Schneider Electric Square D 48539 NW MasterPact Locking Device is a locking accessory for MasterPact circuit breakers designed to work with the Kirk Key interlock system. Identified by model 48539 NW, it provides a physical lock that secures a MasterPact breaker when a Kirk Key is engaged, preventing unauthorized operation. This device is used in installations requiring Kirk Key interlock safety coordination with MasterPact equipment.
