The trip unit's adjustable overload and short-circuit pickup range covers 1250 A to 2500 A, making it sized for high-current feeders or large motor branch circuits in industrial distribution.
The 250 TMA designation indicates a thermal-magnetic trip unit with an adjustable continuous current rating (Ir) that can be set anywhere between 1250 A and 2500 A. The thermal element protects against sustained overloads; the magnetic element provides instantaneous short-circuit protection. The XT4H frame is designed for panelboard and switchboard mounting, typically with a rotary handle or motor operator for remote switching. The UL/CSA listing confirms acceptance in North American installations per NEC/CEC requirements.
Deployment context
The adjustable trip range lets the same breaker serve different load sizes — a 1600 A feeder today, a 2000 A feeder tomorrow — by simply re-setting the dials, without swapping the breaker.