Inm -- the current of molded case circuit breaker frame level  a, which means the maximum current value of switch and release that can be installed in the molded case circuit breaker.

In -- rated current  a of moulded case circuit breaker, which means the rated current value of thermal release selected in moulded case circuit breaker. In non adjustable fixed thermal release, in = IR1.

Ir1 -- long time delay setting current  a of MCCB, which means the current value set by overload protection release of MCCB.

Ir2 -- short delay setting current  a of moulded case circuit breaker, which means the setting current of short delay release of moulded case circuit breaker, and its value is about  2 ～ 12irl adjustable in electronic adjustable release.

Ir3 -- instantaneous setting current  a of moulded case circuit breaker, which means the setting current of instantaneous release of moulded case circuit breaker. Its value is adjustable about  4 ～ 16irl in the non adjustable fixed release, power distribution type is 5irl and 10irl, motor protection type is 12ir1, and electronic adjustable type is about  4 ～ 16irl.

Ir4 -- single phase grounding setting current  a of moulded case circuit breaker, which means the setting current value of grounding protection release in case of single-phase grounding fault of circuit or equipment protected by moulded case circuit breaker. Its value is about 0.2 ~ 0.6irl, which can be adjusted.

Ire -- leakage action current  a of moulded case circuit breaker, which means the current value set by leakage protection release when abnormal leakage current occurs in the circuit or equipment protected by moulded case circuit breaker. Its value is 0.03/0.1/0.3/0.5a.

Ir0 -- pre alarm action current  a of MCCB, which means that when the load current of MCCB exceeds the preset current, the pre alarm device will send out alarm indication signal, and its value is  0.5 ～ lir1, which can be adjusted.

Ir2 -- setting value of tripping time of short delay release  s, adjustable time is 0.05 ~ 0.45s.