I am looking to run a subpanel in the garage off the main. Was planning on running #2THHN wire for it. According to conduit fill charts, 1" will hold 3-#2 conductors. Is that including the ground wire, or only for current carrying conductors? And as a note, I was going to run a #6 for the ground wire
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Conduit Fill Question
- Thread starter Samh
- Start date
MTW
Well-known member
Fill charts are for the size, type and number of conductors, based on a particular conduit type. Different wire insulation types (size diameter) and conduit type (ID diameter) will affect the number of conductors allowed. It doesn't matter what the conductors are used for, it's a physical dimensional fit rating, with 360-Deg worth of bends in the run. All of the tables use the same size conductors, if you want to mix sizes you need to do the calculation manually based upon what your installing.
The simple way out is to count your ground wire as the same size as the feeder, then use the proper fill table for your conduit and wire type. In your case 4)#2AWG would require a 1 1/4" minimum with PVC Conduit. I would suggest larger if you have a lot of bends or LB fittings in your run. A couple of bucks more on the pipe will make your life easier on getting the wire in, on long twisty runs.
MTW Ω
The simple way out is to count your ground wire as the same size as the feeder, then use the proper fill table for your conduit and wire type. In your case 4)#2AWG would require a 1 1/4" minimum with PVC Conduit. I would suggest larger if you have a lot of bends or LB fittings in your run. A couple of bucks more on the pipe will make your life easier on getting the wire in, on long twisty runs.
MTW Ω
ddawg16
Well-known member
I concur with MTW.
But I have to question your need for #2.
One of the more common mistakes for garages is to over estimate power needed. Unless you are running a commercial setup with multiple people, you don't need anywhere near that much power.
If you do, then you should be running 480Vac 3ph.
But I have to question your need for #2.
One of the more common mistakes for garages is to over estimate power needed. Unless you are running a commercial setup with multiple people, you don't need anywhere near that much power.
If you do, then you should be running 480Vac 3ph.
GJ Sparkies will be able to give OP the exact advice he needs . . .
. . . . IF . . . he provides MORE INFORMATION.
What is needed is Electrical Loads expected in shop, Distance to shop, Electrical Power available at house (including picture of main panel), etc. Will be cheaper to use Aluminum for your feeder cable so 2" plastic conduit to the detached garage would be better idea. While trench is done, put power conduit in the bottom, then backfill 12" dirt and add the smaller 1" plastic conduit for low voltage like internet, CATV, security, phone, etc.
. . . . IF . . . he provides MORE INFORMATION.
What is needed is Electrical Loads expected in shop, Distance to shop, Electrical Power available at house (including picture of main panel), etc. Will be cheaper to use Aluminum for your feeder cable so 2" plastic conduit to the detached garage would be better idea. While trench is done, put power conduit in the bottom, then backfill 12" dirt and add the smaller 1" plastic conduit for low voltage like internet, CATV, security, phone, etc.
1" is a bit small the minimum would be 1 1/4", this assuming PVC conduit, and THHN/THWN conductors, if 1" rigid steel or IMC conduit was used then the conduit could be used as the grounding conductor, but I would not want to be the one pulling the wire, BTW, 2 AWG copper THWN is 115A, #3 AWG is 100A, unless stated otherwise I assume copper conductors.
More information about the loads would be quite helpful......
More information about the loads would be quite helpful......
Fill charts are for the size, type and number of conductors, based on a particular conduit type. Different wire insulation types (size diameter) and conduit type (ID diameter) will affect the number of conductors allowed. It doesn't matter what the conductors are used for, it's a physical dimensional fit rating, with 360-Deg worth of bends in the run. All of the tables use the same size conductors, if you want to mix sizes you need to do the calculation manually based upon what your installing.
The simple way out is to count your ground wire as the same size as the feeder, then use the proper fill table for your conduit and wire type. In your case 4)#2AWG would require a 1 1/4" minimum with PVC Conduit. I would suggest larger if you have a lot of bends or LB fittings in your run. A couple of bucks more on the pipe will make your life easier on getting the wire in, on long twisty runs.
MTW Ω
I am using 1" flexible conduit that was about $1/foot. Going to 1-1/4" flexible is about $5/foot(cheapest I have found so far). My concern had more to do with safety issues versus ease of pulling, because believe it or not, I was able to push the entire run through the conduit.
What is needed is Electrical Loads expected in shop, Distance to shop, Electrical Power available at house (including picture of main panel), etc. Will be cheaper to use Aluminum for your feeder cable so 2" plastic conduit to the detached garage would be better idea. While trench is done, put power conduit in the bottom, then backfill 12" dirt and add the smaller 1" plastic conduit for low voltage like internet, CATV, security, phone, etc.
It isn't a detached garage, just running 220v to the garage to run my shop while I build my new barn.
1" is a bit small the minimum would be 1 1/4", this assuming PVC conduit, and THHN/THWN conductors, if 1" rigid steel or IMC conduit was used then the conduit could be used as the grounding conductor, but I would not want to be the one pulling the wire, BTW, 2 AWG copper THWN is 115A, #3 AWG is 100A, unless stated otherwise I assume copper conductors.
More information about the loads would be quite helpful......
The tools that will be in there will be
- Air compressor
- Lathe
- Phase converter for Mill, Cold Saw, and Drill
- Welder (requires 100A breaker)
And yes, copper conductors will be used. not a huge fan of aluminum unless it is a real long run. As it is, it is only about 25ft from the panel in the basement to the garage.