ABB RA4088802 Rogowski Coil Current Sensor

Overview

The ABB RA4088802 is a Rogowski coil current sensor designed for ABB SACE Emax series air circuit breakers. The ABB RA4088802 is installed inside the circuit breaker to measure primary current and feed sampling signals to the electronic trip unit for overload, short circuit and ground fault protection. It features flexible coil structure and high bandwidth for accurate transient current capture, and is widely used as spare replacement for Emax low voltage main switch maintenance.

Features

The ABB RA4088802 provides linear current measurement for AC power frequency and short-circuit transient current. It has excellent anti-saturation performance compared with traditional iron-core current transformers and will not generate dangerous open circuit voltage under heavy fault current. The ABB RA4088802 matches the internal installation space of Emax frame breaker and directly connects to PR121/P, PR122/P, PR123/P release units. It adopts insulated flexible coil body and industrial-grade wiring terminals for stable long-term operation in distribution cabinets. The ABB RA4088802 follows the original mechanical outline and pin definition for direct drop-in replacement.

Specs

Device Type: Rogowski coil current sensor Model: ABB RA4088802 Applicable Breaker: ABB SACE Emax series air circuit breaker Compatible Trip Unit: PR121/P, PR122/P, PR123/P Sensor Type: Rogowski coil Measurement Object: AC phase current, neutral current Mounting: Internal installation inside circuit breaker Application: Low voltage distribution protection, breaker electronic release current sampling

Principle

The ABB RA4088802 induces voltage signal proportional to the rate of change of primary current through the flexible Rogowski coil. The induced signal is sent to the electronic release for integration and calculation to obtain the actual RMS current value. The trip unit compares the measured current with protection thresholds and executes delay or instantaneous trip logic when fault occurs. The ABB RA4088802 continuously transmits sampling signals during normal operation and fault events, supporting the release to record fault current magnitude.

Applications

The ABB RA4088802 is used for current sampling of Emax main incoming breaker and bus tie breaker in industrial power distribution rooms. It serves current measurement for large capacity low voltage feeder protection loops. The ABB RA4088802 applies to spare stock and emergency repair of existing Emax breaker protection assemblies. It also supports breaker overhaul and protection unit calibration projects.