exception for conductor size 310-16

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stjohnbarleycorn

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In 310-16 it refers you to 240.4 (D) for sizing small conductors. Then to
240.4 (G) for specific conductor applications. I am looking in motors - 430 parts III,IV,V,VI and VII, and I can't find a specific section that tells me, " for motors you can use the table 310-16 without the exceptions on 430.4(D). Is there section that tells you that specifically, or is is expressed in 240.4(G) that these sections listed are exempt from 240.4(D)? I am not clear on this, any help would be appreciated. thanks.
 
The sections listed in 240.4(G) are not required to meet the requirements of 240.4(D).

So for motor feeders, and branch circuits you size your overcurrent protection devices in accordance with Article 430, which does not limit the overcurrent devices to 15 amps for #14, 20 amps for #12 and so on.

Hope this helps,

Chris
 
thanks for the reply, I was hoping to find a sentence that actually stated that, but I don't think there is one clearly stated. I wanted one as a quote to help explain why this is allowed.
 
The first sentence on 240.4(D) states:

"Unless specifically permitted in 240.4(E) or 240.4(G)....."

Then in 240.4(G) the table shows you the sections the specifically permit you sized overcurrent devices without complying with 240.4(D).

Chris
 
I guess the part that seems vague to me is, it doesn't say "you may use the tables on 310.16 for these specific applications"

"overcurrent protection for the specific conductors shall be permitted to be provided as referenced in table 240.4(G)

then it lists the applications in the table, with references to 430, parts III,IV,V,VI,VII, if you read those, I don't see where it says to use 310.16, or at least I have not found it.

I guess I am thinking that a lot of the code is very specific, and this is one of th area where maybe it could be a little more clearly written.
thanks for your response.
 
I don't see where it says to use 310.16, or at least I have not found it.
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Keep in mind that Article 240 is dealing with overcurrent protection, and Table 310.16 gives us allowable ampacities for conductors, but does not tells us how to protect those conductors from overcurrent. We have to go to Article 240 for the general requirements for protecting conductors from overcurrent. There are specific sections and Articles that modify the general overcurrent provisions in 240, some of these are the sections listed in 240.4(G)

Part II of Article 430 deals with motor circuit conductors. This section tells us how to size the circuit conductors for motor applications.

Chris
 
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