Square D QOB330 is a three-pole, 30-amp bolt-on miniature circuit breaker from Schneider Electric’s Square D QO/QOB line, designed for 3‑phase protection on 120/240 V systems. It employs thermal‑magnetic trip technology with a 10 kA interrupt rating at 120/240 VAC and is intended for bolt-on mounting in compatible QOB/QO panels. The breaker accepts 14–10 AWG copper conductors or 14–8 AWG aluminum conductors and occupies roughly 3 in high by 2.25 in wide by 2.91 in deep, with an ambient operating temperature rating up to 40 C.
