Auxiliary contact for motor circuit breaker 3/5 A 1NC+1NO MZ520N

Signal terminals for motor disconnect switch

This additional contact is used to transmit the status signal of the motor disconnect switch – e.g., for control, fault indication or automation. It has one pair of contacts: one normally open (NO) and one normally closed (NC), allowing monitoring of both circuit activation and deactivation. It has no switching contacts or fault‑indication contacts – it is simple but functional.

Installation and connection

It is mounted laterally on the motor disconnect switch – no housing or additional elements required. It is intended for top mounting, meaning it connects directly to the device base without disconnecting wires. The electrical connection is screw‑type – accepts rigid and flexible conductors with a cross‑section up to 2.5 mm². Dimensions are compact: width 9 mm, depth 68 mm – occupies only half a module on a DIN rail.

Application and operating conditions

Operates in AC systems with a rated voltage up to 690 V and frequency 40–60 Hz. Rated current is 3.5 A at AC-15 – suitable for controlling motor circuits where short inrush currents occur. It is not intended for switching large currents – its purpose is only state signalling, not power carrying. Supports operation in temperatures from -25 °C to +55 °C, and storage down to -80 °C. IP20 protection rating provides basic protection against touch and dust – sufficient for installations in control cabinets.

Reliability and durability

Designed for 100 000 mechanical cycles and 50 000 electrical cycles – ensuring long‑term stability even with frequent switching. Total loss power under load is only 0.04 W – does not generate additional heat nor burden the circuit. It is part of the Hager system – compatible with the MM5xx series and other motor disconnect switches of the same type.