The MRM4 is a motor protection relay provides precise and reliable protective functions and is very easy to operate. The MRM4 provides all necessary functions to protect low and medium voltage motors at all power levels. The protection functions are based on current measurement. They supervise the motor start sequence (motor start), they detect a stall or locked rotor condition and they monitor the thermal condition of the motor. Overcurrent and earth overcurrent protection as well as unbalanced load protection are included in the protection package.

The status and operation of the motor will also be monitored by means of the statistic and trend recorder. All important events and measuring values will be logged by means of the start, event, failure and disturbance recorder. The protection functions of the MRM4 have been adapted to comply with the requirements of the VDE AR N 4110:2018.

The MRM4 is available in 192 variants, that cover all combinations of properties that you might need or not need for your application. Each variant is uniquely specified by a typecode of form MRM4-2xxxxx (i.e. 5 digits/letters following the ‘-2’). Check the Order Form (depicted below, or in the brochure DOK-FLY-MRM4-2E or in the user manual MRM4-3.6-EN-MAN) for a complete overview.
With the HighPROTEC Line Woodward offers an outstanding solution for the reliable protection of
distribution and generator applications. The innovative device handling and PC tool with plausibility check and internal fault simulator, combined with high flexible hardware, minimized commissioning, training costs and setting failures. The menu overview can be optimized by hiding not relevant functions.

The line is easily applicable for generator, cable and line, and transformer differential protection,
directional and non-directional feeder protection as well as motor protection. The all-in-one protection
concept for various applications guarantees a high availability of your electrical equipment and your grid. Woodward is an independent designer, manufacturer, and service provider of control solutions for the aerospace and industrial markets. Our aerospace systems and components optimize the performance of fixed wing and rotorcraft platforms in commercial, business and military aircraft, ground vehicles and other equipment.

Its industrial related systems and components enhance the performance of industrial gas and steam turbines, reciprocating engines, compressors, wind turbines, electrical grids and other energy related industrial equipments. The company’s innovative fluid energy, combustion control, electrical energy, and motion control systems help customers offer cleaner, more reliable and more efficient equipment. Our customers include leading original equipment manufacturers and end users of their products.

Woodward MRM4-Family Protection relay : MOTOR PROTECTION

To ensure day-to-day electrical induction motors keep processes running, and to maximize the motor’s operating life, Woodward offers a variety of highly-adaptable Intelligent Electronic Devices to protect them against inadmissible electrical, thermal, or mechanical stress.

The following product lines offer the right Motor Protection products for your needs.

HIGHPROTEC LINE

The new HighPROTEC line is the latest generation of complete protection for medium-voltage power systems.

HighPROTEC Motor Protection Devices:

MRMV4 | MRM4

HIGH TECH LINE

These modular relays combine well-proven technology with easy handling.

PROFESSIONAL LINE

Comprehensive protective functions and competitive performance ratio are the hallmark of these relays.

To explore protection functions and comprehensive series of Woodward products, click here!