention of the second point of contact for the shock.
If the shock is more than just a tingle there has to be a second point of contact to enable current to flow through the body. A tingle is caused by the minute amount of current that can flow via the capacity between the person's body and near by potentials and thus for a tingle a econd point of direct contact is not needed.
I have experienced more than a tingle when touching a wall and a metal kettle. The obvious fault was the kettle was faulty, the actual fault was bare live cables in the damp wall making the wall live. ( before RCDs )
If the shock is more than just a tingle there has to be a second point of contact to enable current to flow through the body. A tingle is caused by the minute amount of current that can flow via the capacity between the person's body and near by potentials and thus for a tingle a econd point of direct contact is not needed.
I have experienced more than a tingle when touching a wall and a metal kettle. The obvious fault was the kettle was faulty, the actual fault was bare live cables in the damp wall making the wall live. ( before RCDs )
Just don't ask him to design any lighting for you while he's there....
[in-joke]
[/in-joke]
I do like a good strong cup of Yorkshire tea
Not heard anything from the OP yet though
Not heard anything from the OP yet though
... but there's always the risk that he might photograph all the 'trangressions' he finds and then 'name and shame' them here in the forum
Kind Regards, John
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I had an almost identical situation a couple of years back, I was the 3rd person to look and the second had bonded all the shower trays associated metal bits which allegeably made the problem worse.
The shower unit was an elderly Dolphin with plastic heater tank and non insulated heating element. An earth wire had come out of its terminal in the pull switch. Repairing it meant the RCD popped as soon as the shower was started.
The shower unit was replaced.
The shower unit was an elderly Dolphin with plastic heater tank and non insulated heating element. An earth wire had come out of its terminal in the pull switch. Repairing it meant the RCD popped as soon as the shower was started.
The shower unit was replaced.
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