Bus Duct - Busway

Note: Our website may not reflect our full in-stock inventory. If you don’t see what you need, call 1-800-328-1842 for a real-time inventory check and options. “Contact us for price” simply means we’ll quote it to confirm configuration and current pricing - not that it’s out of stock.

Square D I-Line Bus Duct CP502G | 200 Amp 277/480 Volt | 3 Phase 4 Wire W/ GRND R&G

Square D I-Line CP502G copper bus duct; 200 amp, three phase, four-wire with ground, 277/480 volt. Reconditioned and guaranteed with a one year warranty.
SKU: CP502G
Contact us for pricing:

Square D I-Line Bus Duct CP504 | 400 Amp 277/480 Volt | 3 Phase 4 Wire R&G

Square D I-Line CP504 copper bus duct; 400 amp, three phase, four-wire, 277/480 volt. Reconditioned and guaranteed with a one year warranty.
SKU: CP504
Contact us for pricing:

Square D I-Line Bus Duct CP504G | 400 Amp 277/480 Volt | 3 Phase 4 Wire W/ GRND R&G

Square D I-Line CP504G copper bus duct; 400 amp, three phase, four-wire with ground, 277/480 volt. Reconditioned and guaranteed with a one year warranty.
SKU: CP504G
Contact us for pricing:

Square D I-Line Bus Duct CP506 | 600 Amp 277/480 Volt | 3 Phase 4 Wire R&G

Square D I-Line CP506 copper bus duct; 600 amp, three phase, four-wire, 277/480 volt. Reconditioned and guaranteed with a one year warranty.
SKU: CP506
Contact us for pricing:

Square D I-Line Bus Duct CP506G | 600 Amp 277/480 Volt | 3 Phase 4 Wire W/ GRND R&G

Square D I-Line CP506G copper bus duct; 600 amp, three phase, four-wire with ground, 277/480 volt. Reconditioned and guaranteed with a one year warranty.
SKU: CP506G
Contact us for pricing:

Square D I-Line Bus Duct CP508 | 800 Amp 277/480 Volt | 3 Phase 4 Wire R&G

Square D I-Line CP508 cooper bus duct; 800 amp, three phase, four-wire, 277/480 volt. Reconditioned and guaranteed with a one year warranty.
SKU: CP508
Contact us for pricing:

Square D I-Line Bus Duct CP508G | 800 Amp 277/480 Volt | 3 Phase 4 Wire W/ GRND R&G

Square D I-Line CP508G copper bus duct; 800 amp, three phase, four-wire with ground, 277/480 volt. Reconditioned and guaranteed with a one year warranty.
SKU: CP508G
Contact us for pricing:

Square D I-Line Bus Duct CP510 | 1000 Amp 277/480 Volt | 3 Phase 4 Wire R&G

Square D I-Line CP510 copper bus duct; 1000 amp, three phase, four-wire, 277/480 volt. Reconditioned and guaranteed with a one year warranty.
SKU: CP510
Contact us for pricing:

Square D I-Line Bus Duct CP510G | 1000 Amp 277/480 Volt | 3 Phase 4 Wire W/ GRND R&G

Square D I-Line CP510G copper bus duct; 1000 amp, three phase, four-wire with ground, 277/480 volt. Reconditioned and guaranteed with a one year warranty.
SKU: CP510G
Contact us for pricing:

Square D I-Line II Bus Duct AP2308G | 800 Amp 600 Volt | 3 Phase 3 Wire W/ GRND R&G

Square D I-Line II AP2308G aluminum bus duct; 800 amp, three phase, three-wire with ground, 600 volt. Reconditioned and guaranteed with a one year warranty.
SKU: AP2308G
Contact us for pricing:

Square D I-Line II Bus Duct AP2310G | 1000 Amp 600 Volt | 3 Phase 3 Wire W/ GRND R&G

Square D AP2310G aluminum I-Line II Bus Duct; 1000 amp, 3 phase, 3 wire with ground, 600 volt. Reconditioned and guaranteed with one year warranty. To view the rest of our Square D busway, visit the Square D bus duct brand page.
SKU: AP2310G
Contact us for pricing:

Square D I-Line II Bus Duct AP2312G | 1200 Amp 600 Volt | 3 Phase 3 Wire W/ GRND R&G

Square D I-Line II AP2312G aluminum bus duct; 1200 amp, three phase, three-wire with ground, 600 volt. Reconditioned and guaranteed with a one year warranty.
SKU: AP2312G
Contact us for pricing:

Square D I-Line II Bus Duct AP2313G | 1350 Amp 600 Volt | 3 Phase 3 Wire W/ GRND R&G

Square D I-Line II AP2313G aluminum bus duct; 1350 amp, three phase, three-wire with ground, 600 volt. Reconditioned and guaranteed with a one year warranty.
SKU: AP2313G
Contact us for pricing:

Square D I-Line II Bus Duct AP2316G | 1600 Amp 600 Volt | 3 Phase 3 Wire W/ GRND R&G

Square D I-Line II AP2316G aluminum bus duct; 1600 amp, three phase, three-wire with ground, 600 volt. Reconditioned and guaranteed with a one year warranty.
SKU: AP2316G
Contact us for pricing:

Square D I-Line II Bus Duct AP2320G | 2000 Amp 600 Volt | 3 Phase 3 Wire W/ GRND R&G

Square D I-Line II AP2320G aluminum bus duct; 2000 amp, three phase, three-wire with ground, 600 volt. Reconditioned and guaranteed with a one year warranty.
SKU: AP2320G
Contact us for pricing:

Square D I-Line II Bus Duct AP2325G | 2500 Amp 600 Volt | 3 Phase 3 Wire W/ GRND R&G

Square D I-Line II AP2325G aluminum bus duct; 2500 amp, three phase, three-wire with ground, 600 volt. Reconditioned and guaranteed with a one year warranty.
SKU: AP2325G
Contact us for pricing:

Square D I-Line II Bus Duct AP2330G | 3000 Amp 600 Volt | 3 Phase 3 Wire W/ GRND R&G

Square D I-Line II AP2330G aluminum bus duct; 3000 amp, three phase, three-wire with ground, 600 volt. Reconditioned and guaranteed with a one year warranty.
SKU: AP2330G
Contact us for pricing:

Square D I-Line II Bus Duct AP2340G | 4000 Amp 600 Volt | 3 Phase 3 Wire W/ GRND R&G

Square D I-Line II AP2340G aluminum bus duct; 4000 amp, three phase, three-wire with ground, 600 volt. Reconditioned and guaranteed with a one year warranty.
SKU: AP2340G
Contact us for pricing:

Square D I-Line II Bus Duct AP2508G | 800 Amp 600 Volt | 3 Phase 4 Wire W/ GRND R&G

Square D I-Line II AP2508G aluminum bus duct; 800 amp, three phase, four-wire with ground, 600 volt. Reconditioned and guaranteed with a one year warranty.
SKU: AP2508G
Contact us for pricing:

Square D I-Line II Bus Duct AP2510G | 1000 Amp 600 Volt | 3 Phase 4 Wire W/ GRND R&G

Square D I-Line II AP2510G aluminum bus duct; 1000 amp, three phase, four-wire with ground, 600 volt. Reconditioned and guaranteed with a one year warranty.
SKU: AP2510G
Contact us for pricing:

When your busway run needs a section replaced or extended, you need a supplier who can pull the right piece today. EMSCO stocks over 25+ miles of bus duct across all major manufacturers and families, in both copper and aluminum, plug-in and feeder styles, and legacy series that are no longer manufactured. 

Shop by Family — Quick Start

If you already know your system, use the Series filter above to narrow fast. These are the families we see most often for replacements, run extensions, and emergency calls:

  • General Electric — Armor-Clad, Spectra & Spectra Low Amp, FVK
  • Square D — I-Line I & II, Round Bar
  • Siemens / ITE — Sentron & Sentron Low Amp, XJ-L, XL-U, XL-X
  • Cutler-Hammer — CP-2 / CP-4
  • Cutler-Hammer / Westinghouse — ST / CST 100 Amp
  • Other brands — call us: Arrow Hart, Federal Pacific, Continental / Crouse-Hinds

Not sure what series you have? Send photos of the nameplate and joint connections — details below. We'll confirm before you commit to an order.

What You Can Source Here — Fast

  • Copper and aluminum bus duct
  • 3-wire and 4-wire
  • Plug-in and feeder bus duct sections
  • Broad amp range — 100A to 5000A depending on series
  • Legacy and obsolete series — if it ran power in an industrial facility in the last 70 years, there's a good chance we have it
  • Matching tap boxes, elbows, T-sections, end caps, and joint packs to complete the run (see Accessories)

How EMSCO Helps You Win the Day

Legacy & Obsolete Systems Are Our Niche

We regularly support GE Armor-Clad, Square D I-Line, Siemens Sentron, ITE/Bulldog, Cutler-Hammer, and other older lines — exactly the stuff that's "not available" through normal channels.

Complete Runs, Not Just One Piece

Need more than a single section? We can help build out a full run, including the accessories you'll wish you'd ordered up front. Don't get halfway through an install short an elbow.

Fast Match Help

When series compatibility, conductor material, wire/ground configuration, and section length all matter, we help you confirm the exact fit before the order ships.

Speed Up the Match — Photos Work

If you want the fastest "yes, that's the one," send what you have. Even incomplete info helps:

  • Series name and part number (if visible on the label)
  • Amperage and voltage rating
  • Wire/ground configuration (3W, 4W, with or without ground)
  • Conductor material (copper or aluminum)
  • Section length (if known)
  • Photos of the nameplate/label, the joint/connection ends, and a side profile shot
Pro tip: A clear photo of the nameplate and a close-up of the connection end will often get you a confirmed match in minutes — faster than any email back-and-forth.

Refurbished Standards — What "R&G" Means Here

  • Inspected for condition, configuration, and conductor integrity
  • Cleaned and checked for safe, reliable operation
  • PEARL-certified — meets Professional Electrical Apparatus Reconditioning League standards
  • Tested and backed by a 1-year warranty

Avoid the Wrong Order

  • Series compatibility matters: Bus duct sections and bus plugs must match the same series. Armor-Clad duct takes Armor-Clad plugs — mixing families causes fit problems every time.
  • Copper vs. aluminum matters: These are not interchangeable within an existing run. Know what your system uses before ordering.
  • Plug-in vs. feeder matters: Plug-in sections have openings for bus plugs; feeder sections don't. Confirm which type you need before placing an order.
  • Wire/ground configuration matters: 3-wire and 4-wire sections are not the same. Ground bars add a fifth conductor — confirm your system's configuration.

Completing the Job — Not Just the Duct

If you're replacing a run, extending capacity, or getting a system back online, the duct sections are only part of what you need. We can help you source the related pieces that keep the project moving:

Need It Now?

Call our 24-hour emergency line or send us what you have — we'll confirm fit, condition, and availability in real time.