2021-08-03 at 11:08 am
#1608
There are no National or Inteernational standard for acceptance value of IR in Power transformer .This is because of the dependancy of the IR value on a no of factors like Amount of IOnsulations , Tyope of insulation , clerance from earth point , water absorption capacity of the insulatuing material and temperature of the transformer etc . The acceptance value is an agreement bett the supplier and the customer . However a reasonably accepted factor is 1 mega Ohm per kv at 60 C subject to minimum 500 Mega ohm .