600 C-9 Bulbs

| snipped-for-privacy@ipal.net wrote: | | So why not call a 15A circuit a 12A circuit, and a 20A circuit a 16A | circuit? | | | Because we call them by their rating.

You're taking my question out of context. I'll rephrase it so it is harder to do that:

Why not refer to the rating of a circuit as the value of the largest single load that can be placed on the circuit?

| 2005 NEC | 210.3 Rating. Branch circuits recognized by this article shall | be rated in accordance with the maximum permitted ampere | rating or setting of the overcurrent device. The rating for other | than individual branch circuits shall be 15, 20, 30, 40, and 50 | amperes. Where conductors of higher ampacity are used for | any reason, the ampere rating or setting of the specified overcurrent | device shall determine the circuit rating.

Stating the rule I was suggesting to be changed as support for why not to make the change doesn't make any sense.

The answer to my question should focus on why the 80% rule exists and what its meaning is in terms of the theories and issues that brought about such a rule. Is the limit of 80% for one single load there because some fuses or breakers could act at 80% current in the worst case scenarios (they can, based on real trip curves and variations in other tolerances of voltages and loads). Or is the limit of 80% to avoid overloading a general use circuit (if so, then it wouldn't have meaning for a dedicated circuit).

If I have a truly 15 amp load and will be providing a single dedicated circuit to supply it, what is the reason for having a rule that requires the overcurrent protection rating for it to be higher (20 amps in this case)?

The facts are the NEC load calculations over kill by 200 to 250 per cent. No. 12 wire is tested per the UL standard using 40 amperes. There is a substantial safety margin built into the code rules that allow for a lot of mistakes, because over the life of an electrical system that lasts from 30 to 50 years many mistakes are anticipated. Who knows who is going to try to modify these systems? So the 80 per cent rule is a good engineering practice. Likewise, the NEC does not have built in reserves for expanding an electrical system. I personally have wire a restaurant el cheapo, only to see the expansion take place before opening. The service had to be redone. I think a 50 per cent load should be maximum for circuits to allow for expansion.

| The facts are the NEC load calculations over kill by 200 to 250 per | cent. No. 12 wire is tested per the UL standard using 40 amperes. | There is a substantial safety margin built into the code rules that | allow for a lot of mistakes, because over the life of an electrical | system that lasts from 30 to 50 years many mistakes are anticipated. | Who knows who is going to try to modify these systems? So the 80 per | cent rule is a good engineering practice. Likewise, the NEC does not | have built in reserves for expanding an electrical system. I | personally have wire a restaurant el cheapo, only to see the expansion | take place before opening. The service had to be redone. I think a 50 | per cent load should be maximum for circuits to allow for expansion.

I'm not disputing the value of having a reserve. I do question the need for the 80 percent rule for single permanent load dedicated circuits. I would suggest that multi-outlet circuits certainly have a planned max single load limit of 50 percent (e.g. if there are anticipated loads over that amount, then either provide a higher capacity multi-outlet circuit or use a dedicated circuit). What I'm objecting to is the way such a reserve is provided for, particularly in its labeling. If no more than X amps is to put on a circuit, it should be labeled as an X amps circuit, not X*1.25 amps.

Phil the 80% rule is in 240.4(D) A 20a circuit (12ga copper) is good for 25a @ 60c (310.16) and

This BS is just code panels run amok. Nobody can control what a user will plug into a receptacle. It is just dillusions of power that lets a CMP write this drivel. We just limit the O/C device to a safe level and hope it operates when it should.

On Wed, 29 Nov 2006 20:04:05 -0500 snipped-for-privacy@aol.com wrote: | On 29 Nov 2006 15:26:56 GMT, snipped-for-privacy@ipal.net wrote: | |>The answer to my question should focus on why the 80% rule exists | | Phil the 80% rule is in 240.4(D) | A 20a circuit (12ga copper) is good for 25a @ 60c (310.16) and | 240.4(D) limits the breaker to 20a. There is your 80% | Why make this complicated?

So what about 10ga?

On Thu, 30 Nov 2006 02:26:27 -0500 snipped-for-privacy@aol.com wrote: | On 30 Nov 2006 03:22:39 GMT, snipped-for-privacy@ipal.net wrote: | |>| A 20a circuit (12ga copper) is good for 25a @ 60c (310.16) and |>| 240.4(D) limits the breaker to 20a. There is your 80% |>| Why make this complicated? |>

|>So what about 10ga? | | | 30a circuits don't usually have multiple outlets

Suppose I have a welder that uses just shy of 30 amps. On a dedicated single outlet I can use it fine. But to roll it around the shop I'll need to use a long unsafe extension cord because the NEC wants to limit me to 24 amps if I make multiple outlets for it (and don't want to waste the money putting in separate branch circuits for each outlet). All because of the risk that I might sneak in a 2nd welder and try to run both on the same circuit and pop a breaker. :-)

Quebec a separate country? Date:Thurs, Nov 30 2006 10:52=A0am

From: snipped-for-privacy@electrician2.com=A0

snipped-for-privacy@electrician2.com

George Fuller wrote:

I attended the very first meeting of the Alaskans for Independence in Fairbanks way back in the early 80's or late 70's as I recall. JopeVogler was there and I got to know him in later years. =A0He was personally offended when the National Park Service cut off access to his mine. =A0However, all he had to do was to apply for a permit and he refused to do so. =A0The Park Service send in a swat team to stop his cat

train and Joe never got over it leaving his cat train in the middle of the wilderness forever. =A0I think it is still there. =A0Joe refused to be buried in the USA and was buried down by Whitehorse from what I hear. The fact is he was just getting revenge and attention with his independence battle and I think he realized it would never happen. Today Alaskans receive much more in federal funds than we give. =A0We would be a darn fool to secede from the USA. =A0Besides with all the military bases here it will never happen. =A0It is my understanding that Alaska voted in statehood because of the military vote in the first place. =A0I was here in those days when Alaska had only 130,000 people and many did not want statehood.

snipped-for-privacy@electrician2.com wrote:

snipped-for-privacy@electrician2.com wrote:

|---------------------------------------/----------------------------------|

|------------------------------------/-------------------------------------|

The previous post was a mistake.

There is a whole section about welders. Those rules are as confusing for the DIY as the motor rules.

On Thu, 30 Nov 2006 22:27:20 -0500 snipped-for-privacy@aol.com wrote: | On 30 Nov 2006 18:33:07 GMT, snipped-for-privacy@ipal.net wrote: | |>On Thu, 30 Nov 2006 02:26:27 -0500 snipped-for-privacy@aol.com wrote: |>| |>| 30a circuits don't usually have multiple outlets |>

|>Suppose I have a welder that uses just shy of 30 amps. On a dedicated |>single outlet I can use it fine. | | There is a whole section about welders. Those rules are as confusing | for the DIY as the motor rules.

And maybe also for kilns? Of course those don't move around as much and won't as likely need multiple outlets for a dedicated load.