live bath problem

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superwol

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hi guys... i used to lurk around screwfix but have got a bit of a headscratcher so thought i'd come ask the talent for advice

just been on a call-out where the tenants of a flat had been getting belts off the towel rail, the shower mixer 'panel' and the plughole. (this was discovered when one of them stood in a bath of water) the towel rail is connected to old iron (i think) pipes but the panel and plughole are all connected by plastic (i have been assured by the landlord and from what i can see from a fairly limited perspective this seems to be true) although the plastic waste apparently does connect to a cast iron waste under the tiled floor... and there is no evidence of any bonding, supplementary or otherwise, in the flat although it's on a communal hot water system and i couldn't gain access to the boiler/switch room. the incoming watermain was also plastic.

the circuit at fault appears to be the lighting circuit for that part of the flat (isolating it removes the problem) and the south african plumber who lives there insisted on giving me demonstrations of where he was getting the belts from by taking off his shoes and touching things. i did ask him not to several times but he seemed to enjoy it. the fool.

so in an adjacent cupboard there was an underfloor heating controller, pump for the jaczi bath thing all held together with block and tape so i disconnected the lot and the problem disappeared. to attempt to prove something was actually at fault i re-connected the underfloor heating at which point a nasty burning plastic smell came from under the bath so i swiftly removed it again but the fault did not return.....

but here lies my problem. i'm not happy with the fault just disappearing like that with no real explanation as to what caused it in the first place. i just don't feel happy walking away without knowing whether or not i have actually solved the problem. for the record the main switch was an rcd although this didn't trip at any point. i intend to go back to satisfy things for myself (including testing the rcd) but can anyone suggest anything i might be missing, however obvious it may seem

apologies for the length, any suggestions/explanations/bright ideas greatly appreciated

 

jckent

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If in doubt - bond it all out.

Bond ,bond and bond some more.

reduce the potential difference to nothing.

If your unsure what i mean earth all metalwork.

if there is plastic to copper pipe bond it.

metal plug basin-bond it, taps bond them.

To earth that is. link it all.

there is a fault somewhere as well.

pick up your 17th edition book and read. Is my best advice.

 

extension15

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If in doubt - bond it all out.Bond ,bond and bond some more.

reduce the potential difference to nothing.

If your unsure what i mean earth all metalwork.

if there is plastic to copper pipe bond it.

metal plug basin-bond it, taps bond them.

To earth that is. link it all.

there is a fault somewhere as well.

pick up your 17th edition book and read. Is my best advice.
Inclined to agree, bonding and check out the rest of the wiring..

 

ABC Technical

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I think you should call out a qualified electrician. Just my opinion.

 

steptoe

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as much as it pains me to say it.

yes i agree,

bond it all together and then to earth.

its very obvious there is a fault somewhere,

but as it may be too laborious and expensive to find,

the quick fix is simply to bond (inc lights to shower/bath/pipes) so everything is at the same potential.

it doesnt fix the problem, but it stops any dangerous voltages floating around.

in this instance I would prob even go as far as to 8mm drill the wall somewhere (under the bath?) in the bathroom and rawbolt a lug to that as well.... :|

 
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To a point; I agree with the bonding theory. However, I would want to know the cause of the problem. Further info req`d here, methinks.

If the pipework is plastic, and the UFH is causing the issue, then there is something strange occuring!

What is the make of the UFH? Could we see photos? what are the meter readings from the screen of the UFH to the exposed metalwork? What is the resistance of the exposed metalwork to earth? Where, specifically, did the burning smell come from? Is the lighting circuit in question fed via the RCD?

Answer these, and some more in depth answers may be forthcoming.

Personally, I couldn`t walk away from this without knowing exactly what the causation was.

 

ABC Technical

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To a point; I agree with the bonding theory. However, I would want to know the cause of the problem. Further info req`d here, methinks. If the pipework is plastic, and the UFH is causing the issue, then there is something strange occuring!

What is the make of the UFH? Could we see photos? what are the meter readings from the screen of the UFH to the exposed metalwork? What is the resistance of the exposed metalwork to earth? Where, specifically, did the burning smell come from? Is the lighting circuit in question fed via the RCD?

Answer these, and some more in depth answers may be forthcoming.

Personally, I couldn`t walk away from this without knowing exactly what the causation was.
My point exactly, what is your trade OP?

 
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Welcome Superwol to the madhouse:D

Remember you wont get no sense after midnight..

or if there is anything good on TV..

or during opening hour's..

or when getting a beer from the fridge..

or when gone down the the stables to feed steptoes horse..

or while welshy's on-line..

or if the word "Earth" appears anywhere in the thread!!

other than that were all here to help/hinder/encourage/confuse/debate*

{*delete as appropriate}

Now thats over..... down to business:D

hi guys... i used to lurk around screwfix but have got a bit of a headscratcher so thought i'd come ask the talent for advice
The Don's boys can permanently rectify lurking around inappropriate location problems.... So I've heard! :eek:

just been on a call-out where the tenants of a flat had been getting belts off the towel rail' date=' the shower mixer 'panel' and the plughole.[/quote']I assume from this statement you are a full time spark... not a diy helping a friend?.. and you have access to proper test gear?

apologies for the length' date='[/quote']Length???? phttttt! I have heard allegations from some certain welsh wizzardy type persons... about other persons writin long posts!! ?:| :eek: :(

but can anyone suggest anything i might be missing' date=' [u']however obvious it may seem any suggestions/explanations/bright ideas greatly appreciated
I think we specialise in the obvious... its about the level of the forum intelligence!

=====================================

As slipshod said I would be interested to know...

what was the voltage giving the belt?

Keep in mind there may be more that one fault!

personally I would want to verify the integrity of every circuit suppling accessories & equipment in the bathroom...

Main earth & bonding intact..

Basic dead tests & live tests with ..

sizes ratings of MCB/fuses etc..

R1-R2.

Polarity.

Insulation Res. etc..

Verify Ze, Zs

Operation of RCD...

only by proving the individual circuit basics can you deduce that other items are at fault

If all of these can be proven... the fault is an accessory

did you say the towel rail was electric? any internal faults.

out of curiosity I would want to measure any continuity between exposed metal work in bathroom. (and the plughole!!!)

do it with the power off and CPC's diss at fusebox

I would then put appropriate bonding in place afterwards

Assuming circuits all test out OK..

this would imply fault is one of the accessories...

Burning smell?? is there an accessory with a melted live wire touching and un-eathed conductive part?

Have all of the accessories been connected correctly...

you haven't got something wired with N & E reversed so working across live & earth? (as RCD is unproven at the moment?)

Is there any damp building materials providing a path for an earth current?

e.g. any metal foil backed items...

cant think of anything else..

but I will as soon as I press "Submit Reply":^O:^O

SL
 

Mr Sworld

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Busy, busy KME. Been looking in from time to time but got a lot on at the moment. Work and non-work has been frantic! :(

 

superwol

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To a point; I agree with the bonding theory. However, I would want to know the cause of the problem. Further info req`d here, methinks. If the pipework is plastic, and the UFH is causing the issue, then there is something strange occuring!

What is the make of the UFH? Could we see photos? what are the meter readings from the screen of the UFH to the exposed metalwork? What is the resistance of the exposed metalwork to earth? Where, specifically, did the burning smell come from? Is the lighting circuit in question fed via the RCD?

Answer these, and some more in depth answers may be forthcoming.

Personally, I couldn`t walk away from this without knowing exactly what the causation was.
thanks all for the responses... well most of them anyway.

for the record yes i am a qualified electricain. experience doesn't come with the certificate though which is where i find it helpful to ask other people. helps with the learning you know.

as i said before as far as i can tell all pipework is plastic except for the towel rail. the ufh was warmup as far as i can remember and the smell came from under the bath (albeit briefly). it appears to be newly refurbed (by the owner i think who also dd a bit of the electrical work from what i can gather) and pretty much everything is inaccessable/out of sight

will try and gather more info and report back later tonight

 

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