Old cooker radial curcuit

[kkynaston]

Hi,
Long time reader, first time poster.

Just bought a house in Market Drayton and am trying to sort out the dodgy electrics (tape used instead of sleeving, overuse of terminal blocks etc)
I was changing a socket face in the kitchen and realised it was fed with 6mm.
This is supplied from the board on a 32A mcb. Now this was obviously a cooker point at some time but would it not be better fed from a 16A if it is now a radial socket?
(The only 16A i have is used for the central heating, could I possibly double it up with that until the CU is replaced?)

Also (sorry so many questions ) The main incommer fuse says PME system but I seem to have an earth rod outside. Is that normal?

Thanks

 

[Adam_151]

Its fine, should be RCD protected though (as should all downstairs sockets), whereas a cooker circuit with no socket is most often not on RCD.

I'd also be fine on a 16A/20A, in short, there is no need for it to be on a 32A, but its doing no harm!

As to the cutout, can we get a pic of that and your CU?, it could be that you have a TNCS earthing terminal but don't make use of it yet (in which case I hope the CU is of the main RCD incommer type), or it could have been connected but electrode left connected, etc

Have you considered having an electrician do you a periodic inspection report?... they are recommended at change of ownership...

 

[kkynaston]

I'm getting an inspection done in the new year after the CU has been replaced, I'll get a pic tonight of the whole thing with a decent camera.
There is no earthing terminal next to the incommer.
There are 3 RCD's in the installation. One 30mA 63A outside the board, fed from the meter, going to a 100mA at the far right of the board.
The bar from the 100mA feeds the lights, (one for the whole house, one for the bathroom)
The 100mA then feeds a 30mA supplying sockets, central heating, and shower

 

[Taylortwocities]

Looks like your board is set up for a TT installation.

Can we get a pic of the "30mA 63A RCD" is it a brown unit with two earth wires in the base??

Also (picture too blurry) is the 100mA RCD an S type (time delayed).??

 

[ban-all-sheds]

I'm getting an inspection done in the new year after the CU has been replaced,

No - you really should get it done first. Any sensible electrician would want to test the circuits before replacing a CU anyway, lest some of them resemble round metal cylinders bearing the legend "Here there be worms".

There is no earthing terminal next to the incommer.

TT supplies are often converted to PME, but it's then the householder's responsibility to change his installation to use it.

The 100mA then feeds a 30mA supplying sockets, central heating, and shower

Gotta say it looks more like one of those Hager twin RCD CUs, not a split-load one, i.e. the 2 RCDs are in parallel with the supply terminals of both connected to the incoming tails, rather than the supply of the 30mA coming from the load of the 100mA.

Except in your case you haven't got an isolator in the CU. Does the external one have a switch you can operate to isolate, or is it literally just an RCD?

 

[kkynaston]

Well here is a shot of the main fuse, meter & RCD that supplies the CU
You can see the main earth in a choc block above the meter
http://i245.photobucket.com/albums/gg72/kkynaston/meterheadtri.jpg

A better picture of the CU
http://i245.photobucket.com/albums/gg72/kkynaston/both_rcd.jpg

And The incomming supply with the earth running out with it
http://i245.photobucket.com/albums/gg72/kkynaston/incoming.jpg

Yeah I think i'll get a test done before I replace the CU.
How would I go about making use of the PME system? I've got a mate that works for eon and he doesn't rate PME for some reason. He's finished on domestics now though and gone onto HV stuff[/url]

 

[DESL]

I think i'll get a test done before I replace the CU.

Inspection, testing and verification will be carried out as part of a CU change.

TBH I think your CU is OK as it stands you have a main isolator on the tails.

It's not the 'tidiest' CU install I've seen.

The important issue is the earthing there is no earth connection to the cut out although it has been labelled PME.

Terminal block on main earth is a NO NO.

Bonding to water and gas should present as well.

Get a Periodic done on installation.

 

[kkynaston]

I will probably give the DNO a call about the earthing block on the cut out.
My plan is to reuse the CU in the garage because I can't find anywhere that supplies MCB's for the board cheap. I had a quote of about £40 for a 40A and I want to get rid of the power shower and put in a nice electric one. Also need an MCB for the outbuildings.
Should the external 30mA crabtree RCD be swapped for an isolator?
Bonding to water is OK, I've yet to check the gas.
I do like things tidy where electrics are concerned! I've been putting sleevings on all socket and light earths over the past 3 weeks when I've had time. Could not find one single earth sleeved in a socket at all. So I want this board tidied up.
Last thing, there is already a separate MCB for the bathroom lights, is this ok on the 100mA or should I move it to the 30mA? They are halogen downlighters.
Sorry so many questions
Thanks for all your input!

 

[Adam_151]

The RCD setup seems most odd, it looks like a split board with the standard 30ma on selected circuits and the main incommer as a 100ma rcd, so far, so good, pretty normal for a TT earthing system... but the 100ma device doesn't seem to be a selective (time delay) type, although it might just be the out of focus pictures

Then you have got a 30ma RCD upstream... it looks a bit older, perhaps you had a an old wylex standard fuseboard previously, and whoever replaced it left it in as it was easier than dealing with the DNO for isolation, etc to get it removed....

The earth connection is under that cover that says 'PME', the problem is that chances are the screw that needs to be slackened to remove it is under the company fuse... which is sealed in. You'd be best to get a MET, locating it on that on the board somewhere out the way, runing 10mm² to your water and gas service intake positions, 16mm² to your CU earth bar, and another 16mm² coiled up and left hanging, then call your DNO and get them to come and connect it in, also when phoning up for this, ask for an isolator to be fitted, central networks should do the isolator for free, hopefully what they'd do, is remove that crabtree main rcd and stick the isolator there

 

[ban-all-sheds]

And The incomming supply with the earth running out with it
http://i245.photobucket.com/albums/gg72/kkynaston/incoming.jpg

Yuk.

And what's that unprotected twin & earth fixed to an outside wall?

 

[ban-all-sheds]

The RCD setup seems most odd, it looks like a split board with the standard 30ma on selected circuits and the main incommer as a 100ma rcd, so far, so good, pretty normal for a TT earthing system... but the 100ma device doesn't seem to be a selective (time delay) type, although it might just be the out of focus pictures

Or, as I suspect, it's not a split board....

 

[kkynaston]

The unprotected T+E is to a floodlight next to that hole. It is being replaced shortly.

Just spoke to the DNO, they want £90 to put in the earth terminal to the service head and add an isolator.
So I rang my mate who works for them, he's coming between christmas and new year to put an isolator in, add the earth terminal and replace the meter tails.
He said he will then test everything for me
At least I will know that everything will be safe for the time being

Thanks for all your input everyone! Excellent Site!

 

[Adam_151]

Or, as I suspect, it's not a split board....

I'm not sure you're right on that... the neutral into the LH RCD... it comes from the neutral bar that has the neutrals from the circuits protected by the RH RCD in

(and looking more closely, the phase to LH rcd seems to disappear behind the other RCD towards the busbar, rather than in with the tails)

 

[ban-all-sheds]

Or, as I suspect, it's not a split board....

I'm not sure you're right on that...

I know I'm not...