Is a circuit breaker just a protection device?

ABB is proud to present to you the result of a long and intense research and development project: the new Tmax XT up to 250A – ABB’s new family of moulded-case circuit breakers.

Due to the need for automation and supervision systems in industrial process and better management of the electrical and technological plants, the circuit-breaker manufacturers have been driven to implement more advance electronic trip units with dialogue interfaces for bus communication even on small frames. In addition to this, the need for energy metering on the protection devices is also emerging.

The ABB XT circuit-breaker, as part of the Tmax family has been designed to consider the need for communication and energy metering, incorporating features which are influenced by the higher ranges of the circuit-breaker. Not only do these functions enhance the performance of the circuit-breaker but they have changed the characteristics from just an open close protection device to an advanced component capable of performing significant actions.
In this new development, factors have been taken into consideration where experience tells what direction should be taken. When there is a normal circuit-breaker in a switchboard most often additional functionalities are needed, having to add accessories around the circuit-breaker. This often creates installation issues to the design and build of the switchboard. The solution is the ABB XT, you don’t need to connect external components to it, everything is incorporated within the circuit-breaker. The compact dimension has made it very suitable to be used where saving space is important. Data centres are such an example.
Simplicity in installation is a key factor. When modification of an existing plant is required you can’t influence change in the environment to a large extent, either your existing equipment needs to be replaced due to aging or an upgrade of the facility is crucial. This is when simple installation can greatly save down time periods and compact dimensions are important.
The ABB XT is more than just a protection device. The measurement capability of this circuit-breaker can cover categories such as:

· Currents (phase, neutral, ground)
· Voltage (phase-phase, phase-neutral)
· Power (active, reactive, apparent)
· Power factor
· Frequency and peak factor
· Energy (active, reactive, apparent)
· Harmonic analysis up to the 11th harmonic

    As we all know, only being able to measure is not good enough to run your plant or keep your customer happy. What is important is the accuracy of these measurements. Within the nominated frame size of the ABB XT circuit-breaker accuracy class of 0.5 for voltage, 1 for current and 2 for power and energy is a fairly accurate measurement!
    It is important to understand the root cause of a failure, and for a complete investigation crucial data is required. Knowing what data you need to have is one problem, how you get the data can be an even greater problem. ABB has implemented advantageous functionalities of the XT that allows you to observe the data that is often important to tackle plants issues. The beauty is you can access this information either from your computer or by standing in front of the circuit-breaker; Indicative signalling functions that can assist in fault finding, alarms for protection and more notably is maintenance data e.g. total number of operations, total number of trips, number of trip tests, number of manual operations, contact wear (%) and record data of last trip. Moreover, the setting of curves and protection thresholds. This can be done through MODBUS communication or by connecting your laptop to the circuit-breaker.
    The ABB XT range have fulfilled the measurement and communication requirements in the very compact size that eases installation and operation for anyone responsible in operation, construction or commissioning.

    For more information please contact our ABB Low Voltage Products Customer Support:

    Phone: 1300 660 299