Question on wire size for 30a

MFL wrote:
Ron, when I did mine, the table I went by said 10/2 out to 50 feet. I needed to go 75 feet so used 8/2. Even though you can get by with 10/2, I would use 8/2, to not worry about drop.

I put in a new 30a breaker in the house panel, and my RV30 outdoor box came with a 30a breaker too.

Jerry

Thanks, I'm going to remeasure tonight when I get home. I think I might be closer to 50 ft than 60. I'm leaning towards going with the 10/2 but we'll see.

Technically no, realistically yes. You would connect the black wire to one of the breaker output and the white wire to neutral. The vacant output would have no connection.
I would not recommend doing it. I would get a single pole breaker and do it right.

Ron, when I did mine, the table I went by said 10/2 out to 50 feet. I needed to go 75 feet so used 8/2. Even though you can get by with 10/2, I would use 8/2, to not worry about drop.

I put in a new 30a breaker in the house panel, and my RV30 outdoor box came with a 30a breaker too.

Jerry

We have a 30 amp breaker in the panel for a 220 v Electric Dryer which we will not be using (we have gas). If I go with the 10/2 Romex, can this breaker be used for the 30a RV receptacle?

Don't know...or care about no code, all I do know is that 30 amp #10 works fine at 50 ft.
And I lived in my MH for 5 months on a 100 ft 12 ga extension off borrowed electric,.....only tripped the 20 amp breaker once,......hit the micro while the A/C was on.

john&bet wrote:

TucsonJim wrote:

Jim

You may not use a breaker larger than 20amp on 12/2 with ground romax or a breaker bigger than 30amp on10/2 with ground romax. That is also in the NEC.

Good point - Forgot about the 20A limit on 12/2.

Jim

TucsonJim wrote:
You're getting a lot of incorrect answers regarding your question. A simple answer is: Yes, 10AWG will meet the NEC electrical code requirements for a 30amp load.

Here's the deal:

In most jurisdictions of the United States, electrical wiring is installed to the requirements of the National Electrical Code table 310.15 B 16. If you refer to the table, you will see that AWG10 will meet the amperage requirements of your load at all rated wire styles and temperatures. In fact, if you used THHN wire, you could use AWG12 for a 30 amp load. THHN is what is commonly sold in home improvement stores. Personally, I'd go with AWG10 and you'll have no problem meeting the requirements. Here's a link to the table:

NEC Table 310.15b 16

Two years ago, I installed a 30amp circuit for my RV. It was part of a significant remodel of my home, and I obtained a building permit. My run was 80 feet. As part of the building permit process, my plans were approved by my building department, and I passed inspection once it was installed. I used THHN AWG 10 for my application which is actually rated for 40 amps at 90C.

With all that said, you need to make sure your run won't drop the voltage too far. You'll still be within code requirements, but you could have some loss. On my application, I have good voltage at the house, so I'm seeing approximately 116V at the 30A outlet.

Your profile information indicates you live in Upland California. If you install this project, you are required to get a building permit. I'd call the building department to verify this, but according to their website, the following information indicates the permit is required:



105.1 Required. Any owner or authorized agent who intends to construct, enlarge, alter, repair, move, demolish, or change the occupancy of a building or structure, or to erect, install, enlarge, alter, repair, remove, convert or replace any electrical, gas, mechanical or plumbing system, the installation of which is regulated by this code, or to cause any such work to be done, shall first make application to the building official and obtain the required permit.

Hope this was helpful.

Jim

You may not use a breaker larger than 20amp on 12/2 with ground romax or a breaker bigger than 30amp on10/2 with ground romax. That is also in the NEC.

Thanks for the info Jim.

You're getting a lot of incorrect answers regarding your question. A simple answer is: Yes, 10AWG will meet the NEC electrical code requirements for a 30amp load.

Here's the deal:

In most jurisdictions of the United States, electrical wiring is installed to the requirements of the National Electrical Code table 310.15 B 16. If you refer to the table, you will see that AWG10 will meet the amperage requirements of your load at all rated wire styles and temperatures. In fact, if you used THHN wire, you could use AWG12 for a 30 amp load. THHN is what is commonly sold in home improvement stores. Personally, I'd go with AWG10 and you'll have no problem meeting the requirements. Here's a link to the table:

NEC Table 310.15b 16

Two years ago, I installed a 30amp circuit for my RV. It was part of a significant remodel of my home, and I obtained a building permit. My run was 80 feet. As part of the building permit process, my plans were approved by my building department, and I passed inspection once it was installed. I used THHN AWG 10 for my application which is actually rated for 40 amps at 90C.

With all that said, you need to make sure your run won't drop the voltage too far. You'll still be within code requirements, but you could have some loss. On my application, I have good voltage at the house, so I'm seeing approximately 116V at the 30A outlet.

Your profile information indicates you live in Upland California. If you install this project, you are required to get a building permit. I'd call the building department to verify this, but according to their website, the following information indicates the permit is required:



105.1 Required. Any owner or authorized agent who intends to construct, enlarge, alter, repair, move, demolish, or change the occupancy of a building or structure, or to erect, install, enlarge, alter, repair, remove, convert or replace any electrical, gas, mechanical or plumbing system, the installation of which is regulated by this code, or to cause any such work to be done, shall first make application to the building official and obtain the required permit.

Hope this was helpful.

Jim

That will yield a 5% drop (to 114 vac) at the receptacle with a 30 amp load. If that is acceptable then 10 gauge is okay.
8 gauge will yield a 2.66% drop to 117 vac
6 gauge will yield a 2.2% drop to 118 vac