The Electrical Test Instruments PI-6000 is a versatile and technologically advanced primary injection test set capable of testing circuit breakers up to 6000 amperes frame size. It incorporates an output transformer with dual primaries to facilitate its use on power sources of 480 VAC as well as 240 and 208 VAC, and dual secondaries to provide optimal impedance matching to a wide range of breaker sizes. An internal voltage sensor automatically configures the AC control power section to be energized only when properly configured for the applied voltage. The PI-6000 is constructed in a rugged steel enclosure with removable sides and top for easy access to internal components. The sides are clear of protruding components, and full-width handles with provisions for lifting hooks are on both ends. Locking swivel castors on all four corners provide ease of mobility. The entire test set has been designed for reliability, ruggedness, and ease of use.