A variable DC voltage is needed to test a circuit breaker. Substation batteries should not be used since this entails considerable risk for testing personnel, testing equipment and also for the equipment being tested.
A good way to ascertain whether or not solenoids and protective mechanisms are sluggish or set improperly is to perform a test at minimum tripping voltage. The minimum trip voltage test is described in a number of international and national standards such as IEC 62271-100, ANSI C37.09 etc.
B10E Power supply units from Megger can be used to test breaker coils in this manner. It provides a ripple-free variable DC voltage that can easily accomodate a high, variable load. Since there is a separate output for supplying spring-charging motors, the B10E Power supply units are ideal for testing circuit breakers where auxiliary voltage is not connected (industrial-truck circuit breakers for example).
The compact Power Supply Unit B10E provides reliable assistance to those who do maintenance on high-voltage breakers. The control panel's intuitive layout makes it easy to operate, and the built-in thermal cut out and overload protector make it safe to use. The B10E Power supply units have been developed in collaboration with breaker manufacturers and testing personnel.