How to specify an explosion-proof enclosure
NEMA 7 and NEMA 9: what each one covers. The NEMA 250 standard describes two enclosure types for hazardous locations: Type 7, for atmospheres with flammable gases or vapors (Class I), and Type 9, for combustible dusts (Class II). The type you need depends on the substance present in your area, not on the enclosure.
Class, Division and Group, explained. The Class tells what is in the atmosphere (gas, dust or fibers); the Division, whether it is present during normal operation (Div. 1) or only under abnormal conditions (Div. 2); the Group, which substance it is. Your engineering team defines that classification for the installation site: with it in your request, we quote on the right specification.
What to send us for a quote. Dimensions or drawing, area classification, material, number and size of entries, the equipment that goes inside, and the quantity. If anything is missing, mark it as “Not sure”: an engineer will call you.