Thermal overload relay for MC9b-40a series contactor, current 18-25A MT-32 18-25A

Motor and Circuit Protection – Thermal Relay MT-32

Thermal relay MT-32 is a reliable device used to protect AC motors and electrical circuits from overloads. Designed to work with MC9b-40a series contactors, it provides effective protection against damage resulting from excessive load, phase failures, prolonged starts, or motor blockage. This minimizes the risk of downtime and costly repairs.

Construction and Application

The MT-32 relay is a bimetallic device that reacts to temperature increases caused by excessive current flow. If the set threshold is exceeded, the relay automatically switches off the circuit, protecting the connected devices. The possibility of mounting directly under the contactor or using a dedicated UZ-63L base provides installation flexibility. This is particularly important in industrial applications where reliability and safety are crucial.

Key Features and Benefits

• Wide adjustment range: The MT-32 relay offers a current setting range from 18 to 25A, allowing it to be adapted to different loads and motors.
• Compatibility: Designed to work with LS Electric MC9b-40a series contactors (MC-9b, MC-12b, MC-18b, MC-22b, MC-32a and MC-40a), which simplifies selection and integration into existing installations.
• Manual and automatic reset: Availability of both manual and automatic reset (depending on the model) increases the functionality of the device and allows it to be adapted to specific application needs.
• Operation indicator: A built-in indicator informs about the operation of the relay, facilitating diagnosis of problems and quick restoration of system operation.
• Durable construction: Made of high-quality materials ensures reliable operation even in harsh industrial conditions.
• Compact dimensions: Dimensions of 45 x 75 x 90 mm allow for easy integration into tight switchgear spaces.
• Safety: Provides effective protection against overload and short circuit – like most circuit breakers in this class.

Additionally, the relay has a rated operating voltage AC Ue up to 690V and a rated impulse withstand voltage Uimp of 6kV. The weight of the device is only 0.17 kg, which facilitates installation.