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Vintage Test Gear and Workshop Equipment For discussions about vintage test gear and workshop equipment such as coil winders. |
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18th Mar 2024, 8:02 pm | #1 |
Triode
Join Date: Jan 2010
Location: Builth Wells
Posts: 16
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Megger insulation tester low voltage
I have a Megger Series 3 MK lll insulation tester, I have tested the output voltage when I crank the handle and it is around 300volts, ( it's a 500v megger) what component inside is likely to be faulity?
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18th Mar 2024, 9:35 pm | #2 |
Nonode
Join Date: Jun 2007
Location: Coulsdon, London, UK.
Posts: 2,173
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Re: Megger insulation tester low voltage
What is the input resistance of your voltmeter when you measure the output voltage of the Megger?
Your voltmeter will simulate faulty insulation as far as the Megger is concerned, and may drag the test voltage down. |
19th Mar 2024, 11:09 am | #3 |
Dekatron
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,109
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Re: Megger insulation tester low voltage
If you have a voltmeter/multimeter with a high input impedance (10 megohms is common these days) and it still shows this low reading, it could be down to a faulty capacitor in the Megger.
My Megger is one of the miniature ones so we're not necessarily comparing apples with apples, however i did manage to restore full voltage with a new capacitor (which of course was a different size and shape from the original) Dave |
22nd Mar 2024, 6:43 pm | #4 |
Triode
Join Date: Jan 2010
Location: Builth Wells
Posts: 16
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Re: Megger insulation tester low voltage
I was measuring the voltage with a 10M Ohm multimeter, I will have a look at the capacitor.
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