Sebastianstrizu
New member
- Location
- Farmland IN
what NEMA ratings meet class 2 division 1 requirements? I know NEMA 9 does. Do NEMA 4 and 12 work?
class 2 div 1
- Thread starter Sebastianstrizu
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petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
have you looked closely at article 502?
IntrinsicSafety
Member
- Location
- Alberta, Canada
Assuming we're talking boxes and fittings, I think it's clause 502.10(B)(4) that says "dusttight". To my understanding that means any NEMA other than 1, 2 or 5 will be OK.
Last one I saw was mainly type 4/4X, since that's a common rating for boxes.
Last one I saw was mainly type 4/4X, since that's a common rating for boxes.
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
I believe I would start with Section 502.10(A)(3) since 502.10(B)(4) applies to Class II, Division 2.
Nevertheless, dusttight is still the operative term. Dust-ignitionproof (Type 9) is becoming somewhat antiquated. Equipment in Article 502, Part III, starting in Section 502.100, "requiring" dust-ignitionproof always recognizes a simpler alternate to dust-ignitionproof.
This is more-or-less because dust-ignitionproof was Class II's alternate to explosionproof, which isn't recognized for use Class II. (See Section 502.5) However, since dusttight is capable of excluding the internal accumulation of dusts, containing an internal explosion is unnecessary. The real issue is exposed external surface temperatures. (See Section 500.8(B)(2) for example)
That said, see Section and Table 110.28 and its notes to see what is recognized as dusttight. Remember the enclosure must also be suitable for other environmental conditions, such as outdoor, if necessary.
Nevertheless, dusttight is still the operative term. Dust-ignitionproof (Type 9) is becoming somewhat antiquated. Equipment in Article 502, Part III, starting in Section 502.100, "requiring" dust-ignitionproof always recognizes a simpler alternate to dust-ignitionproof.
This is more-or-less because dust-ignitionproof was Class II's alternate to explosionproof, which isn't recognized for use Class II. (See Section 502.5) However, since dusttight is capable of excluding the internal accumulation of dusts, containing an internal explosion is unnecessary. The real issue is exposed external surface temperatures. (See Section 500.8(B)(2) for example)
That said, see Section and Table 110.28 and its notes to see what is recognized as dusttight. Remember the enclosure must also be suitable for other environmental conditions, such as outdoor, if necessary.
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