Thermal overload relays, For contactor mounting - Class 10 - Screw Terminals - 3MU7110-0HA0

Product Description

Siemens 3MU7110-0HA0 Thermal Overload Relay – Class 10 Reliable Motor Protection

The Siemens 3MU7110-0HA0 Thermal Overload Relay is a dependable motor protection device from the SINOVA 3MU7 Series, designed to protect three-phase motors against overload and phase-failure conditions. Featuring a 1.6A to 2.5A adjustable current range and a Class 10 tripping characteristic, this relay provides reliable thermal protection for industrial motor control systems, helping prevent motor overheating, insulation damage, and unexpected equipment failures. It is specifically designed for direct mounting on Siemens 3MT7 contactors (Size 0, Size 1, and Size 2).

The relay continuously monitors motor current using a thermal bimetal mechanism that closely follows the heating characteristics of the motor. When overload conditions occur, the relay trips and disconnects the motor before excessive heat can damage windings or insulation. This inverse-time thermal protection ensures dependable operation while minimizing nuisance trips during normal motor startup and operation.

With its Class 10 trip characteristic, the 3MU7110-0HA0 is ideal for motors operating under normal starting conditions. It provides fast response to overload situations while allowing standard motor acceleration currents during startup. Typical applications include pumps, fans, compressors, conveyors, HVAC equipment, packaging machinery, and industrial automation systems.

The adjustable current setting range of 1.6A to 2.5A allows precise matching of protection settings to motor full-load current requirements. The relay has a rated operational current of 2.5A, making it suitable for small motors and light industrial motor control applications.

A major advantage of the Siemens 3MU7110-0HA0 Thermal Overload Relay is its integrated phase-failure sensitivity. In the event of phase loss, the relay accelerates tripping to minimize motor heating and prevent winding damage. This enhanced protection significantly improves equipment reliability and operational safety in demanding industrial environments.

Designed for seamless integration with Siemens 3MT7 contactors, the relay features robust screw terminal connections for both the main and auxiliary circuits. These terminals ensure secure wiring, easy installation, and reliable long-term performance in industrial applications.

The relay includes 1 Normally Open (NO) and 1 Normally Closed (NC) auxiliary contacts for overload indication, alarm signaling, PLC interfacing, and contactor control circuits. This functionality improves system monitoring and simplifies control panel design.

For operational flexibility, the 3MU7110-0HA0 supports both manual and automatic reset functions, allowing users to select the most suitable reset method based on application requirements and safety considerations. A built-in trip indicator further simplifies fault diagnosis and maintenance.

Manufactured according to IEC 60947-4-1 standards, the relay offers 690V insulation voltage, 6kV impulse withstand voltage, IP20 front protection, and reliable operation across industrial environments. Its rugged construction makes it ideal for manufacturing plants, water treatment facilities, HVAC systems, process industries, and automation projects.