PAT Testing

[Newlands]

The school I worked at had the PAT testers in now and again. They hated my workshop - 25 computer workstations with separate plugs for machines and monitors, about 30 soldering irons, a shed load of hand tools, other equipment such as plastic forming, cnc plotters, printers cnc routers etc.
We occasionally had a couple of soldering irons fail because the lead had a burn mark, but nothing apart from that. And I can’t remember any student or parent ever bringing anything electrical onto the site. And no plugs were harmed in the testing of our equipment..

 

[Brad93]

Our electricians do it for our equipment on our site, but they won't touch 3 phase equipment. I can't remember if they said their tester didn't do 3 phase, or if its because they don't class 3 phase as portable... i dunno lol

Well welding machines are definitely portable lol.

When I’ve been involved with two different welding equipment engineers both carried out tests and issued certs for three phase welders

 

[dannyp]

portable it depends on who's definition you go by. i know some that class anything that can be got in, on or draged by a transit van to be portable....

3 phase sets are defantly portable the red plugs are a brilliant way to deal with some clipboard wombels.

 

[brightspark]

any appliance that has a plug on is classed as portable. its not fixed wiring

 

[Pete.]

We've got a 14 ton item of mobile plant with a PAT test on it. The 100amp 3 phase lead that supplies it is barely portable

 

[earthman]

It wouldn't of done.
That's why the first stage is to a visual on each item. Before you plug it in to the machine.

Lol, yeah I know but you are missing my point here. I'm sure that at some time the human eye would not spot something and then plug the machine into the tester. Would the machine show a fail then?

 

[The_Yellow_Ardvark]

Lol, yeah I know but you are missing my point here. I'm sure that at some time the human eye would not spot something and then plug the machine into the tester. Would the machine show a fail then?

That is why there are 35 steps of visual inspection and record taking.
All the machine will measure the resistance between the cores and the insulation resistance.

PAT is a lot more than plugging it into a machine.

The sad thing is a lot of companies use a "Cheap/free PAT" inspection to get a foot in the door.

 

[The_Yellow_Ardvark]

We've got a 14 ton item of mobile plant with a PAT test on it. The 100amp 3 phase lead that supplies it is barely portable

The big open pit rotating shovel arm has a plug on it.
That has a PAT sticker on it.

 

[earthman]

That is why there are 35 steps of visual inspection and record taking.
All the machine will measure the resistance between the cores and the insulation resistance.

PAT is a lot more than plugging it into a machine.

The sad thing is a lot of companies use a "Cheap/free PAT" inspection to get a foot in the door.

My question still stands, how often does the machine on it's own actually shows a 'fail' then?

 

[brightspark]

My question still stands, how often does the machine on it's own actually shows a 'fail' then?

depends on what appliance is been tested and the conditions there used in .heres the tests that are performed https://www.pat-testers.co.uk/produ...MI4qDpx5fT7AIVxbTtCh10QAVaEAAYASAAEgLx2_D_BwE the majority of fails would be on class one appliances corroded earths or mainly pulled out of plugs .earth leakage on washers tumble driers kettles and irons

 

[Endeleus]

Right so then. Say I create a log of all equipment and carry out the PAT testing myself. What would be a good machine to go for?
Grinders, drills, lights, cables etc being the main items, all 110V. But also three phase welder?

We use a Megger PAT450 which also does flash testing for on-site kit, but that's towards the upper end of the PAT range at north of £1k, there are perfectly good testers in the £200 - £500 range it's for your own use rather than testing as a service every day.

Back to your original question on price, around £2 per item is a reasonable price for a qualified / registered / insured inspector, who would likely keep a copy of your test records for 6 years should the audit trail be needed.

If you are contracting someone, they shoudl have Professional Indemnity insurance which covers electrical inspection as well as the usual liability insurance. Anyone registered with one of the professional bodies would likely have their £250k PI insurance validated by the scheme provider (check they are specifically registered for PAT testing).

 

[earthman]

depends on what appliance is been tested and the conditions there used in .heres the tests that are performed https://www.pat-testers.co.uk/produ...MI4qDpx5fT7AIVxbTtCh10QAVaEAAYASAAEgLx2_D_BwE the majority of fails would be on class one appliances corroded earths or mainly pulled out of plugs .earth leakage on washers tumble driers kettles and irons

For those of you guys who use these machines on a daily basis, what kind of percentage would you say? I must have tested hundreds, if not thousands of vacuum cleaners back in the day, I don't recall our PAT machine ever showing a 'fail'.

 

[brightspark]

For those of you guys who use these machines on a daily basis, what kind of percentage would you say? I must have tested hundreds, if not thousands of vacuum cleaners back in the day, I don't recall our PAT machine ever showing a 'fail'.

you probably wont have. most are double insulated and the flexes plastic. if the flexes were rubber and in damp conditions they would show earth leakage if they were perished . only if class one though

 

[earthman]

you probably wont have. most are double insulated and the flexes plastic. if the flexes were rubber and in damp conditions they would show earth leakage if they were perished only if class one though

And your answer to the kind of percentage you are seeing is?

 

[brightspark]

And your answer to the kind of percentage you are seeing is?

testing over 1500 appliances in a school the majority of fails would be visual on flexes and broken plugs as for the machine showing faults a few kettles and burko boilers along with a few irons and mainly extension leads with broken earths . not many

 

[willie.macleod]

What would be a good machine to go for?

Seaward machines are good. When we used to do this at work before it was contracted out I had a Seaward Supernova like @Exuptoy and it was good. Got a personal Seaward 1557 multifunction tester now which is occasionally dragged out for PAT duties as well these days but it's more faff than a dedicated tester.

Whatever machine you get I would get one which can do an earth bond test with a decent current (10A+) especially when testing equipment that has been in a site/workshop environment. Little battery operated devices aren't likely to have this.

 

[earthman]

testing over 1500 appliances in a school the majority of fails would be visual on flexes and broken plugs as for the machine showing faults a few kettles and burko boilers along with a few irons and mainly extension leads with broken earths . not many

Less than 5% would you say?

 

[Chris Snow]

any appliance that has a plug on is classed as portable. its not fixed wiring

The new code of practice has now removed any reference to the term "portable" Even if it's bolted to the wall and has no flex the item must be tested. The issue was the gap in between periodic inspection of fixed wiring and PAT being things like hand dryers.

https://electrical.theiet.org/wirin...spection-and-testing-of-electrical-equipment/
Anybody considering testing things themselves should get a copy. It is well written and explains all the requirements from legal to the tests themselves.

It isn't law to follow it. Buy if you do you will not be in trouble unless negligent.

If you have a good electrical understand you probably don't need the c&g course. However the course was good and ultimately gives you a bit of paper that deems you competent.

My advice to all is to buy the book or borrow from the library ( they still exist!) Then either pay someone to get it done properly (specifically ask that bit be done according to the IET COP and check they do) or buy a basic tester (doesn't need to be fancy and record results, though very handy) and if you can't follow the book do the course.

I understand why there is distrust in PAT but sadly its actually because so many testers don't do it properly.

Visual is where most things fail and anybody can do that. And should be done as pre use inspection. After that it's usually earth bond tests due to a loose connection somewhere.

Ignoring PAT completely is a very unwise thing to do. If you just visually inspected and recorded results regularly you would likely not be in serious trouble should something happen. Do nothing and good luck when HSE com after you....

 

[Exuptoy]

Nice post @Chris Snow

 

[Robotstar5]

Still got my CoP book, don't know how relevant it is now as it's dated 2003