100ms time delay rcd on main domestic unit?g

[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