100ms time delay rcd on main domestic unit?g

[cmp260]

my house has 100ms time delay rcd main switch. why would this have been installed in a house? is it legal?
thanks

 

[guest119]

steve, youre right its rightly failed on some aspects, but wtf does high impedance on 25 on circuits 2 and 3 mean?

Ring main end to end readings?


Boydy

 

[Gentle Ben]

As has been said by others the '25' is probably zs, the total resistance of the earth loop going all the way to the suppliers transformer.

On the table of test results for the circuits that have failed their should be an R1 + R2 result, what are these? This should confirm whether the high impedance is in your installation or on the suppliers side.

Too high a zs can be caused by poor or loose connections. I would always advocate finding the cause and repairing it but you can get round it by down-rating the MCB which allows a circuit to have a higher zs or converting to RCD.

 

[richy3333]

Please stop poking things in sockets mate.

No Trev, he should. Natural selection will then do it's bit for mankind...

 

[Octopus]

heres the doc. i did ring him on fri and asked him, he said hed get back, but hasnt..

hers thendoc http://db.tt/a09WQgKS
cheers

One or two slip ups on there me thinks. How long did it take him to do?

 

[richy3333]

Just a guess, but it looks like the fail comment in respect of the 100mA RCD is because it's protecting circuits? Kitchen RFC in particular?

 

[brman]

reading those results I can see why he failed it. Zs of 50ohm on cct 3 is over 10 times what I would expect for a start so you have a fire waiting to happen there........

As Murdoch said, there are a couple of anomalies on the sheet but it is basically believable so you do need some work done to make it safe.

I still can't see why there is a C2 on the main RCD but, as others have said, why not ask the guy?

 

[brman]

Just a guess, but it looks like the fail comment in respect of the 100mA RCD is because it's protecting circuits? Kitchen RFC in particular?

maybe, but I'd give that a C3 unless of course there is a socket that could be expected to be used for outside equipment. (ie. outside socket spurred off the kitchen ring)

 

[Heisenberg]

Any chance you could also upload the other pages he gave you to Dropbox?

 

[cmp260]

One or two slip ups on there me thinks. How long did it take him to do?

it took him about about 2 1/2 hours for 4 bed house,
when I asked about the 100ms delay, he said thats unsafe since thats long enough for a fatal shock, there should be no delay and thats why it failed. is he right to fail it or is this a grey area?
should he be using a special meter to text the td?

 

[cmp260]

its typed on the form, definitely 25

 

[cmp260]

maybe, but I'd give that a C3 unless of course there is a socket that could be expected to be used for outside equipment. (ie. outside socket spurred off the kitchen ring)

actually, that could be it, there is an outside socket running off the kitchen ring however its one of those aldi kits with a builtin rcd plug that you simply plug into a spare socket in the kitchen.
if thats the case, can you explain how the td would make a difference?
thanks

 

[richy3333]

If a socket is in a position that makes it accessible to being used outside then he would code it accorcdingly. I guess this is the reason, rather than the Aldi DIY job?

 

[Jonny66]

Incredible, 5 pages of guess work, assumptions and opinions based on what? technical information from a DIY bt man with no knowledge of electrical installations? who is a little aggrieved to have been given an unsatisfactory EICR? and cant interpret the certificate? but who owns a multimeter? .........

Come on, he went for the cheapest quote from "MY ----er dot Con":smilielol5:...... where all the monkeys try to out quote each other until only the most desperate, deranged and possibly feeble minded amoeba like DIs are left......and get this, unbelievable I know, he still picks the cheapest.... incredible......and to top it off, like a little cherry on top, he now wants the cheap EICR scrutinised for free by electricians who have not seen the install and who would of most likely charged a decent rate in the first place.......well, what can you say but IMO tough, pay someone a proper rate and get it done again if your not happy.:6:

And just out of interest, why dont we all post up one of our own EICRs (with no other information or further posts to justify what codes you gave) and sit back as they are torn into by others from a distance with guess work and assumptions based on nothing.....silly I know, but I bet no-one would want to.....any takers??

 

[cmp260]

Incredible, 5 pages of guess work, assumptions and opinions based on what? technical information from a DIY bt man with no knowledge of electrical installations? who is a little aggrieved to have been given an unsatisfactory EICR? and cant interpret the certificate? but who owns a multimeter? .........

Come on, he went for the cheapest quote from "MY ----er dot Con":smilielol5:...... where all the monkeys try to out quote each other until only the most desperate, deranged and possibly feeble minded amoeba like DIs are left......and get this, unbelievable I know, he still picks the cheapest.... incredible......and to top it off, like a little cherry on top, he now wants the cheap EICR scrutinised for free by electricians who have not seen the install and who would of most likely charged a decent rate in the first place.......well, what can you say but IMO tough, pay someone a proper rate and get it done again if your not happy.:6:

And just out of interest, why dont we all post up one of our own EICRs (with no other information or further posts to justify what codes you gave) and sit back as they are torn into by others from a distance with guess work and assumptions based on nothing.....silly I know, but I bet no-one would want to.....any takers??

well it is an advice forum, i was looking for advice and I mostly got it, very helpful comments and i really appreciate this. I suppose reading comments from the likes of you with chip on shoulder is fair price to pay for free advice. chill out dude, youll give youself an ulcer..
by the way im not BT, I had one year training in military in electronics and full spectrum of telcomms from landline to microwave to pbx followed by multiple courses in various PBX systems in civvie land and working for major interconnect.

 

[telectrix]

one problem with threads like this is that it's not possible to convey all the info across the internet. otherwise a post could take up 2 pages. then readers of the post have to fill in the blanks and read between the lines. this results in the post being mis-interpreted to a greater or lesser degree and then out come the negative replies. it's a bit like a surgeon trying to remove a tumour when he doesn't know where it is.

 

[Jonny66]

Mate I aint got a chip on my shoulder its more like a baked potato...........the "very helpful comments" were and have to be speculation as they haven't seen, inspected or tested your installation. You paid as little as possible for an EICR, from one of those sites renowned for incompetence and poor workmanship etc, and then dismissed the EICR as rubbish. You then go to a forum to have it scrutinised, probably to justify your own gut feeling that the pittance you "probably" paid means that the EICR maybe inaccurate, especially as it does not give you the satisfactory result you wanted ...seems odd to me.....my advise was IMO very helpful and I'll say it again...pay someone (an Electrician) a proper rate and get it done again if your not happy with it..you cannot test and inspect an installation without actually testing and inspecting the installation.

 

[Jonny66]

one problem with threads like this is that it's not possible to convey all the info across the internet. otherwise a post could take up 2 pages. then readers of the post have to fill in the blanks and read between the lines. this results in the post being mis-interpreted to a greater or lesser degree and then out come the negative replies. it's a bit like a surgeon trying to remove a tumour when he doesn't know where it is.

More like you have a tumor removed by a surgeon on the cheap, then go to a forum to slag off the surgeon and find out how to remove it yourself

 

[cmp260]

stick to the sparks chuckle brothers, similes are not your strong point
tara.

 

[Engineer54]

And just out of interest, why dont we all post up one of our own EICRs (with no other information or further posts to justify what codes you gave) and sit back as they are torn into by others from a distance with guess work and assumptions based on nothing.....silly I know, but I bet no-one would want to.....any takers??

Not a bad idea that Jonny66, it might help more than a few here that haven't got the first clue of how to conduct and code EICR's and the like. I would like to think anyone that is proficient in their trade, wouldn't have a problem showing completed paperwork!! lol!!

 

[brman]

More like you have a tumor removed by a surgeon on the cheap, then go to a forum to slag off the surgeon and find out how to remove it yourself

not entirely fair on the OP or the spark who did the EICR I think. I agree we did not have all the info needed at the start but now we get down to it is clear that the OP has the results of an EICR that he doesn't understand and wants advice. I for one am happy to give that. if I didn't want to I would just ignore the thread. And it is not like the OP has asked how to do the EICR himself......

As to the being done in the cheap, well maybe, and I did make a similar comment earlier but it is now looking like there is only really one code that could be argued with.

 

[brman]

Not a bad idea that Jonny66, it might help more than a few here that haven't got the first clue of how to conduct and code EICR's and the like. I would like to think anyone that is proficient in their trade, wouldn't have a problem showing completed paperwork!! lol!!

Only if I can do it under an anonymous username! I can just imagine how picky we would all be :lol:

 

[Jonny66]

stick to the sparks chuckle brothers, similes are not your strong point
tara.

Hey nothing wrong with the chuckle brothers, in fact they are a dam site funnier than most of the rubbish on tv at moment. Thought it read "smiles" was wondering if I was putting them in the wrong place.......ah similes.....yes your right I'm rubbish.

 

[brman]

actually, that could be it, there is an outside socket running off the kitchen ring however its one of those aldi kits with a builtin rcd plug that you simply plug into a spare socket in the kitchen.
if thats the case, can you explain how the td would make a difference?
thanks

I think I'd need to see that to be sure. It doesn't sound ideal. I'd check with the spark if that is what he was worried about and, if it is, then it would not take much to put in a proper RCD protected socket for outside use. Or perhaps better to change the MCB for the kitchen to an RCBO. That would give you RCD protection on all your sockets - not a bad idea if you are renting the property.

You really need to get either the spark who did the EICR or someone else in to give you some proper advice and a quote to sort it out.

btw. there are two issues with the time delay RCD.
1) it is 100mA which is likely to be fatal if it is going through you. Additional protection against shock requires a 30mA RCD. (or other measures)
2) it is time delay, so does not operate so quickly. To be honest I am not sure how much difference this will really make in practice.........Others might comment.....

EDIT: BTW. I just realised I think I might have made an assumption that it is a 100mA type S (time delayed) RCD........

 

[Octopus]

it took him about about 2 1/2 hours for 4 bed house,
when I asked about the 100ms delay, he said thats unsafe since thats long enough for a fatal shock, there should be no delay and thats why it failed. is he right to fail it or is this a grey area?
should he be using a special meter to text the td?

So add 1 hour at home for the cert and thats 3 1/2 hours - not enough to do the job properly. I's say minimum of 4 hours on site!

 

[Gentle Ben]

well it is an advice forum, i was looking for advice and I mostly got it, very helpful comments and i really appreciate this. I suppose reading comments from the likes of you with chip on shoulder is fair price to pay for free advice. chill out dude, youll give youself an ulcer..
by the way im not BT, I had one year training in military in electronics and full spectrum of telcomms from landline to microwave to pbx followed by multiple courses in various PBX systems in civvie land and working for major interconnect.

Not being funny fella but electronics is a whole different kettle of fish of to electrics. Granted, a lot of the practical skills may well be similar i.e. cable installation, termination etc. but just because you know a lot about telecoms and data does not automatically make you conversant with electrics. It would be like that Charlie Dimmock thinking she's up to running her own professional plumbing outfit because she knows how to plumb a p***ing cherub in someone's garden.... if I were you mate I should leave your electrical problems to the electrician.

 

[cmp260]

er, but I am leaving the problems to professionals:mickey:, I just what to understand it - thats why im asking. :nopity: dont you want to know what your mechanic says when he discusses probs with your car?
the reason I mentioned my experience is not to pretend I can do spark work but to counter assertions that I'm a numpty; I have basics of electric theory and I'm no dummy, if its explained ill understand it.

 

[Gentle Ben]

er, but I am leaving the problems to professionals:mickey:, I just what to understand it - thats why im asking.

Then ask your spark, instead of folks on here, only he knows definitively the information and the reasons you're asking for! Why have you not asked him?

dont you want to know what your mechanic says when he discusses probs with your car

Yes I do but if he fails my car on it's MOT then I accept his judgement, not disagree with him over it, or at least I don't go round other garages showing them the fail sheet and asking them if the guy is talking codswallop because I know a little bit myself about cars.

 

[cmp260]

pay attention ben, as i already stated earlier, I have tried to contact him, he never rang back - thats why im on here!
also, your argument doesnt hold water, many of us have been ripped off by mechanics doing mots, making unessary work when its slow, Now I have a mechanic I can trust. Same principle.

 

[CDM]

pay attention ben, as i already stated earlier, I have tried to contact him, he never rang back - thats why im on here!
also, your argument doesnt hold water, many of us have been ripped off by mechanics doing mots, making unessary work when its slow, Now I have a mechanic I can trust. Same principle.

All the best on your new sparky mate.If your new sparky can identify the System to be TT,then you don't have to worry.If its TT,Ze value should be less than 200 Ohms.

 

[brman]

All the best on your new sparky mate.If your new sparky can identify the System to be TT,then you don't have to worry.If its TT,Ze value should be less than 200 Ohms.

hmm...he doesn't have a problem with his Ze. As far as I can tell it is about 0.2 ohm. It is the Zs on a couple of circuits that are a problem and, RCD or not, a Zs of 50 ohms a typical circuit is a obvious fault.......