What the 3-pole TMA rating means for your panel
The ABB XT4NU3150B6600HXXX is a 3-pole molded case circuit breaker from the XT4N series, fitted with a TMA 150 A trip unit. The TMA designation means thermal-magnetic adjustment: the thermal element handles overload protection, and the magnetic element provides short-circuit response. The 750-1500 A short-circuit range on the description indicates the magnetic trip threshold is adjustable within that band, letting you fine-tune instantaneous pickup to coordinate with downstream devices. Three poles make it suitable for three-phase feeder or motor branch circuits in a distribution panel.
Compliance and certification coverage
The description carries UL and CSA marks, so the breaker is accepted for North American panel builds without a separate evaluation. For an OEM purchasing agent or independent trader, this means the documentation package (UL file, CSA certificate) is standard with the part — no special compliance project needed to use it in a UL 508A or CSA C22.2 No. 5 application.