SIEMENS 3RV1921-1M AUXILARY CONTACT ADD ON BLOCK 10A ALARM SWITCH
SIEMENS 3RV1921-1M is snap-on mounted marine auxiliary contact add-on block, designed for Siemens 3RV series motor protection circuit breakers, widely fitted onboard cargo vessels, tankers and offshore platforms for breaker status feedback and remote alarm signal output. This marine 10A rated auxiliary switch block provides 2 normally open and 2 normally closed potential-free contacts, mechanically coupled with the circuit breaker to transmit trip, overload and operational state signals to vessel control and alarm systems. The marine auxiliary contact module integrates mechanical trip indicator, robust screw terminal connection, surge protection and auxiliary relay interface, supports breaker fault indication, remote status signalling and emergency interlock logic for marine low voltage power distribution supervision. Its breaker status feedback & hardware diagnostics function continuously monitors contact integrity and circuit state, detects contact burnout and abnormal switching status, transmits circuit breaker fault alerts and operating status to vessel AMS alarm console. The breaker status feedback & hardware diagnostics ensures reliable status signal transmission for marine motor protection and low voltage power distribution system. It enables reliable marine 3RV1921-1M auxiliary contact block operation under heavy vessel vibration and salt mist marine environments.

This Siemens 3RV1921-1M auxiliary contact block delivers stable marine auxiliary add-on switch performance clipped onto the side of 3RV motor protection circuit breaker. The breaker status feedback & hardware diagnostics adopts marine-grade insulated housing with EMC shielding against electromagnetic interference and mechanical shock. Marine electrical technicians rely on marine 3RV1921-1M auxiliary block operation to test contact switching action, verify alarm signal output and inspect mechanical linkage condition during routine maintenance. It adopts standard snap-on mounting design for straightforward spare replacement and minimal marine power distribution system downtime. Internal contact components use anti-corrosion treatment to protect against salt mist, condensation and temperature fluctuation. It works cooperatively with 3RV motor protection circuit breaker, control cables and ship integrated alarm monitoring system. It is widely used as auxiliary contact spare hardware for Siemens marine low voltage motor protection and power distribution control system maintenance and retrofit projects.