mactruck
According to Carrier - (Carrier AIR V 15000 btu RV Air Conditioner) this is the power requirements: Draws 14.1 amps cooling mode. 13.8 amps heat mode. Weighs approximately 90 pounds. Using this info you'll need to get a 3000 watt (running, not start-up watts) generator; 2500 would be "ok" but for a/c you'll be using 1700 watts continuous so you don't want to max out your generator. Make sure to use the 20amp receptacle @ 120 volts. It's best to directly read the nameplate rating on the a/c unit itself to be accurate. Note those portable generators are quite noisy.

T C
In addition to what mactruck stated, be advised, you may have to add a hard start to you’re a/c unit due to LRA {lock rotor amps}

akisha13
Anything less than 2000watts cannot handle most of air conditioners. A 2500- 3000watts can run your 1500 btu Carrier air conditioner.