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2CSG152424R1202 ABB ELR72P Residual Current Monitor
ABB ELR72P is a Type A front-panel electronic residual current monitor and relay with adjustable protection settings, a 60% pre-alarm threshold and external toroidal transformer sensing for low-voltage distribution systems.
£456.19
Why Choose the ABB ELR72P Residual Current Monitor?
The ABB ELR72P is a front-panel electronic residual current monitor and relay designed for monitoring and protection of low-voltage electrical distribution systems. Used with an external toroidal transformer and suitable circuit-breaking equipment, it detects residual current caused by earth leakage or insulation faults and provides relay outputs for protective signalling and disconnection.
The ELR72P provides Type A residual-current monitoring, allowing it to respond to sinusoidal alternating and pulsating DC residual currents. Adjustable sensitivity and operating-delay controls enable the device to be configured for different protection and discrimination requirements, while its dedicated pre-alarm function provides an early indication before the main trip threshold is reached.
Designed for 72 mm × 72 mm front-panel mounting, the ELR72P combines TEST and RESET controls with clear LED indication for supply, alarm and fault status. It operates from 110/230/400 V AC auxiliary supplies and complies with IEC/EN 60947-2 Annex M, making it a practical monitoring solution for commercial and industrial switchboards.
Key Advantages
- Type A residual-current monitoring for sinusoidal AC and pulsating DC residual currents.
- Adjustable sensitivity allows protection settings to be matched to the installation.
- Adjustable operating delay supports protection coordination and discrimination.
- 60% pre-alarm threshold provides advance warning before the main residual-current trip level is reached.
- Designed for use with an external ABB TR-series toroidal transformer.
- TEST and RESET pushbuttons support straightforward functional checking and operation.
- LED indication provides clear supply, alarm and fault status information.
Key Features
- ABB ELR electronic residual current relay range.
- Type A residual-current monitoring.
- 110/230/400 V AC operating voltage.
- 50–60 Hz rated frequency.
- 60% pre-alarm threshold.
- Separate alarm and fault relay outputs.
- Front-panel TEST and RESET controls.
- Green supply, yellow alarm and red trip/fault LED indication.
- External toroidal transformer connection.
- Compact 72 mm × 72 mm front-panel format.
Residual-Current Monitoring with Pre-Alarm Protection
The ABB ELR72P operates with an external toroidal transformer through which the conductors of the protected circuit are routed. Under normal operating conditions, the vector sum of the currents is balanced. An insulation fault or earth-leakage path produces a residual current that the toroidal transformer detects and the ELR72P evaluates against its configured protection threshold.
The pre-alarm function provides additional monitoring capability by signalling when residual current reaches 60% of the selected threshold. Together with adjustable protection settings and separate alarm and fault outputs, this allows developing leakage conditions to be identified while supporting coordinated protective disconnection through suitable associated MCB or MCCB equipment.
Typical Applications
- Low-voltage electrical distribution boards.
- Industrial switchboards and control panels.
- Commercial building electrical distribution systems.
- Earth-leakage and insulation-fault monitoring.
- Installations requiring pre-alarm indication of developing residual current.
- Protection schemes using external toroidal transformers with MCBs or MCCBs.
Technical Specifications
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| Monitoring Function | Earth leakage / residual current | |
|---|---|---|
| Series | ELR | |
| ABB order code | 2CSG152424R1202 | |
| Product type | Electronic residual current monitor / relay | |
| Residual-current type | A | |
| Function | Residual-current monitoring for AC electrical systems | |
| Operating voltage | 110/230/400 V AC | |
| Rated frequency | 50–60 Hz | |
| Pre-alarm threshold | 60% of selected residual-current threshold | |
| Controls | TEST and RESET pushbuttons | |
| Status indication | Supply, alarm and fault/trip LEDs | |
| Sensor | External toroidal transformer | |
| Dimensions | 72 mm × 72 mm × 88 mm | |
| Panel cut-out | 68 mm × 68 mm | |
| Mounting | Front panel | |
| Applicable standard | IEC/EN 60947-2 Annex M |
Frequently Asked Questions
What is the ABB ELR72P used for?
The ABB ELR72P is a front-panel electronic residual current monitor and relay used with an external toroidal transformer to monitor earth leakage and provide alarm and protective relay outputs in low-voltage electrical systems.
What type of residual current does the ELR72P monitor?
The ELR72P is a Type A device, designed to monitor sinusoidal alternating and pulsating DC residual currents.
What is the pre-alarm function on the ABB ELR72P?
The ELR72P provides a pre-alarm threshold at 60% of the selected residual-current setting, allowing developing leakage conditions to be signalled before the main protection threshold is reached.
Does the ABB ELR72P require a toroidal transformer?
Yes. The ELR72P operates with an external toroidal transformer that detects the residual current flowing in the monitored electrical circuit.
Which standard applies to the ABB ELR72P?
The ABB ELR72P is designed in accordance with IEC/EN 60947-2 Annex M for residual current relay protection.
Trusted ABB Earth-Fault Monitoring
ABB ELR residual current relays combine adjustable Type A earth-leakage monitoring, external toroidal sensing and practical front-panel controls, with the ELR72P adding pre-alarm signalling for improved supervision of low-voltage distribution systems.
