The only "Thihg" with using a 50 amp Energy Monitor (Surge Protector) on a 30 amp circuit is this.
The unit has many functions.... ONE of them is spike supression.. And a 50 amp unit is like 5 times better at that than a 30 amp unit
So not only will it work, just fine, It will work BETTER.. Just be sure to feed it with a good dogbone.
The only concern.. If you use the unit's built in ammeter to monitor (Personally) how much power you draw.. On 30 amp you need to add L-1 and L-2, on 50 maps you consider them separately.
Example on 30 ampl. readings of say 10 and 15 mean you are drawing 25 amps total (you only have one A/C on )
On 50 readings of 10 and 25 mean "Imbalance exists" (Of course if you turn on the other A/C you may see closer to 23/25 which is "Close enough to call it balanced"
