what size wire for ground?

I am in the process of hooking up my spa panel. This is one of the last things I need to finally get up and running(I have only been working on this for a year and a half). I am planning on running 4 wires in conduit to my spa breaker from my main panel. I have the room in my basement and I'm pretty sure it will be cheaper than 6/4 wire. I know I need 6 gauge for my two hot leads but can I use smaller wire for my ground and neutral? I am using a power cord I bought for a range and it appears the neutral and ground are 8 gauge and the hots are 6. Thanks.

Looking at the 6/3 wire with ground wire at the store, the ground wire is definitely smaller than the other ones.

I'd still go with 6 gauge wire for the neutral though.

How far of a length will the 6gauge be sufficient for? I have to go about 50 feet.

After some more research I think I should go with the 6 gauge wire for the neutral. Now I wonder if the range cord with the smaller neutral wire is safe.

I think you are allowed 10 gauge for the ground wire.

The range cord is probably OK. If you have balanced 120V power usage on each hot wire then you can use a smaller gauge neutral wire. I expect you do because most of your power usage is 240V from hot to hot.

So for example I use a 50A range cord although I can't remember off hand if it's 6,6,8 or 6,6,6. My HLT and BK have 240V elements and I have a 1500W/120V kettle on a PID that I am trying out for HERMS. Also I use a bit of 120V for low voltage stuff like the pump.

Another question, I am now thinking about running 6/4 wire if I don't have to use conduit. It looks like it wouldn't be that much more than individual wire. Do I need conduit if it is attached to my floor joist? Looks like 6/4 wire isn't that much more and not having to piece conduit together through my basement would be a lot easier. I know regular 12/2 romex is fine like that. Some of the reading I have done says that putting the 6/4 in conduit inside could be dangerous so I am just a little confused.

BWN said:

Another question, I am now thinking about running 6/4 wire if I don't have to use conduit. It looks like it wouldn't be that much more than individual wire. Do I need conduit if it is attached to my floor joist? Looks like 6/4 wire isn't that much more and not having to piece conduit together through my basement would be a lot easier. I know regular 12/2 romex is fine like that. Some of the reading I have done says that putting the 6/4 in conduit inside could be dangerous so I am just a little confused.

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Really? Now you've got me worried about something new.

It's usual to run individual wires through conduit just because they are easier to pull. There are also code requirements about overheating when putting bundled wires through conduit.

alien said:

It's usual to run individual wires through conduit just because they are easier to pull. There are also code requirements about overheating when putting bundled wires through conduit.

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It's more than usual, it's by code. You buy the number of feet needed of each color then pull the wires through the conduit together. Sheathed wire is not designed for conduit.

Also, for larger amperages with 2 poles & a neutral, it's typical & usual to run the neutral a size smaller.

Also, if it's metal conduit all the way the conduit itself is the safety ground & you don't need the 4th wire. But this is assuming the conduit is installed correctly with all of the screws, etc properly tightened. This is true for metal pipe and EMT and flexible metal conduit.

You can run sheathed wire like Romex through conduit under certain conditions. Processhead has it right in this thread.