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Square D

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Product Image of QO 40 Space, 60 Circuit Indoor Convertible Load Center Main Breaker, Plug-On Neutral, 1 Phase (200A)
$980.17 each
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Product Image of 3/4" Conduit, Safety Switch Plate Hub For Load Centers, Rb Devices, B075
$29.58 each
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Product Image of 1-1/2 hp, 10 VA , Elec. Mech. Screw Clamp General Purpose Relay 40 at 277 VAC & 5 at 600 V, DPDT, 480 VAC at 50/60 Hz, 63.6mm x 58.8mm x 79.4mm, 8501CO16V29
$96.31 each
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Product Image of Double Lug Kit for Heavy Duty Safety Switches (200A), AL20DTF
$168.03 each
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Product Image of Manufactured Enclosure with Mounting Plate and Key Lock (15.7 x 11.8 x 5.9)
$286.88 each
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Product Image of Starter Transient Suppressor For Type S Enclosure, 9999ST2
$74.37 each
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Product Image of 4 Pole Jumper Bar Base Assembly w/ Left Wiring (100A)
$29.99 each
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Product Image of 3 Pole Definite Purpose Starter, Enclosed (25A, 1PH, 208-240/220VAC Coil), 8911DPSG23V09
$517.68 each
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Product Image of Contactor Thermal Unit, A.78
$24.12 each
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Product Image of ClimaSys Forced Vent. IP54, 850m3/h, 230v, w/Outlet Grille and Filter G2
$408.48 each
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Product Image of QO 40 Space, 60 Circuit Outdoor Convertible Load Center Main Breaker, Plug-On Neutral, 1 Phase (200A)
$1,609.17 each
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Product Image of Homeline 16 Circuit Overhead/Underground Ring-Type Meter Main Service Breaker, 8 Space (200A)
$361.39 each
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Product Image of Plain Mounting Plate, for Electrical Enclosure, H1000xw800mm, Galvanised Steel, Reversible
$92.20 each
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Product Image of Contactor Thermal Unit For B Series, B11.5
$41.48 each
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Product Image of Contactor Thermal Unit (Type A, Melting Alloy, Class 20), A14.1
$22.23 each
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Product Image of 10 VA , Elec. Mech. Screw Clamp General Purpose Relay 10 Amp at 110 V & 4 Amp at 220 V, DPDT, 120 VAC at 50/60 Hz, 63.6mm x 58.8mm x 79.4mm, 8501CO22V20
$121.27 each
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Product Image of 8 Pole N/O Mechanically Held Lighting Contactor (30A, 600V, 110/120VAC Coil), 8903LXO80V02
$1,034.36 each
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Product Image of 3 Pole Panel Mount Molded Case Circuit Breaker, Electronic Trip (100A, 600V), HJL36100M73
$2,067.83 each
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Product Image of Mechanical Lug Kit for PowerPacT M/P Circuit Breakers (800-1200A, 3/0 AWG to 500kcmil, Aluminum), AL1200P24K
$194.66 each
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Product Image of NEMA Combination Starter, 30A Fusible Disconnect (Size 1, 27A, 10HP at 600VAC, 3 Phase, NEMA 1), 8538SCG14V02S
$1,707.03 each
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Product Image of Circuit Breaker Mechanical Lug 14-1/0, 8-1/0 AWG, AL2500RK
$128.68 each
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Product Image of Manufactured Enclosure with Mounting Plate and Key Lock (19.7 x 15.7 x 5.9)
$234.43 each
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Product Image of Circuit Breaker Mechanical Lug 12-4, 14-4 AWG, AL50FA
$52.54 each
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Product Image of Contactor Auxiliary Contact Kit For SA-SD Contactor, Includes Auxiliary Contact Kit, 9999SX11
$89.01 each
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Product Image of 2 Pole Definite Purpose Starter, NEMA 1 (30A, 1PH, 208-240VAC Coil), 8911DPSG32V09
$538.99 each
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Product Image of Contactor Thermal Unit, A.86
$32.70 each
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Product Image of Plug In 8 Pin Relay, DPDT, Flat (Faston type) Terminals (120V), 8501KUR12V20
$21.00 each
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Product Image of 2-1/2" Conduit, Safety Switch Plate Hub For Load Centers, Rb Devices, B250
$87.13 each
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Product Image of QO 42 Space, 52 Circuit Indoor Convertible Load Center w/ Main Lugs, Plug-on Neutral w/ Ground Bar, 1 Phase (225A)
$898.15 each
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Product Image of Flange Mounted Variable Depth Fusible Disconnect Switch & Operating Mechanism (60A, 600V), 9422TDF63
$731.12 each
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Product Image of Plain Mounting Plate, for Electrical Enclosure, H1200xw1000mm, Galvanised Steel, Reversible
$169.21 each
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Product Image of DPDT Time Delay Relay 10 Contact Amp, 110 VDC & 120 VAC, 9050JCK11V20
$86.33 each
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Product Image of Control Transformer, 150VA (208VAC Primary, 120VAC Secondary)
$383.50 each
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Product Image of NEMA Type S 3-Pole Motor Starter
NEMA Type S 3-Pole Motor Starter
SKU: 8536SFO1V02S
Square D
SKU: 8536SFO1V02S
Brand: Square D
$2,580.93 each
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Product Image of Homeline 40 Space, 80 Circuit Convertible Load Center w/ Main Lugs, PoN w/ Ground Bar, 1 Phase, 120/240V (225A)
$717.54 each
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Product Image of 3 Amp, 250 VAC, 65 VDC, 1 Pole, DIN Rail Mount Circuit Protector Thermal Magnetic Trip, 16-10 AWG, 64mm x 80mm, 9080GCB30
$84.91 each
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Product Image of Contactor Thermal Unit For C Series, CC156.0
$42.94 each
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Product Image of Contactor Thermal Unit, A14.8
Contactor Thermal Unit, A14.8
SKU: A14.8
Square D
SKU: A14.8
Brand: Square D
$34.90 each
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Product Image of 100A Fusible General Duty Safety Switch, 2 Pole, NEMA 3R Enclosure w/ Bolt on Hub Provision and Neutral (240VAC)
100A Fusible General Duty Safety Switch, 2 Pole, NEMA 3R Enclosure w/ Bolt on Hub Provision and Neutral (240VAC)
SKU: D223NRB
Square D
SKU: D223NRB
Brand: Square D
$389.88 each
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Product Image of 2 hp, 10 VA , Elec. Mech. Screw Clamp General Purpose Relay 10 Amp at 600 V & 40 Amp at 277 VAC, SPST, 277 VAC at 50/60 Hz, 63.6mm x 50.3mm x 63.2mm, 8501CO6V04
$66.39 each
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Product Image of Control Transformer (150VA, 1PH), 9070EO3D1
$400.80 each
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Product Image of 20 Amp, 277 V, 1 Pole, Bolt On Miniature Circuit Breaker 18 kA Breaking Capacity, 12, 14 AWG, EDB14020
$156.96 each
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Product Image of 2 Pole N/O Electrically Held Lighting Contactor (30A, 110/120VAC Coil), 8903SMO1V02
$538.03 each
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Product Image of Mechanical Lug Kit for PowerPacT P Circuit Breakers (800-1200A, 3/0 AWG to 500kcmil, Aluminum), AL1200P25K
$295.29 each
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Product Image of 250 Amp Circuit Breaker Mechanical Lug For PowerPact J-Frame, AL250JD
$177.42 each
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Product Image of Top Mount Fuse Block Control Transformer (50VA, 1PH), 9070TF50D2
$240.23 each
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Product Image of 100 Amp, 240 VAC, 3 Pole, Panel Mount Miniature Circuit Breaker 12-2/0 AWG, QOU3100
$492.24 each
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Product Image of QO 20 Space, 24 Circuit Convertible Load Center w/ Main Lugs, Plug-On Neutral w/ Ground Bar, 1 Phase (125A)
QO 20 Space, 24 Circuit Convertible Load Center w/ Main Lugs, Plug-On Neutral w/ Ground Bar, 1 Phase (125A)
SKU: QO120L125PG
Square D
SKU: QO120L125PG
Brand: Square D
$297.07 each
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More About Square D

Square D is an electrical equipment manufacturer founded in 1902, now a brand of Schneider Electric since 1991. Square D produces QO and Homeline load centers, circuit breakers, panelboards, safety switches, surge protection devices, and motor control equipment for residential, commercial, and industrial electrical applications. The QO circuit breaker introduced in 1955 became the industry standard for residential panel construction. Available through electrical and HVAC wholesale distributors including SupplyHouse.

Square D Product Lines

  • QO Load Centers and Circuit Breakers: Professional-grade residential panels and breakers with Visi-Trip indicator.
  • Homeline Load Centers and Breakers: Value-tier residential panels and circuit breakers.
  • Commercial Panelboards and Breakers: QOB and QOP breakers for NQ, NF, and I-Line commercial panelboard systems.
  • Safety Switches: Fusible and non-fusible disconnects for HVAC equipment and motor circuits.
  • Surge Protection Devices: Whole-home and commercial transient voltage protection.
  • Motor Control and Starters: Contactors and starters for commercial HVAC and industrial motor circuits.

Why Contractors Specify Square D

Square D QO is the most widely stocked residential circuit breaker in North America. Safety switches cover the amperage and voltage ratings required for most HVAC equipment disconnects. Broad availability through HVAC and electrical wholesale distribution.

How to Choose a Square D Product

Match the circuit breaker series to the panel brand and series already installed. For HVAC disconnects, select the safety switch based on equipment amperage, voltage, and whether fusible or non-fusible is specified by the equipment manufacturer.

Frequently Asked Questions

  • QO vs. Homeline? QO is professional-grade for QO panels; Homeline is value-tier for Homeline panels; they are not interchangeable.
  • Who owns Square D? Schneider Electric, since 1991.
  • HVAC circuit breakers? Square D covers the single-pole, double-pole, and three-phase ratings required for residential and commercial HVAC circuits.
  • When is a safety switch required? NEC requires a within-sight disconnect for HVAC equipment; size per the equipment installation instructions.
  • Available at HVAC distributors? Yes, including SupplyHouse.