Looking for opinions (especially from NC ECs)

[hardworkingstiff]

I just received a set of plans for a marina to bid. The plans show a #4 type W cable feeding a power center with (2) 50-amp receptacles. This is a common wiring practice in this area and I've done it many times. Last year I discovered we are not compliant with 310.14(C) because we are using the ampacities of Table 400.5(B) (with our application the #4 at 75c is rated 115-amps) and not Table 310.16 (which at 75c is rated 85-amps).

With competition the way it is (others will be bidding this) and I'm pretty sure the AHJ in this area will not catch this issue would you just bid it this way or would you bring it up and cause a fuss and ruckus?

 

[Rewire]

I just received a set of plans for a marina to bid. The plans show a #4 type W cable feeding a power center with (2) 50-amp receptacles. This is a common wiring practice in this area and I've done it many times. Last year I discovered we are not compliant with 310.14(C) because we are using the ampacities of Table 400.5(B) (with our application the #4 at 75c is rated 115-amps) and not Table 310.16 (which at 75c is rated 85-amps).

With competition the way it is (others will be bidding this) and I'm pretty sure the AHJ in this area will not catch this issue would you just bid it this way or would you bring it up and cause a fuss and ruckus?

at 100 a or less aren't you suppose to use 65 C ?

 

[hardworkingstiff]

at 100 a or less aren't you suppose to use 65 C ?

The breaker and pedestal terminations are rated and listed for 75c so I think we are OK there.

 

[hardworkingstiff]

Last year I discovered we are not compliant with 310.14(C) because we are using the ampacities of Table 400.5(B) (with our application the #4 at 75c is rated 115-amps) and not Table 310.16 (which at 75c is rated 85-amps).

That should have been 110.14(C)

 

[growler]

With competition the way it is (others will be bidding this) and I'm pretty sure the AHJ in this area will not catch this issue would you just bid it this way or would you bring it up and cause a fuss and ruckus?

I would call the AHJ and get a ruling on the matter before bidding. Them not catching something and getting permission to do something is a whole different thing.

Either the AHJ is OK with it or they or not and it's better for everyone to find out before the job starts.

 

[Dennis Alwon]

Lou if the cord is suitable for the application then why would you not be allowed to use T. 440.5B. I assume the cords are not in raceways.

 

[hardworkingstiff]

Lou if the cord is suitable for the application then why would you not be allowed to use T. 440.5B. I assume the cords are not in raceways.

Dennis, 110.14(C)(1) says we must use 310.16 ampacities for terminations. The only thing that may allow it is if we agree that Chapters 1-4 are the general code requirements and the later chapters modify it. If this logic can hold up, then we might be able to say that 555 allows the ampacity of Table 400.5(B).

The handbook (2008) example on page 482 disagrees though.

 

[ceb58]

I would call the AHJ and get a ruling on the matter before bidding. Them not catching something and getting permission to do something is a whole different thing.

Either the AHJ is OK with it or they or not and it's better for everyone to find out before the job starts.

Agreed, get a ruling before you bid. This will at least bring it to there attention. If you lose out the other guy may do as you planed and get tagged for it