Rule 14-104 and Table 13

No the rule of 15A applies, unless some other rule (after section 14) over rules it and allows a higher ampacity. That could be motors, generators, transformers, capacitors, heat...etc. In that case you could go to table 13 for information, but that table is useless in my opinion.

In short, you can't just ignore rule 14-104 and jump straight to table 13.

Yup....I'm with Frunk on this one. That wierd little guy is right this time.:jester::laughing:


Table 13 is essentially useless unless you are looking at motors, generators or transformers.

Christ, you're really thinking too deep into this.

Table 2 refers you back to 14-104(2) for 14, 12 and 10 AWG. They changed these values to help us when derating, you still need to product the conductor as you always have.

And like Rollie said, table 13 is for motors.

In my opinion Table 13 should be sent straight to File 13,nobody knows what good it is.

jza said:

Table 2 refers you back to 14-104(2) for 14, 12 and 10 AWG. They changed these values to help us when derating, you still need to product the conductor as you always have.

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I know a few guys who are having a hard time getting past the idea of these changes in Table 2 being only for derating purposes.

#14 is now good for 25 amps in the table but only for derating which allows us to cram 20- #14's in a 1" pipe and still have a rating of 17.5 amps on it. (25A x 70%) However 14-104 explicitly tells you that the max O/C device for a number 14 copper is 15 amps.

It does nothing more than allow us to make full use of the space in the conduit.:laughing:

silver50032000 said:

In my opinion Table 13 should be sent straight to File 13,nobody knows what good it is.

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As far as I'm concerned....Table 13 does nothing but give you a list of the readily available sizes of O/C devices on the market.:laughing:

Rollie73 said:

As far as I'm concerned....Table 13 does nothing but give you a list of the readily available sizes of O/C devices on the market.:laughing:

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I agree and it works great for that. Tell that to students though and they get all confused:blink:

eddy current said:

I agree and it works great for that. Tell that to students though and they get all confused:blink:

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Yes they do.....I tried to explain it to a class I was teaching on motor controls.

BTW.....motor controls is the most failed section of the IP exam here in Nova Scotia, thats why our union hall puts on courses dedicated to it.

When the 2012 code came out we had ESA come to the office and do an update on the changes for the estimators and the foremen.

I remember watching the president and some of the estimators eyes light up when the instructor started talking about the changes to table 2.

Then he got to the part about the conductors still having to be protected as before...they did not look very happy after that. But then he explained how it was to help with derating...they got happy again.

Ok rule 14-104 still overrides table 13. That makes sense.

In my opinion table 13 and rule 14-104 needs some work done to it in the next edition of the code. It could be better written.


*edit* It code be better written. Not a good place to make a spelling mistake haha.

The whole book could be better written.

lynes.nathan said:

Ok rule 14-104 still overrides table 13. That makes sense.

In my opinion table 13 and rule 14-104 needs some work done to it in the next edition of the code. It code be better written.

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There's no overriding. They're two completely different things.

FrunkSlammer said:

The whole book could be better written.

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The whole book was written by a female divorce lawyer who was married to an electrician. She hates us.:laughing:

lynes.nathan said:

Ok rule 14-104 still overrides table 13. That makes sense. In my opinion table 13 and rule 14-104 needs some work done to it in the next edition of the code. It code be better written.

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You need to READ the code book, follow the references and appendices. Had you read appendix b, you would have seen this:

" Rule 14-104
Although Item (a) permits overcurrent devices larger than the conductor ampacity, they are restricted in rating or setting to the upper limits of Table 13. The conductor size should be determined and then Table 13 consulted only when an overcurrent device of the exact rating is not available. In other words, Table 13 is the last resort, although the use of time-delay fuses or fuses referred to in Rule 14-212(b) will assist in selecting a fuse of proper rating due to their availability in a greater range of values."

How much better written do you need it to be?

lynes.nathan said:

Rule 14-104 (2) has to override table 13. If it does not then based on table 13 I can put a 14 AWG on a 20 amp breaker (For general circuits, not referring to motors, transformers, and heaters) 14-104 (2) Except as provided for by Subrule (1)(c), the rating of overcurrent protection shall not exceed (a) 15 A for No. 14 AWG copper conductors; (b) 20 A for No. 12 AWG copper conductors; (c) 30 A for No. 10 AWG copper conductors; and (d) 15 A for No. 12 AWG aluminum conductors.

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You still didn't read it huh?

14-104 (1) (c) is the gateway for motors and heat.

14-104 (2) says except for specific rules that govern specific items, you follow these rules.

You really need to read the appendix B information. It is VERY clear on the role of table 13.

Table 13 is the "table of last resort". Every other section of code deals with OC devices for conductors in their section and I can almost guarantee that.

If you call for an inspection and tell the inspector when e asks why you ran #8 for a 60amp sub and quote table 13 he will laugh and tell you to change it.

If you include table 13 into your math for your install, your not doing your job right.

lynes.nathan said:

Rule 14-104 (2) has to override table 13. If it does not then based on table 13 I can put a 14 AWG on a 20 amp breaker (For general circuits, not referring to motors, transformers, and heaters)

14-104 (2) Except as provided for by Subrule (1)(c), the rating of overcurrent protection shall not exceed
(a) 15 A for No. 14 AWG copper conductors;
(b) 20 A for No. 12 AWG copper conductors;
(c) 30 A for No. 10 AWG copper conductors; and
(d) 15 A for No. 12 AWG aluminum conductors.

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Lmao okay, keep arguing your "point".

l0sts0ul said:

Table 13 is the "table of last resort". Every other section of code deals with OC devices for conductors in their section and I can almost guarantee that.

If you call for an inspection and tell the inspector when e asks why you ran #8 for a 60amp sub and quote table 13 he will laugh and tell you to change it.

If you include table 13 into your math for your install, your not doing your job right.

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But even following table 13 you cannot put a #8 on a 60 amp breaker.