IP 295: Determination of electric strength of insulating oils

Document options

EI Technical Partners get free access to publications. You will need to Login or Register here

  • Method adopted/last revised: 1983
  • Method reapproved: 2005
  • REF/ISBN: IP295-2935231
  • Status: Current
  • First printed in STM books: January 1983


This method gives a measure of the electrical insulating properties of oils and enables this property to be expressed numerically as the mean breakdown voltage under the specified test conditions. It is designed essentially for new oils and its application is restricted to oils having a viscosity of not more than 50 centistokes at 20 °C.

NOTE 1: IP 295 can be used for new and used oils. It is included in numerous national specifications. IP 295 is a `breakdown' test. Users requiring a `hold' type test should refer to the Electric Strength Test in BS 5730 Code of Practice for Maintenance of Insulating Oil.

Members Benefits

Are you an EI Member? If yes, register/log in now to ensure you receive free access or discounts to EI publications.

If you are not a Member, why not join today and receive all of the benefits of EI Membership? EI Members are entitled to a 25% discount on most EI publications.