Apply to be a TradeMaster!
Filter menu expanded

Filters

1,751 items
Reset

SORT

Product Availability

Show In Stock Only (568)

Price Range

$1 to $5 (2)
$5 to $10 (12)
$10 to $15 (20)
$15 to $20 (40)
$20 to $25 (50)
$25 to $30 (44)
$30 to $35 (49)
$35 to $40 (76)
$40 to $45 (56)
$45 to $50 (38)

Square D

Help Face
Need a little help?
1751 items
Grid
List
Compare
Product Image of Starter Replacement Toggle Kit For Type FW Manual Starter, Type KW Manual Starter, 9998HW1
$35.73 each
In Stock
Get 1 by Mon, Aug 17 - Tue, Aug 18
In Stock
Get 1 by Mon, Aug 17 - Tue, Aug 18
Compare
Product Image of No Enclosure, 3 Pole, Electrically Held Lighting Contactor 30 A (Tungsten), 110 VAC at 50 Hz, 120 VAC at 60 Hz, 8903SMO2V02
$450.03 each
In Stock
Get 1 by Mon, Aug 17 - Tue, Aug 18
In Stock
Get 1 by Mon, Aug 17 - Tue, Aug 18
Compare
Product Image of QO 42 Space, 52 Circuit Indoor Convertible Load Center Main Breaker, Plug-on Neutral w/ Qwik-Grip, 1 Phase (200A)
$1,145.21 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of Circuit Breaker Mechanical Lug Kit 3/0 AWG, AL1200P6KU
$848.57 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of Contactor Thermal Unit, A25.2
Contactor Thermal Unit, A25.2
SKU: A25.2
Square D
SKU: A25.2
Brand: Square D
$35.72 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of Safety Switch Neutral Block, 100A Rated, Sn0310
$106.67 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of Push-Button Control Station, Momentary, NO/2NC, Start & Stop 2 Pushbutton Operators, Projecting Push Button Operator, 13, 3, 4 & 4X NEMA Rating, 9001SKY201
$577.42 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of Top Mount Fuse Block Control Transformer (50VA, 1PH, 131F Temp Rise), 9070TF50D20
$369.85 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of 3 Pole Panel Mount Miniature Circuit Breaker (15A, 120/240VAC, 10kA), QOU315
$440.00 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of QO 20 Space, 24 Circuit Convertible Load Center Main Breaker, Plug-On Neutral, 1 Phase (100A)
$483.24 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of 1,000 Amp Circuit Breaker Operating Mechanism 600 V Control Voltage,, for PowerPact M or P Frame Circuit Breaker, 9421LW1
$331.19 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of Contactor Thermal Unit (Type B, Melting Alloy, Class 20), B0.81
$38.41 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of QO 3 Pole Miniature Circuit Breaker (120/240V, 20A, 10kA)
$149.99 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of 100A Double Throw Non-Fusible Disconnect Switch, 3 Pole, NEMA 1 (240VAC, 250VDC), DTU323
$1,789.79 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of TeSys D Control Relay 10A (240V)
TeSys D Control Relay 10A (240V)
SKU: CAD326U7
Square D
SKU: CAD326U7
Brand: Square D
$146.96 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of Contactor Thermal Unit For B Series, B32.0
$44.04 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of Pushbutton Switch Kit, 4280416
Pushbutton Switch Kit, 4280416
SKU: 4280416
Square D
SKU: 4280416
Brand: Square D
$199.60 each
In Stock
Get 1 by Mon, Aug 17 - Tue, Aug 18
In Stock
Get 1 by Mon, Aug 17 - Tue, Aug 18
Compare
Product Image of 3 Pole N/O Electrically Held Lighting Contactor, NEMA 1 (30A, 600V, 277VAC Coil), 8903LG30V04
$559.74 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of Tesys Vario - Switch Body For Switch Disconnector - 3 Poles - 20A, V01
$117.10 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of Contactor Auxiliary Contact Kit For SA-SJ Contactor, Includes Auxiliary Contact Kit, 9999SX13
$123.01 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of 0.66 min Delay, DPDT Time Delay Relay 10 Contact Amp, 110 VDC & 120 VAC, 9050JCK18V20
$99.52 each
In Stock
Get 1 by Mon, Aug 17 - Tue, Aug 18
In Stock
Get 1 by Mon, Aug 17 - Tue, Aug 18
Compare
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, 12 VDC, 63.6mm x 50.3mm x 63.2mm, 8501CDO6V51
$58.26 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of VisiPacT 30A Fused Heavy Duty Safety Switch, 3 Pole, NEMA 1 Enclosure w/ Viewing Window & Neutral Installed (600VAC)
$421.10 each
In Stock
Get 2 by Mon, Aug 17
In Stock
Get 2 by Mon, Aug 17
Compare
Product Image of Buck Boost Transformer, NEMA 3R (100 VA, 120/240V, 12/24V)
$262.75 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of QO 2 Space, 4 Circuit Outdoor Load Center w/ Main Lugs, 1 Phase, 120/240V (70A)
$76.28 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of 250 Amp Circuit Breaker Standard Shaft Kit, for PowerPact H & J Frame Circuit Breaker, 9421LJ1
$373.52 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of Circuit Breaker Shunt Trip (24V AC/DC, 30VDC), for PowerPacT M/P/R, S33659
$708.12 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of 20 Amp, 120 VAC, 1 Pole, Bolt On Miniature Circuit Breaker 14-8 AWG, QOB120HM
$42.20 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of 3 Pole Phenolic Power Distribution Block (135A Aluminum, 175A Copper, 600VAC, 1 Primary Connection), 9080LBA362106
$177.93 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of Safety Switch Fuse Clip Kit For Heavy Duty Safety Switches, Hrk1020
$47.42 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of 30mm Potentiometer, 9001SK20
30mm Potentiometer, 9001SK20
SKU: 9001SK20
Square D
SKU: 9001SK20
Brand: Square D
$385.83 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of Single Pole Bolt On Miniature Circuit Breaker (20A, 277V, 35kA), EGB14020
$305.45 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of Buck Boost Encapsulated Transformer (0.75kVA, 1PH, 120 x 240V Primary, 16/32V Secondary), 750SV46F
$1,018.14 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of Definite Purpose Replacement Coil for 8910DPA 50A & 60A Contactors (110/120VAC 50/60Hz), 9998DA2V02
$60.10 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of 3 Pole Definite Purpose Starter, Open Enclosure (30A, 1PH, 208-240/220VAC Coil), 8911DPSO33V09
$483.46 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of Buck Boost Encapsulated Transformer (0.15kVA, 1PH, 120 x 240V Primary, 12/24V Secondary), 150SV43A
$386.34 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of Disconnect Switch Shaft Extension for 30-60 Amp GS2 Switches
$25.14 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of 3 Pole Phenolic Power Distribution Block (255A Copper, 600VAC, 1 Primary Connection), 9080LBC363101
$248.11 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of QO 3 Pole Miniature Circuit Breaker (120/240V, 40A, 10kA)
$104.13 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of TeSys 1 N/O & 1 N/C Signalling Auxiliary Contact w/ Screw Clamp Terminals, 2.5 A
$45.99 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of Electrical Enclosure, Spacial CRN, Wall Mount, Steel, H600xw400xd200, LP66, IK10, RAL7035
$123.57 each
Out of Stock
Get it by Thu, Aug 27 - Thu, Sep 3
Out of Stock
Get it by Thu, Aug 27 - Thu, Sep 3
Compare
Product Image of Contactor Thermal Unit (Type A, Melting Alloy, Class 20), A1.63
$29.37 each
In Stock
Get 2 by Mon, Aug 17 - Tue, Aug 18
In Stock
Get 2 by Mon, Aug 17 - Tue, Aug 18
Compare
Product Image of ClimaSys Forced Ventilator, IP54, 300m3/h, 115v, w/Outlet Grille and Filter G2
$236.25 each
Out of Stock
Get it by Thu, Aug 27 - Thu, Sep 3
Out of Stock
Get it by Thu, Aug 27 - Thu, Sep 3
Compare
Product Image of Service Ground Kit for PowerPacT L Circuit Breaker Enclosures (250-600A, 6-250kcmil), PKOGTA4
$189.51 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of Motor & Contactor Isolated Overload Relay Alarm for Melting Alloy Overload Relays (Type S, N/C), 9999SO5
$155.43 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of 3 Pole Bolt On Miniature Circuit Breaker (100A, 480Y/277V, 18kA), EDB34100
$1,091.67 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Compare
Product Image of Multi-fixing LED Lamp Without Socket - 230 VAC - 10w
$102.24 each
Out of Stock
Get it by Thu, Aug 27 - Thu, Sep 3
Out of Stock
Get it by Thu, Aug 27 - Thu, Sep 3
Compare
Product Image of QO Single Pole Dual Function Miniature Circuit Breaker (120V, 20A, 10kA)
$87.41 each
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Backorder
Get it by Fri, Sep 11 - Fri, Oct 9
Resources
FAQs, Manuals & Videos
Videos
Articles
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.