at 117v, your perfectly fine, i personally have never seen a 15v swing in my life, but i guess it happens
for new construction, i doubht you will see a big fluctuation, i would check it a couple times, hottest day etc. i personally think your going to have 0 issue, that was a pretty minimal drop, just make sure the compressor was running and not just the fan, some units take a couple minutes for the compressor to fire up, but again if your over 108 nothing to be concerned about.
gl hope i saved you some money. remember your pretty close to max, Microwave/ water heater on electric/ coffee maker/toaster etc are all going to blow the breaker if the ac is on etc.. one big load at a time...
