I don't have lots of experience with inverters.
I have a brand new Phoenix 12/1200 inverter that I am want to use as portable backup power source.
I tested the inverter using a curling iron; I measure this device with a KillAWatt at drawing around 2.5A on 120V - about 300W.
The Phoenix inverter goes into overload very quickly when I turn on the iron. On the Victron app (I have a VE.Direct adapter), I see the meter go up to about 700VA before overloading.
This is quite far from the 12/1200 rating: continuous 1000W and no where near the 2200 W peak.
I know about the de-rating with increased temperature, my garage is at 11 Celsius.
I also tested with my sump pump that draw close 500W with no problem. I cycle it couple of time without issue.
So I really don't understand why the relative small 3 amp load from the iron push the Phoenix into overload.