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Square D

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Product Image of Homeline 30 Space, 60 Circuit Convertible Load Center w/ Main Lugs Plug-on Neutral, 1 Phase, 120/240V (225A)
$449.13 each
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Product Image of 15 Amp, 125 VAC, 65 VDC, 1 Pole, DIN Rail Mount Circuit Protector Thermal Magnetic Trip, 16-10 AWG, 64mm x 80mm, 9080GCB150
$85.60 each
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Product Image of Contactor Thermal Unit For C Series, CC132.0
$43.26 each
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Product Image of NC 10 Amp Electrical Switch Contact Block, XACS102
$24.23 each
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Product Image of Buck Boost Encapsulated Transformer (0.5kVA, 1PH, 120 x 240V Primary, 16/32V Secondary), 500SV46B
$689.80 each
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Product Image of Top Mount Fuse Block Control Transformer (500VA, 1PH, 131F Temp Rise), 9070TF500D50
$1,104.10 each
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Product Image of Circuit Breaker Interlock Attachment For QOU Circuit Breaker, QOU2DTILA
$26.16 each
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Product Image of 2 Pole N/O Electrically Held Lighting Contactor, NEMA 1 (30A, 600V, 110/120VAC Coil), 8903LG20V02
$523.32 each
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Product Image of Altivar 212 Variable Speed Drive, 11kW, 3PH (480V, 15 HP)
$1,654.91 each
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Product Image of QO 30 Space, 30 Circuit Indoor Load Center Main Breaker, 3 Phase, 240V (125A)
$1,683.59 each
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Product Image of Electrical Enclosure, Spacial CRN, Wall Mount, Steel, H500xw400xd150, LP66, IK10, RAL7035
$97.62 each
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Product Image of 3 Pole Bolt On Miniature Circuit Breaker (100A, 120/240VAC, 22kA), QOB3100VH
$826.86 each
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Product Image of 3 Pole Bolt On Miniature Circuit Breaker (20A, 480Y/277V, 35kA), EGB34020
$1,305.15 each
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Product Image of 15 Amp, 120 VAC, 1 Pole, Bolt On Residual Current Circuit Breaker with Overcurrent Protection 14-8 AWG, QOB115GFI
$204.91 each
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Product Image of 2 Pole N/O Electrically Held Lighting Contactor (100A, 110/120VAC Coil), 8903SQO1V02
$1,564.63 each
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Product Image of Circuit Breaker Handle Padlock Attachment 3/0 AWG, QBPA
$57.97 each
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Product Image of 8 Pins, 1 hp at 277v & 1/3 hp at 120v, 3 VA , Octal Elec. Mech. Plug-in General Purpose Relay 10 Amp at 250 VAC, DPDT, 48 VDC, 34.9mm x 50.3mm x 35.4mm, 8501KPDR12V56
$69.39 each
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Product Image of 1 Pole, 500 Al, 620 (Copper) Amp, Phenolic Power Distribution Block 600 VAC, 2 Primary Connection, 9080LBA165202
$140.82 each
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Product Image of Easy TeSys DPER Thermal Overload Relay (0.16 - 0.25A, Class 10)
$26.92 each
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Product Image of TeSys D Non-Reversing Normally Open Contactor w/ Low Consumption Coil, 3P, 38A (24V)
$286.78 each
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Product Image of Pressure Switch Bracket
Pressure Switch Bracket
SKU: 9049A54
Square D
SKU: 9049A54
Brand: Square D
$21.99 each
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Product Image of QO 8 Space, 16 Circuit Indoor Load Center w/ Main Lugs & Surface Cover, 1 Phase, 120/240V (100A)
$120.11 each
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Product Image of Push-Button Switch, 0.87" Mounting Hole Dia, Momentary NO, XB4BA51
$38.98 each
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Product Image of Circuit Breaker Auxiliary Switch For PowerPact, S29450
Circuit Breaker Auxiliary Switch For PowerPact, S29450
SKU: S29450-SQUARE-D
Square D
SKU: S29450-SQUARE-D
Brand: Square D
$290.59 each
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Product Image of Circuit Breaker Standard Shaft, for All 9421L Operating Mechanism, PowerPact H & J Frame Circuit Breaker, 9421LS8
$33.70 each
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Product Image of QO 18 Space, 18 Circuit Indoor Load Center w/ Main Lugs w/ Ground Bar, 3 Phase, 240V (200A)
$399.32 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, 24 VDC, 63.6mm x 58.8mm x 79.4mm, 8501CDO16V53
$109.34 each
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Product Image of Starter Reset Mechanism, for 8538/8539 Starters, 9066RB2
$57.03 each
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Product Image of Circuit Breaker Handle For 9421LW7 Operating Mechanism, 9421LHP48
$170.98 each
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Product Image of QO 42 Space, 52 Circuit Outdoor Convertible Load Center Main Breaker, Plug-on Neutral, 1 Phase (225A)
$1,861.31 each
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Product Image of Selector Switch, 2 Positions, Maintained , Black Knob NEMA4X & 13, XB4BD21
$32.00 each
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Product Image of Contactor Thermal Unit, A1.39
Contactor Thermal Unit, A1.39
SKU: A1.39
Square D
SKU: A1.39
Brand: Square D
$36.50 each
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Product Image of Circuit Breaker Mechanical Lug Kit 14-3/0 AWG, AL150HD
$124.00 each
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Product Image of 200 Amp, Safety Switch Equipment Ground Lug, Pkogta2
$50.84 each
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Product Image of Transformer Bracket, 9070SF41A
Transformer Bracket, 9070SF41A
SKU: 9070SF41A
Square D
SKU: 9070SF41A
Brand: Square D
$25.89 each
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Product Image of QO 2 Pole Bolt On Miniature Circuit Breaker (120/240V, 45A, 10kA)
$55.63 each
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Product Image of QO 42 Space, 42 Circuit Indoor Load Center Main Breaker, 3 Phase, 240V (200A)
$1,827.15 each
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Product Image of 3 Pole Panel Mount Molded Case Circuit Breaker, Thermal Magnetic Trip (70A, 250VDC/600VAC), HDL36070
$1,560.60 each
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Product Image of QO 2 Pole Miniature Ground Fault Protecting Class A 6 mA Circuit Breaker (120/240V, 50A, 10kA)
$396.80 each
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Product Image of 3 Pole Phenolic Power Distribution Block (310A Aluminum, 380A Copper, 600VAC, 1 Primary Connection), 9080LBA365106
$389.70 each
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Product Image of Wall Mounting Transformer Bracket, for Type V Transformers, WMB361362
$706.70 each
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Product Image of Contactor Thermal Unit (Type CC, Melting Alloy, Class 20), CC20.9
$36.46 each
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Product Image of 70 Amp, 240 VAC, 1 Pole, Panel Mount Miniature Circuit Breaker 12-2/0 AWG, QOU170
$96.72 each
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Product Image of 3 Pole, 30 Amp Inductive Load, Definite Purpose Contactor 40 Amp Resistive Rating, 8910DPA33V02U1
$124.03 each
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Product Image of 3 Pole Definite Purpose Starter, Open Enclosure (50A, 1PH, 110/120VAC Coil), 8911DPSO53V02
$865.36 each
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Product Image of Fuse-Disconnector TeSys, 3P 30A, Fuse Size 0.41" x 1.5", Screw type
$71.19 each
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Product Image of 20 Amp, 480Y/277 V, 3 Pole, Bolt On Miniature Circuit Breaker 18 kA Breaking Capacity, 12, 14 AWG, EDB34020
$772.06 each
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Product Image of NEMA Size 4 Melting Alloy Replacement Overload Relay (600VAC), 9065SDO15
NEMA Size 4 Melting Alloy Replacement Overload Relay (600VAC), 9065SDO15
SKU: 9065SDO15
Square D
SKU: 9065SDO15
Brand: Square D
$464.11 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.