#12 romex homerun for 15A lite circuits?

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Re: #12 romex homerun for 15A lite circuits?

Originally posted by al hildenbrand:
Originally posted by Shockedby277v:
bigger wire less resistance less money .... on the electric bill
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This is not true if the bulb on big wire, and on small wire, is the same 100 W incandescant.
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I have to disagree here, the customer is getting less ligh output and paying to heat the wire.

This IMO is the definition of less efficiency.
 
Re: #12 romex homerun for 15A lite circuits?

Say I have a customer with 100 100W incandescant lights in a display in the front of their warehouse.

I come along and sell them a new larger electrical service and fatter wires on all the homeruns supplying the display, on the promise that the lower resistance of the wiring will cut the electric bill for the display.

Nothing else changes. The display is on a timeclock, before and after my work, and runs exactly the same amount of time.

Imagine my customer's ire when he opens the next electric bill. The bill has increased.
 
Re: #12 romex homerun for 15A lite circuits?

And not only is his bill higher, (never mind he is refusing to pay me now) but the bulbs are burning out faster and he has to pay more for labor to service the display to keep all the lights good.
 
Re: #12 romex homerun for 15A lite circuits?

Or the customer is happier as now more of electric bill is being used to light their product up just as brightly using lower wattage lamps.

No matter how you spin it larger conductors result in greater electrical efficiency.

You could always offer to install a dimmer or 130 volt lamps. ;)
 
Re: #12 romex homerun for 15A lite circuits?

My customer was already concerned with efficiency. That's why he jumped at my sales pitch:
bigger wire less resistance less money .... on the electric bill
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He already had energy saving lamps and liked the light output the way it was.

I just created a call back and a collection problem for myself.
 
Re: #12 romex homerun for 15A lite circuits?

Originally posted by al hildenbrand:
I just created a call back and a collection problem for myself.
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I know people that can help with the collections, but you may need to do them a favor sometime in the future..... :D
 
Re: #12 romex homerun for 15A lite circuits?

Side question why can electricians not spell "Light" ? Hint: it is not Lite
If anyone should know the proper spelling....... [/QB][/QUOTE]

Electricians also take the path of least resistance.
 
Re: #12 romex homerun for 15A lite circuits?

Originally posted by iwire:
but you may need to do them a favor sometime in the future..... :D
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Heh!

Brings a whole new spin to the meaning of "call back".
 
Re: #12 romex homerun for 15A lite circuits?

They are not lites, and they are not lights, they are luminaires. Who wants to write that out all the time on a panel schedule?? :D

Steve
 
Re: #12 romex homerun for 15A lite circuits?

So here I am today labeling a panel when I run out of room on the line. I laughed to myself and thought about this thread. If I write "Lites" it will fit if I write "Lights" it will not. It was that tight. I erased and started over. :D

[ February 14, 2006, 06:06 PM: Message edited by: electricmanscott ]
 
Re: #12 romex homerun for 15A lite circuits?

Originally posted by iwire:
I know people that can help with the collections, but you may need to do them a favor sometime in the future..... :D
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All of their last names end with a vowel. :eek:
 
Re: #12 romex homerun for 15A lite circuits?

This thread has taken an interesting twist, and it behooves me to add my opinion. Disclaimer: we're talking about resistive loads only here; well, I am.

If a given load, or group of loads, is being fed with marginal conductors, and then they're replaced with large ones, the electric bill will increase.

A higher percentage of power is being productive, yes, but the overall current has increased. Bulbs will burn slightly brighter; someone will pay for that power.

Smaller bulbs could be used to bring the power consumption back down. NOW they're saving money, because less electricity is being used to attain a given light level.

That's where efficiency comes into play; not less cost directly, but less waste. The result can be used to ultimately lower operating costs. The costs must be weighed against the gains.
 
Re: #12 romex homerun for 15A lite circuits?

I oversize my homeruns all the time. This is not for energy savings, but for voltage drop. This is only done were the run is over 100 feet. I also do this for low voltage lighting runs. Voltage drop for LV lighting is insane.
 
Re: #12 romex homerun for 15A lite circuits?

Originally posted by LarryFine:
That's where efficiency comes into play; not less cost directly, but less waste. The result can be used to ultimately lower operating costs. The costs must be weighed against the gains.
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Well put.

That "weighing" is a complex calculation. A quantity of the efficiency gained is altruistic, having no monetary value.

Most comptrollers will tip the scales towards lower energy cost, and will avoid the contractor fees for installing heavier wire, and will just put in lamps that put out more lumens per watt.
 
Re: #12 romex homerun for 15A lite circuits?

Back to my original statement that started all this.

Originally posted by Shockedby277v:
[QB] bigger wire less resistance less money .... on the electric bill

How do you figure 'less resistance less money'?

Jim
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Assume 100 volt supply, 100 ohm resistive load, current draw 1 amp, power consumption 100 watts...........agreed?

Add resistance in series from the length of the wire run of 5 ohms.

Now, 100 volt supply, 105 ohm total resistive load, current draw 0.95 amps power consumption 95 watts...........agreed?

Greater resistance the lower the power consumption, the lower the electric bill. Addition heat load causing strain on the HVAC system (but how many BTU's) and inductive motors are not factored in. The title of the thread is 'lite (light) circuits' correct?

Yes, heat is given up in the wire as a by-product of resistance but do the math. The electricity used will be less.

Jim
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Re: #12 romex homerun for 15A lite circuits?

Originally posted by jmd445:
Yes, heat is given up in the wire as a by-product of resistance but do the math. The electricity used will be less.

Jim
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Jim we can go round and round on this. :p

Lets see if we can clear it up.

Using smaller wires may reduce the electric bill if you can accept lower light output or less work being done. If the light or work must remain constant the smaller wires will end up costing more money in the electric bill.

You are throwing away the electricity that is heating the wire, that fact can not be escaped.

Lets think of an extreme example, imagine a circuit so long that the resistance is so high that the lamp has does not even light.

Will that circuit still spin the meter when voltage is applied?
 
Re: #12 romex homerun for 15A lite circuits?

Iwire, you were doing GREAT, and I agree with all until your final statement............

"Lets think of an extreme example, imagine a circuit so long that the resistance is so high that the lamp has does not even light.

Will that circuit still spin the meter when voltage is applied?"

No, your meter will not spin, since the resistance is so great, there is no power flow. No power flow with in reason, we can quibble about mili and micro amps all day long.

Jim
 
Re: #12 romex homerun for 15A lite circuits?

Originally posted by iwire:
Using smaller wires may reduce the electric bill . . .
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Present tense.

So, I take it you are talking about a design choice prior to new construction, only?

If the installation is existing, then the light output is what it is. When the wire size is increased, I have to decrease the light output if it is to remain constant, which means still more "improvement" cost added to the cost of the wire size increase. All this cost lengthens the payback period before I actually start saving money.
Lets think of an extreme example, imagine a circuit so long that the resistance is so high that the lamp has does not even light.

Will that circuit still spin the meter when voltage is applied?
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Effectively, No.

If the lamp is not lighting, it is not heating. No heat implies no current. No current results from a near infinite resistance in the wire, or at something like six orders of magnitude.
 
Re: #12 romex homerun for 15A lite circuits?

Originally posted by jmd445:
No, your meter will not spin, since the resistance is so great, there is no power flow. No power flow with in reason, we can quibble about mili and micro amps all day long.

Jim
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I said the resistance is so great the light will not light, that is not the same as the resistance is so great there is no voltage at the lamp.

The meter will spin, it is a complete circuit and will use power heating the wire.
 
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