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Advice Please - Hi Tuff Cable

Posted: Fri Feb 20, 2009 3:03 pm
by JAP
Hi,

Just wanted to run this past the forum please. I need to run a radial circuit from the kitchen to the hallway and into the consumer unit under the stairs. As the flooring in the kitchen has been completed need to drill a hole through the outside wall and run the cable outside along the wall of the house and back into the hallway.

Rather than use a SWA cable I thought I could use Hi-Tuff cable (cheaper and easier to use than SWA) I would clip the cable against the wall side of the house. The cable would be about 15 inches from the ground.

Can anyone see any issues with this I know I will need to get an electrician to certify the work, Will this type of circuit meet the regulations? What other bits and peices will I need to purchase it's just going to run 1 double socket to feed a fridge.

Thanks in advance for constructive posts

Advice Please - Hi Tuff Cable - additional info

Posted: Fri Feb 20, 2009 4:59 pm
by JAP
Further to previous post - I could just use 2.5mm twin and earth and place it a 20mm conduit along the side of the house, would this be a better option? More safer and protected than a high tuff cable?

I should explain I am running a separate radial circuit because im finding the fridge keeps tripping the house electrics when wired on to a mcb on the RCD side of the consumer unit. I have connected it temporarily on to a mcb and placed on to the non RCD of the CS and no problems at all.

Posted: Fri Feb 20, 2009 7:35 pm
by kbrownie
Hi Jap,
The fact you are running the cable outside would mean it needs RCD protection, So i'd put an RCBO on this circuit as protection. Your electrician should be able to come up with a solution to your problems. Sometime it's stares you in the face but you just can't see it.
KB

Posted: Fri Feb 20, 2009 11:47 pm
by rosebery
"Can anyone see any issues with this"

Yes see below.

"I know I will need to get an electrician to certify the work,"

No electrician should certify work he has not done himself. If he does you should look to see where he parks his horse.

Cheers

Posted: Sat Feb 21, 2009 1:57 pm
by JAP
Thanks guys will have a chat with my electrician my concerns with an RCBO is that it will also trip the Fridge its a new american style fridge and can only assume it's sensitive????

Posted: Sat Feb 21, 2009 5:22 pm
by kbrownie
JAP,
It should not trip RCD or RCBO unless excessive earth leakage on circuit. One fridge/freezer will not do this unless fridge is faulty or your RCD is!
Most electrical appliances have a degree of earth leakage, if a number of these are on the same circuit and are being used at the time this could cause trip problems.
KB

Posted: Sun Feb 22, 2009 10:28 am
by JAP
Thanks KBrownie,

I have an electrician coming tomorrow to test the circuit, he may find the issue. However I have been doing some reading and noticed that the 17th edition mentions having separate circuits for avoiding nuisance tripping.
Hence I thought I would put in a separate radial circuit.

All my checks seem to lead to the fridge as being the issue . Its a new fridge and I think it will be difficult to prove that its faulty to get an exchange. It normally takes about 24 hours for it be be left on and then start tripping the electrics. I have it wired temporarily on to a mcb on the non side of the RCD for over a week now and it has not tripped once. I have been in the house for over 5 years and not had any issues with nuisance tripping and the kitchen electrics are on the circuit protected by
the RCD.

I'll see what the professional says tomorrow but thought I would start work on the radial circuit anyway by doing some of the labour to cut down on the cost, i.e run the cable outside and back in to the house. I bought some 20mm conduit from B & Q yesterday.

regards

Posted: Sun Feb 22, 2009 11:35 am
by moggy1968
what about a 'c type' breaker?
can the other sparks offer an opinion on this?
your earth needs to be good enough to support this, although the use of an RCD gives you a lot more latitude. Your electrician can advise.

Posted: Sun Feb 22, 2009 1:23 pm
by JAP
Moggy1968,

By C type breaker are you referring to an RCBO e.g:

Wylex 30mA Single Module SP RCBO (Type C)

Google "tlc.direct.co.uk" and search their site for consumer units and then check out Wylex.

(I have a wylex split board CS hence searched uner wylex)

If so that could be a good idea I could put the kitchen ring on an RCBO instead of an MCB (RCD side) and connect the fridge up again and see if it starts tripping again. I presume I would get the same protection from an RCBO circuit than one protected by RCD??

I'll check with the electrician tomorrow no doubt he will test for earth leakage.

Thanks for your post.

Posted: Sun Feb 22, 2009 6:38 pm
by kbrownie
Sounds like a good idea getting electrician in, even though you intend to carry out some of the donkey work yourself. it's wise to have electrician to oversee and make sure things are done correctly. RCBO sounds logical choice, this device should be fitted to the side of CU that is not protected by RCD. Otherwise you could still have trip problems they act both as MCB and RCD.
Good Luck
KB

Posted: Wed Feb 25, 2009 8:09 pm
by JAP
Thanks KB,

regards

Posted: Wed Feb 25, 2009 8:17 pm
by moggy1968
using a RCBO is a good idea anyway for a freezer circuit because of the interference (i.e. your food thawing out!) if the RCD trips on one of your other circuits (which they do very easilly). Thats not what I meant by a c type breaker though. A B type breaker is the standard one used in a domestic setting, a c type though has less tenedency to trip when exposed to things like computers or other items with high start up currents such as motors. If yours is a very Gucci fridge it may be the problem, but equally I may be clutching at straws! thats why you need a spark really to have a look, and to swap your current MCB on the RCD side to an RCBO on the non RCD side