Polarization Index (PI) for oil-filled transformers
Polarization Index (PI) for oil-filled transformers
(OP)
Is there any standard that specifies Polarization Index (PI) for oil-filled transformers ?
I know PI is applicable for solid insulation like generator/motor windings. But trafos ?
I know PI is applicable for solid insulation like generator/motor windings. But trafos ?
* How do centenarians handle peer pressure ? *






RE: Polarization Index (PI) for oil-filled transformers
RE: Polarization Index (PI) for oil-filled transformers
* How do centenarians handle peer pressure ? *
RE: Polarization Index (PI) for oil-filled transformers
How much peer pressure could there be?
RE: Polarization Index (PI) for oil-filled transformers
RE: Polarization Index (PI) for oil-filled transformers
Strictly PI is not a clear indication of dryness of insulation in oil filled equipment and should be handled with caution.This will be very much affected by the resitivity of oil used.So most of the customers do not insist for minimum values.The advantage of PI is that it is not temperature sensitive ie value will not change with temperature.But there are utilities who insist for minimum values for PI eg one utility in India insist for minimum value of 2 for PI and 1.5 for dielectric absorption factor ie R 60sec/R15 sec for new transformers.With new transformers with new oil having high resistivity it is extremely difficult to achieve such high values.
RE: Polarization Index (PI) for oil-filled transformers
"With new transformers with new oil having high resistivity it is extremely difficult to achieve such high values."
This is exactly our client is facing (we are doing the generator for them but they came to me with this problem with their new trafo). Since I haven't heard PI mentioned in re trafos, I came here. I will pass your on your tip to them. Thx once again.
* How do centenarians handle peer pressure ? *