Increase wire size for every 75'

[kwired]

Now calculate the savings for an escalator with a 10 Hp motor that runs all the time, it's a couple hundred feet from the panel and the electric bill contains both an energy charge and a demand charge.

That is not really the same thing as having to run larger, more expensive, harder to terminate wires and dealing with box fill issues just because a there is a spot at the end of the hall that needs a receptacle.

And the end result might not be the same for a 208 volt supplied motor vs same motor supplied with 480 volts.

To automatically increase conductor size if over 75 feet may sort of work as a general rule, but will still be overkill for some items and not enough for others.

 

[Strathead]

And the end result might not be the same for a 208 volt supplied motor vs same motor supplied with 480 volts.

To automatically increase conductor size if over 75 feet may sort of work as a general rule, but will still be overkill for some items and not enough for others.

In fairness while it wasn't part of the statement by the OP, I am used to seeing these clauses, however, they are either on a building with a 12/208 service, or the clause delineates between 120/208 distance and 277/480 distance, so that is usually not an issue.

 

[Ingenieur]

I don't know if you are trying to validate or argue against increasing the wire size, but these figures are WAY off base. First it assumes that every load is subject to a 4% voltage drop 24 hours a day. Never going to happen.

I'm not advocating any position
just trying to get an order of magnitude

Based on averages
but valid
at times no load/no drop, others big load/higher drop
assumes an avg current 11.4 A, not fully loaded
when running at an avg drop of 4% vs 2%

Either way it appears it would take years for payback
but capacity reduction over 10's of millions of homes could be significant

 

[Ingenieur]

I don't know if you are trying to validate or argue against increasing the wire size, but these figures are WAY off base. First it assumes that every load is subject to a 4% voltage drop 24 hours a day. Never going to happen.

let's give it a shot
480/3 vac
fla 11
drop reduction (0.04 -0.02) x 480 ~ 9.6
P savings ~ sqrt3 x 11 x 9.6 = 0.183 kw
0.183 kw x 365 days/yr x 24 hrs/day = 1600 kw-hr/yr
usage $190
demand ???

might be additional factors
since v is higher i will be lower, so consump savings increase
but since i is less our i^2 savings will be a bit less
pf and eff should improve again drawing less current
again, off setting

 

[mwm1752]

Should we get into the larger carbon footprint to excavate/ transport/refine & develop the raw materials in order to save energy? Didn't we run out of oil in the 70"s

 

[Ingenieur]

Should we get into the larger carbon footprint to excavate/ transport/refine & develop the raw materials in order to save energy? Didn't we run out of oil in the 70"s

that calculus needs performed

 

[mwm1752]

12# = 6530 cir mils = 1.485 lbs @ 75’ x 3condutors in a12-2nm = 4.44 lbs
10# = 1038 cir mils = 2.355 lbs @ 75 ‘ x 3condutors in a10-2nm = 7.065 lbs
There is a approx. 63% more copper needed to upgrade for VD now convert that to the process of excavate/ transport/refine & develop the extra raw materials increasing all factors by 63%


Just a thought

 

[Ingenieur]

12# = 6530 cir mils = 1.485 lbs @ 75’ x 3condutors in a12-2nm = 4.44 lbs
10# = 1038 cir mils = 2.355 lbs @ 75 ‘ x 3condutors in a10-2nm = 7.065 lbs
There is a approx. 63% more copper needed to upgrade for VD now convert that to the process of excavate/ transport/refine & develop the extra raw materials increasing all factors by 63%


Just a thought

one time incremental cost
savings are forever
less fuel required
lower T&D losses
longer motor life running at lower i

I don't know
guessing it depends how long you calc savings for

 

[mwm1752]

does copper regenerate in the earth? resource used -- hardly incremental @ 63% in a small everyday use branch circuit --

 

[GoldDigger]

does copper regenerate in the earth? resource used -- hardly incremental @ 63% in a small everyday use branch circuit --

No, it does not. Even less than fossil fuel resources regenerate.
Less accessible copper ores become available and will be used through discovery and improvements in extraction technology, and, in theory, if the price of copper goes up.
Perhaps someday we will mine old dump sites to reclaim copper?
Refining copper is nowhere near as energy intensive as refining aluminum, FWIW.

 

[Ingenieur]

does copper regenerate in the earth? resource used -- hardly incremental @ 63% in a small everyday use branch circuit --

wiring lasts many years,20-40
it can, and is recycled
Integrate savings over 30 years

I don't know if it is ecologically or economically feasible
I DO know your arguement does not make the case either way

apparently you do

 

[Ingenieur]

7. In 2014, around 34 percent of domestic copper was recovered from recycled material with the rest generated from newly mined ore. While wire supply is produced predominantly from newly refined copper, nearly two-thirds of the amount used by other segments of industry, including copper and brass mills, ingot makers, foundries and others comes from recycled material.

https://www.thebalance.com/facts-about-copper-recycling-2877923
Cu holds 90% of its new value when recycled

 

[Ohms law]

From my experience at a specific hospital my company does all the work for, our prints always specify 20 amp branch circuits with home runs longer than 75' shall be ran in 10awg. We then switch to 12awg.

They also typically specify no more than 3 circuits in a home run. Any special purpose receptacles or feeders to a panelboard typically have specified conduit and wire size.

Good luck.

Sent from my SM-G930V using Tapatalk

 

[mwm1752]

wiring lasts many years,20-40
it can, and is recycled
Integrate savings over 30 years

I don't know if it is ecologically or economically feasible
I DO know your arguement does not make the case either way

apparently you do

do not make assumptions during debates -- you may state for yourself without doubts -- it's much safer that way -- just a thought

 

[Ingenieur]

do not make assumptions during debates -- you may state for yourself without doubts -- it's much safer that way -- just a thought

it is ALL assumptions
no facts have been presented, only conjecture
you position is staked out clearly
you believe the disadvantages outweigh the advantages
I don't know
just a thought