Square D QO-330MQ125 3-Phase C...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$1,106.71
Square D QO-330MQ125 3-Phase Convertible Main Breaker Load Center

Square D QO-330MQ125 3-Phase Convertible Main Breaker Load Center

(No reviews yet) Write a Review

Model: QO330MQ200

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

$1,106.71
Adding to cart… The item has been added
Free Shipping on orders over $199
We price match and offer bulk discounts! Click Add to Quote. It's quick and easy.
✨
Earn points with this purchase! You can redeem points for giftcards, iPads, XBox's and more. View Rewards
Free Keying on all locks
You may also like

Square D QO-330MQ125 3-Phase Convertible Main Breaker Load Center, NEMA 1

The Square D QO-330MQ125 3-Phase Convertible Main Breaker Load Center is built for residential and industrial electrical systems that need dependable 3-phase power distribution. This QO Series load center accepts QO breakers, ground fault interrupters, arc fault interrupters, and surge arresters, and features a convertible main breaker configuration suited to 3-phase 3-wire or 3-phase 4-wire installations. This model is offered across a range of Motor FLA main breaker ratings from 125A through 225A, letting contractors match the load center to the amperage demands of the job. Housed in a NEMA 1 indoor enclosure with a tin-plated copper busbar and a 25 kA short circuit current rating, it delivers code-compliant protection for demanding electrical loads.

Key Features

  • Convertible Main Breaker: Configurable for 3-phase 3-wire or 3-phase 4-wire systems, simplifying field installation.
  • Main Breaker Rating Range: Available in Motor FLA ratings of 125A, 150A, 200A, and 225A to fit a variety of load requirements.
  • Durable Construction: Welded sheet steel enclosure with a baked enamel gray surface finish for long-term durability.
  • Tin-Plated Copper Busbar: Provides reliable, corrosion-resistant current-carrying capacity.
  • Voltage Rating: Rated for 240/120 V delta AC, 208Y/120 V AC, and 240 V delta AC service.
  • Short Circuit Rating: 25 kA short circuit current rating for robust fault-current protection.
  • Wire Range: Accepts AWG 4 through 300 kcmil aluminum/copper conductors terminated via lugs.
  • NEMA 1 Enclosure: Indoor-rated enclosure suitable for ambient operation from -5 to 40 degrees Celsius.

Certifications and Compliance

  • UL Listed
  • Mercury Free
  • NEMA 1 Indoor Enclosure Rating

Technical Specifications

  • Main Breaker Rating Options: 125A, 150A, 200A, 225A
  • Voltage Rating: 240/120V
  • Warranty Period: 18 months
  • Product Certifications: UL Listed
  • Load Center Type: Main Breaker
  • Mercury Free: Yes

Typical Applications

  • Residential and Industrial Electrical Systems
  • 3-Phase Power Distribution
  • Panelboard and Load Center Wiring
  • Indoor NEMA 1 Installations
  • Renovation and New Construction Projects

Why Square D?

Square D QO Load Centers pair a tin-plated copper busbar and welded steel enclosure with a 25 kA short circuit rating and UL Listing, giving electricians and contractors a dependable platform for 3-phase distribution across the full 125A-225A Motor FLA range. The convertible main breaker design and broad AWG 4-300 kcmil wire range make this load center a practical, code-compliant choice for demanding residential and industrial electrical work.

[{"name": "Product Type", "value": "Load Center"}, {"name": "Voltage Rating", "value": "240/120V"}, {"name": "Amperage Rating", "value": "125A-225A"}, {"name": "Configuration", "value": "3-Phase Convertible Main Breaker"}, {"name": "Finish", "value": "Baked Enamel"}, {"name": "Listing", "value": "UL Listed"}, {"name": "Standards", "value": "NEMA 1"}]

Manufacturer Resources

Product Specs

Product Type:
Load Center
Configuration:
3-Phase Convertible Main Breaker
Voltage Rating:
240/120V
Product Finish:
Baked Enamel Gray
Listing:
UL Listed
Standards:
NEMA 1
Product Material:
Welded Steel
Department:
Electrical
Product Group:
Power Distribution
Product Subgroup:
Panelboards & Load Centers

Square D QO330MQ200 – Frequently Asked Questions

1) Can the Square D QO 3-phase main breaker load center be used on a 3-phase 4-wire 208Y/120V system?
Yes. The QO 3-phase main breaker load center is convertible, so it can be set up for either 3-phase 3-wire or 3-phase 4-wire service in the field. Its voltage ratings cover 240/120V delta, 208Y/120V, and 240V delta. For a 208Y/120V wye service you use the 4-wire configuration with the neutral, which is what gives you 120V line-to-neutral for lighting and receptacle circuits off the same panel.
2) What size wire will the main lugs on the Square D QO 3-phase load center take?
Main terminations accept AWG 4 through 300 kcmil, aluminum or copper, landed on lugs. That range covers the feeder sizes you would normally pull for a 125A through 225A main, in either conductor material, so you don't need a separate lug kit for aluminum feeders.
3) Is this Square D QO panel rated for outdoor or wet locations?
No. It is a NEMA 1 enclosure, which is indoor use only, with an ambient operating range of -5 C to 40 C. If the panel is going on an exterior wall, in an unheated shed, or anywhere it can see rain or washdown, you need a rainproof enclosure instead. The ABB TL24415R is a 150A 3-phase 4-wire 208Y/120V load center in a NEMA 3R enclosure for that situation, though it is main-lug-only rather than main breaker.
4) Which main breaker amperages does the Square D QO 3-phase convertible load center come in?
Four sizes: 125A (QO330MQ125), 150A (QO330MQ150), 200A (QO330MQ200), and 225A (QO342MQ225). Note that the three smaller mains share the QO330 chassis while the 225A is on the QO342 chassis, so the circuit capacity is not the same across the group. Pick the main to match the calculated service load, then confirm the chassis has the spaces you need.
5) Will GFCI and AFCI breakers fit in this Square D QO 3-phase panel?
Yes. The panel takes QO branch breakers, including ground fault and arc fault interrupters, plus QO surge arresters. If you are already standardized on QO breakers across a building, the same stock fits this 3-phase panel, which keeps one breaker inventory for both your single-phase and 3-phase panels.
6) If the panel is going outdoors, can I use the Square D QO 3-phase convertible main breaker load center or do I need a different enclosure?
The Square D QO 3-phase convertible main breaker load center is built in a NEMA 1 welded steel enclosure, which is an indoor rating - it should stay inside a dry mechanical room, electrical closet, or utility space. For an exterior wall or any location exposed to rain, look at a NEMA 3R panel instead, such as the ABB TL24415R, a 150A 3-phase 4-wire 208Y/120V MLO load center in a NEMA 3R enclosure, or the ABB ReliaHome load center, which uses a NEMA 3R aluminum enclosure. Confirm the ampacity and wire configuration match your service before swapping.
7) What is the difference between the Square D QO 3-phase load center and the ABB TL24415R?
The Square D QO unit is a convertible main breaker load center, meaning it carries a main breaker that can be set up for 3-phase 3-wire or 3-phase 4-wire service, in a NEMA 1 indoor steel enclosure rated 240/120V. The ABB TL24415R is an MLO (main lug only) load center, 150A 3-phase 4-wire 208Y/120V, in a NEMA 3R enclosure. The practical distinction is where the disconnect lives and where the panel mounts: the QO brings its own main disconnect and is an indoor panel, while the TL24415R relies on upstream overcurrent protection and is rated for outdoor use. Breaker families are not interchangeable between the two.
8) What is the short circuit current rating on the Square D QO 3-phase load center?
25 kA. That is the panel's short circuit current rating, so it can be applied where the available fault current at the service point is 25,000A or less. On industrial feeders and close to a large utility transformer, check the fault current calculation for the location before you set it.
9) Is this Square D QO load center UL Listed for a permitted commercial job?
Yes, it carries a UL Listing, and it is a NEMA 1 indoor enclosure. It is also built mercury free, which matters on institutional and government specs that restrict mercury content. Those are the compliance points on record for this panel.
10) What is the difference between a main breaker load center like this one and a main lug only panel?
This QO is a main breaker load center, meaning the disconnecting means and overcurrent protection for the whole panel are built into the enclosure. That is what you want as service equipment or where code requires a local disconnect at the panel. A main-lug-only panel, such as the ABB TL24415R 150A 3-phase 4-wire unit, has no main device and is fed from an upstream breaker that provides the protection, typically as a downstream distribution panel. If you already have protection ahead of the panel, MLO is the simpler buy; if you do not, you need the main breaker version.
11) Is the ABB ReliaHome load center a substitute for the Square D QO 3-phase panel?
They serve different jobs. The ABB ReliaHome is a plug-on neutral load center in a NEMA 3R aluminum enclosure, aimed at outdoor residential-style distribution. The Square D QO unit is a 3-phase convertible main breaker load center in a NEMA 1 welded steel enclosure rated 240/120V, intended for indoor 3-phase distribution and accepting QO breakers, GFCI and AFCI devices, and surge arresters. If your load is 3-phase and the panel is mounting indoors, the QO is the right family; the ReliaHome is not a drop-in for it, and the breaker lines do not cross.
12) My service is 208Y/120V 3-phase 4-wire. Which panel fits that, the Square D QO or the ABB TL24415R?
Both can serve a 208Y/120V 3-phase 4-wire system. The Square D QO convertible main breaker load center is rated for 240/120V delta, 208Y/120V, and 240V delta service, and its main is configurable for 3-phase 3-wire or 3-phase 4-wire, with a 25 kA short circuit current rating and lugs taking AWG 4 through 300 kcmil aluminum or copper. The ABB TL24415R is fixed at 150A, 3-phase 4-wire 208Y/120V and is main lug only. Choose on whether you need a main disconnect in the panel and whether the location is indoors, since the QO enclosure is NEMA 1 and the TL24415R is NEMA 3R.
13) What is the enclosure made of and what does it look like once it's installed?
Welded sheet steel with a baked enamel gray finish. It is a painted steel indoor box, not aluminum or stainless, so it suits mechanical rooms, back-of-house corridors, and electrical closets. For an aluminum enclosure you would be looking at a different line, such as the ABB ReliaHome load center, which uses an aluminum NEMA 3R enclosure with plug-on neutral.
14) Why is the busbar material worth checking on a 3-phase panel?
This QO uses a tin-plated copper busbar. Copper carries current with lower resistance than aluminum bus, and the tin plating resists corrosion at the breaker stab connections, which is the joint that oxidizes and heats up over years of service. On a continuously loaded industrial 3-phase feeder that is the part of the panel you least want degrading.
How fast can I get the Square D QO330MQ200 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 QO330MQ200 come with a warranty?
Absolutely. The Square D QO330MQ200 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 QO330MQ200?
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 QO330MQ200 from ZenSupply?
ZenSupply makes it easy to get the commercial door hardware you need—fast shipping, expert support, and rewards on every order. Our team is always ready to help you choose the right product for your project.
!