"Square D DU-321 General Duty ...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$129.61
"Square D DU-321 General Duty Non-Fusible Safety Switch, 3-Pole, 240VAC"

"Square D DU-321 General Duty Non-Fusible Safety Switch, 3-Pole, 240VAC"

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Model: DU321

In Stock (leaves warehouse same day if ordered before 3pm ET)

$129.61
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Square D DU-321 General Duty Non-Fusible Safety Switch, 3-Pole, 240VAC, NEMA 1

The Square D DU-321 general duty safety switch from Schneider Electric is a non-fusible, 3-pole, 3-wire disconnect switch built for residential and light commercial applications where durability and economy are prime considerations. Rated 240VAC with a NEMA 1 enclosure, this Single Throw Safety Switch is available in Motor FLA ratings from 30A to 200A (30A, 60A, 100A, 200A), letting you match the disconnect to the connected load while keeping the same rugged non-fusible switch design and lug electrical connections across the family. It is well suited to lighting, air conditioning, and appliance loads in residential and light commercial circuits.

Key Features

  • Configuration: 3-pole, 3-wire non-fusible disconnect switch for general duty applications.
  • Amperage Range: Available in Motor FLA ratings of 30A, 60A, 100A, and 200A to match connected load requirements.
  • Voltage Rating: Rated operational voltage (Ue) of 240V AC for residential and light commercial circuits.
  • Motor Power: Rated 7.5 hp at 240V AC 60 Hz for 3-phase motors, and 3 hp at 240V AC 60 Hz for 1-phase motors.
  • Wire Range: Accepts AWG 14...AWG 6 copper or AWG 12...AWG 6 aluminum conductors, with a tightening torque of 30-30 lbf.in (2.08-13.3 mm²).
  • Electrical Connection: Lug-style connections for reliable field wiring.
  • Operating Mechanism: Quick-make, quick-break operating mechanism for dependable switching performance.
  • Enclosure Rating: NEMA 1 degree of protection for general indoor use.
  • Overcurrent Protection: Provides over-current and short circuit protection as part of the disconnect assembly.

Certifications & Compliance

  • UL Listed, File E2875
  • NEMA 1 Enclosure Rating
  • RoHS Exemption Information: Yes
  • Mercury Free

Technical Specifications

  • Wiring Configuration: 3-wire
  • Connection Type: Lugs
  • Warranty Period: 18 months
  • Toxic Heavy Metal Free: Yes
  • Mercury Free: Yes
  • Sustainable Packaging: Yes
  • Average Life Duration: 15 year(s)
  • China ROHS In Scope: No
  • ROHS Eur In Scope: Yes

Typical Applications

  • Residential Electrical Disconnects
  • Light Commercial Electrical Installations
  • Lighting Circuit Disconnects
  • Air Conditioning Equipment Disconnects
  • Appliance Circuit Disconnects

Why Square D?

Square D safety switches from Schneider Electric are UL Listed and built with a quick-make, quick-break mechanism for dependable, code-compliant disconnect performance across the full 30A-200A Motor FLA range. With mercury-free construction, sustainable packaging, and an 18-month warranty, this general duty switch family delivers durable, economical protection for residential and light commercial electrical systems.

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Manufacturer Resources

Product Specs

Product Type:
Safety Switch
Voltage Rating:
240V
Configuration:
3-Pole
Connection Type:
Lugs
Listing:
UL Listed
Standards:
NEMA 1
Department:
Electrical
Product Group:
Power Distribution
Product Material:
Steel
Amperage Rating:
30A - 200A
Product Subgroup:
Safety Switches & Disconnects
Number Of Poles:
Three-pole

Square D DU321 – Frequently Asked Questions

1) Can the Square D DU-321 safety switch be used outdoors or in a wet location?
No. The DU-321 general duty switch comes in a NEMA 1 steel enclosure, which is indoor-only general purpose protection with no rain or sleet rating. For an outdoor disconnect you need a NEMA 3R enclosure, such as the Eaton DH366URK K Series non-fusible switch in NEMA 3R.
2) Which DU-32x part number do I order for a 60 amp AC disconnect?
Amperage sets the part number across the family: DU321 is 30A, DU322 is 60A, DU323 is 100A and DU324 is 200A. So a 60 amp air conditioning or appliance disconnect is DU322. All four share the same 3-pole non-fusible design, 240VAC rating and lug terminations.
3) Will a Square D DU-321 work on a 480V three-phase circuit?
No. The rated operational voltage is 240V AC, so it is limited to 120/240V single-phase and 240V three-phase systems. For 480V or 600V class service, a heavy-duty 600V switch is the right class, for example the ABB THN3365A 400A 3-pole 600V or the ABB TC-72367 Spec-Setter fusible switch at 600V AC.
4) What size wire can I land in a Square D DU-321 safety switch?
Lug terminals accept AWG 14 through AWG 6 copper, or AWG 12 through AWG 6 aluminum. That wire range is the practical ceiling on the smaller ratings, so size your feeder against it before you commit, especially on long runs where you have upsized for voltage drop.
5) Is the Square D general duty switch rated to disconnect a motor, and how big?
Yes, it carries horsepower ratings: 7.5 hp at 240V AC 60 Hz on three-phase motors, and 3 hp at 240V AC 60 Hz single-phase. The switch is also ordered by Motor FLA (30A, 60A, 100A, 200A), so match the rating to the motor's full load amps rather than to nameplate horsepower alone.
6) What is the general duty alternative to the Square D DU-321 safety switch if a fusible disconnect is needed?
The DU-321 family is non-fusible, so overcurrent protection has to come from upstream devices. When the opening calls for fuses in the disconnect itself, the ABB TG-Series Spec-Setter is a general duty fusible safety switch, matching the DU-321 on general duty construction while holding fuses locally. Both are general duty products rather than heavy duty.
7) What non-fusible disconnect covers amperages above the Square D DU-321 range?
The DU-321 family tops out at 200A, with Motor FLA ratings of 30A, 60A, 100A and 200A. For larger services, the Eaton DH366URK K Series is a 600A non-fusible safety switch, and the ABB THN3365A is a 400A 3-pole heavy-duty switch. Both go above the DU-321 ceiling while the Eaton stays non-fusible like the DU-321.
8) Is the Eaton DT-223UGK double-throw switch a substitute for the Square D DU-321?
Not for the same job. The DU-321 is a single throw, 3-pole non-fusible disconnect for a single supply. The Eaton DT-223UGK is a heavy-duty double-throw non-fused switch in a painted steel NEMA 1 enclosure, used to transfer a load between two sources such as utility and generator. They share the non-fused approach and NEMA 1 enclosure, but the double-throw serves a transfer function the DU-321 does not.
9) Is general duty good enough, or do I need a heavy-duty disconnect?
General duty is built for residential and light commercial work, lighting, air conditioning and appliance circuits at 240V, where economy matters and switching is infrequent. Heavy duty is what you spec for industrial service, higher fault environments and 600V systems, and for double-throw transfer duty, like Eaton's heavy-duty double-throw non-fused switch in painted steel NEMA 1. If the drawing says heavy duty or 600V, the DU-321 is not a substitute.
10) Is the Square D DU-321 a 3-pole 3-wire switch, and does it have a neutral?
Three-pole, three-wire. All three ungrounded conductors are switched; there is no switched neutral pole. If your installation needs a neutral landed in the enclosure, you add a separate neutral kit, since none is part of the switch itself.
11) When is a heavy-duty safety switch specified instead of the general duty Square D DU-321?
The DU-321 is a general duty switch for residential and light commercial lighting, air conditioning and appliance loads at 240V. Where a drawing calls for heavy duty, the ABB TC-72367 Spec-Setter and ABB THN3365A are heavy-duty 600V 3-pole switches, and the Eaton K-series DT-223UGK is heavy duty as well. The ABB TG-Series is the general duty option on the ABB side if the spec allows general duty with fuses.
12) Can I standardize disconnects across a portfolio of apartment AC units with this switch?
That is what the family is set up for. One design, one 240VAC rating, one NEMA 1 steel enclosure and lug terminations across 30A, 60A, 100A and 200A, so maintenance techs see the same switch and the same wiring method on every unit and only the amp rating changes. Mercury free construction and a quick-make, quick-break mechanism are common to all four.
13) What torque should the lugs be tightened to on a Square D DU-321?
Terminal tightening torque is listed as 30-30 lbf.in for conductors in the 2.08 to 13.3 mm2 range. Torque the lugs to that figure with a calibrated driver; hand-tight aluminum terminations are the usual cause of heat damage at a disconnect.
How fast can I get the Square D DU321 delivered?
Most orders ship the same day from our distribution partners, with quick delivery throughout the continental U.S. Need it urgently? Contact Us for expedited shipping options.
Can I return it if it doesn’t work for me?
Yes—ZenSupply offers a hassle-free return policy. If the product isn’t the right fit, reach out to our support team for a return authorization or setup a return by following our return instructions.
Does the Square D DU321 come with a warranty?
Absolutely. The Square D DU321 is backed by a manufacturer’s warranty. For full warranty terms, check the product documentation or Contact Us.
How do I get technical support or installation help for the Square D DU321?
You can call, text, or email our expert support team for fast answers. We’re here to help with product selection, installation tips, and troubleshooting. Contact Us
Why buy the Square D DU321 from ZenSupply?
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