Abstract: A rotatable circular platform is used for automatically testing power transformers. The rotatable circular platform is provided with a plurality of carrier tracks equally spaced around the periphery of the rotatable circular platform; each one of the carrier tracks is adapted to carry a power transformer to be tested and is provided with a corresponding connecting post having a pair of connecting contact points. Around the outer periphery is a plurality of stationary posts, each one of which has a pair of stationary contact points to allow a sliding engagement with the connecting contact points of the connecting posts. Each pair of the stationary contacts is electrically connected to a test instrument to test the performances of power transformers, while each pair of the connecting contact points is provided with a pair of clamps to clamp onto the test terminals of a power transformer loaded on a corresponding carrier track.