Dedicated AC line...12/2 or 14/2?

[PA BAMBI II]

I am getting ready to run electrical wiring on the Bambi II. I plan to use Romex...wondering what size wire I need for a dedicated AC line and one for possible electric hot water heater in the future.

I am not concerned about the regular electrical outlets for plug in lights, etc...but I want to be sure to have heavy enough wire and circuit for the AC unit (plan to use a stand alone unit- not roof mounted).

Ben

[dbj216]

I ran 12 ga for the AC, and another 12 ga wire for the microwave. I used separate 20 amp breakers for each. The AC can pull 1800 watts running on max.

Check your owner's manual. Your trailer may already be wired for a future air conditioner. This was an Airstream common practice. All trailers got the wire if not the breaker or air conditioner.

David

[lewster]

Originally Posted by PA BAMBI II

I am getting ready to run electrical wiring on the Bambi II. I plan to use Romex...wondering what size wire I need for a dedicated AC line and one for possible electric hot water heater in the future.

I am not concerned about the regular electrical outlets for plug in lights, etc...but I want to be sure to have heavy enough wire and circuit for the AC unit (plan to use a stand alone unit- not roof mounted).

Ben

12/2 with ground ONLY!!!!! Along with a 20 amp dedicated circuit breaker with nothing else on that line. Do yourself a favor and use 12/3 stranded marine cable. Much easier to use and has no possibility of work hardening from vibration and breaking.

BTW, a circuit for a roof A/C, or any A/C should be rated at 20 amps, hence the 12 AWG cable. Remember, you are protecting the wire with the circuit breaker, so the ampacity rating of the cable must match the circuit breaker value.

[PA BAMBI II]

[QUOTE=dbj216;1472890]I ran 12 ga for the AC, and another 12 ga wire for the microwave. I used separate 20 amp breakers for each. The AC can pull 1800 watts running on max."

This is very helpful...should the same be considered true for the water heater/fridge, or do they draw less current?

Thanks!

[dbj216]

The AC and the microwave are the big AC wattage appliances in my Airstream. There are no other AC appliances in my trailer as everything else runs on 12 volts or propane. There are 15 amp 115v outlets around the trailer for coffee makers, hair dryers, electric heaters, lamps, TVs and the like.

Our Airstreams have 30 amp service or about 3000 watts of power and that's all you get! Use it wisely! The AC will pull 1800 watts on max, and a big honking microwave could pull 1200 watts, and the wife's hair dryer could be 1500 watts on high. My electric heater is 1500 watts. All these things won't run simultaneously. Many Airstreams have a circuit switch that allows EITHER the air conditioner OR the microwave, but not both. If you overload your 30 amp circuit, the main breaker in your breaker box, or the breaker on the pole in the camp ground will open the circuit and protect us from our largeness.

I have a dedicated circuit for the AC, and a dedicated circuit for the microwave outlet, both on 20 amp breakers.

David