Overload and short-circuit protection range
The TM240 thermal-magnetic trip unit gives you an adjustable overload Ir from 88 A to 125 A, so you dial it to match the continuous load — a 100 A motor circuit or a 125 A feeder, for example. Short-circuit pickup Ii is adjustable 5 to 10 times In (625 A to 1250 A at the 125 A setting), enough to ride through motor inrush without nuisance tripping.
This breaker mounts into a standard DIN-rail enclosure or panel-mount base. The 4-pole configuration with an unprotected N conductor suits 3-phase + neutral systems where the neutral doesn't need its own overcurrent protection — common in North American-style panelboards or OEM switchgear. The nut keeper kit is a small but welcome detail for DC Power OEM builds in China; it keeps the terminal hardware from walking loose under vibration on a factory floor.