Most enclosures cannot withstand the dangers presented in hazardous locations. NEMA type 1 enclosures? No way. Type 2? Absolutely not. Type 3? Forget about it. The two types of enclosures we will discuss today, however, NEMA type 7 and type 8, are designed to withstand certain threats. When “completely and properly installed and maintained,” these enclosures can protect the equipment enclosed from the dangers presented in specified locations (source). To better understand what you can expect from NEMA type 7 and type 8, please scroll down.
First, let’s take a look at NFPA 70, as it applies to both NEMA type 7 and type 8. Also known as the National Electrical Code (NEC), NFPA 70 is a standard used to ensure safe electrical design, installation, and inspection in order to protect both people and property from electrical hazards. NEMA type 7 and type 8 enclosures come in handy in some environments defined by the NEC.
NEMA Type 7 and Type 8
Protections Offered by a NEMA Type 7 Enclosure
Like NEMA type 10 enclosures, type 7 enclosures are designed to “contain an internal explosion without causing an external hazard.” Constructed for indoor use only, NEMA type 7 enclosures suit hazardous locations with the following classifications: Class I, Division 1, Groups A, B, C, and D as defined in NFPA 70. They are most often used for Class 1 locations (environments that potentially contain explosive gas or vapor).
Protections Offered by a NEMA Type 8 Enclosure
Although similar to type 7 enclosures, NEMA type 8 enclosures offer a unique protection: they prevent combustion through the use of oil-immersed equipment. You can use them both inside and outside in hazardous locations with the following classifications: Class I, Division 1, Groups A, B, C, and D as defined in NFPA 70.
Protections by Environment
You can expect the following protections in the specified environments from type 7 and type 8 enclosures. However, note that a product suitable for one class/group may not suit another class/group unless specifically marked on the product (source).
- In Group A environments, they provide a degree of protection against atmospheres typically containing acetylene.
- In Group B environments, they provide a degree of protection against atmospheres typically containing hydrogen and manufactured gas.
- In Group C environments, they provide a degree of protection against atmospheres typically containing diethyl ether, ethylene, and cyclopropane.
- In Group D environments, they provide a degree of protection against atmospheres typically containing gasoline, hexane, butane, naphtha, propane, acetone, toluene, and isoprene.
Ready to Purchase an Enclosure?
NEMA type 7 and 8 enclosures are designed to be used in hazardous locations. So what should you do if you’re seeking an enclosure for a non-hazardous location? In that case, we would recommend that you take a look at the following NEMA enclosure types:
- Type 1
- Type 2
- Type 3 (and 3R, 3S, 3X, 3RX, 3SX)
- Type 4 (and 4X)
- Type 5
- Type 6
- Type 6P
- Type 12 (and 12K)
- Type 13
To view all of the NEMA enclosure types, please visit the NEMA website.
Finally, if you’re on the hunt for a company that can manufacture premium metal enclosures on your behalf, check out American Products Contract Manufacturing. Our high-quality, innovative enclosures enable our customers to assist the telecommunications industry in expanding and improving their network services. We offer NEMA type 1, type 2, type 3, type 3-R, type 3X, type 4, and type 4X metal enclosures. Plus, we manufacture these enclosures from aluminum, galvanized steel, carbon steel, and stainless steel to create a rugged and reliable structure and to meet your environment conditions. Give us a call at 1-877-960-3703 to learn more, or request a free quote online.