RCD Fail - What code?

[Manator]

Thats the one Sidewinder thank you

 

[Sidewinder]

I seem to remember having rambled on about this, there are another two as well from the esc.

I am sure I have had this or one of the others for a few years, there are a couple more kicking around from other sources.

The BEAMA RCD handbook is useful as well.

The RCD Handbook - Guidance Documents

 

[Manator]

Yes there have been quite a few the other ones I can remember are from around the year 2000, I think the IET where responsible for one set of tests and reports, I will have to have a look see.

I have found the 2006 report from ERA which tested the rcd's under load. I can not find the earlier tests, but I was sure I had them.

 

[WarrenG]

Warren,Just to draw a little more info and debate, that is all.

You say a code 1, OK.

Now a code 1 demands that the inspector makes emergency repairs as there is an imminent danger to life or property.

This is explained in several industry documents and examples such as exposed live parts are used.

Can you please elaborate a little more on how you feel that a failed rcd is a code 1.

There would have to be another fault present or dangerous action undertaken for this to give imminent danger to life in the same way as an exposed conductive part?

Also what immediate emergency action would you undertake to make the installation more safe prior to leaving say?

Well interestingly there appears to be two sides of the coin based on this debate and it generally boils down to the earthing arrangements.

My thinking was (as I have seen plenty of times before) individual circuits not being able to achieve the loop times and therefore requiring additional protection of an RCD. 'D' Type or Type 4 MCB's spring to mind.

Or even some defective buried DIY work thats producing high loops

in the need for an RCD. ADS isn't going to do its job in time.

I would agree a fault would need to be present in order for the additional RCD protection but surely thats the reason we use such a low level protective device @30mA to protect the imminent danger to life or property?

My view was that we would have failed too late if the ADS couldn't be achieved on any circuit and we were dependant on a faulty RCD.

Anyway whilst digging around I came across this which hopefully will clear up some of the mist and will probably answer the questions in this thread....

Q & A of the Day - What Code deviation for an RCBO that fails to trip? - Voltimum UK - Electrical Installation Products and Contracting

 

[Sidewinder]

Warren,

In no particular order.

The link in the Voltimum article is to the ESC bpg on pir's.

There is nothing new in here.

It only gives a 1 for an rcd on a tt.

The 30mA is for personal protection, though not property, that would normally be a higher rating.

Fitting an rcd in absence of correct circuit design and construction imho is completely wrong.

If you need a D/4 mcb then you should design your circuit accordingly.

There are ways of reducing the efli.

Also fitting an rcd to circumvent fault rectifications of bodged diy modifications or repairs is again imho a complete no no!

I believe that it is down to risk assessment as has been mentioned, and one of the major factors to assess is the supply arrangement.

I don't think that when it comes to some serious code 1/2 defects that the line is clear cut.

It seems some people, and this is not aimed at you, seem to think that missing db circuit schedules are a code 1.

YES I have seen that on a pir!

 

[steptoe]

I don't agree, a faulty rcd on a tt is a code 1 no it is not, unless it is a front end. , no main earth NO such thing is a code 1, both require additional faults to become a danger to life.

Im in RED and both of your statements are wrong, misleading, and potentially scaremonger tactics, IMHO,,

and I can find nothing to back you up so I would be grateful if you could please help yourself.

it has already been posted about the TT front end so you may well have to find a reg that contradicts that one,

and I really have NO idea where you are going to find a reg relating to a MAIN earth.

 

[Manator]

It is very good logic that you have followed Warren, however earthing aside, another fault has to be present for the failure to warrant a code 1.

Back to the earthing, most will agree that the indication of this is that a RCD will be fitted if the earthing arrangement is a TT, and as such the failure in this case would be a code 1. Again I must stress that in the event of a failure of a devise I will always agree with an assessment of risk by the inspector.

 

[steptoe]

It is very good logic that you have followed Warren, however earthing aside, another fault has to be present for the failure to warrant a code 1.Back to the earthing, most will agree that the indication of this is that a RCD will be fitted if the earthing arrangement is a TT, and as such the failure in this case would be a code 1. Again I must stress that in the event of a failure of a devise I will always agree with an assessment of risk by the inspector.

but this is dependant on the RCD arrangement surely Manator,?

dual 30mA RCD board protected by a 100mA front end.

on what failure would you warrant a code 1.?

 

[Manator]

For the TT the indication that a RCD failure would warrant a code 1 would apply to the front end, just as you indicated in your above post, I did not intend to imply that any RCD failure in a TT install would be a code 1, which when I look over my post is ambiguous.

Thanks for highlighting that error.

 

[WarrenG]

Warren,In no particular order.

The link in the Voltimum article is to the ESC bpg on pir's.

There is nothing new in here.

It only gives a 1 for an rcd on a tt.

The 30mA is for personal protection, though not property, that would normally be a higher rating.

Fitting an rcd in absence of correct circuit design and construction imho is completely wrong.

If you need a D/4 mcb then you should design your circuit accordingly.

There are ways of reducing the efli.

Also fitting an rcd to circumvent fault rectifications of bodged diy modifications or repairs is again imho a complete no no!

I believe that it is down to risk assessment as has been mentioned, and one of the major factors to assess is the supply arrangement.

I don't think that when it comes to some serious code 1/2 defects that the line is clear cut.

It seems some people, and this is not aimed at you, seem to think that missing db circuit schedules are a code 1.

YES I have seen that on a pir!

The article does cover both code 1 and 2 - it was the article I was referring to and not the well know ESC PIR for download.

I am aware 30mA is for personal protection and normally higher for property.

We are talking about PIR's and not circuit design and construction - agreed.

If I were designing a circuit for a type 'D' then I would design it with that protection in mind. For PIR's I have failed many a Type 4/D that is unable to meet loops and still in service. Proof ADS is un-achievable.

I am aware of ways of reducing loops.

I wasn't stating that you should fit an RCD for bodge work but merely the fact that bodge work has been carried out and the protection of the RCD is necessary.

Just to throw another spin, no one has mentioned that if there were absence of an RCD protecting a socket outlet (other than SELV or shaver socket outlets) in a bathroom or shower room it would be given a code 1

 

[steptoe]

The article does cover both code 1 and 2 - it was the article I was referring to and not the well know ESC PIR for download.I am aware 30mA is for personal protection and normally higher for property.

We are talking about PIR's and not circuit design and construction - agreed.

If I were designing a circuit for a type 'D' then I would design it with that protection in mind. For PIR's I have failed many a Type 4/D that is unable to meet loops and still in service. Proof ADS is un-achievable.

I am aware of ways of reducing loops.

I wasn't stating that you should fit an RCD for bodge work but merely the fact that bodge work has been carried out and the protection of the RCD is necessary.

Just to throw another spin, no one has mentioned that if there were absence of an RCD protecting a socket outlet (other than SELV or shaver socket outlets) in a bathroom or shower room it would be given a code 1

I havent yet worked in a bathroom BIG enough for a socket outlet to be allowed, and if I came across one inside the prohibited Zone then I would issue a EDN and disconnect(if permitted), if in the permitted area and without RCD protection then code as required and again issue danger notice.

 

[ichinen]

It depends on the earthing arrangement and where it is fitted.

For instance, if the rcd is fitted to protect a special location with no suppl. bonding, etc. then code 1.

 

[philbas]

I havent yet worked in a bathroom BIG enough for a socket outlet to be allowed, .

Most bathrooms would allow a socket to be fitted, under the bath, as long as you need a screwdriver to remove the bath panel , Although I cringe at the thought of doing it.

 

[steptoe]

Most bathrooms would allow a socket to be fitted, under the bath, as long as you need a screwdriver to remove the bath panel , Although I cringe at the thought of doing it.

well, we could fit some 500W halogens too then, :slap

yes,

I get your point,

but I think we are talking usable points,

and some of mine aren't even repeatable.!

:|