For what it's worth, Type 12 isn't for hazardous locations either. In fact, Table 110.28 identifies it as an indoor enclosure. Throughout Articles 500 to 503, various General Purpose (UL calls them "Ordinary Location" as opposed to "Hazardous Location") enclosures are recognized as suitable...
I am assuming you have read NEC Section 502.10(B) carefully. Subsections 502.10(B)(1),(2),and(3) cover acceptable wiring methods. Subsection 502.10(B)(4) specifically states that enclosures shall be dusttight. If you read the Notes to Table 110.28, you will discover that there are several...
From Section 501.10(A)(3) Boxes and Fittings. All boxes and fittings shall be approved for Class I, Division 1.
A fitting (LB) that is only identified as Type 4 is not sufficient for Division 1.
My interpretation of Section 501.15(A)(1)(2) may be misleading. I should have said something like IF 501.15(A)(1)(1) doesn't already apply THEN where the conduit entry is less than 2" OR only contains "terminals, splices, or taps", the enclosure is NOT required to be sealed, even though it is...
I don't want to confuse the issue more, but I don't know what the reference to "'exhibit 501.17' on the same page" refers to. I couldn't find an antecedent reference in your previous or current posts.
By the way, I am citing the 2011 NEC.
This may seem convoluted, but we may as well begin as...
1) In Division 2, simply using an explosionproof enclosure does not necessarily require it to be one. Seals are not necessary if the equipment isn't required to be explosionproof.
2) This is correct conceptually, but is more based on whether equipment described in Article 501, Part III...
Unless an application is within the scopes of Articles 511 - 516, it is virtually impossible to classify a location from the NEC alone. You need to refer to one of the Standards in the Fine Print or Informational Notes (FPN/IN) listed in Section 500.4(B); particularly FPN/IN No.4. The most...
Tagalog or Hindi would have been even better.
My former employers (I'm retired) availed themselves of these "high value" design centers. I want to make clear these engineers/designers were NOT stupid, but very unfamiliar, especially if US domestic standards were required. For a long time...
Since "explosionproof” is typically an NEC, “Division” term, I will tell you that, if the only mark on the motor is E Exe II, it is not explosionproof.
While DRWeig is correct saying “Ex d” is closer, it still isn’t explosionproof; it is IEC “flameproof”. While they are similar in concept, they...
See NEC Section 430.7(A)(5). The motor's "rated temperature rise or the insulation system class and rated ambient temperature" will be marked on the nameplate.
A T3 "T Code" implies an acceptable temperature of 160C [200c x .8]. That's still above boiling water. No conventional motor will run...
Interestingly enough, PEs (usually electrical, but occasionally others) are not required to create/review/approve electrical area classification by FedOSHA unless it is to NEC "Zone" standards and the NEC has removed the requirement for PE review altogether in Article 505. Offshore rigs have a...
Section 110.26(C)(2)(b) applies to either or both switchgears where 110.26(A)(1), Condition 3 exists. That is, only one of them must be 1200A or greater since it alone still must have entrance/egress from the workspace at each end or meet 110.26(C)(2)(b). [110.26(C)(2)(a) is virtually impossible...
Generally no. See NEC Section 501.15(C)(1). It may not be immediately obvious but it is the fittings that are primarily "listed" and most seal manufacturers have their products listed with their own proprietary sealing compound. In other words, if a compound manufacturer claims their product is...
If you bond and ground things properly, the grounding electrode system shouldn't see much fault current either. Fault currents should bypass the grounding electrode system via the equipment grounding conductors. The grounding electrode system may see lightning strike currents or step & touch...
