Description
ABB ACA 4,2525,5 ΜF3 3BHB020695R0010
Technical Specifications Contact configuration 4 normally open plus 4 normally closed contacts; rated operational current 6A under AC-15 utilization category; rated insulation voltage 690V AC; rated impulse withstand voltage 6kV; mechanical endurance 10,000,000 operating cycles; electrical endurance 300,000 cycles at rated load; clip-on front mounting; compliance with IEC 60947-1, IEC 60947-2 and IEC 60947-5-1.
Functional Features Mechanically couples with the circuit breaker operating mechanism to reflect the true mechanical state of the breaker. Provides isolated contact signals for remote status indication, interlock logic and fault alarm. Separates auxiliary signal circuits from the main high-current power circuit of the molded case breaker. Supports wiring for multiple independent status monitoring circuits through four NO and four NC contacts. Matches breaker trip state when the breaker trips from overload or short-circuit conditions.
Application Scenarios Low-voltage power distribution cabinets, motor control centers, industrial plant power monitoring systems, building electrical distribution, data center power supply breaker remote status acquisition.
Performance Parameters High mechanical cycle life for frequent breaker operation; stable contact resistance under rated signal load; reliable state tracking even during fast short-circuit breaker tripping; high dielectric strength between auxiliary contacts and main power circuit.
Material Composition Contact carrier housing is flame-retardant thermoplastic resin; contact springs and contact pieces are silver alloy for low contact resistance; internal mechanical linkage is reinforced engineering plastic; terminal screws are zinc-plated steel alloy.
Structural Characteristics Small rectangular clip-on accessory designed to fit the front designated mounting cavity of Tmax molded case circuit breakers. External screw terminal blocks for control signal wiring. Internal cam linkage engages directly with the breaker switch mechanism. No separate mounting hardware is required for installation.
Working Principle When the main circuit breaker operating handle moves to open, closed or tripped position, the internal mechanical cam linkage of the auxiliary contact block actuates the spring contact assemblies. The four normally open and four normally closed contacts change state synchronously with the breaker mechanical position. The contacts provide dry contact signals to external control circuits to indicate breaker status.
Installation Requirements Verify compatibility with the target Tmax circuit breaker model before installation. Snap the auxiliary contact block into the dedicated front mounting cavity of the circuit breaker until the clip locks. Route low-voltage control signal wires to the screw terminals and fasten terminals with the specified torque. Test contact state change by manually opening and closing the circuit breaker.
Precautions for Use Do not apply loads exceeding the 6A AC-15 rated contact current to auxiliary contacts. Keep the auxiliary contact area free of dust and metal debris. Do not use these auxiliary contacts for primary power switching duties. Inspect contact function after breaker short-circuit trip events.
