The thermal-magnetic trip unit is a TM210 with fixed overload protection set at Ir = 40 A and fixed short-circuit protection at Ii = 10 × In (400 A). That fixed setting simplifies ordering: no adjustment dials to mis-set on site, but also no field flexibility — the breaker is locked to its 40 A rating, so the load must match exactly. The N conductor is unprotected (solid neutral), and the breaker includes a nut keeper kit — a detail that speeds DIN-rail or mounting-plate installation in OEM panel builds, especially for the DC Power OEM channel in China this variant targets.
The 4-pole format occupies four module widths; plan for adequate heat dissipation if grouping multiple breakers in a sealed enclosure — the TM210 trip curve assumes free-air ambient at 40 °C.