J_butterfield
Member
- Location
- Spokane,wa
Is parallel 3x500 al xhhw 4/0 neutral 1/0 ground sufficient for 600A 480v service 300' away installed in 4" pvc underground
600A 480 service paralleled 300' away
- Thread starter J_butterfield
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kwired
Electron manager
- Location
- NE Nebraska
Other then voltage drop it is fine. How much actual load you have and how much voltage drop can be tolerated will be the determining factor.
ADD:
Does "parallel 3 x 500" mean two 500 conductors per phase or three conductors per phase? Three per phase definitely probably can compensate for any voltage drop pretty well - this just a guess, I didn't do any calculations. 300 feet at 480 volts doesn't drop voltage too rapidly in general with minimum ampacity conductors for the appliction.
ADD:
Does "parallel 3 x 500" mean two 500 conductors per phase or three conductors per phase? Three per phase definitely probably can compensate for any voltage drop pretty well - this just a guess, I didn't do any calculations. 300 feet at 480 volts doesn't drop voltage too rapidly in general with minimum ampacity conductors for the appliction.
Last edited:
kwired
Electron manager
- Location
- NE Nebraska
I missed that. Perhaps confusion with terminology?
J_butterfield, look in art 100 for definitions relating to "service" and those relating to "feeder" as well as "branch circuits", if you are not getting what is being said about this.
J_butterfield
Member
- Location
- Spokane,wa
OK taking 600A feeders to new building 300' away from existing 1200amp service will have approximately 480 amps connected load on new 600A feed. Do I not to carry over a ground? I thought I did of coarse I will connect to uFer electrode on new building. Using 2 500's per phaseOther then voltage drop it is fine. How much actual load you have and how much voltage drop can be tolerated will be the determining factor.ADDoes "parallel 3 x 500" mean two 500 conductors per phase or three conductors per phase? Three per phase definitely probably can compensate for any voltage drop pretty well - this just a guess, I didn't do any calculations. 300 feet at 480 volts doesn't drop voltage too rapidly in general with minimum ampacity conductors for the appliction.
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
If it taps directly off the service conductors coming in, it does not need a separate EGC. You wire it like a service because it is.
If it connects anywhere downstream of your main service disconnect (with its 1200A OCPD) it will be a feeder and you need to run both neutral and EGC.
In either case you need a local ground electrode (system) at the new building.
J_butterfield
Member
- Location
- Spokane,wa
feeds off 600A disconnect downstream of 1200amp service. thank you so 2 conduits each consisting of 3x 500 xhhw 4/0 xhhw neutral and 2/0 xhhw ground is sufficient and correctly sized?
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
This got me thinking...I don't have 230.40 in front of me, but I don't think that could be done compliantly could it?
It is correct if you don't apply derating factors like temperature and more than three current carrying conductors in the same raceway, Vd is only 1.1% with that load.
I don't know your neutral load to calculate that feeder, 2/0 is correct for the EGC by 250.122.
Tom
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
I do not see why not. As long as it stays outside any building until it gets to the first OCPD and is sized for the calculated load.
You might have to use multiple breakers (up to six) at the new panel instead of a single breaker though.
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
If the second structure is served by a service drop or service lateral, but if it is served by a set of service entrance conductors, which exception to 230.40 would you use?
kwired
Electron manager
- Location
- NE Nebraska
This can be more complicated by considering we now have a "service point". What is on the utility side of the service point is not covered by NEC, even though art 100 definitions define service drop and service lateral as being on the utility side of that point.
Utility sometimes does have overhead or underground feeds that supply multiple customers, and we have no control over that and neither does NEC. I believe if you supplied two underground service conductor sets to two separate buildings from the "service point" you would be NEC compliant.
Utility sometimes does have overhead or underground feeds that supply multiple customers, and we have no control over that and neither does NEC. I believe if you supplied two underground service conductor sets to two separate buildings from the "service point" you would be NEC compliant.
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