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PAT testing - Is it legally required

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Re: PAT testing - Is it legally required

Postby Hugh Robjohns » Sat May 07, 2011 10:55 am

geefunk wrote:once the school sees 'fail', they just assume it's gospel, and won't pay to have it re-tested.


The person doing the test has to have recorded the test result values and why the extension cable failed. A copy of these test results should be given to the 'responsible person' in your establishment.

If the extension cable failed because of an inappropriate fuse or the lack of an RCD, you can easily remedy that and return the cables to service.

If it has failed because or poor earth continuity, the test report should indicate that a proper resistance calculation was included in assessing the earth continuity. If that wasn't done the tester isn't competent and the company would be obliged to provide a free restest at the very least. ;)

But this is all speculation on my part... The bottom line is that the responsible person in your establishment (or you acting as their representative) have to talk to the company and/or the actual testing person to find out precisely why these extention reels (and the other things) failed.

After all, they were bought in good faith from a reputable company that is not allowed by law to sell unsafe electrical products. Moreover these things represent a significant financial investment and were purchased specifically to facilitate what you do.

If they have failed a PAT then they have to be removed from use by law... fair enough... but you should be told why and whether they can be repaired or rendered usable.

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Re: PAT testing - Is it legally required

Postby planetnine » Sun May 08, 2011 10:02 am

Geefunk, I'm going to muddy the waters now I think, on reflection I would not have failed that extension lead.

I can't remeber whether it was the 15th or 16th edition regs, but the number of recommended fuses for BS1363 plugs was reduced. Out of 3A, 5A, 10A and 13A, the 5A and 10A fuses are "non-standard" and 3A and 13A are the "recommended" ones. This is disputed by some elecricians and it makes me uncomfortable.

The fuse value chosen is decided by the manufacturer of the equipment, determined by the feed cable size and the load characteristics of the equipment. For low current devices (below 700W a 3A fuse is usually used along with a 0.5 or 0.75 sqmm cable (a manufacturer may recommend a 5A fuse to prevent nusiance fuses blows based on surge or start-up currents). Above 700W a 13A fuses is usually recommended.

If your PAT tester was testing according to the 3rd edition of the IEE Code of Practice, he's actually deviated on two points, but I know why and I agree with him to a degree; I'll come back to this in a minute.

The IEE code of practice states for formal visual inspection: "The fuse recommended by the manufacturer should be fitted." and for combined inspection and testing: "inspect the plug as for a formal visual inspection".

In appendix VII, Checks to be made on a plug, a cable and an extension lead: "Check the rating of the fuse. The manufacturers recommendation should be followed." and "Most appliances up to about 700W should have a 3A fuse fitted (red). Appliances over about 700W should have a 13A fuse (brown) fitted."

I presume that Jo-Jo have chosen the 13A fuse to deal with heavy startup/inrush currents that might be present on some appliances used with the extension lead (remember not a fixed appliance-type here). A 13A fuse should protect a 1sqmm lead against fire (if unwound) -it may get hot, but the fuse will blow before the cable melts. A 10A fuse would protect it better, but the 13A fuse is within regs.

I bet the reel is clearly marked with "Max rating 10A" and "Do not use above nn Amps unless fully unwound", thus placing clear duty of care on the user to keep within safe limits ;)

I would pass this item, but put a note in the results that a 10A fuse would be safer unless nusiance blowing is a problem. Being a Jo-Jo, I bet it also has an integral overcurrent breaker that will trip if more than 10A constant current is drawn (different time characteristics to the fuse to allow for transient currents). I do worry about 13A fuses in 0.75 sqmm (I just fit 5A and record it) or 1.0 sqmm IEC (kettle) leads though, as you never know which is as supplied and which is just user replaced.

Sorry if this appears confusing, but I hope there is enough info to take your PAT tester to task with this item. If he's failed it on a another aspect, that would be a different matter though.

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Re: PAT testing - Is it legally required

Postby geefunk » Mon May 09, 2011 10:53 am

Nathan, thank you for all of that information, most appreciated. I've just spoken to the PAT tester, and the reels failed simply becasue they are 10A cable, and need to be 13A.

That's all he said....
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Re: PAT testing - Is it legally required

Postby James Perrett » Mon May 09, 2011 12:03 pm

I have an older Jo Jo cable which is probably similar. In an industrial situation (like a school), the fuses have to be rated for the worst case situation. In that case it should be the rating of the cable when fully wound inside the case. Being cased, the temperature rise is probably going to be even higher than if it was an open reel so the fuse must be even more conservatively rated. The built in cut out is at the socket end of the cable so it will do nothing to protect the cable if there is a problem. If you want the cable to pass then just fit an appropriate fuse (probably 3 or 5 amps) and retest.

In future don't buy an extension lead with less than 13A capacity when fully wound.

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Re: PAT testing - Is it legally required

Postby Hugh Robjohns » Mon May 09, 2011 12:27 pm

Hmmm... I don't think he's right on that.

The IEE Code of Practice (3rd edition) doesn't explicitly rule out extension reels with cables below 1.25mm^2 (the size certified for 13A).

It discusses maximum lengths from the perspective of voltage drop for specific cable CSAs, and requires cables over those prescribed lengths to be protected by RCDs. Your extension reel certainly falls into that category.

Clearly, the cable should also be protected in some way to ensure it doesn't carry excess current -- and that's what the plug fuse and/or thermal cutout are for.

Despite the current standards not mentioning the 10A fuse, as geefunk states, it is still a properly certified value under BS1362, and personally I would fit a 10A fuse or lower to provide additional safety to augment the reel's own thermal cut-out protection. In fact, I'd fit an RCD plug too...

But whatever, I think he's wrong to have failed them purely on the basis of cable diameter.

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Re: PAT testing - Is it legally required

Postby planetnine » Mon May 09, 2011 2:05 pm

I would tend to agree with you Hugh, but the IEE PAT guide says what the manufacturer recommends, and then only states two fue sizes in its appendix. A ten Amp fuse would would also stop someone pulling 13A through it continually (it would blow within half an hour or shorter).

By the Guide, a 10A extension lead is permissible up to 10m in length, providing it has an earth conductor and that is within its required minimum resistance (0.1+R, =0.295 ohms). I make my leads from 1.5 (and 2.5) sqmm so I can have them longer and suffer less volt drop.

Having to put a 5 or even 3 Amp fuse to protecr against heavy use with the cable unwound does seem to be bordering on the ridiculous though -maybe the reels should be locked away and only used with supervision?

-saying that, I have had to fail extension reels because the cable was a solidified lump in the middle and wouldn't un-peel off the drum (hippy arts group) :crazy:

>

Edit: of course if the PAT tester is testing to a school or local authority schedule or policy (additional to the IEE guide) then the 10A reel may be outside its scope. I've had additional conditions place upon testing for appliances use by young people (labels and fuses) so this would be feasable...

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Re: PAT testing - Is it legally required

Postby planetnine » Mon May 09, 2011 2:18 pm

James Perrett wrote:...If you want the cable to pass then just fit an appropriate fuse (probably 3 or 5 amps) and retest.

In future don't buy an extension lead with less than 13A capacity when fully wound.

James.

Not sure you can at 10m, think even 1.5sqmm would have to be de-rated fully wound, and 2.5 wouldn't fit in the plugs and sockets easily.

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Re: PAT testing - Is it legally required

Postby ef37a » Sat Sep 10, 2011 4:54 pm

Standard IEC mains leads are only rated at 10A but crack open almost any 13PT and you will likely find a 13A fuse.

You won't find 10A plug fuses in a filling station at 10.35 on a Sunday night which is when the average muso needs one! It might not be absolutely right but it is better than fag packet foil!

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Re: PAT testing - Is it legally required

Postby dmills » Sat Sep 10, 2011 7:16 pm

One other point, in something like one of those jojo reels you could argue that the fuse exists to protect the cable in the event of a short circuit, the trip providing the limit on I^2T let through required to prevent the cable melting on the difference between 10A and 13A.

I would have passed the thing.

After all if you had an appliance internally fused or breakered at 10A, you would not think twice about feeding it from a 13A fuse, and this is pretty much that situation if you squint just right.

Now that said, most DIY shop extension reels are crap, but it is not the testers job to be the arbiter of quality, only of 'is it safe at the moment'.

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Re: PAT testing - Is it legally required

Postby Kendo Phil » Thu Dec 15, 2011 7:51 pm

Many years ago, as part of my engineering HNC I took a course and gained a qualification to instal 3 phase and single phase conections (to BS 1363 if my memory serves) the exam comprised being given a length of flex and a plug. You had to strip the flex and wire the plug then hand it in to the examiner, who then took it apart and checked for stray strands, correct installation and stripped lengths of cable etc.

On the table you had all the correct tools and a few rogue ones, such as a stanley knife. If you used the wrong tools and put a cut in any of the shielding you failed. Whenever I wired something I tried to maintain those standards to make sure what I did was safe.

However, being a cautious sole, I would be much happier to give my kit to somebody else to PAT test and let them take the responsability. Even if the problem was caused by somebody abusing my kit, I would have the legal backing of having put a system of protection in place, which could mean protection from a large fine. A fine that I suspect would be many times that of the cost of PAT testing.
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Re: PAT testing - Is it legally required

Postby ef37a » Thu Dec 15, 2011 9:35 pm

One precaution I took at my last but one employer was not to use my normal initial..Still my name! But I included the first letter of my middle name.

Since I was testing 100 or so production items a month I did not want anything coming on top with my monica forged on it!

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Re: PAT testing - Is it legally required

Postby agent funk » Thu Jul 26, 2012 5:26 pm

One thing to add (sorry if someone already has lots of replys here) is that I must say the testers do work in many situations where a visual test alone wouldn't have found the fault. Just in case some people might think they are a waste of time. Besides the obvious one of the earth connection hanging on by a single strand - passing the high current through burns it out and you get the fail - there is also the insulation test. The tester puts a high voltage across the connections and can spot many potential problems such as a hairline crack in the insulation of the wires, esp where they have rubbed on a chassis screw or fitting. There might be no connection, but the high voltage arcs across revealing the potential trouble. Of course you still have to use your eyes to find the fault, which can take awhile!, but at least you have confidence in it once it passes.

Some equipment might not like the insulation test, but I think most high voltage stuff would benefit from it. Not even sure if it's part of the PAT "test", even though the testing equipment can do it.
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Re: PAT testing - Is it legally required

Postby blinddrew » Sun Oct 22, 2017 5:13 pm

Looking to get some kit re-tested at the moment and getting some quotes, obviously one question is "how many bits of kit to be tested?"
I have done some reading around but it's not clear if a cable and a unit are tested separately or together?
I.e. if I have an amp that has a non-captive cable (standard IEC) then is that two tests or one?
Thanks
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Re: PAT testing - Is it legally required

Postby Hugh Robjohns » Sun Oct 22, 2017 6:07 pm

blinddrew wrote:I have done some reading around but it's not clear if a cable and a unit are tested separately or together?

They should be tested, logged, and labelled as the entirely separate electrical items that they are.

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Re: PAT testing - Is it legally required

Postby blinddrew » Sun Oct 22, 2017 8:56 pm

I thought as much. I shall double my estimate...
Thanks Hugh :)
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