IT Equipment Testing

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IT Equipment Testing

Postby danwanna » Tue May 30, 2017 11:36 pm

Hi All,

I am new to PAT Testing and have been roped in by my office manager to complete the PAT Testing for the office (around 20-25 PC's, screens, printers etc). They have put me on a course and purchased an Apollo 400.

During the course, we discussed Earth Resistance and Insulation Tests and carried them out so happy with those. The A400 has these tests already pre-built into it, however the insulation test is being ran at 500v. Should I change this to 250v if being done on IT equipment (different websites say different things)?

Also, I am seeing different sites carrying out different tests on IT equipment, what is the best test to complete on IT equipment? Assuming it is CI Earth Resistance and Insulation or should I be doing an IT PE Current Test or IT Touch Test?

I believe the A400 tests at 200mA for Earth Resistance, I am right in saying that this is safe for IT equipment (some refer to it as a 'soft test'/'safe test')?

Sorry for all the questions, I don't want to destroy the IT estate! Thanks in advance for your answers!

Cheers
danwanna
 
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Re: IT Equipment Testing

Postby southseas » Fri Jun 02, 2017 9:59 am

What standard are you testing this IT equipment to? (or what country?) 200mA as an C1 Earth Resistance Test won't damage IT gear, equally, Insulation Resistance testing any item with a Portable Appliance Tester at 500V equally won't cause any harm to IT equipment.

What tends to "damage sensitive IT equipment" is sparkies with Insulation resistance testers, not knowing what they are doing, or PAT sticker jockeys using a 25Amp/10Amp Earth Bond test.

With regard to your second question, a current leakage test is required by the standard that I test to (AS/NZS 3760) for any equipment that has soft touch controls/ relay controlled/SC controlled circuits that may not be connected to the incoming Active & Neutral lines. Again, depending on where you are testing, it's not what is "best for IT equipment", it's what ensures that unsafe equipment is identified, and removed from the workplace.

How long was the course that your company sent you on? What sort of liability will fall on you if you get it wrong?

If you are testing Laptop Power supplies and their IEC C5 Leads, watch out for LS15 leads,there was a recall (in Aus/NZ at least) a couple of years ago, because these leads had been manufactured with dodgy reclaimed plastic, and their Insulation Resistance was breaking down and they can catch fire- I've found a number that initially tested fine 99Meg, and over a couple of years have gone down to .1-.25 of a Meg (Ohm)
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Re: IT Equipment Testing

Postby danwanna » Sat Jun 03, 2017 12:09 am

Thanks Southseas for your detailed response.

I am based in the U.K therefore PAT testing isn't law (we do follow the IET Code of Practice) but a "nice to have" - most businesses do have their equipment tested to "prove" they are compliant. I believe I'm right in saying a Class 1 Earth Resistance and Insulation on the appliance and an IEC test (Earth Resistance, Insulation and Polarity test) are sufficient?

The course was a day however it was very intense and very focussed (wasn't a cheap and nasty course / don't have much to compare too but seemed very well ran and went into lots of necessary detail).

The Apollo400 only produces 200mA for Earth Resistance and up to 500v for Insulation so that has reassured me :)
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Re: IT Equipment Testing

Postby southseas » Sat Jun 03, 2017 10:23 pm

The reason that PAT testers are unlikely to damage IT (or any appliance) when performing an Insulation Resistance test is that the PAT's internal configuration will parallel up the Active and Neutral and then measure IR between these and the Earth conductor, or between the coupled up A&N and the test probe- done this way, all internal components should experience 500v on all parts of their circuits/components, rather than on one side and trying to flow through (which could damage them). this is also why sparkies tend to fry components when they zap an item with their "Megger", as they forget to ensure that one clip is bridging the A&N of the items plug, and the other on the Earth pin.

If you can choose which IR test to run (500v or 250v), and decide that 250v is the best option, then running a Current Leakage test also, would be a prudent idea.

Not aware of any country that "mandates" appliance testing. In NZ, our Electrical Safety Regulations require that owners of electrical installations be mindful of the safety of those installations and appliances connected to them, they also provide some guidance to situations where appliances that have been tested to the cited standards will be "deemed safe" if bearing a pass tag issued in accordance with those standards- so not mandatory, more a "get out of jail free" card if things go pear shaped and a business owner has an employee fried by a defective appliance.
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