EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: blueskull on April 08, 2017, 01:44:39 am
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In another thread I mentioned I'm building a AC/DC power supply for my laptop (see here: https://www.eevblog.com/forum/projects/a-46win3-power-adapter-with-active-pfc/ (https://www.eevblog.com/forum/projects/a-46win3-power-adapter-with-active-pfc/)).
Since I don't want myself killed, I think I should be able to test my finished product with an insulation meter.
According to UL60950-1, for world wide input voltage (I mostly live in the US, but I go to China every year to visit my family), it needs to withstand 2.5kV peak transient.
The transformer I used is designed for telecommunication system and is only certified at 1.5kV RMS isolation (2.1kV peak), therefore I need to test it myself to see if it will withstand 2.5kV.
Is there a good insulation meter that can do 2.5kv testing? So far I know Uni-T has some cheap ones, particularly UT533 and UT502A. I'm not interested in the much more expensive UT513A. My budget is $300 or less.
I don't need high accuracy -- just a qualitative test. For precision works, I have a Keysight U1461A and a Keithley 2410 SMU, but both only go to 1.1kV, even series connect them together it is still not enough to generate 2.5kV test voltage.
Any recommendations? Thanks in advance.
Bought UT502A.
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You could ask an electrician to test it. Cheaper than buying your own equipment.
If you want to work on the design, and possibly fix issues, then one of the cheap Chinese instruments is probably adequate. Ideally you should verify that it is doing what it should (you will need an HV probe and suitable resistive loads), just in case it isn't quite up to specification.
An independent test house will have to certify it if you intend on selling this commercially -- the cost will make your eyes water. For your own use it is more a case of making sure you don't risk a fire or other problem, because insurers will use that as an excuse not to pay out.
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It seems to me that you should just buy whatever has the features you might want within your price range. If you are able to characterise any critical usage then you should be fine with a cheaper, potentially less reliable, instrument.
There are also combined DMM / insulation testers, but I don't recall any rated higher than 1 kV.
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Uni-T 533 can do 2.5kV testing while still having DMM functionality. I guess I will get that one, it's only $40 higher than the 502A, so for the buck, having a backup DMM is actually not bad.
I think that only gets to 1 kV. That is what is marked on the case.
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Motors, etc might be OK for 1kV testing but anything we test has sensitive electronics, we only test to 500V for leakage and that's medical.
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I have a Duoyi DY30-2, see: http://www.dyinstrument.com/duoyi/?q=insulation_resistance_tester/DY30-1/DY30-2 (http://www.dyinstrument.com/duoyi/?q=insulation_resistance_tester/DY30-1/DY30-2)
Very similar specs as your UNI-T UT502A.