SQUARE D
SQUARE D QOU345 45 A 3 Pole 120/240 V AC circuit breaker
A 45 A three-pole miniature circuit breaker rated 120/240 V AC and 48 V DC with a 10 kA interrupting rating for QO load centres
- 45 A three-pole protection for 120/240 V AC circuits
- 10 kA interrupting rating handles high fault currents
- Slotted box lug terminals accept reversible line and load wiring
- DIN-rail or surface mounting fits QO panelboards
- 48 V DC rating adds low-voltage versatility
QOU345 45 A three-pole breaker
The Square D QOU345 is a miniature circuit breaker rated 45 A with three poles for 120/240 V AC and 48 V DC systems. It provides standard over-current protection for air-conditioning, refrigeration and heating equipment. The device mounts on a surface or DIN rail and fits QO-series panelboards. Its 10 kA interrupting rating at 120/240 V AC suits residential and light-commercial loads.
Compatibility checks before ordering
Verify that the load centre or panelboard accepts QO-series breakers and that the bus can supply three poles at 45 A. Confirm the available mounting space suits a surface or DIN-rail installation. Ensure the circuit voltage does not exceed 120/240 V AC or 48 V DC and that the prospective fault current stays within the 10 kA rating. Check local codes for any restrictions on this breaker type.
Reversible slotted box lugs
The terminals use slotted box lugs that accept line or load conductors in either orientation. This reversibility simplifies wiring when cable entry direction varies on site. No additional accessories or software are bundled with the breaker. The lug design is the only feature that changes the installation experience compared with fixed-orientation terminals.
Highlights
- 45 A three-pole protection for 120/240 V AC circuits
- 10 kA interrupting rating handles high fault currents
- Slotted box lug terminals accept reversible line and load wiring
- DIN-rail or surface mounting fits QO panelboards
- 48 V DC rating adds low-voltage versatility
Specifications
| Brand | SQUARE D |
|---|
Questions about this item
Does the QOU345 breaker ship with mounting hardware or must that be purchased separately?
The unit mounts on a surface or DIN rail and uses slotted box lugs for line and load connections; mounting hardware and wire are not included.
When should I choose the 45 A three-pole version instead of a lower-amperage model?
Select the 45 A three-pole breaker when the circuit requires 45 A of overcurrent protection across three phases at 120/240 V AC.
What does the 10 kA interrupting rating mean for my panel?
The breaker can safely interrupt up to 10 kA of fault current at 120/240 V AC, so the panel’s available fault current must not exceed that value.
Also in this aisle
People compared these
Same shelf, same checkout — eight coins and a 30-minute rate lock.



