# Lets talk about Capacitance



## Lone Crapshooter (Nov 8, 2008)

Most of the new meggers 1000 volts or greater will check capacitance wile they are checking insulation resistance.What does knowing the capacitance do for me ? Are there any standards that say what is good capacitance and what is bad capacitance. I have not been able to find much on insulation capacitance.
I do not believe it is the same as DOBLE testing for insulation power factor and dissipation factor .

Thanks LC


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## joebanana (Dec 21, 2010)

Knowing the capacitance can mean the difference between blowing your socks off and a properly discharged test circuit.
Other than that, it's for dissipation factor


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## trentonmakes (Mar 21, 2017)

I used it before to check conditions of....wait for it....capicitors.
If its on lower end of scale its bad/going bad.
Most capicitors have a range marked on them. 

Texting and Driving


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## splatz (May 23, 2015)

From what I gather reading the "Stich in Time" book, it seems like measuring the capacitance is just part of the process to get to where you're no longer filling the capacitance of the system and the current the megger sees is really getting through the insulation. 

Like most things, and this is just a guess, I'd think the system you are testing should have stable capacitance - if you see a trend, change over time it's something to look at. Or if you have a major change in capacitance one day maybe it's a red flag that the system has changed.


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