Table 501.1 does not exist in the NEC. There is such a Table in the NEC Handbook and it is a fair summary of requirements. However, it is important to know the Handbook?s commentary is not ?officially? authoritative. See the 2nd paragraph in the Section ?Notice Concerning Code Interpretations? on the front inside flyleaf.Yes, table 501.1 in the N.E.C. also -not sure of the article but it states that the requirements are not contingent on the voltage.
Table 501.1 does not exist in the NEC. There is such a Table in the NEC Handbook and it is a fair summary of requirements. However, it is important to know the Handbook?s commentary is not ?officially? authoritative. See the 2nd paragraph in the Section ?Notice Concerning Code Interpretations? on the front inside flyleaf.
The Scope statement in Section 500.1 notes that Articles 500 through 504 apply to all voltages; however, those Articles occasionally recognize certain conditions that may alter ?general? requirements; this is especially true with low power (not voltage) applications. There are also some special provisions for shielded instrumentation type cables and other cable constructions.
Without specific knowledge of the entire installation, it is virtually impossible to make an absolute statement about the sealing requirements. Seals are probably necessary, but even that isn?t the whole story.
In that scenariao, Section 504.70 would apply directly; a boundary seal is required but it is not required to be explosionproof.Bob,
If we are to pass an IS cable through a solid concrete wall that separates Cl.I, Div.1 environment from a nonclassified area, would it need to have and XP seal, or a sealing method equivalent to the solid wall be sufficient?
In that scenariao, Section 504.70 would apply directly; a boundary seal is required but it is not required to be explosionproof.
In this case, identified is the key term. See Section 500.8(A)(3)[2008 NEC] with CMP14's view.
The next term to note is minimize, not necessarily prevent.
Now remember, I'm not too keen on nonexplosionproof seals in the first place; but several materials, such as duct seal, have been suggested. The idea being a product that tends to be stable in a fairly broad range of enviornments and generally avoids shrinking. Several of the major Hazloc manufacturers have toyed with creating a listable material; but, to my knowledge, no NRTL has created a test standard.
The number does exist - it's just in the wrong place at the moment. Its in 501.15(E)(2). Section 501.15 FPN No. 1 refers to it while recognizing even explosionproof seals can't actually prevent migration.I know and as an engineer I hate unquantified terms, such as 'minimize'. Gimme a number......
...
The number does exist - it's just in the wrong place at the moment. Its in 501.15(E)(2). Section 501.15 FPN No. 1 refers to it while recognizing even explosionproof seals can't actually prevent migration.