I've got a Truma Aventa Comfort aircon on my van with the specs in the picture.
I'm looking at getting a Victron 12/1200 Pheonix inverter.
Am i correct in my calculations that the power draw is 'power consumption 4.2amp X 240v = 1008W'
Am i correct that the listed 2400w rating is the refrigeration power, not the power consumption.
Being that the 1008w draw is under 1200w capacity, would you think the 12/1200 Pheonix will run the airconditioner?
Hi @Rb20tez,
It is really hard to say how an inverter will handle an air conditioner load.
The best way is to find someone that has the exact combination.
You're correct the heating and cooling energy rating is higher than the electrical energy rating.
However there is another factor that needs to be considered here, that start up current surge which is listed as 28A - 6400 W !
This high start up current surge is common for Inductive loads that typically include motors, such as pumps, drills, and saws, as well as compressors used in refrigeration and air conditioning.
Inductive loads have two qualities that need consideration in off-grid design:
1. Inductive loads have a reactive power factor. This means the peak of the voltage and the peak of the current are not perfectly in alignment on the AC sine wave. The consequence of this is that the 'rated' power on the tool is not the complete picture when sizing.
2. Inductive loads typically have a surge on startup. The amount of surge varies between appliances. Some inductive loads such as fridges and modern air conditioners now use an 'inverter compressor' design that almost entirely eliminates this surge component.
If you are finding that the surge from inductive loads (like a non-inverter air conditioner) is overloading the inverter, a solution might be to retrofit a ‘soft start’ accessory - https://community.victronenergy.com/questions/133369/use-of-soft-starter-with-multiplus-and-ac-motor.html
https://community.victronenergy.com/questions/83505/easy-start-compatibility-issues-with-victron-inver.html
I believe the air-conditioner has a soft start function in it because that 28A you mentioned is only for 150milliseconds. Would that mean it is a soft start?
It's so hard to tell how it will all interact before you actually do it.
I don't think 28A startup current is a soft start though.
I would continue asking your Victron dealer, other online groups, and even the air con supplier if they have direct personal experience with how the two models interact. My gut feeling is that model inverter will be too small.
