The Megger transformer test van is a vehicle equipped with a number of instruments for on-site condition assessment of power transformers. The biggest advantage of the van solution compared to separate or multi-functional instruments is its instantaneous readiness to test, quick proceeding to results and clean up at end of testing. All leads are on drums, preconnected to instruments, through automatic switching no need to climb several times. This results in increased productivity, safety and user comfort, considering an air-conditioned office like work environment.