how many outlets on a breaker

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Beverly said:
:-? what method of electrical calculation do you use to figure out, how many outlets to put on a 15 & 20 amp circuit breaker ?
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Beverly, There is no limit as to how many receptacles you can connect to one breaker in a dwelling. However, good judgement is imperative.
 
There is a method according to Nec code 220.4 each outlet is counted as 180 va 15 amp breaker would be 10 outlets volts x amps (120v x 15 amps)= 1800 divide by 10 = 180va per outlets
 
i always felt that its better to do recepts in residential on #12. You never can know what a homeowner is going to plug into it and its just a better set up, no chance of nasty backstabbing by another uninspired young helper, or homeowner. And it just gives you alot more room ot layout a big house. I also will do flood packages in number 12 for a variety of reasons.
 
tonyou812 said:
i always felt that its better to do recepts in residential on #12. You never can know what a homeowner is going to plug into it and its just a better set up, no chance of nasty backstabbing by another uninspired young helper, or homeowner. And it just gives you alot more room ot layout a big house. I also will do flood packages in number 12 for a variety of reasons.
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IMO, #12 is residental is a waste except for whats required...
 
I wish I could talk the boss into using 20 amp circuits for all recepticle outlets in houses. Had ANOTHER service call thursday for tripping circuit, and it was the usual culprit-the 12 amp vacuum on 15 amp circuit!
 
JohnJ0906 said:
I wish I could talk the boss into using 20 amp circuits for all recepticle outlets in houses.
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...and the boss wishes he could talk the HO's, GC's and everyone else signing the checks to also use a 20A ckt ;)

Unless the customer is willing to pay for something above code, bare minimum is what they get.
 
celtic said:
...and the boss wishes he could talk the HO's, GC's and everyone else signing the checks to also use a 20A ckt ;)

Unless the customer is willing to pay for something above code, bare minimum is what they get.
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absolutely, but I'm the knucklehead explaining why brand new vacuum trips circuit in brand new house when the TV is on! (fugedaboutit, I'm just venting)
 
JohnJ0906 said:
absolutely, but I'm the knucklehead explaining why brand new vacuum trips circuit in brand new house when the TV is on! (fugedaboutit, I'm just venting)
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So your saying a TV and a vacuum will trip a 15a breaker? Pretty interesting... I've never seen this happen...:roll: Tell the HO to plug the vacuum into the dining room...:grin:

Installing #12 wire for a mere 600 watts more per circuit does not make sense to me....
 
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stickboy1375 said:
Installing #12 wire for a mere 600 watts more per circuit does not make sense to me....
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It's not just the capacity; it's also a matter of performance of the system. Lighting-circuit loads are predictable, while receptacle loads are not.

I also separate lighting from receptacles when possible. The reduction in light dimming when a plugged-in load turns on is perceived as quality.

Voltage drop is the enemy. I'll use feeders and sub-panels if the house is large enough. Feeders can take advantage of load diversification.
 
stickboy1375 said:
Installing #12 wire for a mere 600 watts more per circuit does not make sense to me....
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I couldn't agree more. And I have wired a few monster homes when I lived in CT (and I now hold an E1 license). We always used 14/3 home runs for all the bed room circuits (before the AFCI days) and loads of #14 throughout the rest of the house where not required to use #12 by code. All #12 for residential wiring is a complete waste.
 
LarryFine said:
It's not just the capacity; it's also a matter of performance of the system. Lighting-circuit loads are predictable, while receptacle loads are not.

I also separate lighting from receptacles when possible. The reduction in light dimming when a plugged-in load turns on is perceived as quality.

Voltage drop is the enemy. I'll use feeders and sub-panels if the house is large enough. Feeders can take advantage of load diversification.
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I don't see lighting loads as predictable, I don't ever recall roughing in a house with a fixture spec sheet...,But I agree with every thing else you mention...:smile:
 
peter d said:
I couldn't agree more. And I have wired a few monster homes when I lived in CT (and I now hold an E1 license). We always used 14/3 home runs for all the bed room circuits (before the AFCI days) and loads of #14 throughout the rest of the house where not required to use #12 by code. All #12 for residential wiring is a complete waste.
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I use this for my bedroom feeders...
romexextracircuit2.jpg
 
LarryFine said:
It's not just the capacity; it's also a matter of performance of the system.
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Larry what do you see happening if we allow a bit of voltage drop in a home?

What loads really care about a rock solid voltage?

My PC can run from 90 to 135 volts, incandescent lamps any voltage.

In my own home I ran 10/2 for a dedicated 12,000 BTU AC unit, it could have been on 14 AWG.

I wish I ran the 14, now when the compressor kicks it flickers the rest of the house. (see below) If I ran 14 in place of the 10 I bet I would not notice the rest of the house flickering and the fact that the compressor would take .25 seconds (;)) longer to come up to speed would not bother me. :)

I can't change the fact that the power companies transformer is down the street and picks up 1/2 dozen other homes along with mine, I only have so much capacity available from the source.
 
stickboy1375 said:
Installing #12 wire for a mere 600 watts more per circuit does not make sense to me....
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That 12 amp vacuum would be 60% of cicuit capacity, not 80%. This seems to be the one appliance I see problems with.
 
iwire said:
I wish I ran the 14, now when the compressor kicks it flickers the rest of the house. (see below) If I ran 14 in place of the 10 I bet I would not notice the rest of the house flickering and the fact that the compressor would take .25 seconds (;)) longer to come up to speed would not bother me. :)
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Could you elaborate on this, what you're saying is new to me.
 
iwire said:
Larry what do you see happening if we allow a bit of voltage drop in a home?

What loads really care about a rock solid voltage?

My PC can run from 90 to 135 volts, incandescent lamps any voltage.

In my own home I ran 10/2 for a dedicated 12,000 BTU AC unit, it could have been on 14 AWG.

I wish I ran the 14, now when the compressor kicks it flickers the rest of the house. (see below) If I ran 14 in place of the 10 I bet I would not notice the rest of the house flickering and the fact that the compressor would take .25 seconds (;)) longer to come up to speed would not bother me. :)

I can't change the fact that the power companies transformer is down the street and picks up 1/2 dozen other homes along with mine, I only have so much capacity available from the source.
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Bob, you're sort of answering your own question. This is as much a matter of perception of system performance as it is genuine system performance. It's not that the loads can't tolerate a bit of voltage drop, it's that customers often see light dimming as a problem with the electrical system.

Why should the overhead light in a room dim when the TV is turned on? It's easily avoided (okay, minimized), and taking care in circuit layout is easy. Wiring two or three bedrooms with one each separate lighting/fan and receptacle circuits is just as easy as using two circuits that each have some lighting and some receptacles.

georgestolz said:
Could you elaborate on this, what you're saying is new to me.
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If I'm correct, he's saying that he'd rather have the majority of the starting-current-induced voltage drop occur on the compressor's feed than the house's feeder. Reducing the compressor's supply size would reduce the voltage sag on the rest of the system. Of course, the compressor will have a slightly shorter life.
 
LarryFine said:
If I'm correct, he's saying that he'd rather have the majority of the starting-current-induced voltage drop occur on the compressor's feed than the house's feeder. Reducing the compressor's supply size would reduce the voltage sag on the rest of the system. Of course, the compressor will have a slightly shorter life.
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Is it that the inrush current is greater with the larger conductor to the A/C "because it can be"?
 
tallgirl said:
Is it that the inrush current is greater with the larger conductor to the A/C "because it can be"?
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Sort of. Let's look at the instant of greatest voltage drop as a static, frozen-in-time moment. The entire length of current pathway impedance contributes to the voltage drop. The voltage drop, relative to the source, increases as you travel from the source to the load. However, you can shift the voltage drop location by juggling the impedance of different sections of the current pathway.

The percentage of total voltage drop that one circuit's load causes on the other loads on the same panel depends on where each part of that total voltage drop occurs. In other words, the voltage drop before the panel affects the voltage delivered to all of the loads, causing light dimming and other voltage-related effects on sensitive equipment.

The voltage drop on the offending equipment's supply conductros only affects that equipment. Since the most voltage drop occurs on the highest-impedance section of conductor pathway, you can juggle the voltage-drop effects a bit by shifting the location of the voltage drop. Increasing the comnpressor's feed impedance, you decrease the voltage drop along the rest of the pathway.

By reducing the compresor's feeder size, Bob can reduce the voltage drop on the house's supply conductors (drop, SE, feeder, etc.) to the point that, while the compressor may suffer, the light dimming can be reduced. It's not so much that the inrush current is lower, but that there is less voltage drop ahead of the branch-circuit's OCPD.
 
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