Siemens 3VF5212-2MK47-7KN1 Moulded Case Circuit Breaker UnitCircuit Breaker

Module Feature

3VF5212-2MK47-7KN1 is a three-pole moulded case circuit breaker of Siemens 3VF series.

It integrates thermal-magnetic trip function. The thermal part responds to overload condition with inverse time delay, while the magnetic part provides instantaneous protection against short circuit. It supports optional auxiliary contacts and shunt release, widely used in industrial low voltage distribution cabinets.

Working principle

Under overload, the bimetallic sheet heats and deforms to trigger the trip mechanism.

When short-circuit current flows through, the magnetic coil generates instant electromagnetic force to open the main contacts quickly, isolating the fault circuit and protecting cables and downstream electrical equipment.

Onboard components

Bimetallic thermal trip, magnetic trip coil, main contact set, arc quenching chamber, operation handle and flame retardant plastic housing.

LED indicators

No built-in LED, circuit status is shown by mechanical handle position.

Hardware self‑diagnosis

Check contact abrasion, carbon accumulation in arc chamber and mechanical latching condition manually. Trip parameters are adjusted by front adjustment dial.

Programming software

Not applicable, locally adjustable circuit breaker.

Electrical & Process Parameters

Model: 3VF5212-2MK47-7KN1 Brand: Siemens Device type: Moulded case circuit breaker Function: Overload and short circuit protection for low voltage distribution circuit

Mechanical & Structure

Mounting: Panel mounting inside distribution cabinet Protection class: IP40 (front panel) Housing: Flame retardant reinforced plastic

Environmental

Operating temperature: -25℃ ~ +70℃ Storage temperature: -40℃ ~ +85℃ Ambient humidity: 5~95% non‑condensing

Certification: CE Status: Original Siemens electrical spare

Installation

Cut off upstream power supply before replacement.

Fix the breaker on the mounting base, connect incoming and outgoing cables, confirm trip setting, test switching and tripping performance after commissioning.

Interface

Three-phase main power terminals, optional auxiliary contact terminals, shunt release terminals.

Diagnostic

Overload trip: Load current exceeds set value, insufficient heat dissipation. Instantaneous trip: Short-circuit fault on load side. Fail to close: Mechanical latch jam or internal interlock triggered.

Product Brief

3VF5212-2MK47-7KN1 breaker, Siemens 3VF 3-pole thermal-magnetic moulded case circuit breaker spare for low voltage power distribution cabinet replacement.