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2CSG252120R1202 ABB ELR72 Residual Current Monitor 72mm
ABB ELR72 is a 72 mm front-panel Type A residual current monitor with Fail Safe and automatic reset functions for earth leakage monitoring and protection of low-voltage electrical distribution networks.
£328.40
Why Choose the ABB ELR72 Residual Current Monitor?
The ABB ELR72 is a compact Type A electronic residual current monitor and relay designed for monitoring and protection of low-voltage electrical distribution networks. As part of ABB’s Earth Monitoring Devices range, it operates with an external toroidal transformer to detect residual current and provide a trip signal to associated circuit protection equipment.
The ELR72 is designed for 72 × 72 mm front-panel mounting and combines adjustable residual current protection with Fail Safe and automatic reset functions. Used together with a compatible ABB toroidal transformer and suitable MCB or MCCB protection, it provides a flexible earth leakage monitoring solution for commercial and industrial electrical installations.
With a rated voltage range of 110–230 V, operational supply options of 110 V AC/DC or 230 V AC and a rated frequency of 50–60 Hz, the ELR72 is suitable for a wide range of low-voltage distribution applications. Its compact front-panel format enables straightforward integration into switchboards, control panels and industrial electrical equipment.
Key Advantages
- Electronic Type A residual current monitoring for low-voltage electrical networks.
- Compact 72 × 72 mm front-panel format for switchboard and control-panel installation.
- Designed for use with an external toroidal transformer for flexible residual current sensing.
- Fail Safe functionality supports dependable electrical protection.
- Automatic reset functionality for flexible system operation.
- Designed for coordinated protection with suitable MCBs and MCCBs.
Key Features
- ABB ELR residual current relay series.
- Type A residual current detection.
- Fail Safe and automatic reset functions.
- 110–230 V rated voltage.
- 110 V AC/DC or 230 V AC operational voltage.
- 50–60 Hz rated frequency.
- Designed for mixed-system applications.
- Operates with compatible external ABB toroidal transformers.
- Front-panel mounting for integration into electrical enclosures.
- No pre-alarm threshold function on the standard ELR72 version.
- Complies with IEC/EN 60947-2 Annex M.
Reliable Residual Current Monitoring for Low-Voltage Networks
The ABB ELR72 operates with an external toroidal transformer through which the active conductors of the protected circuit are routed. Under normal operating conditions, the currents passing through the toroid balance each other. When insulation deterioration or an earth fault creates a residual current imbalance, the transformer detects the leakage and provides the corresponding signal to the ELR72.
The relay monitors this residual current and can operate associated tripping equipment when the configured protection conditions are reached. In combination with suitable MCBs or MCCBs, the ELR72 provides a coordinated residual current protection system compliant with IEC/EN 60947-2 Annex M, while its Fail Safe and automatic reset functions provide additional flexibility for commercial and industrial applications.
Typical Applications
- Industrial low-voltage distribution systems.
- Commercial electrical switchboards.
- Electrical distribution and control panels.
- Industrial machinery and automation systems.
- Earth leakage monitoring with external toroidal transformers.
- Protection systems incorporating suitable MCBs or MCCBs and tripping accessories.
Technical Specifications
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| Monitoring Function | Earth leakage / residual current | |
|---|---|---|
| Product group | Earth Monitoring Devices | |
| Series | ELR Residual Current Relays | |
| ABB order code | 2CSG252120R1202 | |
| Product type | Residual current monitor / electronic residual current relay | |
| Residual current type | Type A | |
| Application | Low-voltage residual current and earth leakage monitoring | |
| Function | For mixed systems | |
| Rated voltage | 110–230 V | |
| Rated operational voltage | 110 V AC/DC; 230 V AC | |
| Operating voltage tolerance | ±20% | |
| Frequency | 50–60 Hz | |
| Fail Safe function | Yes | |
| Automatic reset | Yes | |
| Pre-alarm threshold | No | |
| Sensor type | External toroidal transformer | |
| Mounting type | Front-panel mounting | |
| Dimensions (H × W × D) | 72 × 72 × 88 mm | |
| Power loss | 4 W | |
| Standard | IEC/EN 60947-2 Annex M | |
| EAN | 8012542733928 |
Frequently Asked Questions
What is the ABB ELR72 used for?
The ABB ELR72 is an electronic Type A residual current monitor and relay used with an external toroidal transformer to monitor earth leakage and provide residual current protection for low-voltage electrical distribution networks.
What type of residual current does the ABB ELR72 detect?
The ELR72 provides Type A residual current detection, making it suitable for monitoring sinusoidal AC and pulsating DC residual currents.
What supply voltage does the ABB ELR72 use?
The ELR72 supports 110 V AC/DC and 230 V AC operational supplies with a tolerance of ±20%.
Does the ABB ELR72 require a toroidal transformer?
Yes. The ELR72 is designed to operate with a compatible external toroidal transformer, which detects residual current imbalance in the protected circuit conductors.
Where is the ABB ELR72 typically installed?
The ELR72 is designed for front-panel mounting in electrical switchboards, distribution panels and industrial control equipment, with a compact 72 × 72 mm front-panel format.
Trusted ABB Earth Leakage Monitoring
ABB ELR residual current relays provide dependable earth leakage monitoring for low-voltage distribution networks, with the compact ELR72 combining Type A detection, Fail Safe operation and automatic reset functionality for commercial and industrial electrical protection systems.
