Sharing Neutrals

[ronball]

I Am Pulling 3 -120 Volts Circuits In 1" Pvc To Parking Lot Lights. Using # 10 Wire. Coming Off Three Phase House Panel. Can I Pull Three Hots And Share 1 Neutral, With A Groung.

 

[cadpoint]

Well tell us more, how many lights, how far between lights, how far from the home run to the first light?

What size wattage are the lights? Don't forget to add the vertical distance of the pole, to the light!

If you have an even number of lights "of 3",(for example three sets of 3) then there should not be an inbalance but if you have 1 additional or 2 additional lights, thats where the unbalance comes into play... you'll be adding the one or two sums of the amps for the neutral (which the neutral will see)

Frankly, depending on the lengths, I be more worried about voltage drop!

 

[Mule]

I havent checked NEC08 myeslf, but the other day had a fellow GC tell me that the 08 made some changes reguarding sharing neutrals on 3ph branch circuits. Is this true?

 

[LarryFine]

I Am Pulling 3 -120 Volts Circuits In 1" Pvc To Parking Lot Lights. Using # 10 Wire. Coming Off Three Phase House Panel. Can I Pull Three Hots And Share 1 Neutral, With A Groung.

Yes, as a generalization. In fact, this is cheaper and electrically more efficient than running three separate 2-conductor circuits would be.

I havent checked NEC08 myeslf, but the other day had a fellow GC tell me that the 08 made some changes reguarding sharing neutrals on 3ph branch circuits. Is this true?

Only that a 3-pole breaker, or at least a handle-tie, is required. The change is that this applies even if you have all line-to-neutral loads.

 

[Hairbone]

I Am Pulling 3 -120 Volts Circuits In 1" Pvc To Parking Lot Lights. Using # 10 Wire. Coming Off Three Phase House Panel. Can I Pull Three Hots And Share 1 Neutral, With A Groung.

Why are you not running the lights at 208? HB