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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Electrical Questions >> Self Build Electrical site safety https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1090751777 Message started by horlicks on Jul 25^th, 2004, 11:36am

Title: Self Build Electrical site safety
Post by horlicks on Jul 25^th, 2004, 11:36am

I am about to start a new self build house project. I am considering the question of a temporary electrical supply. Can someone give the the definitive answer to the question of whether 240V is legal on a single dwelling construction site. ? I appeciate that the majority of contractors use 110V but my question is, is this a definite legal requirement from a HSE point of view.

I have heard that 240V is allowed provided that ceeform connectors are used.

If I have to go down the 110V route I will have to buy all new power tools.

Title: Re: Self Build Electrical site safety
Post by The_Trician on Jul 25^th, 2004, 2:32pm

I reckon you couldn't do the job without 240v on site mate!

From 240 comes 110 via a suitable transformer.

If you are employing tradespeople, then they'll bring 110v kit with them. It is not lawful for THEM to use anything other whilst on site.
BUT - if it is YOU who is carrying out the works, then I cannot see the difference between using a 240v hedge-trimmer and a 240v cement mixer, so long as it is not a tradesman who is using it.

Any tempory 240v supply should be protected via an RCD rated at 30ma and have a 0.2 sec disconnection time, not 0.4 secs.

I'll get some more views on this from others who have direct site experience.

TT

Title: Re: Self Build Electrical site safety
Post by Beanzy on Jul 25^th, 2004, 4:54pm

Yep 230V kit is legal on a site but other precautions have to be taken. Whole sheebang has to be 30mA RCD protected and ideally a 240-240v isolating transformer should be used. Heck you can use 11kV on a site if it's in the correct circumstances, and correctly done (ie for crane supplies etc.) hand-held stuff has to be 30ma protected, but RCDs fail so 110v with 55v to earth is used as eliminates most of the risk without additional special measures.

A good starting point is to get a copy of HSG141 "Electrical safety On Construction Sites" Then get a properly designed system put in. You can either build it to suit or there are ready built systems you can get from suppliers like "The Rubber Box Company". Why not get your electrician to design something which will give you an isolating transformer with downstream RCD protection and a second 110V transformer fed on its' own breaker?.

Title: Re: Self Build Electrical site safety
Post by Lectrician on Jul 25^th, 2004, 5:00pm

The IEE regs require 110v for hand tools.

Many a construction site uses 240v - battery chargers and radios commonly get plugged in an extension lead from the site hut :-)

I dont think you will get a definitive answer, if you put a 110v trani on site then atleast other trades have access if required, and you can use your 240v.

Most people use petrol mixers on site.

Title: Re: Self Build Electrical site safety
Post by L.Spark on Jul 25^th, 2004, 5:02pm

you can always get site generators that generate at 110V

Title: Re: Self Build Electrical site safety
Post by HandyJon on Jul 26^th, 2004, 11:22pm

you can always get site generators that generate at 110V

or 240V! ;)

Title: Re: Self Build Electrical site safety
Post by L.Spark on Jul 27^th, 2004, 12:56am

lol yea if you like ::)

Title: Re: Self Build Electrical site safety
Post by plugwash on Jul 28^th, 2004, 2:50am

im sure all but the smallest portable generators i have seen have had both voltages

btw a point about 240-240 isolation transformers the output of them is not bound to earth in any way so putting a rcd on thier output is totally pointless (ie you will never trip it)

Title: Re: Self Build Electrical site safety
Post by tellondon on Jul 28^th, 2004, 7:35pm

If you provide a 110V transformer at the source of the 240v supply at least you have covered yourself
If the tradesmen havnt got 110v and they plug into the 240 thats there problem if something happens
Seems like health and safety is all about covering your arse these days
As long as you provide a safe option, if they choose to take a different option thats there problem not yours

Basically just cover your own arse and provide a safe way for the contracters to work,then if they want to take the risks thats up to them

Title: Re: Self Build Electrical site safety
Post by L.Spark on Jul 28^th, 2004, 10:57pm

and at least half is good stuff anyway, I always use PPE if i have it with me and if its needed, the HSE don't want people claming because they havnt took good precautions, and no one else wants to fork out for the people who didnt use it either, when they need NHS treatment or anything else ::)