Switch feeder wire size in middle of run

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glb

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I have a question concerning the legality of increasing my 60amp subpanel feeder wire gauge size in the middle of the run. I am planning to run 6awg from the service entrance panel for about 100 feet and then switch (increase) the wire size to 4awg for the final 50feet, ending at the subpanel. I am doing this because of the possibility of voltage drop.
Note, It would be very hard to increase the first half to 4awg as I would like.
Is there a problem with 2 different size feeder wires to a subpanel?:bye:

Thanks in advance for input
 
Dennis Alwon

Dennis Alwon

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I agree with Bob- not a problem - but don't forget you must increase the size of the egc in that portion of the run. 250.122(B)
 
david luchini

david luchini

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jumper said:
why am i thinking that you would run the large wire first and then switch to the smaller?
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Wouldn't make a difference, the voltage drop would be the same.

He could run 100' of #6 then 50' of #4, or

50' of # 4 then 100' of #6, or

50' of #6 then 50' of #4 then another 50' of #6. The voltage drop would be the same on each arrangement.
 
Dennis Alwon

Dennis Alwon

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jumper said:
is the 50 ft. of #4 even worth it then? i guess it depends on the load. motors vs lights.
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It may not be necessary but it would depend on the load of his sub panel. If the load is 45 amps on the 60 amp feeder than @150' you are good with #6. At 50 amps it would change but again it does depend on the loads.
 
roger

roger

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jumper said:
is the 50 ft. of #4 even worth it then? i guess it depends on the load. motors vs lights.
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Derek, David's example doesn't really need to be anything but hypothetical, the point is it doesn't matter where in the circuit the different sized conductors are used as long as the VD is limited at the individual loads.

Roger
 
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