A. Thank you for your email inquiry and for your purchase. Let’s walk through some simple steps. There is a reasonable explanation. We have a 15k BTU Dometic Penguin II and a Honda EU2000i generator at NetworkRV with a SoftStartRV installed. With temperatures at 102-103°F, we can successfully, consistently start and run this A/C on our Honda. Our measurements indicate about 150 watts to spare. We can’t claim that it would work unless we were sure. Many, many RVers have also achieved consistent startups with similar setups and Honda EU2000i generators. Please answer a few questions to begin the troubleshooting: 1) A/C MODEL QUESTION Do you have a Brisk, Brisk II Penguin I, Penguin II model of the Dometic 15k? If you have a complete model number, we can research it. Usually you can take a picture of the electrical diagram on the inside of the electrical panel area. 2) A/C QUESTION What precisely do you mean by “shutting off”? Does the A/C’s compressor start-up and run on the generator, but then suddenly it shuts off a short time later? Or does the compressor of the air conditioner fail to start? 3) GENERATOR QUESTIONIs the generator lighting indicating its “Overload” LED. Does the generator turn OFF its AC output power? 4) BE A GENERATOR MYSTERY DETECTIVE because a 15k BTU A/C can draw ups to 1800W of power and occasionally higher in hot weather, there will not be much capacity available on your 2000W generator to support power to other appliance loads. You may not be aware that other loads are on and drawing power In particular, check to be positive that your hot water heater and refrigerator are manually switched to propane. Then, you must find out if your battery charger/ converter is running or not. Converter/battery chargers are usually the most mysterious ancillary load. Plus, you may not know where its circuit breaker is located. Converter/battery chargers can pull upwards to 1000W -that’s HUGE in rapid charge mode. Additionally, if you have a lot of 12V loads such as lights, fans, etc. turned on inside. Because the converter attempts to power these 12V loads by converting the accessible AC power to DC power to prevent discharging the batteries. Consequently, a smart test is to locate and turn off the circuit breaker for the converter to eliminate if it is the problem. If you have a clamp-on ammeter, then suggest you connect it between the cord you have plugged into the generator and the generator itself. This test will enable you to measure the exact amount of current the generator is providing, even before the A/C is turned on. Doing this will more accurately determine if any of the auxiliary loads are causing you startup problems.