ABB 2CSJ202001R0002 RD3M 1-500mA 230-400V AC DIN-Rail Residual Current Monitoring Relay

The ABB RD3M (2CSJ202001R0002) is a DIN-rail mounted residual current monitoring relay designed to continuously supervise insulation integrity and detect earth leakage currents in AC electrical installations. Part of the ABB RD3 series, the RD3M provides adjustable sensitivity from 1 to 500 mA at rated voltages of 230 to 400 V AC, making it suitable for early fault detection in control panels, machinery, and distribution systems. Rated at just 3.6 W power consumption, this compact unit measures 52.8 × 85 × 65 mm and weighs only 223 g.

Technical Specifications

Certifications & Standards

• RoHS: Compliant with EU Restriction of Hazardous Substances Directive
• REACH: Compliant with EU REACH chemical safety regulation
• EU Directive 2011/65/EU: RoHS recast directive compliance
• Amendment 2015/863: Compliance with updated RoHS substance restrictions
• IEC EN 60947-2 Annex M: Residual current device requirements per IEC/EN 60947-2 Annex M
• IEC EN 60947-2: Low-voltage switchgear and controlgear — circuit breakers standard
• EN 60947-2: European harmonised standard for low-voltage circuit breakers
• WEEE: Compliant with EU Waste Electrical and Electronic Equipment Directive

Applications & Use Cases

The ABB RD3M residual current monitoring relay is ideal for continuous earth leakage monitoring in industrial control panels, building electrical installations, and machine tool enclosures. Its wide adjustable current range (1–500 mA) enables both sensitive insulation monitoring for critical equipment and higher-threshold monitoring for general distribution boards. The DIN-rail form factor integrates seamlessly into standard control cabinets, supporting proactive maintenance strategies by providing early warning of insulation degradation before nuisance tripping or equipment damage occurs.