The Model DDA-1600 Circuit Breaker Test Set incorporates proven transformer design with the latest development in high-current instrumentation and control. This new design means the DDA-1600 is fully compliant with NEMA AB-4 test guidelines. This combination provides the user with a portable, economical, high-current source for primary injection testing. Model DDA-1600 provides all the controls, instrumentation and output capabilities to test low-voltage circuit breakers in a three-module configuration.