Originally Posted by Robbbyr
You can accomplish your goal with a Progressive Industries Electrical Management System (EMS). They offer units that are hardwired and have a remote display that shows volts, amps, frequency, and any errors if there are any. But more importantly they protect your rig from those problems before something like low voltage burns up your AC compressor's motor. Compared to the cost of replacing fried components, cheap insurance IMHO.
I have their 50-amp version so I see the load and voltage on both legs.
+2 I have the 30A hard-wired system with remote display. It showed me this last weekend, that when the hot water tank is cold, it draws a lot of amps when 1st turned-on. Took my reading from 5A up to 28A, then dropped to 26A for another 30 seconds. Then over the next 5 minutes it dropped down to 17A. This is why my 30A breaker outside on the pole tripped, right after I turned on my water heater, then the AC.
So I used LP setting for the HW tank until the water got hot, so I could use the AC. Once the water was hot, I went back to electric setting. When both HW & AC were running, I would hit 30A, but the breaker didn't trip again.