SQUARE D QO315 15A 3 Pole 120/240V AC Circuit Breaker

QO315 Three-Pole Breaker for 15 A Circuits

The SQUARE D QO315 is a 15 A miniature circuit breaker built for three-phase 120/240 V AC panels. It carries a 10 kA interrupting rating at that voltage and also handles 48 V DC circuits. The plug-in design fits QO load centres and NQ panelboards with a 100 A frame size. Electricians and panel builders use it to protect lighting, receptacle and small motor branches.

15 A Trip Rating Matches Branch Load

The single figure that decides fit is the 15 A continuous current rating. A breaker must match the wire ampacity and the calculated load of the circuit it protects; a higher or lower rating would violate code and leave the circuit unprotected. Verify the branch conductor size and load calculation before selecting this pole count and amperage.

10 kA Interrupting Capacity Holds Under Fault

Under sustained fault current the breaker is rated to interrupt up to 10 kA at 120/240 V AC without damage. The thermal-magnetic trip unit responds to prolonged overloads and short-circuit peaks, keeping the contacts intact through repeated events. Pressure-plate terminals maintain low resistance during thermal cycling, so the breaker continues to trip at the calibrated 15 A level over its service life.