AC 20amp breaker trips mid day

3 tons wrote:
Myredracer:

“107 volts is getting very low. Low voltage causes an AC unit to draw more current. Anything below 105 volts can result in damage to the AC unit over time. Not what you want to hear, but you should probably stop running it. An autoformer would cure that problem.”

Usually YES, but it’s possible to cite ‘a few’ outlier scenarios where an autoformer might be just a paperweight - consider the low a available potential when operating near the upper limits of a 30a pedestal’s amperage...In this case, I simply reduce my power demands (e.g. shutting off converter charger, etc) to allow the autoformer necessary headroom to function properly... An autoformer is not a substitute for poor power management, and with only 30a to work with..... Can't argue with that, so I won't. :) With autoformers, power in equals power out. The highest boost level of a Hughes autoformer is 10%. If CG voltage happened to be at 100 volts, the max you can get out is 3,000 watts (30 amps x 100 volts) and the most you'd can get after the autoformer is 27 amps *if* 100 volts was boosted up to 110 volts, which is plenty to keep the AC unit going. Not sure what internal losses the Hughes autoformer has?

I also have a Soft-Start installed (as an alternative to a properly sized and functioning capacitor), but in ‘my case’ have found the autoformer a better solution...I would note too that (try as I might), I find it somewhat odd that the manufacturer will not divulge what makes it work...In search of a solution, this admittedly didn’t keep me from trying it though... I looked at that Micro-air soft start starter ($300!) and was also disappointed in lack of tech. info. Would be nice to have seen a time-current graph. I used to work with "soft" start starters in large AC motors and tech. data was readily available. Not sure why the secrecy as it could easily be copied.

No, an autoformer isn't an all round cure but can be a life-saver if you do some energy management along with it as needed. Kills me when some people out there insist running 2 AC units on 30 amps is no problem and they have no idea what the voltage is or what they are doing to the AC units.