We are buying a portable generator to with power outages. The one I am thinking of is rated at 4400 watts starting and 3500 running watts. A question has arisen about when two appliances, a new 10,000 BTU window ac and a new refrigerator try to start at the same time, in which case each would try to draw its maximum inrush current which would slightly exceed the rated starting wattage of the generator. The missus has talked to some electricians and is under the impression that this is a serious problem. I, on the other hand, think that the peak inrush power is probably measured in tenths of seconds and because of that, this type of simultaneous starting situation would be relatively rare. Furthermore, the consequences of the motors/compressors NOT having immediate access to peak wattage would not be catastrophic and would probably mean the motor would start slightly slower, again measured in tenths of seconds.
Somehow, sizing a generator by adding up the peak current draw of all motors or compressors which could be running seems like a it would result in a generator twice the size which I always thought necessary.