Eaton 3MTB800RC Main Terminal Box - UL Listed
Part Number: 3MTB800RC
Quick Summary
Eaton 3MTB800RC Main Terminal Box provides robust high-capacity power distribution for large electrical systems. This solution helps engineers avoid miswiring and phase errors when landing heavy feeds in 800 A, four-wire, three-phase configurations. UL Listed certification and a NEMA 3R enclosure rating deliver compliance and outdoor resilience, while copper bus bars and top/bottom feed simplify installation. Designed for overhead and underground applications, it accommodates multiple large conductors per phase and supports 120/208 V systems. By enabling reliable, weather-resistant performance in demanding environments, this terminal box helps facilities reduce downtime, streamline maintenance, and lower total cost of ownership through long-term durability and straightforward serviceability.
Product Information
Extended Description
3MTB800RC Eaton: Eaton Main Terminal Box, 800A, Copper, NEMA 3R, Overhead/underground, Four-wire, Three-phase, 120/208V, (2) 250-500 kcmil
Product Name
Eaton main terminal box
Catalog Number
3MTB800RC
UPC
782114556153
Product Length/Depth
11.19 in
Product Height
47.7 in
Product Width
20.17 in
Product Weight
88 lb
Warranty
Eaton Selling Policy 25-000, one (1) year from the date of installation of the Product or eighteen (18) months from the date of shipment of the Product, whichever occurs first.
Certifications
UL Listed
Catalog Notes
For (4) 1/0-300 kcmil or (2) 1/0-750 kcmil cables per phase, order 3MTB800BLK. For compression lug Landing kits, order 3MTB1200CLK (includes landings for 3-phases and neutral).
Amperage Rating
800A
Bus material
Copper
Feed type
Top/bottom
Phase
Three-phase
Voltage rating
120/208 V
Wire size
(2) 250-500 kcmil
Utility approvals
NY : Consolidated Edison (ConEd) NC : Dominion VA : Dominion MT : NorthWestern Energy NE : NorthWestern Energy SD : NorthWestern Energy WY : NorthWestern Energy
Enclosure
NEMA 3R
Number of wires
4
Residential and Light Commercial, Metering Products, Volume 1 Tab 4
Eaton Specification Sheet - 3MTB800RC
Feature: 800 A amperage rating with copper bus. Business impact: Supports substantial load without overheating, enabling fewer parallel feeds and improved voltage stability. Application: Large industrial facilities and commercial campuses requiring robust single-point distribution. Feature: NEMA 3R enclosure. Business impact: Provides weather resistance and durable outdoor operation, reducing enclosure-related failures. Application: Outdoor substations, rooftops, and outdoor meter installations. Feature: Top/bottom feed configuration. Business impact: Flexible wiring paths save installation time and reduce ducting, enabling faster project commissioning. Application: Limited-space panels and retrofit work where side-entry is impractical. Feature: Cable landing capacity (2) 250-500 kcmil per phase; four-wire, three-phase. Business impact: Simplifies conductor management and minimizes splicing, improving call-forward reliability. Application: Large feeders for high-capacity electrical distribution. Feature: Compatibility with lug kits (3MTB1200CLK) and landings for four-phase configurations. Business impact: Expands retrofit options and reduces stocking costs by supporting multiple termination schemes. Application: Upgrading existing installations to accommodate larger cables and neutral landings. Feature: Warranty and compliance. Business impact: Provides assurance and support through Eaton’s policy, reducing risk and maintenance surprises. Application: Industrial installations with strict uptime requirements.
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FAQs
The 3MTB800RC is designed for overhead or underground installations with top or bottom feed options. Plan for a footprint of approximately 20.17 in wide by 47.7 in high and 11.19 in depth, and account for the 88 lb weight when choosing mounting hardware and supports. Ensure clearance for cable access and serviceability, and verify alignment with UL-listed installation practices and local codes.
This terminal box accommodates (2) 250-500 kcmil conductors per phase across four wires, suitable for heavy feeders in three-phase 120/208 V systems. For additional landings and lug configurations, order 3MTB1200CLK lug kits, which include landings for all phases and neutral, enabling expanded termination options without fabricating custom hardware.
Yes. The enclosure is rated NEMA 3R, providing weather resistance for outdoor and semi-exposed sites such as substations, rooftops, and outdoor meter banks. UL Listed certification further supports compliance with safety standards, reducing the risk of weather-induced failures and simplifying regulatory compliance.
The 3MTB800RC carries UL Listed certification and is housed in a NEMA 3R enclosure, indicating suitability for outdoor service. Eaton’s policy provides a one-year warranty from installation or eighteen months from shipment, whichever occurs first, offering protection during initial field deployment and early operation.
With copper bus bars, top/bottom feed options, and rugged NEMA 3R construction, maintenance intervals are reduced due to improved electrical reliability and fewer splices. The robust 800 A rating supports high-current distribution with lower heat and voltage drop, contributing to longer service life, reduced downtime, and a favorable return on investment for large facilities.