HIPOT

[Brian Su]

hello guys,

Just wondering, because I often seen a sticker saying 'HI-POT' tested
ok. on appliance which have transformers in them. what exactly is this
'HI-POT'?

Thanks.

 

[Andrew Gabriel]

hello guys,

Just wondering, because I often seen a sticker saying 'HI-POT' tested
ok. on appliance which have transformers in them. what exactly is this
'HI-POT'?

At a guess, it means it's had a earth leakage test done using
a high test voltage to earth. 500VDC is used for doing this
during PAT testing procedure in the UK. However, not all
appliances are suitable for HI-POT testing, and for those
that aren't, alternative methods have to be used, such as
measuring the earth leakage in normal operation.

Alternatively, it might mean the appliance is OK to HI-POT
test. Equipment conforming to BS EN 60950 should be OK to
test at up to 500VDC, but unless IT equipment is so marked,
you should assume such a test might damage it.

 

[Ben Miller]

hello guys,

Just wondering, because I often seen a sticker saying 'HI-POT' tested
ok. on appliance which have transformers in them. what exactly is this
'HI-POT'?

Thanks.

It means the appliance passed a high potential (Hipot) test. This is
generally done at 1000 volts plus 2 x voltage rating, or 1240 volts for a
120 volt appliance. It checks the integrity of the insulation, and also that
adequate spacings exist between terminals of opposite polarity. This is a
standard test that is done on the manufacturing line for most appliances.

Ben Miller

 

[John Phillips]

It means the appliance passed a high potential (Hipot) test. This is
generally done at 1000 volts plus 2 x voltage rating, or 1240 volts for a
120 volt appliance. It checks the integrity of the insulation, and also that
adequate spacings exist between terminals of opposite polarity. This is a
standard test that is done on the manufacturing line for most appliances.

Ben,

You are referring to a DC high potential test. The test could as well
be AC and the type test is usually specified as in DC Hi Pot test. In
fact, .1 Hz high potential test sets were used for a time on large
generator stator windings since DC tests overstress resistance grading
on the end turns.



Regards,

John Phillips