How then would you be able to gain accurate test readings? Surely by doing it this way you'd essentially be testing the appliance?

Also, if it were to fail (not now necessarily, but in the future), how would you know which item had caused the fail?

If you have loads of items for test, for the sake of saving time, new tester kits are peanuts in comparison when the time saved is amortised.

Pete,
The above posts are good.
Also please do not get sucked into the PAT everything every 12 months and don;t touch inbetween as that is almost useless!
Especially as you seem to be involved with engineering.
Empower the users to undertake user checks and encourage them to do them and report any failures for repair and that these failures must not be used!
Then get a competent check "perhaps" monthly and record it.
There is MORE to "PAT" than the annual combined inspection & test.
Oh and your director is plain wrong!

p.s. i have PM'd again.

"A moment of shame is preferable to a lifetime of ignorance, as the saying goes, so here goes:
How does one "PAT" test an extension cable? Let's assume I can plug it in to the tester, and let's assume too there's a calibrated wander-lead I can clip on somewhere (maybe using the earth pin cannibalised from a plug) to enable earth integrity to be tested.
Presumably the remaining test (for a Class 1 cable) involves the PAT machine joining all phase connections together and testing the insulation resistance to earth.
Do I really need some other appliance involved to enable a loop to be made? If the insulation is going to breakdown, then surely it will, regardless?
Double insulated cables could only sensibly be 'tested' using a hand-held probe, not something I would want an electrician doing in my office (the 30 A wander lead for earth testing is bad enough!) - so I guess there's no sensible PAT field test (outwith a purpose built test bench) for Class II cables or appliances these days? Or has PAT testing moved on since I was last involved? What exactly does a modern PAT meter do to a Class II appliance when I press the "test" button?"

Class I cables should be subject to an earth bond test, an insulation test and polarity test as far as I'm aware.
Class II appliances should be subject to an insulation test and a leakage test. Class II cables only a visual inspection. As far as I'm aware.

"How then would you be able to gain accurate test readings? Surely by doing it this way you'd essentially be testing the appliance?

Also, if it were to fail (not now necessarily, but in the future), how would you know which item had caused the fail?"

That was my line of thinking too......

"Pete,
The above posts are good.
Also please do not get sucked into the PAT everything every 12 months and don;t touch inbetween as that is almost useless!
Especially as you seem to be involved with engineering.
Empower the users to undertake user checks and encourage them to do them and report any failures for repair and that these failures must not be used!
Then get a competent check "perhaps" monthly and record it.
There is MORE to "PAT" than the annual combined inspection & test.
Oh and your director is plain wrong!"

We have set up an SSoW in which all employees are expected to make user checks on all equipment before any works and report faults immediately. I was going to use some advice and my own knowledge of just how much and what conditions the tools are used in and implement the following; IT and office equipment PAT every 12 months, 110v tools every 6 months and 240v tools every 3 months with any tools going "on-site" to be moved onto a 3 monthly schedule. We have a separate polishing shop and was thinking all tools in there (mostly 110v) to be done every 3 months due to the dust levels. Does that sound sensible? This is our first attempt at getting a decent H&S system and procedures in place so everything we're currently doing is subject to ongoing review but I thought that was a good starting point. Any feedback would be appreciated......

I was rather hoping Paul Skyrme would pick up on my confessional.............. when I was closely involved with PAT, my machine was a two-man lift, and came in a range of colours lifted from a Morris Marina brochure!

Nick, out of interest, in all that time (don't know how long you've had your program running) have you recorded any failure that a formal visual wouldn't have picked up?
My own view is that there is a strong business case for not PAT testing IT kit at all. The tests themselves are very limited. Failures are (IMHO) non-existent. IT kit tends to be replaced/ upgraded within a 5yr cycle anyway.
The only real risk issues arise from abuse of power cables and extension leads, (or a ring-main needing upgraded!) which a proper culture and system of formal visual and workplace inspections should pick up anyway?

Mainly because our office is subject to contamination, especially metal particles, more than most offices. Our office is attached to the workshop and everyone is free to wander in and out. We will often go out and work on the workshop floor when its busy and I can see plenty of aluminium swarf already building up on the carpet again. Good house keeping reduces this but its just impossible to completely avoid. Given the circumstances, you think I'm being excessive?

Pete,
Yes I do think you are still being excessive with kit that is not moved for 12 months at a time, IF that is the case.
IT kit or any transportable kit that is rarely if ever moved IMHO does not need testing every 12 months, HSE & IET guidance is there on the frequency.
However, leads on the floor to these items could be subject to damage from metal swarf, thus these should be visualled more often and possibly full I&T annually.
The only thing with the IT and other stationary kit would be the ammount of true metal dust in the atmosphere of the office.
Almost no PAT testers would take the case off the PC to check inside for metallic contamination and it may not necessarily show up on the test immedtiately.
There is circuit protection for this.
Many pc's have their cases locked to prevent entry by unauthorised persons in large organisations anyway, data & parts thefts etc.
Your informal & formal visuals should soon build a picture of your needs, you could then pro-actively manage your inspecting & testing intervals accordingly
Dust contamination is a bit hit and miss to be picked up on a PAT of any form, if it is really bad, perhaps PPM's need to be looked at?

Ron H,
How would I know you worked with the PAT machine Noah used! ;)
I was not going to get into the technicalities of your post when I last replied, as I was very tired! ;)

HTH

Paul;

I see what your saying, in our case specifically; most office cables are in cable runs attached to the walls so should be pretty safe from contamination. I was more concerned about metal dust gaining access through fans or vents (as we don't have lockable cases), a thorough visual should pick up on significant contamination, as you say; so, I concede. Having thought about it more fully I agree with your view. Originally I based our schedule on some recommendations made to us, however, after reading HSG 107 it seems clear that advice was given on the basis of us being a "construction" firm. Which we're not. We do not have the same risks as site work or heavy engineering, so I've actually changed my mind about most of the frequencies (tools in our polishing shop being the only exception).

stillp;

I agree with these points, however, it is something I have been asked to do by my employers. We have a written SSoW (for portable electrical tools) which explains all the user checks we expect (and have trained staff) to carry out. I've managed to convince my director he was wrong about his "dummy appliance" ideas, now I've got a bit of back-up! New kit on the way.

The point of the thread wasn't so much about PAT in general; but about this concept of testing extension cables with this odd suggestion. Still, its been very useful getting some more experienced opinions and viewpoints. Thanks everyone for the input and taking the time to help out!

Phil,
Obviously I see your point, but, IF the full implementation is done as per our last "agreement" then you have like 12 MOT's a year! ;)
Smileys would be good on here as well as an EDIT facility!!!

Iwas still hopeful that someone could educate me as to what a PAT test machine actually does to a Class II appliance when the 'test' button is pressed?

Much obliged for that Grizzly. Confirms what I recall from my testing days a long time ago.
As you say, many appliances don't have exposed metal parts (or where they do there isn't any way to clip to them). Some appliances with instant-release on/off switches would need these clamped closed too during the test.

For me this illustrates the real importance of the visual inspection -particulary regarding cable damage. Cable insulation could be nicked down to the copper conductor, but the test machine won't "see" that.

Ron, you make a very valid point, and this is why I suggest that a user check/pre use check, if carried out correctly is an vital part of any maintenance regime. I would go as far as to suggest that IF it is done, and done propoerly, that it is the most important part.

Grizzly, but they are (or at least can be) separate aren't they? While I absolutely agree that a formal visual should be an integral part of the PAT there are plenty of occasions when a PAT is not necessary but a formal visual would be. This is an approach recommended by the HSE for many items of kit, mainly class 2 to which Ron referred earlier.