MCCBs extend safety coverage

An ABB Automation Tech (LV Products) product story

Edited by the Engineeringtalk editorial team Feb 12, 2004

Two new models extend the coverage offered by the Tmax range of moulded case circuit breakers to include virtually any low-voltage application up to 630A.

ABB has built on the success of its new generation Tmax moulded case circuit breakers (MCCBs) by launching two further versions - the T4 and T5 - which now extend the coverage offered by the Tmax range to include virtually any low-voltage application up to 630A.

The Tmax T4 and T5 have been designed by ABB to offer optimum performance, including high breaking capacity and high limitation of specific let-through energy, in a compact package, and this is the first time that a rated ultimate short circuit breaking capacity of 200kA at 415V AC has been achieved in such a small sized unit.

The Tmax T4, which is rated for an uninterrupted current of 320A, has a frame depth of 103.5mm and is 205mm in height and 105mm wide.

This makes the T4 the most compact circuit breaker of this capacity with high performance at all voltage levels.

The T5 is rated for an uninterrupted current of 630A, and offers the same breaking capacities as the T4 within the same height and frame depth and a width of 140mm.

The T4 and T5 are available in three versions: fixed, plug-in and withdrawable.

Both the Tmax T4 and T5 offer a high duty breaking capacity (Ics) of 100% of the ultimate short circuit breaking capacity (Icu) which guarantees high service continuity at all times, while high breaking capacities of 80kA at 690V as well as high Icu values at 1000V (both AC and DC) make them the ideal circuit breakers for all requirements.

The capability of the Tmax T4 and T5 to offer both high limitation of the specific let-through energy and the short circuit peak current allows for the optimum sizing of cables, busbar ducts and relate supports, as well as the co-ordinated load side apparatus.

High values can also be achieved for back-up, which is particularly useful for reducing the size of load side equipment.

The T4 and T5 also enable high levels of discrimination to be achieved with other load side devices.

This simplifies selection of the circuit breaker during installation studies.

A complete range of fully interchangeable electromagnetic and thermomagnetic releases are available for the T4 and T5.

The electronic PR221DS and PR222DS/P or PD are the ideal solution for the protection of AC installations thanks to their simplicity, precision and wide range of settings.

The TMA thermomagnetic releases are designed for protection of DC installations.

The Tmax T4 and T5 offer a fully co-ordinated motor protection solution up to 250kW at 400V AC.

In addition to the traditional solution, based on the circuit breaker with magnetic only release, contactor and external relay, there is now a fully integrated approach offered by the PR222MP release in combination with the contactor.

The PR222MP offers all the required protection functions including U protection against phase unbalance aand R against rotor block.

The Tmax T4 and T5 are available with a complete range of accessories.

These include a stored energy motor operator and a range of residual current releases up to 630A as well as a variety of termination and mounting solutions.