Square D QO Circuit Breaker, 3-PH 40A

Square D QO Circuit Breaker, 3-PH 40A

The Square D QO340 QO Circuit Breaker, 3-Phase, 40A is a 3-pole thermal-magnetic breaker built for reliable overcurrent protection and switching in AC/DC systems. It features a trip-free over-center toggle with quick make/quick break action, plus VisiTrip trip indication for fast visual confirmation when the breaker has tripped and interrupted the circuit. With plug-in mounting and a 10 kA interrupt rating at 120/240 VAC, it’s a dependable choice for QO load centers that require a 40A 3-pole breaker.

Country of Origin: Varies by production batch

Key Features / Specifications

• Brand: Square D (Schneider Electric)
• Model / Part #: QO340
• Product Type: Miniature circuit breaker
• Series / Range: QO
• Circuit Breaker Type: Standard
• Poles: 3P
• Current Rating: 40 A
• Voltage Rating: 120/240 V AC (also rated for 120 V AC and 240 V AC)
• Mounting Type: Plug-in
• Electrical Connection: Box lugs
• Interrupt Rating: 10 kA at 120/240 V AC (also 10 kA at 120 V AC and 240 V AC)
• Panel Spaces Required: 3
• Wire Size Range: AWG 8 to AWG 2 (copper or aluminum)
• Tightening Torque: 44.3 lbf·in (5 N·m)
• Trip Indication: VisiTrip visual trip indicator
• Toggle Mechanism: Trip-free with positive handle indication; quick make/quick break
• Ratings: HACR rated
• Certifications: UL Listed (UL File E84967); CSA Certified (Master Contract 153555)
• Dimensions (H × W × D): 3.0″ × 2.2″ × 2.9″ (76 × 57 × 74 mm)
• Net Weight: 0.800 lb (0.363 kg)

Ideal For

• QO load centers needing a 3-pole 40A plug-in breaker
• Overcurrent protection for 120/240V branch or feeder circuits
• HVAC and refrigeration applications requiring HACR-rated protection
• Faster troubleshooting with VisiTrip trip indication
• Installations using AWG 8–2 copper or aluminum conductors with box lugs