Polarization index 1

[setiawanmarten]

Dear all,
I have this transformer 6000 kva , primer 11.000 v , sec 245 v, teh dga result was indicating high h2, i am planning to do polarization index, is it save to inject 500v dc to secunder for 10 minutes for pi test the secunder? (twice the nominal rating of the secundr)From the standard bellow 600 v i think it would be 1000 v?

Thank you

Marten

 

[DanDel]

500VDC is acceptable. The recommended voltage for Insulation Resistance testing for windings <600V is 1kVDC per NETA Table 5, so 500V will not cause a problem.

Not sure what a PI test will tell you about hydrogen production. This is typically cause by partial discharge or hydrolysis.

 

[setiawanmarten]

Thank you dandel