PAT test and RCD protection.

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PS - "the floorlayers will be using welders" :?: :?:

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I am guessing from your question that you are being told by the main contractor that you must have your equipment PAT'd before going on site.

As others have said there is no fixed time period laid down anywhere but for construction sites the suggested norm from the IEE is a full Inspection/test every 3 month formal visual every month and a user visual WEEKLY

The main contractor will also enforce their own H&S policy on top of the guidance so in a nutshell if their policy is a full visual and test every week thats how often it needs doing. Usually though they go with the IEE guidelines.
 
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I thought a user visual each time it is used is more appropriate.
 
I agree with you it makes sense to check each time its used but suprisingly the guidelines for a 110v piece of equipment (withot going into the the discussion about moveable hand held etc) is weekly but if 230v every time its used
 
I am guessing from your question that you are being told by the main contractor that you must have your equipment PAT'd before going on site.

As others have said there is no fixed time period laid down anywhere but for construction sites the suggested norm from the IEE is a full Inspection/test every 3 month formal visual every month and a user visual WEEKLY

The main contractor will also enforce their own H&S policy on top of the guidance so in a nutshell if their policy is a full visual and test every week thats how often it needs doing. Usually though they go with the IEE guidelines.

No site not asking me. Im a assessor for flooring and the installers i assess keep asking me how often there electric goods should be tested. (electrical testing has nothing to do with what i assess)

I was under the impression that they needed a PAT test every 12 months and visual inspection EVERY time they use the tool.

Hence i have posted up here to try and get a idea of when electrical equipment should be tested.


I also get asked if they can use a RCD extenstion rather than 110volt. I cant seem to find a answer off the site formans

Basically im trying to find out what is correct so i can pass on the info when asked.
 
Tell them it varies from site to site, and that they have to check with each one before they start work.

Suggest that they only equip themselves with 110V tools and also buy a portable site transformer for when they're in environments where 110V isn't available.
 
Tell them it varies from site to site, and that they have to check with each one before they start work.

Suggest that they only equip themselves with 110V tools and also buy a portable site transformer for when they're in environments where 110V isn't available.


That is bascically what i say!


But going back to PAT testing are we saying this should be done every 3 months?
 
PAT testing bit has been answered but as to 230v that is not so cut and dried.

The problem is provision of 110v there are two main types of transformer the yellow brick and the steel cased hard wired.

In the main the hard wired transformer used on many building sites is a very good system.

However the same tools are wanted by the tradesman one sites which are not all out building sites but sites where building work is being done. The norm here is the yellow brick.

The yellow brick has a problem in to get the unit as small as possible it is common to fit a trip on the incoming supply rather than the out going supply.

If one of the 55v lines go to earth then the current will be 230/55 times bigger on the 110v side to 230v side so a 12A MCB will allow 50A to flow before the trip will open. Now 50A down a 1.5mm flex does cause it to over heat some what in fact it melts.

So there is a real problem in does the transformer make things safer or not.

Now the BS7671:2008 has the same rules for a 55-0-55 supply and a 230v supply and both must have an RCD with socket under 20 A (411.3.3) but under 32A (704.410.3.10) the "or"s include

"(ii) automatic disconnection of supply (Section 411) with additional protection provided by an RCD having the characteristics specified in Regulation 415.1.1, or

(iii) electrical separation of circuits (Section 413), each socket-outlet and item of hand-held electrical equipment being supplied by an individual transformer or by a separate winding of a transformer, or"

So using a 230v supply with an RCD is by many considered safer than the 110v bricks. It will be noted that BS EN 61558-1 and BS EN 61558-2-23 has to be on the yellow brick to show it complies and it is rare to find the numbers to show the transformer complies.

If the transformers complied I am sure the adverts would have it splashed all over them that the complied with it. But they don't say they comply. Also the standard covers auto-transformers and up to 1000 volt and it does not necessary cover external plugs and sockets so even it the transformer does comply it may not have the trips required by the regulations.

I would like to see yellow bricks banned as they cause so many fires having by-passed all the safety which would normally trip with a line / earth fault.
 
Now the BS7671:2008 has the same rules for a 55-0-55 supply and a 230v supply and both must have an RCD with socket under 20 A (411.3.3) ......

A socket supplied from a 110v reduced low voltage system does not require RCD protection, see note 2 below reg 411.3.3
 
Matty, site tools should be fully PAT tested every 3 months. Some sites will insist on tools being PAT tested by their sparks they day you start on site. No big deal really, I've had drills etc PAT tested almost once a month some years back. One drill I owned had more stickers on it than a F1 racing car had adverts. ;) ;)
 
Matty, site tools should be fully PAT tested every 3 months. Some sites will insist on tools being PAT tested by their sparks they day you start on site. No big deal really, I've had drills etc PAT tested almost once a month some years back. One drill I owned had more stickers on it than a F1 racing car had adverts. ;) ;)

And if your tools are Class II, what tests are actually required?
(Hint: Only two tests are usual, one is non-applicable, the other is pointless)
Formal Visual Inspection - two minutes and a sticker, job done.
 
411.8.3 Requirements for fault protection
Fault protection by automatic disconnection of supply shall be provided by means of an overcurrent protective device in each line conductor or by an RCD. and all exposed-conductive-parts of the reduced low voltage system shall be connected to Earth. The earth fault loop impedance at every point of utilisation, including socket-outlets, shall be such that the disconnection time does not exceed 5 s.

In the main the earth loop impedance for a supply taken from a yellow brick type transformer will not allow automatic disconnection of supply within the 5 s allowed with the built in overcurrent device. So in most cases Note 2 of 411.3.3 will not apply and a RCD will be required.

The internal resistance of the secondary windings of the yellow bricks are often too high to get the readings required that is of course if you have a meter able to work on 55 volts which is also a problem.

You will also note it says "in each line conductor" so the idea of having a overload on the supply side to protect the output is not permitted. So all the yellow bricks I have seen to date don't comply with BS7671:2008 and as such should not be allowed on site.

As I said the larger metal cased transformers with MCB's on each output are good and in the main comply. I am told there was a dispensation and it is permitted to have two 16 A sockets supplied from one 20 A MCB but to date no one has been able to show me where they have officially seen this. It would be interesting if anyone can confirm this?

This yellow brick problem give the safety man a problem as to require people to install the larger transformers for a small job is unreasonable and so once pointed out that one can't use the yellow brick he has to find an alternative. The only way I can see is to use the in-line RCD units but not sure about a unit that could be un-plugged?
 
Why do you think a portable plug in transformer (yellow brick) will come under the Requirements for Electrical Installations BS7671:2008?
 

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