Bell Alarm & Auxiliary Switch
The Bell Alarm switch is used to signal a breaker trip operation. Common uses for bell alarm switches include indicating lights, external control relays, interlocking schemes, and any other application that requires remote indication of breaker trip. The switches are available in either normally open (NO) or normally closed (NC) configuration. Auxiliary switch contacts hange position due to any operation of the circuit breaker (overcurrent trip, push to trip from the front cover, shunt trip/undervoltage release or toggle handle operation). Bell alarm contacts do not change position due to an operation of the toggle handle or push to trip button.
The auxiliary switch provides remote indication of the primary contact position. Auxiliary switches are commonly used anywhere remote indication of breaker position is desired. These switches are available in normally open (NO) and normally closed (NC) configurations; the contacts change position upon changing of position of the primary contacts regardless of method of operation.

Shunt Trip & Undervoltage Release
The shunt trip is used to remotely open the circuit breaker. Like all other accessories, the hunt trip is UL listed for field installation and does not require exposure to current carrying parts for installation. Both the shunt trip and Undervoltage Release are low power consumption devices. MC9 breakers feature a kiss-free design, which ensures that the primary contacts do not come into contact when a closing attempt is made with a shunt-trip or undervoltage release energized.
The undervoltage release is used to trip the circuit breaker when a control signal is removed, or drops below 35–70% of the rated voltage. If an attempt is made to re-close the circuit breaker without re-application of control power to the undervoltage release, the breaker will be held trip-free, preventing the contacts from closing.