Few electrical questions.

[xr4x4]

Hello all,

I have been asked by a very good / old friend of mine to have alook at helping them with redoing there kitchen.

Now im going to be project managing / fitting the kitchen and have some questions before i start ringing round for quotes...basicly what i can and cant do so i can tell him the plan and pricing.

He has a old metal re-wireable CU with fuses for sockets, lights, cooker and immersion. now to get the kitchen done the sockets are going to have to be moved, new added and FCUs for appliances etc.

Now first question, if i get electrician in to look at the wiring for the kitchen, will it need to be RCD protected? ie a CU change.

Can the CU be changed on its own? can the existing sockets and wiring remain if it passes the tests, i guess most of the sockets and wiring is 1950/60s.

If the CU is changed, is it a good idea to have a seprate curcuit for the kitchen?

Now last question is the main earth. Power comes in out of the wall in a metal conduit, this conduit is fixed to the bottom of the CU with a nut and gland. So im asuming that the earth is connected to this inside the CU and uses the conduit as the earth itself...? Can the new earth for the new CU be connected to this conduit?

Sorry for all the questions, thanks in advance.

 

[Spark123]

Now first question, if i get electrician in to look at the wiring for the kitchen, will it need to be RCD protected? ie a CU change.

Yep, the easiest method will probably be a CU change.

Can the CU be changed on its own? can the existing sockets and wiring remain if it passes the tests, i guess most of the sockets and wiring is 1950/60s.

50 year old wiring is probably getting towards the end of its life, however if it does pass all the tests then it may remain. It is the call of the spark on the day.

If the CU is changed, is it a good idea to have a seprate curcuit for the kitchen?

Yep

Now last question is the main earth. Power comes in out of the wall in a metal conduit, this conduit is fixed to the bottom of the CU with a nut and gland. So im asuming that the earth is connected to this inside the CU and uses the conduit as the earth itself...? Can the new earth for the new CU be connected to this conduit?

Sorry for all the questions, thanks in advance.

It is the call of the spark on the day I'm affraid, personally I like to see 16mm green and yellow as opposed to relying on the conduit.

 

[sparkwright]

The kitchen sockets would definitely be best on their own circuit, particularly if you intend not touching the rest of the installation.

It may be possible to run a 16 mm earth through that conduit.
Or the electrician may decide to remove the conduit altogether and replace with larger tail cables.

Is all the cable pvc?
In the 50s pvc, rubber and vir were used.

Does the lighting circuit have earth throughout including the switch drops.
10 mm earth to gas, water, etc?

 

[ban-all-sheds]

50 year old wiring is probably getting towards the end of its life, however if it does pass all the tests then it may remain. It is the call of the spark on the day.

If the wiring is VIR cable, then even if it does pass all the tests I would hope the spark would replace it.

 

[wingcoax]

As BAS says it is preferable to replace vir as over the years it can and does go brittle, it may pass test but as soon as you try moving it it can fall apart.

 

[xr4x4]

The kitchen sockets would definitely be best on their own circuit, particularly if you intend not touching the rest of the installation.

It may be possible to run a 16 mm earth through that conduit.
Or the electrician may decide to remove the conduit altogether and replace with larger tail cables.

Is all the cable pvc?
In the 50s pvc, rubber and vir were used.

Does the lighting circuit have earth throughout including the switch drops.
10 mm earth to gas, water, etc?

Trouble is the conduit is buried in the wall, as its flats above shops, theres a meter cupboard outside which hold all the cutouts. replacing tails and running new earths will be almost impossible.

Will check wiring, pretty sure its pvc, water will be earthed. no gas.

What worrys me is, the other two flats (rented) have both had the CU changed, the conduit was left as was and the tails where run into a henley and from there into CU.... no trace of an earth.

Now i remember a few years ago when these where changed the bloke was talking about new regs and earth cable sizes. Now i know he run them along the roof spaces and asking about gaining access to the roof space of the other flat so he could finish running the earth cables to the meter cupboard....i dont think he ever did...

...So it scares me to think it... but i dont think these other two flats have earths....!!

 

[xr4x4]

50 year old wiring is probably getting towards the end of its life, however if it does pass all the tests then it may remain. It is the call of the spark on the day.

If the wiring is VIR cable, then even if it does pass all the tests I would hope the spark would replace it.

sorry... VIR?

 

[Spark123]

Vulcanized indian rubber, basically the conductors are coated in rubber with a waxed fabric over then in an outer sheath. Your spark will make the call on this when he inspects and tests the installation prior to the works.

 

[sparkwright]

If the tails cannot be replaced and a separate earth cannot be added then the electrician will leave it as it is if he thinks it is acceptable;
or he will find another way.

Are the other two flats anything to do with you or your friend? If so it would be advisable to get someone to check the earthing; or inform someone who can arrange this.

 

[xr4x4]

He rents them out yes, he lives in this one.

I will be going over there tues, so i will speak to him then.

Thanks very much, you all have been most helpfull.

 

[ban-all-sheds]

VIR is actually pretty good stuff - we all trust our lives to it whenever we travel in road vehicles or aeroplanes.

It is mechanically stronger than PVC, more flexible, and has better resistance to heat and chemicals.

But it doesn't have such a long life, so where mechanical strength, flexibility, heat and chemical resistance aren't important (i.e. fixed wiring in houses, offices, shops etc) it's no longer the material of choice.

It's probably more expensive than PVC too...

 

[FrankE]

As well as a ktchen specific ring main circuit, have a separate circuit for the fridge freezer and another for the washing machine.
Then, if anything trips the kitchen ring main RCBO or breaker or it is switched off for any reason eg the housholders are on holiday or they have someone in installing a new socket then food damage is minimised

Similarly with the W/M circuit their clothes won't get stuck mid cycle

 

[xr4x4]

Ok just thought of one more...

I was thinking about this poss earth problem in the other flats.. is there anyway i can test if the earth is connected with a multimeter at the CU?

Ie, a volt test between live and the earth post in the CU?

 

[scousespark]

Get an electrician (or 3) to come and quote. They will be able to advise what is needed and the options for the kitchen.

A PIR will tell you if the installation is up to scratch.