Replies

1. 
   JTC1 | Dec 03, 2009 03:46am | #1

   Limitations on length of circuit are determined by acceptable voltage drop at the device.

   In order to calculate voltage drop, you will need to supply the total wattage of the chandelier, i.e. "load", at the end of that 140' circuit.

   Probably one answer if it is a 100 watt load, may be different if a 800 watt load.......

   Jim 

   Never underestimate the value of a sharp pencil or good light.
1. 
   Doobz26 | Dec 03, 2009 03:51am | #3

   Hmm... not sure exactly on what the load will be... but could be around 600-700 watts.

1. 
   JTC1 | Dec 03, 2009 04:36am | #5

   Using the voltage drop calculator - linked by Stuart

   700 watts = 5.83A load

   14awg copper wire, 140' length (1/2 of 280' round trip)

   Calculated drop:

   5 volt drop at chandelier or 4.2% drop assuming there are no other loads on the circuit.

   You will be fine unless your load changes.

   Many incandescent lights are operating at a 10% drop - just a bit dimmer and a bit warmer in color temperature.

   JimNever underestimate the value of a sharp pencil or good light.

1. 
   Doobz26 | Dec 03, 2009 04:44am | #7

   Interesting.  So 4.2% is okay?  What would you figure the maximum drop can be?   I was just thinking abou the rest of my upstairs and I am pushing things for length.  I was misunderstanding the length I guess..  The lenght to the furthest load is acutally only half the lenght of the circuit... i am just wondering if I should add a subpanel in the upstairs... I already put one in the garage.   Breaker box is in the basement top floor is two stories above....

    

1. 
   JTC1 | Dec 03, 2009 05:08am | #10

   >>What would you figure the maximum drop can be?<<

   Assuming this chandelier is the farthest load on this circuit and there are no other loads on it.

   5% per NEC, Article 210.19, (A), FPN No.4

   Gets stickier with other loads on the same circuit.....

   Jim

    Never underestimate the value of a sharp pencil or good light.

2. 
   gfretwell | Dec 03, 2009 08:41am | #12

   FPNs are just informational, not code.
   There is a movement to try to get voltage drop in the code but it is largely unenforceable for most circuits.

3. 
   JTC1 | Dec 03, 2009 02:18pm | #14

   Thanks, knew that but it did provide a finite percentage from an authoritative source which the OP seemed to "need".

   >>

   ......it is largely unenforceable for most circuits.<<

   Very true, especially in residential.

   Jim

    

    Never underestimate the value of a sharp pencil or good light.

2. 
   Stuart | Dec 03, 2009 03:50am | #2

   The concern is voltage drop, which will increase as the wire gets longer. It's also a function of the actual load on the circuit - if the only load is the chandelier, you may be ok. There are a number of voltage drop calculators online, this is the one I use most often: http://www.csgnetwork.com/voltagedropcalc.html Ideally, you want the voltage drop to be less than 3%, fill in your numbers and see what it says.

   - The calculator asks for 1/2 the total circuit length, so plug in 140 feet (the total length of the circuit is from the panelboard to the chandelier and back.)
   - Add up the total watts of the bulbs and divide by 120 volts to get the amps.

   
   

   ---

   Edited 12/2/2009 7:55 pm by Stuart

1. 
   Doobz26 | Dec 03, 2009 04:29am | #4

   Thanks for the link to the calculator.  It's not looking good... I may have to bump up to 12 awg wire (I used 14 due to box fill concerns... but if i make the chandelier the only load on the circuit i think i can make 12 wire work).   Even with 12 awg wire I can only get about 6.5 amps.   Does that mean I would have to put a breaker that small on the circuit? 

    

1. 
   JTC1 | Dec 03, 2009 04:41am | #6

   Huh?

   #12 produces a voltage drop of 3.1v or a 2.6% drop - home computers and such will run happily at that voltage.

   Lighting is much less critical - #14 is fine.

   Re: Breaker size / rating - breakers protect the wire not the load, so #14 wire = 15A breaker, #12 wire = 20A breaker. You can use an undersized breaker if desired.

   Jim

   Never underestimate the value of a sharp pencil or good light.

   Edited 12/2/2009 8:46 pm ET by JTC1

2. 
   Stuart | Dec 03, 2009 04:45am | #8

   No, you can leave the circuit breaker as is (assuming it's 15 amps.) Note that the 3% or less voltage drop is recommended but it's not an absolute...if it ends up a little bigger it will still be ok. Like JTC1 said, it's not as critical for lighting.

   Edited 12/2/2009 8:47 pm by Stuart

3. 
   gfretwell | Dec 03, 2009 04:47am | #9

   Voltage drop is not code, it is just a guideline.
   600 watts is 5a and that comes out to a tad over 3%. I wouldn't worry about it. If they follow the new energy rules they will be using CFLs and that might get you down to a couple hundred watts or less

1. 
   Doobz26 | Dec 03, 2009 05:08am | #11

   Ahh.... I'm overthinking it.  Thanks for the help everyone.  My other upstairs circuits have the potential for maybe 8 volt drop, or 6%... and from what everyone seems to be saying... that probably aint much of a problem. 

1. 
   brucet9 | Dec 03, 2009 09:25am | #13

   Voltage drop is really only important if there were a motor or electronics or fluorescent lights on the circuit. For incandescents, as another poster said, the only effect is slightly dimmer and yellower, or warmer, light color.BruceT

2. 
   BillHartmann | Dec 03, 2009 04:38pm | #16

   "For incandescents, as another poster said, the only effect is slightly dimmer and yellower, or warmer, light color."Actually "long life" bulbs are just ones that are designed for a higher voltage.Or for a few of the common size you can buy 130 volt bulbs.And he is getting longer life for free..
   William the Geezer, the sequel to Billy the Kid - Shoe

3. 
   junkhound | Dec 03, 2009 03:03pm | #15

   Like others have advised, you have no problem with just area lighting.

   heck, i even run a 1 HP compressor at the end of close to 500 ft of old extension cord when needed