QO Series Circuit Breakers

	Current Current

	Voltage Voltage

120V AC

240V AC

48V DC

	Number of Poles Number of Poles

	Manufacturer Series Manufacturer Series

QOB

	Mounting Location Mounting Location

Breaker Box

Panel Board

	Breakthrough Current Breakthrough Current

5,000 A @ 48 V DC

10,000 A @ 120 V AC

10,000 A @ 240 V AC

	Circuit Breaker Type Circuit Breaker Type

Magnetic

Thermal

	Wire Connection Type Wire Connection Type


Snap On	Screw-Clamp Terminals

	Frequency Frequency

50Hz

60Hz

	Width Width

3/4"

1 1/2"

2 1/4"

	DFARS (Defense Acquisition Regulations Supplement) DFARS (Defense Acquisition Regulations Supplement)

DFARS Specialty Metals
COTS-Exempt

	Specifications Met Specifications Met

UL 489

UL Listed

	REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) REACH (Registration, Evaluation, Authorization and Restriction of Chemicals)

REACH Compliant

	RoHS (Restriction of Hazardous Substances) RoHS (Restriction of Hazardous Substances)

RoHS Compliant

RoHS Compliant with
Exemptions

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33 Products

Square D Load-Center Circuit Breakers

QO Series, 1 Pole

QO Series, 2 Pole

QO Series, 3 Pole

QOB Series, 1 Pole

QOB Series, 2 Pole

QOB Series, 3 Pole

Match these circuit breakers to Square D breaker boxes or panel boards of the same manufacturer series. They meet UL 489 requirements for branch circuit protection, so they protect downstream equipment and wiring from overloads and short circuits. Because they are thermal-magnetic, these breakers trip two different ways. They either trip when heat is generated by sustained low-level overload current or quickly when the magnetic coil senses a high-current short circuit.

Circuit breakers with ground fault sensitivity will trip if they detect a current leak above 6mA. This minimizes the risk of electric shock to workers and equipment.

Breakthrough current is the maximum current that the circuit breaker can safely stop in the event of a short circuit.

For technical drawings and 3-D models, click on a part number.

QO Series
Current, A	Voltage	Frequency, Hz	Breakthrough Current	Mounting Location	Wire Connection Type	Wd.	Specifications Met		Each
1 Pole—Toggle Style
15	120V AC/240V AC/48V DC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC 5,000 A @ 48 V DC	Breaker Box	Snap On	3/4"	UL 489, UL Listed	00000000	000000
20	120V AC/240V AC/48V DC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC 5,000 A @ 48 V DC	Breaker Box	Snap On	3/4"	UL 489, UL Listed	00000000	00000
30	120V AC/240V AC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC	Breaker Box	Snap On	3/4"	UL 489, UL Listed	0000000	00000
40	120V AC/240V AC/48V DC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC 5,000 A @ 48 V DC	Breaker Box	Snap On	3/4"	UL 489, UL Listed	00000000	00000
2 Pole—Toggle Style
15	120V AC/240V AC/48V DC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC 5,000 A @ 48 V DC	Breaker Box	Snap On	1 1/2"	UL 489, UL Listed	00000000	00000
20	120V AC/240V AC/48V DC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC 5,000 A @ 48 V DC	Breaker Box	Snap On	1 1/2"	UL 489, UL Listed	00000000	00000
30	120V AC/240V AC/48V DC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC 5,000 A @ 48 V DC	Breaker Box	Snap On	1 1/2"	UL 489, UL Listed	00000000	00000
40	120V AC/240V AC/48V DC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC 5,000 A @ 48 V DC	Breaker Box	Snap On	1 1/2"	UL 489, UL Listed	00000000	00000
50	120V AC/240V AC/48V DC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC 5,000 A @ 48 V DC	Breaker Box	Snap On	1 1/2"	UL 489, UL Listed	00000000	00000
60	120V AC/240V AC/48V DC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC 5,000 A @ 48 V DC	Breaker Box	Snap On	1 1/2"	UL 489, UL Listed	00000000	00000
70	120V AC/240V AC/48V DC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC 5,000 A @ 48 V DC	Breaker Box	Snap On	1 1/2"	UL 489, UL Listed	0000000	000000
3 Pole—Toggle Style
15	120V AC/240V AC/48V DC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC 5,000 A @ 48 V DC	Breaker Box	Snap On	2 1/4"	UL 489, UL Listed	00000000	000000
20	120V AC/240V AC/48V DC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC 5,000 A @ 48 V DC	Breaker Box	Snap On	2 1/4"	UL 489, UL Listed	00000000	000000
30	120V AC/240V AC/48V DC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC 5,000 A @ 48 V DC	Breaker Box	Snap On	2 1/4"	UL 489, UL Listed	00000000	000000
40	120V AC/240V AC/48V DC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC 5,000 A @ 48 V DC	Breaker Box	Snap On	2 1/4"	UL 489, UL Listed	00000000	000000
QO Series with 6mA Ground Fault Sensitivity
1 Pole—Toggle Style
20	120V AC	50/60	10,000 A @ 120 V AC	Breaker Box	Snap On	3/4"	UL 489, UL Listed	00000000	000000
30	120V AC	50/60	10,000 A @ 120 V AC	Breaker Box	Snap On	3/4"	UL 489, UL Listed	00000000	000000
2 Pole—Toggle Style
20	120V AC/240V AC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC	Breaker Box	Snap On	1 1/2"	UL 489, UL Listed	00000000	000000
30	120V AC/240V AC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC	Breaker Box	Snap On	1 1/2"	UL 489, UL Listed	00000000	000000
QOB Series
1 Pole—Toggle Style
15	120V AC/240V AC/48V DC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC 5,000 A @ 48 V DC	Panel Board	Screw-Clamp Terminals	3/4"	UL 489, UL Listed	00000000	00000
20	120V AC/240V AC/48V DC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC 5,000 A @ 48 V DC	Panel Board	Screw-Clamp Terminals	3/4"	UL 489, UL Listed	00000000	00000
30	120V AC/240V AC/48V DC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC 5,000 A @ 48 V DC	Panel Board	Screw-Clamp Terminals	3/4"	UL 489, UL Listed	00000000	00000
40	120V AC/240V AC/48V DC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC 5,000 A @ 48 V DC	Panel Board	Screw-Clamp Terminals	3/4"	UL 489, UL Listed	0000000	00000
2 Pole—Toggle Style
15	120V AC/240V AC/48V DC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC 5,000 A @ 48 V DC	Panel Board	Screw-Clamp Terminals	1 1/2"	UL 489, UL Listed	00000000	00000
20	120V AC/240V AC/48V DC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC 5,000 A @ 48 V DC	Panel Board	Screw-Clamp Terminals	1 1/2"	UL 489, UL Listed	00000000	00000
30	120V AC/240V AC/48V DC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC 5,000 A @ 48 V DC	Panel Board	Screw-Clamp Terminals	1 1/2"	UL 489, UL Listed	00000000	00000
40	120V AC/240V AC/48V DC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC 5,000 A @ 48 V DC	Panel Board	Screw-Clamp Terminals	1 1/2"	UL 489, UL Listed	00000000	00000
3 Pole—Toggle Style
15	120V AC/240V AC/48V DC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC 5,000 A @ 48 V DC	Panel Board	Screw-Clamp Terminals	2 1/4"	UL 489, UL Listed	00000000	000000
20	120V AC/240V AC/48V DC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC 5,000 A @ 48 V DC	Panel Board	Screw-Clamp Terminals	2 1/4"	UL 489, UL Listed	00000000	000000
30	120V AC/240V AC/48V DC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC 5,000 A @ 48 V DC	Panel Board	Screw-Clamp Terminals	2 1/4"	UL 489, UL Listed	00000000	000000
40	120V AC/240V AC/48V DC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC 5,000 A @ 48 V DC	Panel Board	Screw-Clamp Terminals	2 1/4"	UL 489, UL Listed	00000000	000000
50	120V AC/240V AC/48V DC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC 5,000 A @ 48 V DC	Panel Board	Screw-Clamp Terminals	2 1/4"	UL 489, UL Listed	00000000	000000
60	120V AC/240V AC/48V DC	50/60	10,000 A @ 120 V AC 10,000 A @ 240 V AC 5,000 A @ 48 V DC	Panel Board	Screw-Clamp Terminals	2 1/4"	UL 489, UL Listed	00000000	000000