Description
DEIF
TYPE: RMP-121D
REVERSE POWER RELAY
255448.20
MEAS VOLTAGE: 110VAC
MODULE: 63.3V
MEAS POWER: 563W
SCALE: 0.99
SUPPLY: 24VDC
COUPLING: 1W3
600V CAT III.
The DEIF RMP-121D is a reverse power relay designed to detect and respond to reverse power flow conditions within marine electrical power generation and distribution systems. As a critical protective component within the Marine Control System category, it monitors active power and trips generator circuit breakers when power flow reverses, preventing motoring of alternators and protecting prime movers from damage. Its role is fundamental to the safe and reliable operation of onboard power management systems, particularly in parallel generator configurations common across commercial and offshore vessels.
Key Features
✓ Reverse power detection with a measurement voltage of 110VAC, measured power of 563W, and a scale factor of 0.99, providing precise threshold monitoring suited to marine generator protection applications.
✓ Operates on a 24VDC supply with a module reference voltage of 63.3V and a 1W3 coupling configuration, making it compatible with standard marine panel power supply architectures.
✓ Rated to 600V CAT III, indicating suitability for measurement and protection tasks within distribution-level electrical environments typical of shipboard power systems.
✓ Designed for integration with DEIF power management and control panels; compatibility with specific switchboard configurations or controller versions should be confirmed against system documentation prior to installation.
✓ As a protective relay, replacement should be carried out in accordance with the vessel’s planned maintenance schedule or following a protective function test failure, with correct parameter configuration verified during commissioning.
Marine Applications
✓ Generator protection in parallel operation aboard merchant vessels, where reverse power relays are essential to prevent generator motoring during load transfer or prime mover failure events.
✓ Power management control panels on offshore support vessels, platform supply vessels, and anchor handling tugs where reliable generator protection is operationally critical.
✓ Switchboard protection systems on ferries, RoPax vessels, and passenger ships where multiple generators operate in parallel and reverse power events must be detected rapidly.
✓ Retrofit and upgrade of existing DEIF-based power control systems where an original reverse power relay has reached end of service life or requires replacement following a fault event.
✓ Commissioning and testing of new generator control panels during shipbuilding or major refit projects, ensuring protective relay settings are verified against system design parameters.
Why Marine Engineers Choose
DEIF reverse power relays are a recognised standard in marine power management, valued for their reliable protective performance, integration with DEIF control architectures, and the clearly defined electrical specifications that simplify configuration and verification during installation and maintenance.
Ideal For
Merchant cargo vessels, offshore support and platform vessels, ferries, passenger ships, fishing vessels, and any commercial or industrial marine application operating DEIF-based generator control and power management systems.
Technical Support & Compliance
Technical assistance is available to support remote troubleshooting, onboard fault diagnosis, testing and commissioning, and integration of this relay into existing or upgraded power management systems. Retrofit suitability and compatibility with specific DEIF control panels or switchboard configurations is subject to confirmation. To confirm correct fit and application, buyers are encouraged to share nameplate photographs, the original part number, relevant electrical drawings or panel schematics, the system model and software version where applicable, and vessel name or IMO number. Providing this information ensures the correct relay variant and parameter settings are identified before supply or installation.
