Solar Panel wire through conduit

TooncesToonces Solar Expert Posts: 31 ✭✭
I'm trying to set up my system to be expandable as time and money permits, and I would like to install the wiring from the combiner box to the charge controller in conduit to allow for flexibility in the future. I'm wondering if I should install two sets of conduit (one for immediate use and one for future use) or if I just use one larger conduit for both.

Would there be any problem with running a set of #6 conductors for immediate use and then adding another set of #6 (or larger) conductors in same conduit?

Would there be any problem with interference? They would be running underground for 150'

Comments

  • newlnewl Solar Expert Posts: 53 ✭✭✭✭
    Re: Solar Panel wire through conduit

    There is nothing wrong with planning for the future. My preference is and has been to run additional conduit to eliminate any issues while attempting to pull new cabling (I did this on my most recent 20m trench run). As you suggest, you may also choose to initially install larger conduit that is capable of handling the expected cabling sizes that you'll be using.
  • TooncesToonces Solar Expert Posts: 31 ✭✭
    Re: Solar Panel wire through conduit

    Thanks Newl, I wasn't sure if running sets of DC wiring together for long distances was ok, but it sounds like I'm ok with doing so. thanks again!
  • solarixsolarix Solar Expert Posts: 713 ✭✭
    Re: Solar Panel wire through conduit

    I would go with the larger conduit and run a cheap rope or twine through it along with the wire to aid in pulling the future addition. Even feeding a wire snake trough a conduit with wire in it is usually impossible.
  • ggunnggunn Solar Expert Posts: 1,973 ✭✭✭
    Re: Solar Panel wire through conduit
    newl wrote: »
    There is nothing wrong with planning for the future. My preference is and has been to run additional conduit to eliminate any issues while attempting to pull new cabling (I did this on my most recent 20m trench run). As you suggest, you may also choose to initially install larger conduit that is capable of handling the expected cabling sizes that you'll be using.
    You need to keep in mind, though, that as you add conductors to a conduit, the ampacity derating of those conductors may change.
  • WNY DaveWNY Dave Registered Users Posts: 23 ✭✭
    Re: Solar Panel wire through conduit

    Also per the NEC (National Electric Code) there is a max. conductor fill for conduit based on the size of the wire, area, etc... many use about 40% FILL ratio. There are online calculators to figure out the maximum number of conductors based on AWG size and recommended trade conduit sizes. always good to error on the high side and not overfill the conduit.
  • TooncesToonces Solar Expert Posts: 31 ✭✭
    Re: Solar Panel wire through conduit

    Thanks guys! I decided to take Solarix's advice and install one 4" schedule 35 pvc pipeline so I have plenty of room for snaking wires. The cost difference between this and using 2 sets of 2" pipe were about the same, but this should be a little less work. Thanks again!
  • YehoshuaAgapaoYehoshuaAgapao Solar Expert Posts: 280 ✭✭
    Re: Solar Panel wire through conduit
    WNY Dave wrote: »
    Also per the NEC (National Electric Code) there is a max. conductor fill for conduit based on the size of the wire, area, etc... many use about 40% FILL ratio. There are online calculators to figure out the maximum number of conductors based on AWG size and recommended trade conduit sizes. always good to error on the high side and not overfill the conduit.

    http://www.electriciancalculators.com/
    Scroll down past the sales pitch where the table starts

    Code Calculators

    Click here to see screenshots of Code Calculators

    Now updated to the 2011 NEC. Includes Print Preview and Print functions!

    Updated to the 2011 NEC on 04/06/2011. New ambient temperature ranges added and appropriate changes made to ampacity values from Table 310.15(B)(16).

    Code Calculators has been REVISED with Visual Basic 2010.

    Code Calculators includes a Main Menu where these five programs can be selected.

    (1) Raceway {Conduit} fill program
    (2) Voltage Drop program
    (3) Table 310.15(B)(16) program with a voltage drop {Wire size calculator with voltage drop}
    (4) 3-phase Voltage Drop program using NEC Table 9
    (5) Power, Watts, Amperes calculation programs.

    Explanatory notes and examples are included.
    This is a Visual Basic 2010 ClickOnce application that downloads and installs on your computer that includes a desktop icon. It can be removed using the windows control panel.
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