Square D QOB350 Miniature Circuit Breaker

The QOB350 features a bolt-on connection designed specifically for Square D NQ and NQOD panelboards. It cannot be used in standard residential QO load centers, which require plug-on circuit breakers.

The terminal box lugs require a tightening torque of 44.3 lb-in (5 N.m) when securing 8 to 2 AWG copper or aluminum conductors.

Yes, the QOB350 is HACR rated, meaning it is certified for use with heating, air conditioning, and refrigeration equipment that require this specific rating.

For applications requiring a plug-on connection, such as standard QO load centers, the direct equivalent is the Square D QO350.

Yes. If your system requires a higher fault current rating, you can specify the QOB350VH for 22kAIC or the QHB350 for 65kAIC at 240VAC.

Yes. When terminating aluminum conductors in the box lugs, standard electrical practice and NEC guidelines require the application of a listed antioxidant joint compound to prevent oxidation.

This breaker includes a built-in Visi-Trip visual indicator that displays a highly visible red flag in the window when the breaker has tripped due to a fault, making it easy to identify in a fully populated panelboard.

Yes. Because standard Square D QO and QOB thermal-magnetic circuit breakers are not marked with "Line" and "Load" designations, they can safely be back-fed or reverse-fed in a panelboard or enclosure.