Hipot or Dielectric Strength Testing

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One space of confusion in manufacturing security testing is the dielectric power take a look at, generally identified the as dielectric face up to take a look at or “hipot” take a look at.

This take a look at is often utilized between the secondary output and chassis floor after which between the AC connection (primary) and floor / secondary. This take a look at can determine any meeting errors akin to a pinched wire.


You will need to guarantee to quick the road and impartial collectively through the take a look at, and when making the primary to secondary take a look at, join the secondary aspect to chassis. Brief the output terminals collectively if testing a standalone power provide. Failure to do that may end up in harm to the power provide.

A routine query is “ought to the take a look at voltage be AC or DC?” Nearly all of power provide producers use a DC voltage as a result of the leakage present by way of the “Y” capacitors can masks one other fault.

The “Y” capacitors are recognized in a really simplified diagram under are used to cut back EMI and electrical noise.


As might be seen, making use of an AC enter to chassis hipot take a look at would end in mill-Amps of present flowing by way of the capacitors

Nearly all of security requirements permit DC hipot voltages. As a substitute of making use of 1500VAC, one would use the height voltage of the AC, √2 x 1500 = 2121VDC. Add 10% to cut back the take a look at time from 1 minute to 1 – 2 seconds.

Apply the DC voltage slowly to permit the capacitors to cost up with out tripping the present restrict of the take a look at gear. Keep in mind to discharge the capacitors after the take a look at.