Thermal overload relay for MC9b-40a contactor series MT current 0.1-0.16A MT-32 2.5-4A MT-32 2,5-4A

Motor and Circuit Protection – Thermal Relay MT-32

This thermal relay from the MT series, designed to work with MC-9b-40a contactors, is a key element in protecting electrical installations. It serves to protect AC motors and circuits from the effects of overloads, phase failures, prolonged starts and jams. This ensures reliable operation and extends the life of connected devices.

Construction and application

The MT-32 relay uses a bimetallic construction that reacts to temperature changes caused by current flow. If the set tripping threshold is exceeded, the circuit is disconnected, protecting sensitive components from damage. The ability to mount directly under the contactor or using a dedicated UZ-63L base provides installation flexibility.

This relay finds application in a wide range of industrial and commercial applications where reliable protection of motors and electrical circuits is required. It is ideal for protecting pumps, fans, conveyors and other devices powered by electric motors.

Key features and benefits

• Wide adjustment range: The MT-32 relay is available in a current range of 0.1-0.16A and 2.5-4A, allowing it to be adapted to different loads.
• Protection against various disturbances: It protects not only against overload, but also against phase failures and motor jams.
• Universal mounting: Direct or dedicated UZ-63L base mounting options make integration with existing installations easier.
• High reliability: The bimetallic construction ensures precise and stable operation in various working conditions.
• Safety: Rated impulse withstand voltage at 6kV guarantees protection against overvoltages.
• Compact dimensions: Dimensions of 45 x 75 x 90 mm allow for easy integration into tight installation spaces.
• Light weight: A weight of only 0.17 kg makes installation and operation easier.

The rated operating voltage AC Ue is 690V, and the rated insulation voltage Ui is also 690V. The relay withstands a rated impulse withstand voltage Uimp of 6kV and works with a network frequency f of 50/60 Hz. The rated operating current AC-3 for Ue=400V is 0.16A (for the 0.1-0.16A range) or 4A (for the 2.5-4A range).