RCD tripping

[Jacobssi]

Johnny

Any other circuits on the load side of the RCD?

 

[JohnnyTheFox2010]

have you tried as i suggested??

I haven't as I haven't had time yet, but I'm not sure what it would demonstrate if I did?

 

[JohnnyTheFox2010]

Johnny

Any other circuits on the load side of the RCD?

Hi

Sorry, I don't know what that means How would I find that out?

 

[JohnnyTheFox2010]

...........and the winner is........

Isolator switch could either be a pull cord switch (in the bathroom) or a wall mounted switch outside.... a common fault is the neutral burning out,, that's what I was meaning that you should check!

Circuit tested by electrician. Neutral burnt out in isolator switch. Isolator replaced. Spot on Nozspark. Thanks.

 

[ltheb]

God help us all! The RCD has not a been specific requirement of the regs. apart from recent changes in the 17th edn. A 30ma RCD gives personal protection: 50 - 70ma could kill you so a 100ma RCD is not there for the same reason. Manufacturers' recommendations should be followed provided they don't directly contradict the regs., and most recommend the RCD. Correct cable and fuse sizing has always been important and the length and route of the circuit are often generally ignored (insulation for example seriously reduces the cable rating) but Part 'P' building regs specify 10mm cable.
The RCD measures relatively small imbalances in current flow between live and neutral - 'earth leakage' the idea being to make sure you aren't the leak path. Therefore, loose connections, particularly on the neutral can cause problems, so look for these first. Any cable will deteriorate over time if it overheats and running a 9k shower on 6mm cable could be causing the pvc insulation to break down. A qualified electrician (and these days he/she MUST be a Part 'P' qualified) can test the insulation resistance. Is there properly installed supplementary bonding on all the pipework? Is it linked to the cpc (earth) of the shower circuit?
Final question - does the RCD only serve the shower or a bank of circuits. It appears that the tripping ocurs when the shower is in use, but it might be somthing else!

 

[ltheb]

Just read the last post properly - job done. I hope you don't mind the other info if it helps!

 

[JohnnyTheFox2010]

Just read the last post properly - job done. I hope you don't mind the other info if it helps!

Thanks, but it was the original 7.5kw shower that started tripping the RCD 6 weeks ago. The 9kw was fitted just a week ago because I was originally told that the shower unit was the cause and should be replaced, so I think the 9kw is a red herring. So, the 7.5kw shower burnt out the neutral, not the 9kw.

The new 9kw was run today for 12 minutes with no tripping, so problem solved.

 

[ban-all-sheds]

Part 'P' building regs specify 10mm cable.

No it doesn't.

P1 Reasonable provision shall be made in the design and installation of electrical installations in order to protect persons operating, maintaining or altering the installations from fire or injury.

A qualified electrician (and these days he/she MUST be a Part 'P' qualified)

Part P is not a qualification.

God help us all!

Indeed.

 

[kernow1]

If Part P isn't a qualification why do you have to pass an exam to get it?
(EAL Accreditation) How else would you get it? Plumbers have also to pass an exam called 'Part P Defined Scope' if they wish to wire boilers, showers etc.

 

[ban-all-sheds]

If Part P isn't a qualification why do you have to pass an exam to get it?

You don't.

You can't.

Part P is a part of the Building Regulations.

How else would you get it?

Get what?

A part of the Building Regulations?

Plumbers have also to pass an exam called 'Part P Defined Scope' if they wish to wire boilers, showers etc.

No they don't.

They can't.

Part P is a part of the Building Regulations.

 

[martinxxxxxx]

If Part P isn't a qualification why do you have to pass an exam to get it?

You don't.

You can't.

Part P is a part of the Building Regulations.

How else would you get it?

Get what?

A part of the Building Regulations?

Plumbers have also to pass an exam called 'Part P Defined Scope' if they wish to wire boilers, showers etc.

No they don't.

They can't.

Part P is a part of the Building Regulations.

Come on BAS; you know what he means, we know it is a regulation, but to be able to self certify, one has to pass an assessment to join one of the organisations that run competent person schemes. This is commonly understood or misunderstood to be a part p qualification and there is a defined scope scheme for kitchen fitters and plumbers.a
Please dont swear at me

Martin

 

[JBPElectrics]

I cannot believe youve not had a snide reply yet.

 

[Firkin]

Ah c'mon you guys, BAS has helped a lot of folks out on these columns and so what if he gets up his own shirt sometimes - he is only trying to stop many of us burning our fingers - or worse!

I welcome his argy bargy ways - it makes a lot os us stop and think if we are going about it the right way or not. In my book that's okay

Firkin

 

[ban-all-sheds]

Come on BAS; you know what he means, we know it is a regulation, but to be able to self certify, one has to pass an assessment to join one of the organisations that run competent person schemes. This is commonly understood or misunderstood to be a part p qualification and there is a defined scope scheme for kitchen fitters and plumbers.

Misunderstood is right.

And misunderstandings, sloppy, lazy, inaccurate thinking, and sloppy, lazy and inaccurate terminology are unacceptable.