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White Square D QOU240 miniature circuit breaker with black toggle switch and slotted box lug terminals

SQUARE D

SQUARE D QOU240 Miniature Circuit Breaker 40A 2 Pole 120/240V AC

SKU CH-Q3M4-D1XTS

A 40 A two-pole miniature breaker rated 120/240 V AC and 48 V DC with a 10 kA interrupting rating for QO load centres

  • 40 A rating protects 120/240 V AC circuits
  • 2-pole design covers single-phase loads
  • 10 kA interrupting capacity clears faults safely
  • Slotted box lug accepts line or load either way
  • Fits QO panelboards for direct installation

Square D QOU240 40A 2-Pole Breaker

This Square D QOU240 miniature circuit breaker provides 40 A over-current protection on a 120/240 V AC supply. It fits QO-series load centres and mounts on a surface or DIN rail with a reversible slotted box lug for line or load connections.

Suits single-phase panels needing 10 kA interrupting

The breaker suits residential or light-commercial panels where a 40 A two-pole device with a 10 kA AIR rating at 120/240 V AC is specified. It is not for installations that require a higher interrupting rating, a different pole count, or a DC-only rating above 48 V.

40 A continuous capacity with 10 kA fault headroom

The device carries 40 A continuously and clears faults up to 10 kA at 120/240 V AC. It also carries a 48 V DC rating for limited low-voltage use. Headroom ends at the 40 A thermal trip point or the 10 kA interrupting limit.

How it compares

Measured against everything we stock in Breakers & Circuit Protection, at today’s prices. Recalculated every night.

Price $38.99
Cheaper than about 64% of the 1,135 comparable items (median $54.99).

Specifications

Product
Brand nameSQUARE D

Questions about this item

What panelboard series must I already have for this QOU-series 40 A breaker to fit?

It is compatible with QO-series panelboards or load centres; the breaker mounts on surface or DIN rail within those enclosures.

Can I install this 2-pole 40 A breaker beside older single-pole breakers in the same QO panel?

Yes, it occupies two adjacent poles in a QO load centre and operates at 120/240 V AC alongside existing single-pole devices.

How do I confirm the breaker is operating correctly after wiring it to my A/C circuit?

Switch the toggle to ON; the handle stays firmly latched and the connected air-conditioning or refrigeration equipment runs without nuisance tripping.

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