IT Equipment & Other Sensitive Equipment

[stules2905]

Fairly new to PAT Testing. Been qualified for a while but not done any!

Been asked to carry out all the PAT testing in the office of our company.

Fairly mythed as to the testing of IT equipment and sensitive stuff such as monitors, printers, fax machines and the like.

I am using a Fluke 6200. It does not have an option to decrease the IR voltage and was wondering whether to leave it and just do the 200mA bond.

Got some monitors to test and didn't know whether they were susceptible to damage? Not only ones with IEC leads but also ones with DC Power straight from the plug.

Also like I said, fax machines, boosters, printers, franking machines. If anyone can shed any light on this it would be great!!

Cheers

Stu

 

[Marvo]

I can't help thinking PAT testing IT equipment that's classII beyond a visual check is likely to cause more heartache than it's worth. Even if you connect the L+N together an test using 250v range, the day you come across a piece of equipment with an earth referenced comms system you're still probably going to blow the comms card with a N-E voltage of anything over 30v or so.

 

[Sintra]

If you check your tester you will find that it shorts out the L & N pins and conducts the test to earth. Therefore it doesn't damage anything.

 

[telectrix]

Plug-in PSUs can only be inspected visually. the IT equipment they feed is selv, so there again, visual. afaik, PAT teaters do the IR by linking L-N and testing to E, so should not damage the equipment. and the earth bond test should be carried out using the 100mA setting.

 

[Simlec]

Everything you need to know is in "Code of practice for in-service inspection & testing of electrical equipment"
4th edition

 

[Marvo]

RS232 comms with internal earth referencing possibly won't survive an IR test to earth even with the L+N shorted during the test.

 

[stules2905]

Everything you need to know is in "Code of practice for in-service inspection & testing of electrical equipment"
4th edition

Yes but its very contradictory and vague. Just like the 17th Edition.

 

[Simlec]

Yes but its very contradictory and vague. Just like the 17th Edition.

Which part/page are you having trouble with?
As far as IET comics go this ones very easy to follow.

 

[stules2905]

At 500vDC? Could you test monitors and PC's at that?

 

[stules2905]

If you check your tester you will find that it shorts out the L & N pins and conducts the test to earth. Therefore it doesn't damage anything.

So you could test all of the things I've mentioned above with a 500vDC IR test as long as the bond was done at a low current??

 

[stules2905]

RS232 comms with internal earth referencing possibly won't survive an IR test to earth even with the L+N shorted during the test.

Everybody seems to be contradicting each other with this. Its a nightmare!

 

[stules2905]

Also. What might be the reason for a high reading on a low current earth bond test to a monitor?

 

[Marvo]

Everybody seems to be contradicting each other with this. Its a nightmare!

My statement was from a comms point of view, earth referenced comms cards are very sensitive to N-E voltages. I'm in Africa so I'm not familiar with what your guidelines or regs say but if you're insured and they say it's fine to indiscriminately test networked electronic devices at 250v then I suppose go for it. Personally I wouldn't be so keen on doing this.

Also. What might be the reason for a high reading on a low current earth bond test to a monitor?

Is it a classII insulated device perhaps?

 

[stules2905]

My statement was from a comms point of view, earth referenced comms cards are very sensitive to N-E voltages. I'm in Africa so I'm not familiar with what your guidelines or regs say but if you're insured and they say it's fine to indiscriminately test networked electronic devices at 250v then I suppose go for it. Personally I wouldn't be so keen on doing this.

Is it a classII insulated device perhaps?

As mentioned before, the tester I'm using doesn't have the function to go to 250v IR. Only 500 DC.

As for the monitor, i can't see anything stating that its class 2. The reading is not non existent. Just too high to pass the test. Testing for the earth on the VGA input.

 

[tazz]

I worked with one of the first manufactures of PAT equipment in 1988, Seaward...in these day pat testing was explained as it should be class 1 and 2, with level results being recorded and checked.
Class 1 would be insulation , earth leakage, load, and bonding, with possible flash......class 2 would only be insulation, earth leakage and load.......there is no possible way of damaging a computer or it device by testing class 2....butit makes great marketing to sell such equipment

 

[goodconnection]

HI Stules

Have a look at this https://www.youtube.com/watch?v=3jKLnfsneBs

It's how to test or not to test ( depends on your point of view ) a low voltage mains to USB power supply using a Metrel delta Pat unit

These people distribute Metrel devices in Australia and although the plug standards are different the same electrical principles apply with regard to keeping equipment users safe.

I'm a newbie with regards to performing pat tests but would offer you this advice Firstly do understand how your pat tester works and the way it gathers the data to produce the test results... You will also need to have an idea of what's under the bonnet so to speak of the class of equipment that is being subjected to a test.

Part of the IET testing ethos is that testers should know their own limitations and capabilities Qualifications obviously do help but passing a driving test does not necessarily make you a good driver. For example there are plenty of incorrect test procedures being carried out by established testers on IT equipment and it's mainly due to ignorance and poor understanding of their own test equipment. I hope you manage to find the data you need in order to accomplish the task that you have been given good luck !