DEIF RMC‑131D/2 Differential Current Relay

Technical Specifications

Model:RMC‑131D/2

Brand:DEIF

System compatibility:Uni‑line series non‑stabilised three‑phase differential protection relay,ANSI code 87,variant /2 version. Requires CTs installed at generator line‑side and neutral‑side. Designed for generator stator winding internal short‑circuit protection. Suitable for marine and industrial genset systems,works with other Uni‑line protection relays to build complete generator protection solution。

Function:Hardware‑based differential current relay. Compares incoming and outgoing current of each phase via dual‑side CT signals,adopts peak‑value sampling for fast fault response. Front‑panel potentiometers adjust differential current threshold and trip time‑delay. Two independent change‑over relay outputs:one for breaker trip command,the other for remote fault alarm signal. No PC configuration software required,all parameters adjusted locally by potentiometers。

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

Interface:

‑Terminal block:three‑phase dual‑side CT current input terminals

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

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

‑LED status indicators for power supply,differential fault and relay action

‑Auxiliary power supply terminals

Circuit feature:Analogue hardware measuring logic,fault response time＜50ms,surge suppression for CT input terminals,3250V 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. CT secondary 1A/5A adaptable. Non‑stabilised measuring principle,CT wiring polarity must be strictly verified during commissioning,incorrect polarity will cause false tripping。

Diagnostic:Front‑panel LED indicates power‑on status,differential fault detection and relay activation. Independent alarm contact transmits 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/2 differential relay detects internal short‑circuit faults inside generator stator winding. When differential current exceeds preset threshold,it outputs trip contact to rapidly open generator breaker to avoid severe winding damage. Widely used for marine and industrial generator protection cabinet spare‑part replacement

Product Brief

RMC‑131D/2 belongs to DEIF Uni‑line series spare‑part family,non‑stabilised generator differential protection relay(ANSI 87). Dual‑side CT wiring and polarity check are mandatory before commissioning. Parameters adjusted by front‑panel potentiometers without configuration software. Widely applied for power‑equipment maintenance and renovation. ESD anti‑static protection shall be followed during installation.