Im running electrical for a mini split which requires a 240 line and there has to be a GFCI outlet near by so I'm running that too. The only way to get it there is through conduit (not buried) so I want to run both lines from the panel to the location and then probably a junction box to split them outside. Everything I've read says this is fine as long as I don't go over the capacity of the conduit which I'll probably do 1" for future proofing. Any issues, can they share a ground?

1 Answer 1


There should be no problem doing what you want, as long as all the conductors and overcurrent devices are sized properly. As per National Electrical Code, you'll size the equipment grounding conductor (EGC) based on the largest overcurrent device used. Which means the EGC will likely be sized based on the size of the breaker protecting the 240 volt circuit.

National Electrical Code 2014

Chapter 2 Wiring and Protection

Article 250 Grounding and Bonding

250.122 Size of Equipment Grounding Conductors.

(C) Multiple Circuits. Where a single equipment grounding conductor is run with multiple circuits in the same raceway, cable, or cable tray, it shall be sized for the largest overcurrent device protecting conductors in the raceway, cable, or cable tray. Equipment grounding conductors installed in cable trays shall meet the minimum requirements of 392.10(B)(l)(c).

  • Is there any issue with having the conduit terminate in a box that hosts the outlet and from there pull a flexible conduit to go to the compressor? Commented May 19, 2015 at 15:24
  • It's not a problem, as long as the box is big enough. You need to have a disconnect for the condensing unit. So you'd go from the box to the disconnect, then to the condensing unit. It's common to use a disconnect like the one shown in this answer.
    – Tester101
    Commented May 19, 2015 at 15:49
  • This answer, and this answer may help you calculate what size box you need.
    – Tester101
    Commented May 19, 2015 at 15:52
  • 1
    @RyanDetzel I think the rule is, if the condensing unit is not within sight of the breaker, you need a disconnect. But I could be wrong about that. So you're not working on the unit, and somebody flips on the breaker.
    – Tester101
    Commented May 19, 2015 at 16:46
  • 1
    National Electrical Code 2014 440.14 Location. Disconnecting means shall be located within sight from and readily accessible from the air conditioning or refrigerating equipment.
    – Tester101
    Commented May 19, 2015 at 16:59

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