Could PAT testing cause damage??

[seasonalbiz]

Hi,

We had PAT testing carried out the other day and since the engineer left... one of the laser printers in the office has packed up. It powers up ok, and the green LED indicating its ready to print is lit... but it hasn't printed a page since the guy tested it, and it won't print a test page - so its defo a problem with the printer itself. Its only 2yrs old and its a Hewlett Packard Laser - I have always used HP printers and they have always lasted years.

I was quite surprised at the "crackle" noises made by the things he tested. I haven't contacted the company yet as I'm sure I'll get a load of flannel if I don't seek independent advise first.


Thanks.

 

[GLENNSPARK]

basic tests (minimum requirement) are an IR test (typically at 500V) although some manufacturers test equipment will perform IR at 250V...continuity test (which should give polarity on leads)....and the earth bond test (class 1 or 3)

 

[GLENNSPARK]

the other tests (such as load/run/earth leakage) are not a requirement as laid out in the code of practice but are useful to determine whether an appliance is running properly at its rated output. the earth leakage test can be used as a substitute for an IR test (if an IR test could cause damage to the equipment) a dielectric strength test (sometimes refered to as flash or hipot testing) is not normally required as this is usually undertaken by the appliance manufacturer..........

 

[KFH]

While I would not run a 25A test on electronic equipment and I know that the data side will be connected to earth I still think that a piece of modern electronic equipment should not normally be damaged by less than 12V appearing on the earth connection. I have measured much higher voltages than this on various data cable earths, usually when the user gets sparks when connecting equipment together. There are all sorts of standards around, the numbers of which which I can never remember, that apply to the resistance of electronic equipment to misc voltages flying around.

 

[Engineer54]

Right!! ....Let's all Pat Test IT equipment at the 25A setting on the earth bond test then, and see what happens?? Obviously no reason for 100mA settings for IT pat testing!! ....Geezus!!!

 

[GLENNSPARK]

While I would not run a 25A test on electronic equipment and I know that the data side will be connected to earth I still think that a piece of modern electronic equipment should not normally be damaged by less than 12V appearing on the earth connection. I have measured much higher voltages than this on various data cable earths, usually when the user gets sparks when connecting equipment together. There are all sorts of standards around, the numbers of which which I can never remember, that apply to the resistance of electronic equipment to misc voltages flying around.

I am sorry mate but i have to agree with eng here.....most pat testers have the ability to test class 3s at 100mA....so why run the risk?.....

 

[72-van]

In defence of the guy who did the pat testing ..

The client should be aware before testing starts that items can fail during testing.

Not everythings gonna get a shiny pass sticker

Things do fail ..

especially when you switch something off thats been running for years non stop

had this been a especially valuable bit of kit or something that could not risk being turned off for whatever reason it is possible on some testers to do in situ testing at 200 ma /or soft tests .

In defense of older laser hp printers generally they are quite robust and i cant say i have ever had a problem but with inkjets well.

what type of hp printer is it..laser inkjet plotter ?

 

[GLENNSPARK]

In defence of the guy who did the pat testing ..

The client should be aware before testing starts that items can fail during testing.

Not everythings gonna get a shiny pass sticker

Things do fail ..

especially when you switch something off thats been running for years non stop

had this been a especially valuable bit of kit or something that could not risk being turned off for whatever reason it is possible on some testers to do in situ testing at 200 ma /or soft tests .

In defense of older laser hp printers generally they are quite robust and i cant say i have ever had a problem but with inkjets well.

what type of hp printer is it..laser inkjet plotter ?

yep....just use a tip (test in place) lead....for the earth bond.....

 

[KFH]

Can I ask where I have said, implied or even hinted at: that we should be running 26A tests on electronic equipment or that it WILL NOT be damaged by such tests?

 

[the pict]

My thoughts are if he was not testing in accordance then I think there would be more that one item affected, but there is always the attitude that the last one to pee must have left the seat down
Pict

 

[GLENNSPARK]

My thoughts are if he was not testing in accordance then I think there would be more that one item affected, but there is always the attitude that the last one to pee must have left the seat down
Pict

well....at least he performed the tests......too many "1 day wonder" pat testers now just sticker happy clowns...lol...........

 

[the pict]

Exactly, I had a phone discussion with a prospective client for PAT when I quoted £1.60 per test he said I was thinking more like 50P, My reply was " if you want to spend 50p I will give you the phone number of a printer and you can stick them on yourself" "or you can have it done properly your choice," two days later I got the go ahead
Pict

 

[GLENNSPARK]

well we charge £99 for the first 60 items...which for a FULL INSPECTION AND TEST of a portable aint bad.........half of em dont even know what they are looking for......take fuses for example.......we all know its 3A upto 700W..then 13A 700W onwards......but what if the appliance is say 650W....but an inductive?...I`d go for a 5A here........

 

[Engineer54]

Can I ask where I have said, implied or even hinted at: that we should be running 26A tests on electronic equipment or that it WILL NOT be damaged by such tests?



#If the tester had set the wrong values for the bond test he would have run a max of 25A through the CPC to the metal part the probe was on but at less than 12V. This would only be running through the earth path of the equipment, I would not expect this to cause a problem on modern equipment. #

So what do you call this quote?? That to me sounds as if your saying that a 25A earth bond/screen test isn't or shouldn't, cause a problem!! There are as i say, components within electronic IT equipment that are directly connected to the frame earth that start to conduct on certain conditions, similar to suppression filters and the like. And that's the point i'm trying to make, shoving 25A through such a system test ain't gonna do that equipment any good at all.

Pict,

On a lot if not most Pat Testers, you need to toggle parameters on the tester for each test item. Very easy to make a mistake and toggle once too often and test at the wrong current level. Some IT compliant test kits do now set parameters automatically when set to IT mode, but i think most still require manual set-up...

 

[GLENNSPARK]

So what do you call this quote?? That to me sounds as if your saying that a 25A earth bond/screen test isn't or shouldn't, cause a problem!! There are as i say, components within electronic IT equipment that are directly connected to the frame earth that start to conduct on certain conditions, similar to suppression filters and the like. And that's the point i'm trying to make, shoving 25A through such a system test ain't gonna do that equipment any good at all.

Pict,

On a lot if not most Pat Testers, you need to toggle parameters on the tester for each test item. Very easy to make a mistake and toggle once too often and test at the wrong current level. Some IT compliant test kits do now set parameters automatically when set to IT mode, but i think most still require manual set-up...

Yes well i got all the codes for that seaward that i was given eng........so i can just tap those in which will ommit the tests i dont want...such as hipot......

 

[GLENNSPARK]

if you want the codes for yours i will PM them to you eng......