Why Choose the ABB RD3P-48 Residual Current Relay?
The ABB RD3P-48 is a modular electronic residual current relay designed for earth leakage protection and monitoring in low-voltage industrial electrical installations. As part of the ABB RD3 residual current relay series, it operates with an external ABB TR-series toroidal transformer to detect residual currents and control associated circuit-breaking equipment when an earth fault occurs.
The RD3P-48 combines adjustable residual current sensitivity with adjustable intervention time, allowing protection characteristics to be coordinated for different circuits and installation requirements. The RD3P version adds a 60% pre-alarm threshold and LED bar indicator, providing useful advance indication and visual monitoring of residual current conditions before the selected trip threshold is reached.
With a 12–48 V AC/DC operating voltage, sensitivity settings from 0.03–30 A and tripping-time settings from 0–10 seconds, the RD3P-48 provides flexible residual current protection for industrial distribution systems. Its compact 3-module DIN-rail format enables straightforward integration into electrical distribution boards and control panels.
Key Advantages
- Electronic residual current protection and monitoring for industrial installations.
- Wide 0.03–30 A selectable residual current sensitivity.
- Adjustable 0–10 second tripping delay supports protection coordination.
- 60% pre-alarm threshold provides advance warning of leakage conditions.
- LED bar indicator provides clear visual residual current monitoring.
- 12–48 V AC/DC operating voltage suits low-voltage auxiliary control systems.
- Designed for use with ABB TR-series external toroidal transformers.
- Two output contacts provide status and control signalling.
- Compact 3-module DIN-rail mounting simplifies panel integration.
Key Features
- ABB RD3P-48 electronic residual current relay.
- 12–48 V AC/DC operating voltage with +10% / -15% tolerance.
- 50/60 Hz auxiliary supply frequency for AC operation.
- Frequency filter for improved residual current monitoring.
- Type A detection up to 5 A IΔn and Type AC for higher residual current settings.
- Sensitivity settings of 0.03, 0.1, 0.3, 0.5, 1, 2, 3, 5, 10 and 30 A.
- Tripping-time settings of 0, 0.06, 0.2, 0.3, 0.5, 1, 2, 3, 5 and 10 seconds.
- 60% pre-alarm threshold.
- LED bar indicator for residual current status.
- Two output contacts rated up to 8 A at 250 V AC.
- Remote reset connection up to 15 m.
- IP20 protection degree.
Reliable Residual Current Protection and Monitoring
Residual current relays detect earth leakage by working with an external toroidal transformer installed around the active conductors of the monitored circuit. When the measured residual current reaches the selected threshold for the configured intervention time, the relay can operate associated switching or tripping equipment to isolate the affected circuit.
The ABB RD3P-48 is designed for use with ABB TR-series toroidal transformers and can be combined with ABB S200 miniature circuit breakers and compatible Tmax/XT moulded-case circuit breakers. Its pre-alarm function and LED bar indicator also enable residual current conditions to be monitored before the protection threshold is reached.
Typical Applications
- Industrial low-voltage electrical distribution systems.
- Residual current and earth leakage protection systems.
- Industrial switchboards and distribution panels.
- Machinery and automation control panels.
- Installations using 12–48 V AC/DC auxiliary supplies.
- ABB S200 miniature circuit breaker protection arrangements.
- Tmax and XT moulded-case circuit breaker applications.
- Systems requiring pre-alarm indication and residual current monitoring.
