DEIF RMF‑112D Over‑Under Frequency Protection Relay

Technical Specifications

Model:RMF‑112D

Brand:DEIF

System compatibility:Uni‑line series frequency protection relay,ANSI code 81,applied for single‑phase or three‑phase generator busbar frequency monitoring. Cooperates with other Uni‑line synchroniser and protection relays to build complete genset protection system,suitable for marine and land‑based power station.

Function:Combined over‑frequency and under‑frequency protection unit. Measures network frequency via PT voltage input. Two independent adjustable threshold potentiometers for under‑frequency and over‑frequency,separate time‑delay setting for trip action. Two potential‑free relay outputs,respectively for under‑frequency fault and over‑frequency fault. Built‑in 0.25Hz hysteresis prevents relay chattering. No PC configuration software required,all parameters adjusted by front‑panel potentiometers.

Installation:35 mm DIN‑rail mounting or base screw mounting inside switchgear cabinet

Interface:

‑Terminal block:PT voltage measuring input

‑2 groups potential‑free relay output terminals(under‑frequency / over‑frequency)

‑Front‑panel potentiometers for frequency threshold and trip‑delay adjustment

‑LED status indicators for power supply,under‑frequency and over‑frequency fault

Circuit feature:Hardware measuring logic,response time＜90ms,surge suppression for AC measuring input,3250V galvanic isolation between input and output,relay contact transient protection.

Feature:Marine classification approved;relay contact rating 250VAC / 24VDC,8A resistive load. Rated frequency selectable for 50Hz / 55Hz / 60Hz,measuring range 40‑70Hz.

Diagnostic:Front‑panel LED reflects power supply,under‑frequency and over‑frequency fault trigger status. Each fault corresponds to independent relay contact output for remote signal transmission.

Power supply:24VDC(18‑32VDC),typical power consumption 2.2W

Protection class:IP20

Horizontal operating temperature:‑25℃ ~ +70℃

Storage temperature:‑40℃ ~ +85℃

Relative humidity:5%‑95% non‑condensing

Shock & vibration:Complies with DNV marine environmental requirement

Weight:0.56kg

Dimensions:145mm ×110mm ×75mm

Certification:DNV,CE,marine type approval

Built‑in function

RMF‑112D frequency relay monitors generator‑busbar operating frequency. It outputs trip relay signal when frequency drifts outside preset allowable range,protects generator and loads from damage caused by abnormal frequency. Widely used for marine and industrial genset switchgear cabinets.

Product Brief

RMF‑112D belongs to DEIF Uni‑line series spare‑part family,combined over‑under frequency protection relay(ANSI 81). Parameters adjusted by front‑panel potentiometers without configuration software. Widely applied for genset protection cabinet maintenance and renovation. ESD anti‑static protection shall be followed during installation.