NEMA 3R Bus Secondary

NEMA 3R Padmounted Secondary Bus Enclosure




EPI NEMA Type 3R Padmounted Secondary Bus enclosures are designed to allow distribution of large amounts of low voltage power. Ampacity ranges from 400 to 5000 amperes at 600 volts and below, single or three phases. Custom sizes and amperages are available.


Made from 12-gauge steel. A drip shield top and smooth seam-free sides, front and back prevent rain, snow or sleet from entering the enclosure. Double doors with continuous stainless steel hinge are operated by a three-point latching mechanism with a handle equipped with padlocking provisions. Continuous stainless steel hinge has a stainless steel pin. All Buss Tapboxes include pentahead bolts on top and bottom of the door. Flanged bottom opening for pad mounting and conductor access. 

Buss Bars

CD 110 Silver Plated Copper is used and bus bars are sized according to one square inch of copper bus per 1000 amperes. Buss bars are insulated with 3”hi 600-volt standoff insulators. Bars are punched with 9/16“ holes at 13⁄4“ each way to accommodate lugs.


The standard finish is Sherwin Williams ANSI-70, light-dove gray inside and out.

Weatherproof Throats

Weather Proof Throats are available in various sizes. The standard finish is Sherwin Williams ANSI-70, light-dove gray.

Industry Standard

Meets National Electrical Manufacturers Association (NEMA) standard for Type 3R (Rain Proof and Sleet/Ice Resistant) enclosures. 


Standard Size based on ampacity and number of lug spaces required. Note: 600 Amps and below only have one row of holes. Some utilities may require two rows.

Custom sizes available.

Width Height Depth Gauge
48 48 33 12
48 60 33 12
60 60 36 12
60 72 36 12
72 72 42 12


NEMA 3R Padmounted Secondary Bus Tapbox