Square D QOU120HM Miniature Circuit Breaker

The "HM" stands for High Magnetic. This specialized trip setting is designed to handle circuits with inherently high inrush currents without nuisance tripping, making it ideal for commercial motor control and HVAC applications.

As a unit-mount breaker, it does not plug into a standard load center bus. Instead, it can be surface-mounted, flush-mounted, or snapped onto a standard 35mm DIN rail using its built-in mounting features.

Yes, while primarily used for 120/240VAC systems, this breaker is also rated for 48VDC systems, providing a 5 kAIC interrupting capacity for direct current control panels.

No. Although it is part of the QO family, the QOU series features a unit-mount (bolt-on) design intended for OEM panels, DIN rail systems, and standalone enclosures. It will not plug into a standard QO residential load center.

The reversible box lugs accept either copper or aluminum conductors ranging from 14 AWG to 2 AWG, allowing flexibility for various industrial and commercial wiring setups.

Yes, it is HACR rated for use with heating, air conditioning, and refrigeration equipment. The high-magnetic trip function is specifically beneficial for the high startup currents typical of HVAC compressors and motors.

"LI" stands for Long-Time and Instantaneous trip functions. The long-time function protects against sustained overloads, while the instantaneous (high-magnetic) function quickly trips the breaker during severe short circuits.

Yes, QOU breakers feature reversible line and load lugs, which provides wiring flexibility when routing conductors inside tight OEM control panels or enclosures.