DEIF RMC‑131D Differential Current Relay

Technical Specifications

Model:RMC‑131D

Brand:DEIF

System compatibility:Uni‑line series non‑stabilised differential protection relay,ANSI code 87,designed for generator stator winding internal fault protection. Requires CTs installed at both generator line‑side and neutral‑side. Suitable for marine and industrial genset,cooperates with other Uni‑line synchroniser and protection relays to build complete protection system.

Function:Hardware‑based three‑phase differential current relay. Compares incoming and outgoing current of each generator phase via double‑set CT signals. Adopts peak‑value sampling for fast fault response,non‑stabilised measuring principle. Front‑panel potentiometers adjust differential current threshold and trip time‑delay. Two change‑over relay outputs:one for breaker tripping command,the other for fault alarm signal. No PC configuration software required,all parameters set locally via potentiometers.

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

Interface:

‑Terminal block:3‑phase dual‑side CT current input

‑2 sets of change‑over relay output terminals(trip and alarm signal)

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

‑LED status indicators for power supply,fault condition and relay activation

Circuit feature:Analogue hardware measuring logic,response time＜50 ms under fault condition,surge suppression for CT input terminals,galvanic isolation between input,output and auxiliary power supply,relay contact transient protection.

Feature:Marine classification approved;relay contact rating 250VAC / 24VDC,8A resistive load. Non‑stabilised type,without restraint‑brake function,CT wiring polarity must be strictly correct during commissioning.

Diagnostic:Front‑panel LED reflects power supply,differential fault detection and relay action status. Separate alarm contact provides remote fault signal.

Power supply:24VDC(18‑32VDC),typical power consumption 2.8W

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:0.74kg

Dimensions:145mm ×110mm ×75mm

Certification:DNV,CE,marine type approval

Built‑in function

RMC‑131D differential relay detects internal short‑circuit faults inside generator stator winding. When differential current exceeds preset threshold,it outputs trip contact to cut off generator breaker rapidly,avoiding severe winding damage. Widely used for marine and industrial generator protection switchgear cabinets.

Product Brief

RMC‑131D belongs to DEIF Uni‑line series spare‑part family,non‑stabilised generator differential protection relay(ANSI 87). Double‑side CT wiring and polarity check are mandatory before commissioning. Parameters adjusted by front‑panel potentiometers. Widely applied for genset protection cabinet maintenance and renovation. ESD anti‑static protection shall be followed during installation.