I want to run electrical cable from service electrical panel in utility room to workshop. I would need to run the cable about 50' under the house to get to the outside, then I could bury the cable to the workshop. Would I need to put the wire from the service panel in conduit that would be under the house, fasten to the floor joist? Or can I do something else to get the wire to the workshop?
You have several options.
- You can run cable (NM-B or similar) through the crawl space and terminate it in a junction box where it will exit the house. In the JB, you join it to individual wires that would then run in conduit to the shop.
- This is what I did a couple of summers ago to run a circuit to my shed.
- You can run wires in conduit through the crawl space then directly out into the buried conduit and into the shop.
- If you do this, make sure you respect the curve limits for conduit and take care of all the other rules around sizing, etc.
- You can run cable in conduit through the crawl space then out to the buried conduit. There are many reasons not to pick this method, including:
- Pulling cable through conduit is difficult at best
- Cable in conduit requires larger conduit than the same number and gauge of individual wires
- Others I'm sure I'm missing...
There are loads of other considerations for getting power to an outbuilding. There are a bunch of questions here that address a wide variety of issues, from circuit count, to wire size, an additional panel in the outbuilding, grounding, etc.
Please be sure to read up on them all to make sure your installation is safe and correct. Once you've read through them and feel comfortable, put together a plan, I'd suggest asking about either the overall plan or individual details of it, here. There are a lot of licensed electricians who would be happy to look over your plan and point out things that may need to change, or reinforce that you've got it right. For example, I posted this question a couple of years ago when I was taking on a task similar to what you're doing and got a lot of good feedback. It also raised a couple of other follow-up questions for me.