12 gauge romex

[Doug]

Originally Posted by lx22f/c

Thanks Doug i feel better leaving it on a 30 amp plug. Just wanting to get it right and not endanger my family.
Thanks again for all replies. This forum is great!!!

If you're going to run an additional outlet from the 2nd 20 amp breaker, use a 20 amp rated outlet if it's a single recepticle.
A 20 amp outlet will receive a 15 amp plug or a 20amp plug.
If you never plan on running any single 20 amp load, then the 15 amp duplex recepticle would be fine.
You can run a 15amp duplex recepticle on a 20 amp circuit. The 15 amp duplex recepticles are able to pass 20 amps between the combined load of the 2 outlets.

Most space heaters are 1500 watts, which canl run on a 15 amp circuit.
JMHO,

Doug

[VicS1950]

What lx22f/c described in post #12 is a good plan. I wouldn't hesitate to use it at all.

Wire size affects voltage drop especially if the system supply voltage is low. Starting currents matter too.

vic

[Doug]

Originally Posted by VicS1950

What lx22f/c described in post #12 is a good plan. I wouldn't hesitate to use it at all.

Wire size affects voltage drop especially if the system supply voltage is low. Starting currents matter too.

vic

Yep,
Agree Vic.
Just a minor input on the 20 amp outlet.

Doug

[RoyBraddy]

I've noticed none of the discussion here brought out to be sure your replacement 12-GAUGE ROMEX has the copper ground wire included with it. It is probably a given that the ROMEX will come with the copper ground wire included but I have seen some 12-2 ROMEX without it.

You will need to run the ground wire all the way back to the distribution panel ground BUSSBAR connection.

My house is wired throughout using 12-gauge ROMEX (12-3) but all of my zone receptacles are the 15-AMP version. My circuit breakers for the 120VAC receptacle zones are 20AMP size. After noticing this I added a couple of 20AMP 120VAC receptacles that were close to the distribution panel in the garage area to support my 30AMP 120VAC Extension Cord hookups I use on my two parked 5th wheel and off-road POPUP trailers. The 20AMP version receptacles have a better current rating contacts. I actually ended up with two zones in the garage that are on separate 20AMP circuit breakers. I think the previous owner had one installed for a 120VAC Air Compressor setup.

One of these days I want to run a standard RV30AMP connection to the outside garage wall.

Roy Ken

[Doug]

Quote: You will need to run the ground wire all the way back to the distribution panel ground BUSSBAR connection.

Roy, why does he have to do this? Won't he pick up the ground for his sub breaker box through the ground in the cord?

Just wondering. Yes, I assumed 12-2 with ground.

Doug

[Doug]

Originally Posted by Doug

If you're going to run an additional outlet from the 2nd 20 amp breaker, use a 20 amp rated outlet if it's a single recepticle.
A 20 amp outlet will receive a 15 amp plug or a 20amp plug.
If you never plan on running any single 20 amp load, then the 15 amp duplex recepticle would be fine.
You can run a 15amp duplex recepticle on a 20 amp circuit. The 15 amp duplex recepticles are able to pass 20 amps between the combined load of the 2 outlets.

Most space heaters are 1500 watts, which canl run on a 15 amp circuit.
JMHO,

Doug

I edited this post to clarify the 20amp rated recepticle recommendation.

Doug

[lx22f/c]

The romex is now run!!! It is 12 gauge with a copper ground. Putting all the shelves in now.
Took a little while to fish it though all the beams and insulation but done for now.
After the first of the year i will mount a new breaker box and connect it to pedestal via a 30 amp cord, then connecting the romex from breaker to the new a/c unit.
Thanks again for all the help!
Robert

[Doug]

Looking like progress :-)
That's the hard part.

Doug

[RoyBraddy]

DOUG - I was just assuming you would probably start your 12-GAUGE (12-2 w/ground) at the AC Power Distribution panel using a dedicated 20AMP CIrcuit Breaker then hook all three wires up inside the AX Distribution Panel..

It will be pretty hard to daisy chain romex in most RV installs as they typically use the flat low profile RV pinch type receptacles which are probably already been placed in a daisy chain layout.

Doesn't matter where the ground wire is attached as long as it originates from the GROUND BUS BAR at the 120VAC distribution panel.

The point was NOT to run just the HOT and NEUTRAL ROMEX wires.

Roy Ken

[Doug]

Originally Posted by RoyBraddy

DOUG - I was just assuming you would probably start your 12-GAUGE (12-2 w/ground) at the AC Power Distribution panel using a dedicated 20AMP CIrcuit Breaker then hook all three wires up inside the AX Distribution Panel..

It will be pretty hard to daisy chain romex in most RV installs as they typically use the flat low profile RV pinch type receptacles which are probably already been placed in a daisy chain layout.

Doesn't matter where the ground wire is attached as long as it originates from the GROUND BUS BAR at the 120VAC distribution panel.

The point was NOT to run just the HOT and NEUTRAL ROMEX wires.

Roy Ken

Thanks Roy,
I may be confused.
I thought he was running a completely separate breaker box and feeding that box with a 30amp power cable that would go to the pedestal.
I thought the ground would just go to the ground bus in his new box.

Doug

[lx22f/c]

Originally Posted by Doug

Thanks Roy,
I may be confused.
I thought he was running a completely separate breaker box and feeding that box with a 30amp power cable that would go to the pedestal.
I thought the ground would just go to the ground bus in his new box.

Doug

Correct Doug
That is what i will be doing.

[Doug]

Originally Posted by lx22f/c

Correct Doug
That is what i will be doing.

Thanks for the update.
I thought I'd had been reading too many posts and got confused

Best regards,
Doug

[VicS1950]

Bob,
Sorry for the delay answering. Lately I got "Maintenance" screens when I clicked the JOF link.

Of course you are correct about this dedicated air conditioning supply.

In my defense (weak as it may be), when I read the original post about adding the air conditioner in my mind I saw a 50 ft coil of extension cord on the ground feeding over to the trailer fed from a detached garage so I was trying to convey that voltage drop was important. That put me off on a tangent.

The 80% load factor is not really applicable to this dedicated feed, but for most convenience receptacle circuits it is best to apply that. As you say, larger wire is never a bad thing, but it can make the installation a bit more difficult.

Sorry for getting off track. vic

Originally Posted by Bob Landry

Heavier gauge wire is not required because of startup. LRA is a lot more than operating amperage, but it occurs for a very brief time, usually less than a second and is irrelevant in sizing wire for a given load. The wire length and size coming from the pedestal is also irrelevant as long as it is sized correctly and there's no need to take that into consideration either. If that's not sized right, you are going to get voltage drop regardless of what you use for the AC.

That said, use #12 wire. The rated amp draw of the AC is based on an ambient operating temperature of 95 degrees. That amperage will increase at a rate of one amp per 10 degree shift in ambient temperature. In fact that's how you check an AC for proper charge without tapping into the system, by measuring amperage and checking amp draw relative to ambient temp. As an example a unit that draws 14.5A in 95 degrees will draw15.5A in 105 temperatures, so you would exceed the capacity of the 15A breaker. When I do my marine installations, I use #12 wire and a 20A breaker for all but the smallest units Along with factoring in the possible changes in ambient temperature, you also have to realize other factors that will affect current draw, condition of bearings and components at the unit ages, dirty filters, lower than normal CG pedestal voltages, so bottom line, go with #12 wire and protect it with a 20A breaker. You can use #10, as no one ever got in trouble using larger wire, but it's more expensive, harder to work with, and just isn't needed.