The test system is designed and customized to carry out 2.55*Intest as per Table 7 (test c) of IEC 60898 (also mentioned for routine testing of MCBs. The test is done at dc current to exactly analyze and correct the bimetallic properties of the MCB as far as thermal tripping is concerned. The unit comes with a pneumatically operated test fixture with in-built dc stepper motor that is controlled by a micro controller / PC to calibrate the breaker into a narrow tripping band programmed by the user.