Why Choose the ABB CMS-121LA 40A Open-Core Current Sensor?
The ABB CMS-121LA, order code 2CCA880226R0001, is a compact 40 A open-core current sensor designed for circuit-level electrical monitoring within ABB InSite energy management systems. Its 18 mm open-core construction is specifically intended for retrofit installation with compatible DIN-rail protection devices and SMISSLINE equipment, making it a practical choice when detailed monitoring needs to be added to an existing distribution board.
The CMS-121LA provides a 0.1–40 A measurement range with accuracy class 1. The open-core design allows the sensor to be fitted around an existing conductor without requiring the conductor to be passed through a permanently closed sensor core, helping simplify retrofit installations and minimise disruption to existing wiring.
Designed for integration into the ABB circuit monitoring architecture, the CMS-121LA communicates through the InSite bus flat-cable interface. Multiple sensors can therefore be incorporated into a scalable monitoring system, providing circuit-level information for energy management, load analysis and improved visibility of electrical distribution systems.
Key Advantages
- Compact 40 A open-core current sensor for circuit-level electrical monitoring.
- Wide 0.1–40 A measurement range for monitoring individual circuits and connected loads.
- Open-core construction simplifies retrofit installation around existing conductors.
- Accuracy class 1 for dependable current measurement.
- Designed for retrofit monitoring of compatible S200, SMISSLINE MCB and SMISSLINE RCBO installations.
- InSite bus flat-cable interface enables straightforward integration with compatible ABB monitoring equipment.
- Compact 18 mm format supports high-density circuit monitoring within electrical distribution boards.
Key Features
- ABB CMS current monitoring system.
- 40 A current sensor.
- 0.1–40 A measurement range.
- Open-core sensor construction.
- Accuracy class 1.
- 18 mm sensor format.
- Designed for retrofit of compatible DIN-rail protection devices and SMISSLINE equipment.
- Suitable for compatible S200 and SMISSLINE MCBs.
- Suitable for compatible SMISSLINE RCBOs.
- Surface mounting configuration.
- InSite bus communication via flat cable.
- Compact design for scalable multi-circuit energy monitoring systems.
Retrofit Current Monitoring for DIN-Rail Protection Devices
The ABB CMS-121LA is designed to make circuit-level monitoring easier to introduce into existing electrical installations. Its open-core construction enables the sensor to be positioned around an installed conductor, avoiding the need to feed the conductor through a closed sensor core and making the device particularly suitable for retrofit energy monitoring projects.
The 18 mm CMS-121LA is intended for compatible S200 and SMISSLINE miniature circuit breakers and SMISSLINE RCBO applications. Through its InSite bus connection, multiple CMS sensors can be incorporated into a central monitoring architecture, providing detailed circuit information for energy analysis, load monitoring and electrical distribution management.
Typical Applications
- ABB S200 circuit monitoring.
- ABB SMISSLINE MCB and RCBO monitoring.
- Retrofit monitoring of existing electrical distribution boards.
- Branch circuit current monitoring.
- ABB InSite energy management systems.
- Commercial and industrial electrical distribution.
- Energy consumption and electrical load analysis.
- Building and facility energy management systems.
