# Length  of  Runs  For  Conductors



## globe trekker (Nov 1, 2011)

Greetings to all!   

Where in the IRC  or NEC can I find the length limitations of various conductor sizes,

( i.e. - formulas or Tables  )?

EX:  A homeowner wants to run  400 feet of "above ground",  wet location type

( Art. 310.8©(2)  ) cable, or possibly in some type of flexible conduit.  They want

to have use of a single circuit for use at an outdoors location,  on their property,

for general use electric tools, radios, chargers, etc.

What is the minimum size of conductor that is required for this length?

Thanks!

.


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## raider1 (Nov 1, 2011)

There are no length restrictions for conductors. 210.19(A)(1) Informational note #4 recommends that a circuit have no more than 3% voltage drop but informational notes are not enforceable as code.

Chris


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## globe trekker (Nov 1, 2011)

Sooooo, how would someone inform the homeowner that their proposed size

of conductor is too small for the application that they intend?

EX: They want to install run 400 ft. of #10 on a 20 amp circuit. Some of the

electric tools they want to use at their site are: circular saw, sawzall, table saw,

corded drills, etc. I do not know specifically, but I'm guessing that there will be

a "multi-plug in" type strip for multiple tools to be plugged in at one time, but

not necessarily used at one time.

Will they need to keep resetting the breaker a bunch of times before they upsize

their 400 ft. run to a # 8 or #6 size conductor?

Did I mention that this particular homeowner ( hypothetical of course ) is cheap?  

FWIW, no enforcement is at play here, just information to assist in the safe,

effective use of the circuit and to help the homeowner decide on what size of

conductor to buy / install.

.


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## rshuey (Nov 1, 2011)

Politely ask them if they want to do the job twice, or just once?

You have really no say, it's up to them. If they do it as mentioned above, they will be cussing like a sailor.


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## fatboy (Nov 1, 2011)

If they're on the cheap, they won't replace the conductors, they'll upsize the breaker untill it doesn't trip, and hope they don't fry the conductors.


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## raider1 (Nov 1, 2011)

globe trekker said:
			
		

> Sooooo, how would someone inform the homeowner that their proposed sizeof conductor is too small for the application that they intend?
> 
> EX: They want to install run 400 ft. of #10 on a 20 amp circuit. Some of the
> 
> ...


Tell the home owner to perform a voltage drop calculation.

HERE IS A LINK to an online voltage drop calculator.

Also keep in mind that the voltage drop is dependent on the ampacity of the circuit and when you are dealing with receptacles and varying loads the voltage drop will vary.

Chris


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## mtlogcabin (Nov 1, 2011)

Tell them to connect 400 ft of # 14 extension cords together and plug in the compressor or use the saw to rip an 8 ft 2x piece of wood. They will then see the need to upsize the wire to make up for the voltage drop. Remember the amps will drop also and that is where the damage will be to the equipment.

Raider1 thanks for the link


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## raider1 (Nov 1, 2011)

mtlogcabin said:
			
		

> Tell them to connect 400 ft of # 14 extension cords together and plug in the compressor or use the saw to rip an 8 ft 2x piece of wood. They will then see the need to upsize the wire to make up for the voltage drop. Remember the amps will drop also and that is where the damage will be to the equipment.Raider1 thanks for the link


If we have a fixed resistance then if the voltage drops the amps will increase.

Chris


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## mtlogcabin (Nov 1, 2011)

I forget a lot in 24 hours never mind 15 years.

Thanks for the correction.


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## globe trekker (Nov 1, 2011)

Thanks ya'll for your input!    

.


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## gbhammer (Nov 1, 2011)

mtlogcabin said:
			
		

> I forget a lot in 24 hours never mind 15 years. Thanks for the correction.


I hear ya. The ICC has done more damage to my short term memory than... What was I talking about. My wife things I have sometimers.


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## raider1 (Nov 1, 2011)

mtlogcabin said:
			
		

> Tell them to connect 400 ft of # 14 extension cords together and plug in the compressor or use the saw to rip an 8 ft 2x piece of wood. They will then see the need to upsize the wire to make up for the voltage drop. Remember the amps will drop also and that is where the damage will be to the equipment.Raider1 thanks for the link





			
				raider1 said:
			
		

> If we have a fixed resistance then if the voltage drops the amps will increase.Chris





			
				mtlogcabin said:
			
		

> I forget a lot in 24 hours never mind 15 years. Thanks for the correction.


Actually I had a brain fart and am incorrect in regards to a fixed resistance.

For a fixed resistance I=E/R so the amps decrease when the voltage is decreased.

I need to not post when I am in a hurry.

Chris


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## ICE (Nov 1, 2011)

globe trekker said:
			
		

> EX: They want to install run 400 ft. of #10 on a 20 amp circuit. Some of the
> 
> electric tools they want to use at their site are: circular saw, sawzall, table saw,
> 
> ...


The tools will be a lot safer to operate.  They might get a little warm but we're getting into winter.


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## fatboy (Nov 1, 2011)

"They might get a little warm but we're getting into winter."

Hey, isn't that going to contribute to global warming?


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## jar546 (Nov 2, 2011)

This is one of the problems created by removing the voltage drop requirement from the NEC.  From a code enforcement standpoint I am not sure what you can do.  Maybe:

110.2 which gives you the authority to approve.  Just a shot.


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## globe trekker (Nov 2, 2011)

Jeff,

Thanks for the input,  however, there is no code enforcement involved on this.

A homeowner simply wanted to know what size of wiring to buy for his

proposed approx. 400 ft. run.   Because he is so cheap, he thought that he

could install the #12 size and could actually operate his power tools and other

things out on the site.

I have informed him of what the experts on here have said.   We'll see if

he actually buys the #12 or something larger.   It is afterall, ..his money!   

.


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