Balancing a panel

[Zeke]

Is it true that balancing the load in your panel will result in using less electricity?

I know 230v is very efficient. 120v usage spread evenly between the busses might help overall? I realize this is an objective during the installation, but is there any reason to measure amps drawn and revise the distribution for a more even draw off each leg?

 

[Stuart in MN]

It won't use any less electricity, but it's still a good idea to balance the loads on each leg as well as you can. It's not going to be perfect since the loads aren't continuous (people turn lights on and off, and plug things into different outlets.)

 

[MoonRise]

Using less electricity? Nope. You use what you use, doesn't really matter which leg (of the two) it came off of.

disclaimer: there may (note "may" ) be a slight theoretical electricity usage increase from I^2*R heating and thus increased resistive in-line wire losses if all/most of the current flow is just on one leg instead of being 'spread' across the two incoming legs. All 240V loads (double-pole breakers) are automatically 'balanced' as they are using both legs/poles inherently.

Seems kind of 'sloppy' though to put all/most of the 120V loads just on one leg with the other leg having vastly different current pull.

 

[rlitman]

. . . disclaimer: there may (note "may" ) be a slight theoretical electricity usage increase from I^2*R heating and thus increased resistive in-line wire losses if all/most of the current flow is just on one leg instead of being 'spread' across the two incoming legs. . .

Yes, but if you're talking about balancing your main panel, that resistance would only be on the neutral between the main panel, and the meter (the resistance of your drop from the pole isn't billed). So it goes from insignificant to imperceptible.

 

[ishiboo]

Is it true that balancing the load in your panel will result in using less electricity?

I know 230v is very efficient. 120v usage spread evenly between the busses might help overall? I realize this is an objective during the installation, but is there any reason to measure amps drawn and revise the distribution for a more even draw off each leg?

Nope. Outside of wiring/device cost, 240v is no more efficient than 120v. 240v simply lets you have half the amperage for the same amount of work, so you can use smaller wire gauges for the same task.

 

[aandpdan]

Nope. Outside of wiring/device cost, 240v is no more efficient than 120v. 240v simply lets you have half the amperage for the same amount of work, so you can use smaller wire gauges for the same task.

Exactly.

Amps is current, watts is work. A 60 watt 120 volt light bulb would produce the same amount of light as a 240 volt 60 watt light bulb.

 

[theoldwizard1]

If we were talking 3 phase (industrial) you might get a different answer.

IIRC, factories that draw significantly more on 1 or 2 lega may get penalized.

 

[Zeke]

Interesting. What I generally see is all the double pole breakers on one side. I know they connect to both legs. Then I see a lot of lighting and plug circuits opposite the double breakers, thus pulling off that one leg. Below this assemblage I see breakers on both sides about even steven. I just wondered why the doubles weren't at the top on both sides even knowing they are using equal amounts of the 120 regardless of position.

The reason I asked is that I am moving breakers around and adding 2 tandems for light load circuits to get space for a 30A double pole in there for a 10 ga twist lock extension cord I plan on using with a small dual voltage inverter welder. I will mount this in a box within the general enclosure for my service panel.

Yes, I am cognizant of the limitations with this setup.

 

[buzz4041]

Interesting. What I generally see is all the double pole breakers on one side. I know they connect to both legs. Then I see a lot of lighting and plug circuits opposite the double breakers, thus pulling off that one leg. Below this assemblage I see breakers on both sides about even steven. I just wondered why the doubles weren't at the top on both sides even knowing they are using equal amounts of the 120 regardless of position.

The reason I asked is that I am moving breakers around and adding 2 tandems for light load circuits to get space for a 30A double pole in there for a 10 ga twist lock extension cord I plan on using with a small dual voltage inverter welder. I will mount this in a box within the general enclosure for my service panel.

Yes, I am cognizant of the limitations with this setup.

Zeke maybe I am confused to how this is written. The left and right side both contain each buss in an alternating fashion so it does not matter which side has double or single pole breakers or whether they are mixed. It could be more unbalanced for instance if their were single pole breakers on every other stab with the ones in between blank which would effectively be putting them on the same phase each time.

 

[Zeke]

You're right, I was not clear about the breakers opposite the double poles. I realize the busses alternate. I guess what I was saying made no sense.

 

[Charles (in GA)]

Yes, but if you're talking about balancing your main panel, that resistance would only be on the neutral between the main panel, and the meter (the resistance of your drop from the pole isn't billed). So it goes from insignificant to imperceptible.

Again, arguing theory here, not practicality, but if you loaded one side of the bus very heavily, and your SE or feeder was marginal to undersized, you could heat up the SE from the meter to the panel and cause losses, but again, it would be imperceptible anyhow.

Charles

 

[Charles (in GA)]

You're right, I was not clear about the breakers opposite the double poles. I realize the busses alternate. I guess what I was saying made no sense.

In theory (again) you would probably want the heavy loads (50 and 60 amp double poles) near the end of the panel that the feeder or service attaches to. In reality, the bus bars are heavy enough to probably not matter. I actually started at the bottom of my panel and filled upward, which put the heavy loads far away from the main lugs.

Just don't do like one pic I saw somewhere, and do a zig zag of single pole breakers so they all end up on one bus.

Charles

 

[Highbeam]

So does a typical residential power meter measure the flow of current through the neutral? That can't be since 220 loads don't use it. Perhaps the meter measures both legs and sums them? Surely the meter isn't driven by a single leg?

 

[ishiboo]

So does a typical residential power meter measure the flow of current through the neutral? That can't be since 220 loads don't use it. Perhaps the meter measures both legs and sums them? Surely the meter isn't driven by a single leg?

I believe it measures both at the same time. If a current transformer is used, they run both hots through it. The analog meters use a coil (or multiple, to handle voltage as well) to turn the disc. They don't care which leg has what current, they just want to know the total.

 

[wuntunearlybko]

dont know how true it is but i have heard that the PoCo takes the heavier leg and doubles it to calculate your cost.

can anyone confirm or deny?

-cutts-

 

[ishiboo]

dont know how true it is but i have heard that the PoCo takes the heavier leg and doubles it to calculate your cost.

can anyone confirm or deny?

-cutts-

Of course not.