Electrical / 15 Amp Circuit Question

DeepWaterDean

Active Member
A 20 amp should handle 16 amps continuous draw. A stage drop may be classified under code differently, id have to check but I suspect not. either way you go, this isn't a stage application and I am very familiar with the residential and commercial power distribution systems. We are also talking continuous load, a 20 amp breaker will take a quick surge of say 18 amps but continuous rating is 80% or 16 amps.
At 120v that’s 1920watts.
And I said 2000
Are we that f’ing far apart?
 

Renfro

Well-Known Member
Some really good info here. Had me scratching my head for a second because I know I'm running my breakers above 80% load. Anyways I think you both are right..

"a reading of the 2011 National Electric Code. Section 210.20(A) of the code basically says that a circuit breaker for a branch circuit must be rated such that it can handle the noncontinuous load plus 125% of the continuous load... There is, however, an exception. When the circuit breaker is listed for operation at 100% of its rating, the additional 25% requirement goes away. [and] If all your loads are non-continuous, you don’t have to worry about the 125% requirement."
Probably best to just assume 80% rated breakers and go from there.

That is true and it gets complicated, but the 100% rating is never applied in residential applications. It's for commercial equipment. Those feeds are hardwired and speced for that equipment and conductor size is determined accordingly.

Here is a good article on the sizing

https://iaeimagazine.org/magazine/2016/07/19/100-vs-80-choosing-the-right-ocpd-solution/
 
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Renfro

Well-Known Member
Your the one calling me out and posting code law when we are talking about an 80watt diff.
I am not "calling you out" persay, I am simply stating the proper way the numbers are calculated for those that wish to know. It's a simple misunderstanding, a failure to communicate. Take it easy and have a good evening. I'm gonna go watch some football.
 

DeepWaterDean

Active Member
I am not "calling you out" persay, I am simply stating the proper way the numbers are calculated for those that wish to know. It's a simple misunderstanding, a failure to communicate. Take it easy and have a good evening. I'm gonna go watch some football.
Don’t equate me to some shit show fest you had once. Insult me and my profession and then say chill out. What I said all along is dead on and your numbers are almost exactly the same. Fucking troll.
 

Renfro

Well-Known Member
Don’t equate me to some shit show fest you had once. Insult me and my profession and then say chill out. What I said all along is dead on and your numbers are almost exactly the same. Fucking troll.
Posting in a thread to add inaccurate information where accurate information has already been provided is simply begging for someone to point that out. It wasn't intended as a personal attack and if you feel triggered I will apologize to you for upsetting you.
 

DeepWaterDean

Active Member
Posting in a thread to add inaccurate information where accurate information has already been provided is simply begging for someone to point that out. It wasn't intended as a personal attack and if you feel triggered I will apologize to you for upsetting you.
At no point was I inaccurate
 

PJ Diaz

Well-Known Member
I've worked a lot of festivals myself, and have seen many an idiot running a generator. Local Fire Marshal is looking hard at Monterey Fairgrounds (Cali Roots Fest, Monterey Jazz, etc) this year to get them up to code. The electrical hasn't caught fire yet, but it's time to get it to proper standards.
 

PadawanWarrior

Well-Known Member
Thats incorrect. You can pull up to 1440 watts on a 15 amp 120v feed. 1300 watts is a safe number.
Sounds about right to me. I have 850 watts of led, 3 6" fans, 3 small Honeywell fans, 2 box fans, and a few miscellaneous really small things running on a 15 amp circuit. I would guess it's right around the 1440 mark. I know I'm pushing it and wouldn't try to add anything else, but am going to get a dedicated 30 amp circuit installed soon. I guess it's only a few hundred. I do have stuff running to different outlets though to spread the load a bit, and I'm using decent surge protectors. That seems to help a little to keep my sockets from getting hot and causing my breaker to trip until I get a dedicated one. But ya the heat outside totally has an influence too I learned, lol.
 

DeepWaterDean

Active Member
2000 ≠ 1920

Spouting general numbers / estimates is not the same as providing accurate information. May work for you in your profession however it's still incorrect.
That’s an easy ref number that people can remember and will work. 1500 watts will fit on a 15 amp circuit all day and all night. And 2000 will fit on a 20 amp all day long too. It’s not going to trip the breaker or cause any problems ever. If you need the real numbers then go back to the first post I made about the math. Ohms law is easy math to do. But maybe you don’t know your voltage exactly so you can fit the Watts I said. It’s not theory, it’s something I do on stages every day for the last 20 years. I’m not just getting lucky, I’m right. I do this for a living.
 

PadawanWarrior

Well-Known Member
That’s an easy ref number that people can remember and will work. 1500 watts will fit on a 15 amp circuit all day and all night. And 2000 will fit on a 20 amp all day long too. It’s not going to trip the breaker or cause any problems ever. If you need the real numbers then go back to the first post I made about the math. Ohms law is easy math to do. But maybe you don’t know your voltage exactly so you can fit the Watts I said. It’s not theory, it’s something I do on stages every day for the last 20 years. I’m not just getting lucky, I’m right. I do this for a living.
Well mine would trip if I had all the power going to the same outlet, so I spread it out to different outlets and that has helped not trip them yet until I get my dedicated circuit installed. And man again, Renfro is the last one I want to piss off on here. He's very helpful.
 

Renfro

Well-Known Member
Well mine would trip if I had all the power going to the same outlet, so I spread it out to different outlets and that has helped not trip them yet until I get my dedicated circuit installed.
If all the receptacles are on the same circuit/breaker then you aren't spreading the load.

Some rooms will be lucky and have more than one circuit, like one on a wall thats shared with a bedroom while the other walls are on a say living room circuit. Another good thing to know is that modern homes have a 20 amp feed for a bathroom and two 20 amp feed for a kitchen. Little beefier feed than the typical 15 amp, can be handy. Seen people run their tent ballasts off the master bathroom circuit with their tent in the bedroom so then can run the portable AC and Dehu.
 

PadawanWarrior

Well-Known Member
If all the receptacles are on the same circuit/breaker then you aren't spreading the load.

Some rooms will be lucky and have more than one circuit, like one on a wall thats shared with a bedroom while the other walls are on a say living room circuit. Another good thing to know is that modern homes have a 20 amp feed for a bathroom and two 20 amp feed for a kitchen. Little beefier feed than the typical 15 amp, can be handy. Seen people run their tent ballasts off the master bathroom circuit with their tent in the bedroom so then can run the portable AC and Dehu.
I know I'm not taking any of the load off the breaker, but what I was having happen was the socket was getting too hot from all the power going to one outlet and apparently it was spreading down to the breaker getting it hotter causing it to trip. I spread it out to different outlets all still in the same circuit, and I can get away with it for now. But like I was saying, I'm Pushing It! At least that's what I think was happening. I also use the bathroom circuit, and have a cord running to another circuit in another room for other stuff. That's why I'm going to get some dedicated ones installed soon. I'm at the MAX for sure, but did have the whole box replaced a few years ago so maybe that helps too, I don't know.
 

Renfro

Well-Known Member
Idk if anyone mentioned it but the same lights on 240 volts draw half the amps
Yes.

I know I'm not taking any of the load off the breaker, but what I was having happen was the socket was getting too hot from all the power going to one outlet and apparently it was spreading down to the breaker getting it hotter causing it to trip. I spread it out to different outlets all still in the same circuit, and I can get away with it for now. But like I was saying, I'm Pushing It! At least that's what I think was happening. I also use the bathroom circuit, and have a cord running to another circuit in another room for other stuff. That's why I'm going to get some dedicated ones installed soon. I'm at the MAX for sure, but did have the whole box replaced a few years ago so maybe that helps too, I don't know.
If you are going to run more feeds you may look into a small 6 space homeline subpanel. Then you can run 240v or 120v circuits off that and only have one feed ran to the switch panel.
 
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