Vacuum Interrupter Testing

Using our portable MAC Test set, our specialist engineers can assess the health of Vacuum Interrupters (VI) in-situ.

Vacuum Interrupter manufacturers have historically measured the internal pressure within their devices using a Magnetron. Until recently, the magnetron was very bulky and difficult to use in the field and was therefore relegated to manufacturer laboratory testing. This same test is now available in a portable unit and can be used to assess the condition of vacuum interrupters.

What is MAC Vacuum Interrupter Testing?

The normal high voltage and/or contact resistance tests will enable you to check the integrity of the VI before re-energising. However, these are go/no-go tests which do not give information on the level of vacuum in the VI, which may be degrading (known as “virtual leakage”). The Magnetron Atmospheric Condition (MAC) test allows the internal pressure of the VI to be measured.

By measuring the internal pressure, it is possible to not only determine whether the VI is functional (go/no-go), but also, by repeated measurements to establish trending, estimate the number of years of remaining useful life. In addition, a more complete health check can be completed by combining with other fairly readily available information (number of operations, contact wear).

A report will be produced with recommendations on future maintenance action.