Question for John T

[Russ from MN]

Recently someone made a statement about balancing the load in a panel. Lets say you are not using any power for anything else, but you have a 1500W 120V heater in a pump house. Would it cost more to operate than a 1500W 240V baseboard heater? (assuming they were on the same amount of time) I realize you should try to balance the load in a panel somewhat but in is not always possible all the time.
 

[Greg K]

sorry not John T here but anyway the answer is no. 1500 watts is the measure of power used whether is be 120 volt 240 volt or 12 volts. Watts are calculated by multiplying the volts times the Amps. so a 1500 watt heater running on 120 volts draws 12.5 amps on one phase of power. A 1500 watt heater on 240 volts draws 6.25 amps on TWO legs of power, equaling the same total power used.

The reason this could save you money is that now you can run a smaller wire to supply your heater if y run it 240 volt. Also with motors they start easier with 240 volt single phase power. A motor will start even easier with 3 phase power, but that is a whole different subject.

Now my question for John T is this. If I use a 100 watt bulb for a heater in one area, and use a resistive 100 watt heater in another, is there any difference in efficiency? Just wondering since when you make light with an incandescent light the heat is a by-product and then potentially wasted(thermal inefficiency?) If used as a heater, then is the light a by-product and also a waste? No real reason for this just wondering
 

[CH(upstate,NY)]

Nope, if you have a 100 amp panel, you can draw 100 amps from each leg without taxing the panel. That being said, it is good practice to "balance" the load.

BSEE and, I'm not a lawyerrrrrr.
 

[Bob M]

[Greg K]

OK that answers that. Thanks for the answer. Now the next question. If I say something and my wife is not around to hear it, am I still wrong?
 

[MarkB_MI]

The main reason to balance the load is to minimize voltage drop. Let's say you have two 100 amp loads on a 200 amp panel. If you have both loads on one side, you have 200 amps on one leg, 200 amps on neutral and zero amps on the other leg. Let's say you have 10 milliohms resistance on each of your service cables back to the transformer. In that case you would have a 2 volt drop on the hot current-carrying leg and a 2 volt drop on the neutral leg, leaving you with a total voltage drop of 4 volts.

Now let's see what happens if you split the load on both sides of the panel: Now you have 100 amps on each hot leg and zero amps on the neutral. This gives you a voltage drop of 1 volt on each leg and ZERO volts drop on the neutral. The total voltage drop on each leg is only ONE volt. By splitting the load and eliminating the neutral current, you reduced the voltage drop by 75 percent!

Of course, if John T chimes in, he'll probably add that he likes things to be symmetrical just out of general principles.
 

[Bob M]

[Russ from MN]

I think I know the answer to that! The light bulb is just as efficient as the heater as long as no light escapes! some of the heat is radiant and it could carry heat out a window, etc.
 

[John T]

Geeee somethings wrong,,me and my fellow sparkies pretty much agree!!!!!!!!! GREAT MINDS THINK ALIKE LOL

I just pulled the RV with my Grand Am in tow into Wal Mart at Dalton GA, gonna have a BEER AND go to bed, drive ahead to N Florida tomorrow

OKAY as posted anytime you reduce or eliminate I Squared R energy heat loss anywhere including Neutral youre putting the energy to use versus wasting it as heat sooooooooo if the load is balanced theres no Neutral current therefore no I Squared heat losses in it LOoKS LIKE WE ALL AGREE

YES its best to balance the load as the other fine gents told you

Since you pay for watt hours, the cost is the same if ran at 120 or 240 EXCEPT FOR THE ABOVE INFO However, even if you loose that I Squared R as heat in a wire heck it goes to heat anyway, so if the wires in the room YOU BREAK EVEN. You still got the heat from the heater or the wire

My Mechanical engineer buddy Bob M has ya covered on the .light bulb,,,The bulb produces heat and light energy so if the light escapes you lost that as far as heat is concerned

No time for chat now cuz I could talk this subject for hours but I got other stuff to do

JohnT
 

[George Marsh]

JohnT,
Someone on the IH forum was talking about Florida Flywheeler. Told him to ask you.

If you don't have your load balanced, you may drag your rear bumber and that comsumes more power, not to mention what it does to the bumper:).

Have fun and have a safe trip.

George
 

[John T]

Mornin George,,,,,,Yes I will be at the February Florida Flywheelers (about my 12th year) Jan 15 to 20 but the bigger show is the one in February. WE stay all week in the RV and drive the golf cart all around and we play music twice a day, Im in hog heaven...........

Hard to balance the load in my RV, depends on if my first wife is sitting in the front or rear lol

John T
 

[showcrop]

I am the one who posted about balancing the load. I could be wrong, Greg, John, others, but you may want to check with your utility on how they measure demand. Around here the demand charge is a hefty part of the bill and elec. bills in NH are about as hefty as they get. It is my understanding that they are measuring both sides to neutral and whichever is the greater is what bumps the demand. Hence if they are kept as close as possible demand will be lower.
 

[buickanddeere]

Ideally both line 1, line 2 and if three phase line 3 should have the same current, that way the neutral current will be zero.
Will little to no neutral current there is less tendency for live stock to receive tingle voltage shocks.