Rubber Cord Ampacity

[Dennis Alwon]

Suppose I have a cord that falls under table 400.5(A)(2) and is 75C rated with 3 conductors. According to the table 3/0 copper has a rating of 241 amps and assume we can use the next size overcurrent protective device.

My question is --Can we install a 250 amp breaker on this cord? I have been told no because of 100.14 but I don't see it.

 

[oldsparky52]

Did you mean to type 110.14(C)(1) ?

You know my answer to this question.

 

[Dennis Alwon]

Did you mean to type 110.14(C)(1) ?

You know my answer to this question.

Yep-- I assumed the members would know .

BTW, this is Lou's (oldsparky52) question. I don't see how this quote from the handbook changes things Lou.

The important factor is that the load (200 amperes
minus the 25 percent increase for those loads considered to
be continuous) supplied by this cable does not cause the
cable to operate at an ampacity greater than that specified
in Table 310.15(B)(16) for a 75°C, 3/0 AWG copper conductor.

 

[oldsparky52]

What about the requirements of 110.14 that state you must use Table 310.15(B)16 unless the equipment is listed and marked otherwise?

No one could ever answer me what listings and markings would be required to allow the higher ampacity listings in Table 400.5

 

[oldsparky52]

I don't see how this quote from the handbook changes things Lou.

For me it just alerted me that connecting a #4 type W cable to a 100A breaker was a violation even though the cord at 75c according to Table 400.5(A)(2) has an ampacity rating higher than 100A. Dang that 110.14

 

[Dennis Alwon]

Looks like everyone else is busy -- no help here---- LOL. Saturday is a day off so I am certain someone else will chime in

 

[jumper]

The ampacity of rubber cords in not given in 310.15(B)(7).

400.5 Ampacities for Flexible Cords and Cables.
(A) Ampacity Tables.
Table 400.5(A)(1) provides the al-
lowable ampacities, and Table 400.5(A)(2) provides the
ampacities for flexible cords and cables with not more than
three current-carrying conductors.

 

[oldsparky52]

The ampacity of rubber cords in not given in 310.15(B)(7).

400.5 Ampacities for Flexible Cords and Cables.
(A) Ampacity Tables.
Table 400.5(A)(1) provides the al-
lowable ampacities, and Table 400.5(A)(2) provides the
ampacities for flexible cords and cables with not more than
three current-carrying conductors.

Are you saying that 110.14(C)(1) does not apply to rubber cord terminations?

No one is disputing that flexible cords and cables ampacities come from article 400, the dispute is whether 110.14(C)(1) limits the ampacity to Table 310.15(B)16 because of the termination limitations.

 

[jumper]

Are you saying that 110.14(C)(1) does not apply to rubber cord terminations?

No one is disputing that flexible cords and cables ampacities come from article 400, the dispute is whether 110.14(C)(1) limits the ampacity to Table 310.15(B)16 because of the termination limitations.

I misread read one of your earlier posts and thought you used 310.15(B)(16) for ampacity and not the 400 tables. I wrote (7) by accident above.

Okay gimme a few to go back and read the thread more closely.

 

[jumper]

Okay I kinda, sorta, maybe, but not really see your point.

I would say let me sleep on it and it may be clear in the morning, but I am doubting it.

Hopefully someone smarter than me will chime in.

 

[oldsparky52]

If you happen to have a 2011 handbook (that's the one I'm looking at), page 511, left column near the top (blue shaded area), review step 3.


Step 3. Evaluate the termination rating. Compliance with the termination temperature requirement of 110.14(C)(1)(b) is met with this 3/0 AWG cable, since its 75c ampacity is 241 amperes. Compliance with 110.14(C) is based on Table 310.15(B)(16) conductor ampacities, and the ampacity from that table for a 75c, 3/0 AWG copper conductor is 200 amperes.


IMO, the only way you can use the cord at the ampacities listed in Tables 400x is to change to a larger conductor prior to termination. Now the question becomes how/where can you make that wire size change, how far from the termination does it need to be? Are all terminations covered by 110.14(C), or only terminations on breakers or electrical usage devices?

I don't know, hence the request for discussion. Dennis and I had discussed this last week and he was not buying into this, and if I'm wrong I would love to know I am and why I am (so I can take it to the AHJ).

Thank you for participating in this.

 

[chris kennedy]

Step 3. Evaluate the termination rating. Compliance with the termination temperature requirement of 110.14(C)(1)(b) is met with this 3/0 AWG cable, since its 75c ampacity is 241 amperes. Compliance with 110.14(C) is based on Table 310.15(B)(16) conductor ampacities, and the ampacity from that table for a 75c, 3/0 AWG copper conductor is 200 amperes.

This part of the commentary is garbage IMO. T400.5(A)(2) clearly states the cable in question is good for 241A @ 75°C, thats the rating of the terminations I'm using.

(Are terminations for finely stranded conductors rated at 75°C?)

 

[don_resqcapt19]

Are you saying that 110.14(C)(1) does not apply to rubber cord terminations?

No one is disputing that flexible cords and cables ampacities come from article 400, the dispute is whether 110.14(C)(1) limits the ampacity to Table 310.15(B)16 because of the termination limitations.

In my opinion, yes. So, in this case the maximum ampacity that the cable in question can be used at is 200 amps.

 

[oldsparky52]

This part of the commentary is garbage IMO. T400.5(A)(2) clearly states the cable in question is good for 241A @ 75°C, thats the rating of the terminations I'm using.

(Are terminations for finely stranded conductors rated at 75°C?)

Just so I'm clear on your position, are you of the opinion that 110.14(C) is not requiring cord/cables to use Table 310.15(b)(16) ampacities for terminations? (I'm assuming you read 110.14(C) ).

The way I read 110.14(C) all terminations no matter what Table you can use for ampacities of the cable or conductor are limited to Table 310.15(B)(16).

I hope someone can show me how this is incorrect interpretation.

 

[Dennis Alwon]

In my opinion, yes. So, in this case the maximum ampacity that the cable in question can be used at is 200 amps.

So what is the purpose of Table 400.5 if we can't use it

 

[don_resqcapt19]

So what is the purpose of Table 400.5 if we can't use it

Just like the 90°C ampacities, there are few legal uses for the full ampacity of the conductor.

 

[seth207]

Could 400.5 be used for attachment plug terminations?

Sent from my HTC6500LVW using Tapatalk

 

[Dennis Alwon]

Just like the 90°C ampacities, there are few legal uses for the full ampacity of the conductor.

90C can be used for de-rating and it often comes into play

 

[chris kennedy]

Just so I'm clear on your position, are you of the opinion that 110.14(C) is not requiring cord/cables to use Table 310.15(b)(16) ampacities for terminations?

Common application;

4/0 type W rated 90°C T400.5(A)(2) tells me 405A
J-series Cam-Lok rated 400A continuous @ 105°C on both ends of cable

I'm going to (and have) use 4 sets for a 1200A temp genny set up.

 

[kwired]

Does 110.14(C)(1)(b)(2) cover this?

Conductors with higher temperature ratings, provided the ampacity of such conductors does not exceed the 75°C (167°F) ampacity of the conductor size used, or up to their ampacity if the equipment is listed and identified for use with such conductors

Not quite clear because we are still talking about a cord rated 75C, but I'm thinking the equipment being listed and identified for use with such conductors is going to be a key no matter what.