The "World's Finest" circuit breakers.

QO(B) circuit breakers come in plug-on or bolt-on options and a complete range of amperages and interrupting ranges to fit into various QO distribution panels. QO is the “World’s Finest” Industry leading offer since 1955, with features engineered for faster installation, reliability and quality.

 
QO and QOB Miniature Circuit Breakers

The industry leader in circuit protection is easily recognized by the industry's only trip indicator — the red Visi-Trip™ Indicator makes it easy to spot a tripped circuit breaker. Compact 3/4 inch wide format for one-pole circuit breakers helps minimize panel space and footprint. The Square D™ exclusive Qwik-Open™ protection is standard on all 15 A and 20 A circuit breakers — trip reaction within 1/60th of a second. No other circuit breaker trips faster.

A comprehensive selection of 10kA rated circuit breakers are available including:

  • QO™ one-pole standard circuit breakers (10 A to 70 A)
  • QO two-pole standard circuit breakers (10 A to 200A)
  • QO three-pole standard circuit breakers (10 A to 100 A)
  • QO tandem circuit breakers (15 A to 20 A)
  • QO ground-fault circuit interrupters (1- and 2-pole, 15 A to 60 A; 3-pole 15 A - 50 A)
  • QO-EPD circuit breakers with 30 mA equipment ground-fault protection (1-pole, 2-pole, 15 A to 60 A; 3-pole, 15 A - 50 A)
  • QO arc-fault circuit interrupters (1-pole, 15 A and 20 A)
  • QO combination arc-fault circuit interrupters (1-pole, 15 A and 20 A)
  • QO Dual Function Circuit Breakers (1-pole, 15 A and 20 A)
  • QO-K circuit breakers, key operated (1-pole, 10 A to 30A)
  • QO-SWN circuit breakers with switch neutral common trip, NEC 514-5 (2- and 3-pole, 10 A to 50 A)
  • QO-HID circuit breakers for circuits feeding fluorescent or high intensity discharge (1-, 2-, and 3-pole, 15 A to 50 A)
  • A full line of factory installed accessories, such as shunt trips, auxiliary switches and alarm switches, is also available
  • QO sub-feed lugs, 2-pole rated 60A, 125A and 225A; 3-pole rated 125A
  • Additional products available with interrupting ratings of 22kA, 42kA and 65kA

Plug-on QO circuit breakers are for use in QO load centers, NQ panelboards or Speed-D switchboard distribution panels. Bolt-on QOB circuit breakers are for use in NQOD panelboards.
 

Benefits

  • Market-leading circuit protection — Designed for superior safety, quality, and reliability. Engineered with the quality and craftsmanship that have made Square D the preferred brand of electrician and homeowners
  • First-to-market innovation — First and only offer in the market to put the game changing Visi-Trip on all the circuit breakers for easy trip detection
  • Multiple applications — QO serves all your needs with wide range of products that serves single and three phase, high interruption ratings, and advanced function devices that offer superior Arc Fault, Combination Arc Fault (CAFI), and Ground Fault (Class A, GFCI), and Dual Function (CAFI and GFCI) Protection
  • Saves Space — Compact 3/4 inch width design for small system footprint
  • Faster installation — Fewer connections
  • Frees gutter space — No pigtails with the innovative Plug-on Neutral design
  • Easier troubleshooting — TIME SAVER Diagnostics provide additional circuit information at the touch of a button
     

Applications

  • Residential & light commercial circuit protection
  • Commercial and Industrial circuit protection
  • Single phase and three phase applications
  • High Interruption rating capabilities
  • Overcurrent protection
  • Short circuit protection
  • Parallel and Series arc fault protection
  • Ground fault protection