B-Line Eaton Quicklag Type QC Industrial Thermal-Magnetic Miniature Circuit Breaker,Industrial miniature ,25 A,10 kAIC,Four-pole,240 V,Thermal-magneti

QC4025H is a four-pole Quicklag Type QC industrial miniature breaker rated 240 V. Four poles means it switches three phases plus a fourth conductor (typically a switched neutral or a fourth phase leg on a corner-grounded or three-phase four-wire arrangement) all on one common trip. If your panel schedule calls for a three-pole 240 V device, this is not the part to order.

It is a cable-in/cable-out breaker, so conductors land directly on lugs at both ends rather than plugging onto a panel bus stab. That matters for how you plan the enclosure: you are wiring line and load conductors to the device itself, which suits stand-alone enclosed applications and industrial control panels. If you need a bus-mounted load center breaker, the cable-in/cable-out style is the wrong configuration.

No. This breaker is rated 240 V only, so it cannot be applied on a 480 V or 480Y/277 V system. For a 25 A four-pole device on 480 V you need a breaker with a voltage rating that covers that system; applying a 240 V rated device above its marked voltage is a code violation and the interrupting rating no longer applies.

The 25 A QC4025H uses a thermal-magnetic trip unit. The thermal element (a bimetal) handles sustained overloads and trips slower the closer the current is to 25 A, which lets motor inrush and normal starting current pass. The magnetic element reacts instantly to a short circuit or ground fault level current. There are no adjustable settings on this type; the 25 A rating is fixed.

Order Eaton B-Line part number QC4025H. Reading the number: QC is the Quicklag Type QC family, the 4 is four-pole, 25 is the ampere rating, and H denotes the 10 kAIC high interrupting version. Distributors cross-referencing a panel schedule should match all four of those attributes, since QC breakers in the same family differ only by pole count, amperage, and interrupting rating.

Published dimensions are 12 in, 5 in, and .6 in, with a product weight of 7.31 lb. Use the 12 and 5 inch figures when laying out gutter space and mounting clearance in the enclosure, and account for the weight when specifying panel backpan support.