Distribution Panel Boards
Distribution Panelboards for Hazardous Location Power Distribution
Distribution panelboards in this category are purpose-built for hazardous locations, rated for use in environments where flammable gases, vapors, or combustible dusts are present under normal or abnormal operating conditions. All units carry NEMA 4/4X (watertight), NEMA 7 (explosion-proof gas), and NEMA 9 (dust-ignitionproof) ratings, making them suitable for Class I and Class II classified areas where standard panelboards cannot be installed. Within Galco's panel boards category, these units address a specific compliance requirement that circuit breaker panelboards for general-purpose installations do not meet.
Available in 100A and 225A ratings across single and three-phase configurations at 120/240VAC, 120/208VAC, and 277/480VAC, these panelboards are designed for sub-distribution duty feeding lights, heating loads, and small motors in classified areas - not high-ampacity feeder distribution. Circuit positions range from 12 to 42, with main lug only (MLO) and main breaker configurations available. MLO units require an adequate upstream overcurrent protective device; main breaker units include integral overcurrent protection within the assembly. All units are aluminum construction rated for both indoor and outdoor installation, consistent with the watertight enclosure rating.
Selection must begin with the area's electrical classification - Class, Division, and Group - established through a formal hazardous location assessment, since the panelboard's certification must explicitly cover the materials present in the classified area. For accessories supporting hazardous location installations, see Galco's prewired circuit breaker panelboards for non-hazardous areas of the same facility.
Frequently Asked Questions
What is the difference between NEMA 7 and NEMA 9 ratings on a hazardous location panelboard?
NEMA 7 covers explosion-proof construction for Class I locations containing flammable gases and vapors. NEMA 9 covers dust-ignitionproof construction for Class II locations containing combustible dusts. These panelboards carry both ratings, meaning the enclosure design has been evaluated and listed for use in both gas/vapor and dust-classified areas. The specific Class, Division, and Group markings on the unit confirm which materials and conditions it is certified for.
Do I need a main breaker or main lug only configuration?
If an upstream overcurrent protective device already protects the feeder conductors supplying this panelboard, an MLO configuration is appropriate. If no adequate upstream device exists, a main breaker configuration is required. In hazardous location installations this decision carries additional weight - confirm the upstream protective device is itself rated for the classified area or is located outside it before specifying MLO.
Can these panelboards be installed outdoors in a classified area?
Yes. The NEMA 4/4X watertight rating covers outdoor installation with exposure to rain, sleet, and washdown, and the NEMA 7/9 hazardous location ratings apply regardless of indoor or outdoor installation. The combination makes these units appropriate for outdoor classified areas common in petrochemical, grain handling, and similar industrial facilities where both environmental exposure and hazardous atmosphere are simultaneous concerns.