Pat Test Failure Whirlpool ADP4501/5

[mike412]

Hi Folks.

I dont have anything to do with PAT testing, I dont possess a Pat tester and dont really want one, so interpreting the results from one is out of the ordinary for me.

I got called to a local school today, reported problem ” dishwasher in staffroom has failed its Pat test”.

On arrival I was met by the site manager who advised that he was responsible for carrying out the pat testing himself, and there were not one but two identical dishwashers, standing side by side and have both failed with an almost identical reading.

I checked one of them with my digital AVO megger (500v) and got an almost perfect reading.

The site manager then produced his Pat tester a Robin Smartpat 5500, cost about a grand of the taxpayers money, all singing and dancing but looking to be a bit of an overkill for the task in hand.
It performed its automatic test sequence and failed the appliance on “Touch Current” with a reading of 1.3mv. The other d/w had a reading of 1.4mv.

Where do I go from here?

I suppose if there is a problem its most likely heating element and I could disconnect components in turn until the Pat tester passes, but could the SM be using the kit incorrectly?. If i had a 1000v megger would this pick up the problem?. Is this touch current test a requirement? Is the bar raised because this is a school?

What would a Whirlpool engineer do If faced with this issue?

I could tell the school to get manufacturers service out and walk away, but its an interesting problem that I would like to know the answer to.

Thanks in anticipation,

Mike

[Specialist01269]

Re: Pat Test Failure Whirlpool ADP4501/5

Hi Mike: It is possible that the operator doesn’t have too much experience of PAT testing or is not that familiar with his PAT tester. From table 15.3 of the IEE code of practice it shows that the maximum allowable touch current for this type of appliance is: 3.5mA.
Assuming that the listed results you gave are in mA not mV then this would indicate that the appliance passed as your tests show, the code of practice shows that the Touch test is an additional or Complementary test to the Insulation test, for use if the Insulation test cannot be used or gives suspect results. 500v is the given voltage for safety testing & fault finding on 230 / 240 volt appliances.
By the way when you say an almost perfect reading, can you remember what it was?

Hope that Helps: Andy

[eastlmark]

Re: Pat Test Failure Whirlpool ADP4501/5

…am out of it too much latley but what is “touch current”? Is that what we oldies called earth leakage? If so its not strictly part of the portable appliance test and many testers dont even have the facility and given the fact that to test it the machine needs to be running and yet the test does not last long enough even to get the start button pushed, yet alone get to the heating phase then it is irrelevent. I had several Bosch dishwashers fail on earth leakage even before the (old fashioned now) double pole on off switch was pushed in. I by passed the mains filters and they passed, ordered 2 new mains filters at customers request and, guess what failed again.
well its health & safety and to cover yourself better advise the tax payer buys 2 new diswhashers and dump the old 2.

[Specialist01269]

Re: Pat Test Failure Whirlpool ADP4501/5

Touch current: The Electric current that passes through a Human or Animal body when it touches accessible parts of an Appliance or Installation & as you said is basically what us oldies call Earth leakage, a lot of testers don’t have this feature & on my course we were told that it was’nt a statutory test.

Andy

[superfix]

Re: Pat Test Failure Whirlpool ADP4501/5

I assume it’s the same as equivilent earth leakage, and as specialist said it’s good at anything below or equal to 3.5mA

I suspect your mate the SM has just got himself a new toy and has been playing with it 8)

[mike412]

Re: Pat Test Failure Whirlpool ADP4501/5

Thanks for your responses folks, all interesting.

I want to glean a bit more info from the site manager but it appears he is away until after the weekend.

I will post again mon/tue on this one.

Thanks once again.

Mike

[bazza500]

Re: Pat Test Failure Whirlpool ADP4501/5

Just read this thread and I have a similar problem.

2 identical Hoover washing machines in a school failed by an electrician with a PAT tester and I got called out. Meggered them with 500V 25A and got a reading >999Mohms. The electrician went back and said they still fail (both with exactly the same reading) and so we are meeting on Wednesday with his test set and me disconnecting parts. I put my money on the mains filter and bet new ones will be the same.

These machines are just a year old and if the new filters fail as well, where does the customer stand with Hoover?

[Specialist01269]

Re: Pat Test Failure Whirlpool ADP4501/5

1 thing to check: If the tester has user settable pass / fail parameters check that these have not been set too low.
What did they fail on? was it the insulation test or touch current? if it’s touch current then this is not listed as a statutory test but supplementary soft test, if it was insulation what were his test results? From table 15.2 of the IEE code of practice the pass level for Insulation resistance is given as 1 Megohm at 500v applied test voltage so going on your results then the appliance is safe.
Can you update us when you have been back & checked it out? would be nice to know the conclusion.

Hope that helps: Andy

[mike412]

Re: Pat Test Failure Whirlpool ADP4501/5

Hi Andy.

I have sent you a PM.

Regards,

Mike

[garn]

Re: Pat Test Failure Whirlpool ADP4501/5

Iv come Across the Same Problem in the Schools wear the caretakers or technicians as There called to day pat Testing They have These Expensive Instruments pat Testers and the appliance Are Showing Failed .

the rpe test is passing
R iso test is passing
but The leak test is failing Only because They don’t Know How to Make The calculation on The length of The Flex.

[mike412]

Re: Pat Test Failure Whirlpool ADP4501/5

Hi Garn.

Thanks very much for your response.

Please could you elaborate a bit on this. If the equipment has the original factory fitted cable with fitted plug, why is the cable length relevant and how can this be incorporated into the auto test of the pat tester?

Regards,

Mike

[garn]

Re: Pat Test Failure Whirlpool ADP4501/5

High Mike
You Got me There Original flex.

I’m talking Through my Own Experience I Look After The local Comprehensive Appliances And The Special Needs handicapped center to.
Some of These Are hard Wired or have Extended flex .

Il have To Dig Out The Info on This i have A Book On it Somewhere :rolls:

i also have A Traning disc Somewhere to. Give Me Some Time And Il dig It Out Maybe upload it to the tube And We All Can Have A look.

give Me Sometime Its been A Few Years since I Seen it.

garn

[bazza500]

Re: Pat Test Failure Whirlpool ADP4501/5

Specialist01269 wrote:Can you update us when you have been back & checked it out? would be nice to know the conclusion.

Went back to this yesterday with the PAT testing electrician. He plugged in his PAT tester pushed the “insulation test” button and it read infinity. He then pressed the “earth leakage” button and it read 3.8/3.9ma. He said it has to be below 3.5ma to pass.

As expected I disconnected the L and N from the machine side of the suppressor and his readings were the same. Disconnected the L and N from the mains lead side and the readings were infinity and 0. Therefore as I previously thought it is the suppressors causing the fault. I have new ones coming but suspect these will read similar to the old ones.
If they do what happens then?

[Specialist01269]

Re: Pat Test Failure Whirlpool ADP4501/5

Hi Garn.

Thanks very much for your response.

Please could you elaborate a bit on this. If the equipment has the original factory fitted cable with fitted plug, why is the cable length relevant and how can this be incorporated into the auto test of the pat tester?

Hi Mike: Bit of a complicated 1, if you send me your email address I can explain it for you in Detail.

Andy

[Specialist01269]

Re: Pat Test Failure Whirlpool ADP4501/5

Went back to this yesterday with the PAT testing electrician. He plugged in his PAT tester pushed the “insulation test” button and it read infinity. He then pressed the “earth leakage” button and it read 3.8/3.9ma. He said it has to be below 3.5ma to pass.
As expected I disconnected the L and N from the machine side of the suppressor and his readings were the same. Disconnected the L and N from the mains lead side and the readings were infinity and 0. Therefore as I previously thought it is the suppressors causing the fault. I have new ones coming but suspect these will read similar to the old ones.
If they do what happens then?

Hi Bazza: Personally I think that your a victim of this Electricians inexperience with PAT testing & there is no easy way around it, he can obviously see on the insulation test that there really doesn’t seem to be any problem but is relying on his PAT tester to think for him. It’s a known fact that filter networks across the Line & Earth terminals can cause unduly low readings in PAT testing but this does not mean there’s a fault on the appliance. Did you test the machine side with it disconnected from the filter? if you did I bet you got a good reading. I checked out a few PAT testers from different Manufacturers earlier & a lot of them don’t even incorporate this test, only the higher end one’s seem to have. If this was a compulsory test then they would all have.

Andy

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