Junction box rating

Postby meldrew21 » Tue May 11, 2010 10:47 pm

Hi there, would appreciate some advice on the use of a junction box.
Hall ceiling is down so I would like to use this opportunity to move an electrical socket which will involve extending original cable.

Can I use a junction box for this, and would it be within regulations to use one that is rated at 20 amps? The socket will only be used to run a vacuum cleaner, drill or possibly power washer.

Thanks in advance.
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Simply Build It

Postby ericmark » Wed May 12, 2010 5:39 am

If the junction box will not be accessible in future then a maintenance free type must be used. These normally use spring clips and have no screws as screws with vibration and expansion/contraction can work lose. Hagar make some.

2.5mm cable rated at between 13.5 and 27 amps according to route and the JB should be rated as good as cable. With a ring since supplied from both ends the cable does not carry full 32A so you can use less than 32A but you must test to confirm it is a ring main and you should raise paperwork to go with buyers pack if house is ever sold to show what you have done and the test results obtained.

The Part P information sheet gives samples of these and the IET web site allows you to down load them without any watermark.

Google "theiet.org/publishing/wiring-regulations/forms/index.cfm"

As to permitted extra sockets the IET had to publish a correction which has the official chart as to what is allowed so you can download this correction here (Google "theiet.org/publishing/wiring-regulations/updates/") top of list last page shows what is permitted.

You are unlikely to get proper JB's in DIY sheds you will need electrical whole sale outlet.
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Postby meldrew21 » Wed May 12, 2010 11:35 am

Thanks for the comprehensive reply, Eric, I'm glad I asked.

Without your advice I would not be aware of maintenance-free JB's and still be under the impression that I could use a general junction box for mains in joist space. This isn't helped by the fact that the DIY sheds only stock the general type, as you say. Not that I would have connected it or replaced the ceiling before approval but it would have cost me the time and money I'd tried to save by doing the donkey work myself.

As it stands I'll run the cable, site the outlet and get a contractor to install the JB and complete the paperwork.

On the subject of paperwork, I had a consumer unit fitted last year. Does that work need to be certified for a homeowners pack?
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Postby ericmark » Wed May 12, 2010 6:45 pm

There are four bits of paperwork which can be required for any electrical job.

1. Completion certificate issued either by LABC or Scheme provider normally on the strength of the other bits listed below. It is not needed for all electrical work but it is required for a consumer unit change.

2&3 Installation certificate or Minor works certificate these can only be issued by people doing the work however they can have three signatures so different person signs as having done the work to having tested the work but to use three signature types normally means direct LABC not through scheme operator.

4 Periodic inspection report should be done every 10 years or on change of occupant these can be done by any appropriately insured electrician since they rely on his skill not his workmanship normal public liability insurance often does not cover and he needs professional indemnity insurance.

Some LABC will accept a "Periodic inspection report" to post event issue a completion certificate although they could demand it is re-done. The main problem is in 2008 the regulations changed so an A1 installation in 2007 could have code 4 non complainant if a "Periodic inspection report" is done now.

Only the Completion certificate is law. Although any electrician worth his salt should issue a "Installation certificate" and if it was not a home he would be breaking the electricity at work act by not issuing one. Part P was basic to extend the law to cover homes the way it covered commercial premises. The informing of the LABC or use of a scheme member is the responsibility of the home owner which is a loop hole used by electricians to avoid prosecution. Only if they claim to be scheme member and are not are they committing a crime. Blame two Jags he brought it in. However you are allowed emergency work and to inform LABC post work. So if the consumer unit was damaged any electrician could do the work to make it safe and inform the LABC after so there is a procedure for post notified work.

It is of course the same for any building work. Although most builders will take care of the LABC for you at end of the day they don't have to. Biggest problem is where an electrician has done work he thinks is covered by an existing notification to LABC as with an extension but builder did not include it on original request.
However unless the electrician has issued a installation certificate he can hardly claim he didn't know as he would realise you need the installation certificate to get completion certificate.
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Postby sparx » Wed May 12, 2010 8:54 pm

jumping in on this one!

The change of a consumer unit must have not only a
full set of installation certificates to IET 17th edition regs.
but is notifiable work to LABC as covered by Part P of building regs.

Whoever did the work should issue you with certs. and notify the job.

You should receive by post a form confirming work notified within 30 days.
This is not only a legal requirement but as you ask it will be a question in the new HIPs pack, eg
"Do you have certs/notifications of all electrical work carried out on the property since 1st January 2005?"
If answer is no you will be required to have a full Periodic Inspection Report carried out before putting property on the market,

sorry for long post but this is going to be quite an issue soon,
regards Sparx
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Postby meldrew21 » Wed May 12, 2010 9:41 pm

Thanks for that info, Sparx. I'll be getting in touch with that contractor.
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Postby meldrew21 » Thu May 13, 2010 8:33 am

Thanks again, Eric. I'll be taking that up with the contractor.
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Postby ericmark » Thu May 13, 2010 12:22 pm

If the work is done by an electrical contractor who are members of NICEIC, NAPIT, ELECSA, or BSI then they have to provide you with the Installation Certificate and as Sparx says the completion cert should arrive within 30 days in post.

If they say they are members and are not the LABC will prosecute.

If the electrical contractor is not a member then the work would need to be pre-notified to LABC.

This is where I feel it is all wrong as it is the owner who has to notify. Most electrical contractors will do it for the owner but they are not obliged to. Unless a installation certificate is provided then any electrical contractor must know the owner can't satisfy the LABC and they must know the work has not been registered so they must be guilty of flaunting Part P. However I have only seen court cases where they have said they are members of one of the scheme operators and are not, or have done well below standard work.

Personally I think the LABC should issue a permit to work and any electrical contractor who is not a member of a scheme should not be able to start work without sight of the permit. However at the moment that is not the case. So all the electrical contractor has to do is say they thought the owner was dealing with Part P and there is very little one can do about it.

Where the electrical contractor is a member of a scheme then if they don't provide the paperwork all you need to do is contact scheme provider and they will sort it all out for you.
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