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PAT testing - Is it legally required

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Re: PAT testing - Is it legally required

Postby planetnine » Sun Apr 24, 2011 10:00 am

dmills wrote:
Nathan wrote:
I gave up fighting it all and bought a computerised tester -the database helps me keep track of tests and equipment locations, and as electrical testing is easy and almost automatic, I actually test many larger flex cables very regularly - some before each job for peace of mind.
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Which to my mind sort of misses the point, it is NOT the test box that should be finding problems, it is the visual inspection!



The test box will for the most part only find things that are already broken, where a good visual (inspect the whole cable for nicks and other damage, open up the plugs and make sure the screws are tight and the fuse is appropriate), will often find loose screws, heat discolouration, damaged fuse holders....


please note the bold text Dan, we're actually in agreement here; most problems are visually spotted, but that won't find many earthing and a good many insulation issues. If you set the correct protection (earth) conductor impedance in your PAT tester for the length and conductor x-sect area of the actual cable (rather than use a default setting), you will find strand loss in earth wires and loose earth sockets in extension sockets that would not show up in a visual (yes, I will test all sockets on a six-way dist box).

Damp in some connectors, cables, light fittings isn't alway easy to detect, but with show up in the insulation test (even if it doesn't fail, I look at trends on my outdoor stuff).

You should know from my previous posts on this subject that we concur on most faults being found visually, and it's one of the things many "quantity" companies skimp on. Don't froget that PAT testers can store the results of visual tests, and you can add notes to an asset on them, I rely on this, as well as it telling me where the asset is located (I have over 1000 items of my own to keep track of now, damn festival cabling). The Supernova I got saves me mucking around with various multimeters and current sources, low impedance testers, etc.

The worse bit is writing out the stickers anyway ;)

By testing I did mean the whole visual and connector disassembly inspection too Dan. I feel the biggest point I "gave in" on was the stickers ;)

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Re: PAT testing - Is it legally required

Postby dmills » Sun Apr 24, 2011 11:08 am

Yea granted, and you do know you can get a sticker printer that plugs into the supernova and even a barcode scanner for it (Ebay quite often).

My point was really for the benefit of those watching, that the IMPORTANT part is the visual.

Regards, Dan.
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Re: PAT testing - Is it legally required

Postby zenguitar » Sun Apr 24, 2011 1:47 pm

Nathan wrote:
zenguitar wrote:
...A friend of mine works as a handyman in a local Care Home and they are putting him through the course because it worked out cheaper than getting an electrician in. We did the sums, and at the going rate he could easily make £40 an hour just doing PAT tests.

One course, one machine, a stock of labels, a white van with magnetic promo panels, couple of sweaters with embroidered PAT TESTER logo's and a white lab coat with one of those fancy pen holders in the pocket. Then approach all the Care Homes for 50 miles.

Andy :beamup:

£40 at £1.50 per test? That's 26 to 27 items an hour. Not testing properly. And some companies are offering £1 a test, ridiculous.

I test for some charities and a couple of businesses I know/work with, but I wouldn't do it commercially. You earn less than running a studio if you do it properly, and feel less ethical than teaching music technology if you slap stickers on at that rate.

I agree Nathan, essentially plugging into the test machine, pressing TEST and printing out the sticker. In the Care Home it is 3 or 4 plugs per resident's room, 2 or 3 lamps and a clock radio (no kettles allowed in the rooms) not a lot to visually inspect, but still nowhere near enough time for each.

The course my friend was sent on to do this was one afternoon.

And that highlights the problem with any sort of testing like this. It is perfectly possible to go on a short course to learn to use the machine and be given a quick 'painting by numbers' guide to visual inspection and pass the course with little or no real understanding.

Done properly as described by previous posters, it is a useful practice. But in most cases it is a box ticking exercise to show that they have a Policy and a means of delivering it.

Andy :beamup:
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Re: PAT testing - Is it legally required

Postby planetnine » Mon Apr 25, 2011 8:25 am

I tested the appliances in a local garage where I get my vehicles serviced. Eighty-odd items over seven or eight hours, and I thought that was going some, considering I had to unthread the computer systems and put them back together again :crazy: -most failures involved re-cabling hand-tools.

Previous testing had been done by an established company (from yellow pages). They swore the guy who turned up had not been on site more than an hour, and we found stickers on hard wired alarm systems that would have needed isolating, on low voltage things like laptops (in addition to their PDUs), and then the number of stickers and asset numbers we found did not correlate with the amount they'd been charged.

This seems to be quite common, too. I can't do a bodge-job, it's not me. I wouldn't make much money PAT testing commercially.

Dan -I've considered the bar-code reader. If it stores the asset number and the item's test code, then that could be good for repeat stuff. Means a lot of mucking about with printing labels though, or an expensive portable printer with expensive proprietary labels.

My, haven't we taken this on a tangent?

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Re: PAT testing - Is it legally required

Postby geefunk » Thu Apr 28, 2011 1:49 pm

I neeed some advice on this too. I'm in a school, and we've just had an annual PAT test, and 8 of my brand new, still in the box power extension reels were failed because they have 10amp cable (13amp plug/fuse), and it is thinner than 13amp cable, so illegal?

We already had one in the school, and it was passed by the company last year, but a different company have failed it this year. What is the situation?

Thanks
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Re: PAT testing - Is it legally required

Postby Hugh Robjohns » Thu Apr 28, 2011 2:32 pm

Quite obviously, a 13A fuse is wholly imappropriate for a cable rated at 10A, and that would fail it instantly. The plug should be fitted with a lower value fuse.

The PAT guidance for extension cables says that they must always be three core (LNE) and should not exceed 12 metres in length for core diameters of 1.25mm2, 15m for 1.5mm2 and 25m for 2.5mm2. Smaller cable core diameters are not specified as far as I know, although where the cable length is longer than those listed above the cable can be used if protected by a 30mA RCD.

The 25m, 2.5mm2 extension cable should be fed via a 60309-2 (16A) plug by the way, rather than the standard BS1363 (13A) plug.

Your 10A cable probably has core diamters of about 1mm2, which is outside the PAT guidance values and so I can see why someone ticking the boxes might fail it on a PAT test.

You don't say how long your extension reels are, or whether they have built in RCDs... both things would affect the test.

However, if the extension cable is less than about 10m and/or has a built-in RCD then I think it would probably be okay assuming a sensible size of fuse in the plug.

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Re: PAT testing - Is it legally required

Postby geefunk » Tue May 03, 2011 10:11 am

Thanks Hugh - I still haven't got to the bottom of this. The reels I bought are these:

"JOJO 10M/10A/4SKT EXTN REEL P/N: 141-4978

JO-JO EXTENSION REELERS
Quad socket extension reel.Features a safety cut out button, just push the button to reset if the overload safety device cuts out.
Suitable for most domestic appliances and power tools.
Colour: Red/Black
Length: 10M - 10A rated "
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Re: PAT testing - Is it legally required

Postby geefunk » Fri May 06, 2011 8:06 am

ok, the company I bought the reels from are now telling me that a 10A cable with a 13A plug can be fitted with a 10 or 13 A fuse?

I'm confused..... :?

Are there any sparkies here who can give me a definitive answer?

Thanks
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Re: PAT testing - Is it legally required

Postby Hugh Robjohns » Fri May 06, 2011 8:58 am

The plug fuse is there to protect the cable and nothing else. If the cable is rated at 10A then it should have a maximum ten amp fuse in the plug. It really isn't rocket science. Putting a 13 amp fuse in the plug means that the cable is no longer adequately protected.

The query is over this 'cut out' device which I presume is in the plug board section. If that is a simple current overload device then it is acting in the same way as the fuse to protect the cable, and that being the case it could be argued that the size of fuse is no longer relevant -- which is what your quote seems to suggest.

However, you are then totally reliant on the cut-out device operating to protect the cable and that would require appropriate certification before it would pass a PAT test. Fuses are approved, and a 10A fuse will pass the test regardless of the action (or not) of the thermal cut out.

On the other hand, if it is an integral RCD device then it offers no specific protection for the cable and we're back to needing a correctly rated fuse.

And then we have the issue of cable length, which as I explained above, if over a set length for the cable cross-sectional area must be protected with an RCD.

So the best course of action as I see it, is to have a discussion with your PAT testing company to establish exactly why the extensions reels failed -- they have to log the reason as part of the test -- and to agree on a plan of action to render them usable... which I suspect will mean fitting 10A fuses and RCDs in the plug-ends.

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Re: PAT testing - Is it legally required

Postby geefunk » Fri May 06, 2011 9:43 am

Thanks Hugh - I really appreciate your advice and knowledge. I was going to call the PAT tester anyway, but just needed to be clear about our side of things before they started talking Amps and Ohms at me! ;)

Thanks again.
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Re: PAT testing - Is it legally required

Postby The Bunk » Fri May 06, 2011 12:01 pm

Sounds like Hugh has answered the question but I work with a fully qualified (to 17th edition) Electrician so am happy to ask him anything on your behalf if needs be....
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Re: PAT testing - Is it legally required

Postby geefunk » Fri May 06, 2011 2:12 pm

The Bunk wrote:Sounds like Hugh has answered the question but I work with a fully qualified (to 17th edition) Electrician so am happy to ask him anything on your behalf if needs be....

Thanks Bunk, and please do - I would appreciate as many opinions as possible. I think one of the problems surrounding this are the different issues that exist because I'm in a school. The fact that the very same extension reel passed last year, but not this year, is a good example.

I think ultimately I am going to just send them all back to the company and buy different ones - but my problem now is just not knowing which ones are going to pass? I would never have thought the ones I did buy wouldn't be suitable, considering they are from a well known supplier, etc. But school rules seem to be different.

It's a bit of a ball ache, to be honest :roll:
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Re: PAT testing - Is it legally required

Postby Hugh Robjohns » Fri May 06, 2011 2:35 pm

Exactly the same rules apply to all -- offices, schools, factories, hospitals and so on -- but there is a degree of application in the rules and not everyone interprets things in quite the same way.

Added to which, although the person doing the PAT must be a 'competent person' my own experience on the receiving end has indicated that some are more competent than others!

Another common problem is that some testing units provide a simple pass-fail indication which some testers take as gospel. However, there are situations where a fail indication doesn't actually mean fail -- and that could be what's happened in your case.

For example, the earth continuity requirement (for a Class 1 device, which an extension cable would be classed as) is for a resistance in the protective earth (cpc) path of not more than 0.1 ohms. And the simple pass-fail testers have that resistance as their test threshold. Any more than 0.1 ohms and they light up the fail flag. End of story.

However, long mains cables have a certain resistance due to their length and cross-sectional area. The longer the cable, the higher the resistance. That's the real world. So a long cable is quite likely to have a resistance rather greater than 0.1 ohms perfectly legitimately.

The actual PAT earth continuity requirement is 0.1+R ohms where R is a value determined by the cross-sectional area and the length of the cable concerned. It's all documented and all you have to do is measure the cable and look up the allowed value... but the simple testers have no facility to account for this extra R, and so issue a fail flag.

A competent tester would work out the actual permitted resistance for the cable and note the measured reading from the test unit to see if the latter is less than the former... in which case the cable passes despite getting a fail flag from the automated PAT unit.

As I said, some PAT technicians might not bother to do the sums and fail things on the basis of what the machine says!

Hugh
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Re: PAT testing - Is it legally required

Postby The Bunk » Fri May 06, 2011 4:19 pm

geefunk, I'll have to wait til Monday now but I'll certainly ask.
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Re: PAT testing - Is it legally required

Postby geefunk » Sat May 07, 2011 8:43 am

Another problem I have though, is because the PAT tester failed things, added to that the majority of people in the school don't understand the rules that govern becoming a PAT tester (the fact that you and I could do it), once the school sees 'fail', they just assume it's gospel, and won't pay to have it re-tested. I'm scuppered really. It's not just about these extension reels, the PAT tester took a few other things from my store room, and it's proving tricky to get them back without an actual electrician giving it the go ahead. It doesn't seem to matter what I say.

But thanks again Hugh - I really do appreciate it.
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