Track Busway Comparison STEEL and ALUMINUM Leaders USA TrackBusway™ & Starline *
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Photos: Top image shows open-slot STEEL Track Busway installed below an acoustical tile ceiling with plug-in PowerDrops. Bottom image shows insulated copper busbars inside the open-slot channel.
Comparing Overhead Plug-In Track Busway Systems
On this page we compare the STEEL USA TrackBusway™ system — an open-slot, plug-in busway — with the leading ALUMINUM Starline * system. This comparison highlights how the two systems differ in housing material, electrical strategy, and availability.
Use the blue links below and quick-access buttons to explore detailed comparisons:
KEY ADVANTAGES OF STEEL TRACK BUSWAY
- Lead Times ↘ STEEL Track Busway has the Fastest Lead Times in the Busway Industry — standard orders within 7 to 10 working days, even as high-ampacity ALUMINUM systems have extended, data-center-driven lead times.
- Material Cost ↘ STEEL Track Busway uses #8 AWG copper conductors rather than the larger, heavier copper bars required for high-ampacity ALUMINUM busway, helping reduce both weight and material cost.
Before diving into those differences, it helps to understand where both systems are similar.
KEY SIMILARITIES
Both STEEL and ALUMINUM track busways use an open-slot, plug-in architecture — a continuous, finger-safe channel of busbars that allows tap-off units to plug in anywhere along the run. This shared design is what makes both systems flexible: power and devices can be easily repositioned, unlike hard-wired junction boxes.
In the busway industry, “open-slot” systems are a specific subtype of plug-in busway — offering continuous plug-in access along the run, rather than fixed-length tap windows used in other plug-in busway designs.
- Voltage Capabilities ↘ Both systems are listed to UL 857 busway standards for use up to 600V in single-phase and three-phase layouts.
- Installation ↘ Both install far faster than hand-wiring conduit-and-junction-box layouts.
KEY DIFFERENCES
- Amperage & Branch Feeds ↘ ALUMINUM systems are typically configured for high-ampacity distribution from centralized tap-box connections (up to 1250A). STEEL Track Busway standardizes at 40A per phase, with branch circuits often fed from splitter enclosures positioned above the tap boxes.
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Configurations & Layouts ↘
Both systems support single-phase and three-phase distribution. STEEL Track Busway uses double-deck lengths to deliver three-phase power, while ALUMINUM systems provide three-phase within a single housing.
STEEL stacked housing can alternatively be used to take advantage of a unique capability: supplying up to four single-phase circuits from the same suspended footprint using (2) 2-pole line feeds — a level of single-phase flexibility not possible with a single ALUMINUM housing.
Track Busway Terminology
- Open-Slot Busway
- A continuous plug-in power channel that allows tap-off units to connect anywhere along the run.
- Branch Power Tap
- A plug-in unit that provides receptacles or equipment power from the busway.
- Single-Phase Power
- A power configuration using one ungrounded (hot) conductor and a neutral, typically delivering 120V or 277V between hot and neutral.
- Three-Phase Power
- A power configuration using three ungrounded (hot) conductors (and often a neutral) to supply balanced loads at 208V or 480V between phases.
- Splitter Feed
- An enclosure that distributes power from a supply source to multiple branch taps along the busway.
- Stacked Housing / Double-Deck
- STEEL Track Busway’s method of increasing circuit capacity by stacking two channels vertically on the same supports, creating a “double-deck” overhead run that can carry additional single-phase or three-phase circuits.
Watch STEEL Track Busway in Action
See how STEEL track busway stacks two channels vertically to support 3-phase or multiple single-phase circuits — all on one suspended run of track busway.
Video summary: The animation shows STEEL Track Busway suspended overhead with two stacked channels. Power feeds energize the busway, and plug-in units are inserted along the run to supply 3-phase or multiple single-phase circuits.
ALUMINUM vs. STEEL Track Busway – Side-by-Side System Comparison
ALUMINUM busway is capable of higher ampacity per feed, while STEEL track busway is designed for lower-amperage distributed feeds. The comparison table below summarizes how each approach impacts installation, ampacity, and future changes. Click any feature name to jump to the matching section in the detailed comparison.
| Feature | USA TrackBusway™ (Steel) | Aluminum Track Busway |
|---|---|---|
| SPEED – Lead Time & Installation ↘ |
• Standard USA TrackBusway™ orders ship in 7–10 working days • Custom lengths & plug-in taps: 3–4 weeks |
• Lead times vary by manufacturer and configuration • Contractor quotes frequently show months-long delivery timelines for aluminum track busway systems, as of November 2025 |
| Material & Construction ↘ |
• 12-gauge cold-rolled STEEL housing • Insulated #8 AWG copper busbars sized for 40 A per phase |
• Extruded ALUMINUM housing • Insulated copper busbars (size increases with ampacity) • Larger copper bars in high-ampacity models can make ALUMINUM busway assemblies substantially heavier overall |
| Amperage (Per Circuit) (Per Phase)↘ |
• 40 A per circuit / per phase • Single-deck single-phase: 2 × 40 A circuits • Double-deck 3-phase: 3 × 40 A circuits • Double-deck single-phase: 4 × 40 A circuits |
• Up to 1250 A per circuit / per phase |
|
Voltage & Circuiting ↘ |
• Supports 120 V, 208 V, 240 V, and 480 V layouts • 1-pole, 2-pole, and 3-pole plug-in options are available • Stacked housing (double-deck) can be used to add additional circuit |
• Supports 120 V, 208 V, 240 V, and 480 V layouts • 1-pole, 2-pole, and 3-pole plug-in options are available |
| Unique Features ↘ |
• Stackable double-deck layout • Flip-select plug-in taps • Over/under bridge runs |
• Built-in metering options • High ampacity per feed • Centralized long-run distribution |
Detailed Technical Comparison
Dive deeper into how aluminum and steel plug-in busway systems compare across construction, electrical performance, flexibility, and installation.
Material & Construction
ALUMINUM track busway systems use lightweight extruded housings and can reach extremely high ampacity ratings (400 A–1250 A). These systems are often chosen for long continuous runs that require fewer incoming feeds. However, higher-amp ALUMINUM designs rely on large copper busbars, which can significantly increase total system weight and structural demands.
- High-ampacity models (up to 1250 A) — reduce the number of homerun feeds for high-load runs.
The STEEL track busway configuration uses #8 AWG copper conductors. Rather than larger and heavier copper busbars along every foot of the run, the STEEL system is optimized around distributed loads for typical industrial and commercial applications.
The steel housing provides a robust mechanical structure for industrial environments and also supports field-stackable busway architecture — allowing two track busway channels to be mounted vertically, adding additional circuit or three-phase capability.
- Stackable double-deck architecture — supports adding additional circuit vertically, while keeping the same overhead track busway footprint.
Voltage
UL 857 Listing & Voltage Compatibility
Both ALUMINUM track busway and STEEL track busway systems are listed to UL 857 busway standards and certified for operation up to 600 V, covering 1-pole, 2-pole, and 3-pole power drops across industrial, laboratory, and manufacturing environments.
Single-Phase Support (Single-Deck)
- 1-Pole 120 V circuits for small equipment.
- 2-Pole 208 V circuits for medium-power loads or dual-phase equipment.
- 2-Pole 480 V circuits for higher-voltage machinery.
Three-Phase & Multi-Circuit Support (Double-Deck)
Adding a second STEEL track busway channel expands both circuit count and voltage capability. The lower channel supports 1-pole and 2-pole single-phase drops, while the upper channel enables full 3-pole, 3-phase power — all within the same suspended footprint.
- 4-Pole 3-Phase capability with the upper deck.
- Up to 4 single-phase circuits in stacked configurations.
- Simultaneous single-phase + three-phase power in one run.
These modular systems create a voltage-flexible electrical backbone that supports expansion and re-configuration without re-wiring.
Amperage
Typical Overhead Power Distribution
In most industrial, manufacturing, and commercial environments, overhead power drops commonly range between 20–40 amps per workstation. STEEL track busway is designed around this reality, delivering multiple 40 A circuits within a compact suspended footprint rather than carrying high ampacity continuously along every foot of the run.
The STEEL track busway configuration uses #8 AWG copper conductors sized for distributed loads, rather than the larger and heavier copper busbars typically found in aluminum systems.
Split Once, Feed Twice — Junction-Box Splitters That Reduce Homeruns
STEEL track busway standardizes on 40 amps per phase, capable of powering various types of equipment.
STEEL Track Busway can be paired with upstream dual-feed splitter enclosures to divide higher-ampacity inputs into multiple 40 A branch feeds. (Other plug-in busway systems also support splitter configurations.)
Because STEEL track busway feeds include integrated breakers, each branch is protected and remains compliant with NEC tap rules as long as the tap length stays within the permitted 25 ft. This approach provides the required capacity without the cost, weight, or structural burden of high-amp ALUMINUM busway.
Unique Features
Three Ways Track Busway Stands Out
The examples below highlight features of the STEEL track busway system that support modular layouts and additional circuiting options.
Modular Double-Deck Layout
Stack two STEEL track busway channels vertically within the same suspended footprint to increase circuit density or combine single-phase and three-phase power without adding new raceways.
On-Site Phase-Select Orientation
STEEL track busway plug-in units for 1-pole circuits can be rotated 180° to select the desired conductor on-site, simplifying load balancing and circuit reassignment.
Over/Under Intersections
Over/under bridge kits route STEEL track busway over aisles, conveyors, and walkways while maintaining continuous power, allowing floor layouts to evolve without extensive rework.
SPEED – Lead Time & Installation
Faster Than Traditional Conduit
Both ALUMINUM track busway and STEEL track busway systems install significantly faster than conduit. With pre-engineered channels and plug-in power modules, these systems reduce field labor, minimize rework, and allow future floorplan changes without cutting or replacing pipe.
This streamlined process minimizes downtime and accelerates the time it takes to energize overhead power—an important advantage for fast-paced projects.
Installers typically follow a straightforward sequence:
- Preparation: Mark hanger points aligned with structure.
- Hanger Installation: Install hangers ~10’ apart.
- Track Assembly: Join lengths mechanically, then engage electrical joiners.
- Plug-In Integration: Insert power drops, power adapters, or device mounts.
- Commissioning: Verify continuity, grounding, and alignment.
Why Contractors Choose USA TrackBusway™
- Reliable U.S. manufacturing and predictable lead times
- 7–10 business day shipping on most components
- Modular architecture reduces field labor
- Stackable design supports multi-voltage overhead layouts
Supported Voltage Options
Click the red + on the wiring diagram to view all supported system voltages, including 120V, 208Y, 208V 3-phase 4-wire, and 480V.
Panelboard ‘A’ may be 120/208V or 277/480V depending on building service.
Available: 208/480V
Line to Neutral Available: 120/277V
Line to Line Available: 1Ph-208V or 1Ph-480V
Available: 208/480V
Frequently Asked Questions about Track Busway Comparison
STEEL Track Busway standardizes on lower-amperage, open-slot plug-in runs (typically 40A per phase) focused on flexible branchcircuits, short PowerDrops, and modular layouts. ALUMINUM systems are usually configured for higher-ampacity distribution, withlarger copper bars inside a lighter aluminum housing, and are often used as part of a higher-amp backbone feeding multiple tapboxes or panels.
Traditional bus duct is typically high-ampacity feeder busway feeding large distribution points, with limited or no plug-inaccess. Open-slot track busway is a plug-in system that allows devices to be connected almost anywhere along the run. Both arelisted to UL 857, but they serve different roles: feeder bus duct for bulk power distribution, track busway for flexiblebranch circuits directly over work areas.
STEEL Track Busway focuses on 40A per phase for flexible, modular layouts in industrial and commercial environments, withsingle-phase and three-phase configurations available. High-ampacity ALUMINUM track busway products typically range from 100Aup to 225A and higher, and are often used where large blocks of power must be delivered along long runs or into dense equipmentrows.
Choose STEEL Track Busway when you need flexible, plug-in power over work areas, labs, manufacturing cells, or commercialspaces – especially where layouts are expected to change and short PowerDrops are preferred over long whips. High-ampALUMINUM systems are more appropriate when feeding large central equipment, dense data-center racks, or long high-loadfeeders where very high amperage per run is required.
