Why Choose the ABB ELR96 Residual Current Monitor?
The ABB ELR96 is an electronic front-panel residual current monitor and relay designed for monitoring and protecting low-voltage electrical distribution systems. Used with an external ABB TR-series toroidal transformer and suitable circuit-breaking equipment, it detects earth-leakage currents and provides an output for initiating protective disconnection.
The ELR96 provides adjustable residual-current sensitivity from 0.03 A to 30 A when used with the appropriate multiplier setting, together with an adjustable operating delay. This flexibility allows the relay to be configured for different earth-fault protection and discrimination requirements across commercial and industrial electrical systems.
Designed for 96 mm × 96 mm front-panel mounting, the ELR96 features sensitivity and delay controls, TEST and RESET pushbuttons, and LED indication for auxiliary supply and trip status. It complies with IEC/EN 60947-2 Annex M and is designed to work with external toroidal current transformers and appropriate MCB or MCCB protection.
Key Advantages
- Wide adjustable residual-current range from 0.03 A to 30 A using the available multiplier settings.
- Adjustable operating delay supports protection coordination and discrimination.
- Type A residual-current monitoring for AC and pulsating DC residual-current waveforms.
- Designed for use with external ABB TR-series toroidal transformers.
- TEST and RESET controls simplify functional checking and resetting.
- LED status indication provides clear auxiliary-supply and trip information.
- Front-panel format provides convenient access to settings and indications.
Key Features
- Electronic residual current relay for low-voltage distribution systems.
- Type A residual-current monitoring.
- Residual-current sensitivity settings covering 0.03–30 A.
- Adjustable delay settings covering 0–5 s using the applicable multiplier.
- 110 V AC/DC, 230 V AC and 400 V AC auxiliary supply options.
- 50–60 Hz rated frequency.
- Maximum consumption of 4 VA.
- 5 A at 250 V output contact capacity.
- Compatible with ABB TR-series toroidal transformers.
- Front-panel TEST and RESET pushbuttons with ON and FAULT LED indication.
Adjustable Residual-Current Monitoring and Protection
The ABB ELR96 operates with an external toroidal transformer that monitors the conductors of the protected circuit. Under normal conditions the vector sum of the currents passing through the toroid is effectively balanced; an earth-leakage or insulation fault creates a residual current that can be detected by the relay. When the configured threshold and operating conditions are reached, the ELR96 output can initiate disconnection through suitable associated circuit-breaking equipment.
Its adjustable sensitivity and time-delay controls allow the protection response to be matched to the installation and coordinated with other protective devices. The ELR96 therefore provides a flexible solution for earth-leakage monitoring in distribution systems where a separate residual-current relay, toroidal transformer and circuit breaker arrangement is required.
Typical Applications
- Low-voltage electrical distribution boards.
- Industrial switchboards and control panels.
- Commercial building electrical distribution systems.
- Earth-leakage and insulation-fault monitoring.
- MCB and MCCB protection schemes using an external toroidal transformer.
- Installations requiring adjustable residual-current sensitivity and operating delay.
