Auxiliary and alarm contacts are supplied in multiple variations for customer application. Auxiliary contacts (AX) indicate ON/OFF status of the MCCB. Alarm contacts (AL) indicate trip status of the MCCB. Alarm trip can be initiated by pressing the test button on the molded case circuit breaker, a trip due to overcurrent, short circuit; or trip due to residual current, shunt or undervoltage release signals. Thermal Trip Contacts (TU): Trips only when the MCCB has detected an overcurrent, short-circuit or protection trip. H and J frame MCCBs have a button to test this feature. Available only for H, J, N, NS and R frames. These contacts are installed by removing the MCCB cover and accessing right-side pockets within the breaker with snap-in mounting provisions. AX2. Suitable for G, H, I and J frames MCCB.