EG4 18KPV - 5 Ton A/C

I wonder if a EG4 18 KPV can handle two (2) 5 Tons A/C. Both are identical and running wattage is around 4 KW in each case. rest of the loads are below 3 KW.

The whole system will be operating around 11+ KW.

It is a totally offgrid operation. My first choice was 2x EG4 6000 XP (easier to expand) but I want to consider a single 18 KPV with lot of batteries.

What’s the starting surge? Sounds marginal to me, inless they are inverter style

Soft starters should be installed on the A/C condensing units to limit inrush current. Micro-Air or HyperEngineering are 2 brands that have been discussed and recommended on the Forum. I believe Schneider has similar products.

An 18kpv will provide 12kW of inverter power, should have no problem running the A/C units with soft starters installed. Would recommend not to start up the units at exactly the same time.

I have an older 4-ton HVAC and even with an EasyStart 368 soft starter, the inrush current can be as high as 63A @240VAC. My Growatt 12k inverter can start it, but it is a low frequency model and has a large transformer. If you have other stuff running when your AC turns on, you might be limited on surge capacity with a single unit. Personally, I'd go with soft starters and three 6000XP for both redundancy and inrush capability. If you're not running AC, you don't need to have all 3 inverters operating...saving you some idle consumption.

Either would be a good option, but make sure both AC cannot try to start at the same time.
Easy Starts are well worth it on non inverter AC units, yours could already be inverter units as Europe is a mile ahead of the USA in this dept.

marmolf said:

I wonder if a EG4 18 KPV can handle two (2) 5 Tons A/C. Both are identical and running wattage is around 4 KW in each case. rest of the loads are below 3 KW.

The whole system will be operating around 11+ KW.

It is a totally offgrid operation. My first choice was 2x EG4 6000 XP (easier to expand) but I want to consider a single 18 KPV with lot of batteries.

Click to expand...

Being fully off-grid, I would lean towards the 6000XP rather than the 18kPV because it's more cost-effective for expansion and the full range of features offered by the 18kPV wouldn't be utilized in an off-grid setting. Additionally, I would take into account the recommendations in this thread.

I have and love my 18, but in your case, I'd go multiple 6000s. Like maybe 4 of them.

You would need some sort of controller to prevent both AC compressors from starting at the same time.
Even with soft start the Inverter will not handle both compressors starting at the same time.
If both AC units are needed to cool the house it is possible to just wire them both to one Thermostat and then run the 24V line to one of the contactor's through a Delay unit like the one linked below.
24V Delay Unit
This would guarantee that both compressors never start at the same time.
The down side is that the whole house is on one thermostat and one part of the house may not need cooling, so some power would be wasted.
Also it would be hard to maintain a perfectly even temperature throughout the house.

Even if both units have soft starts there are concerns if they start at the same time?

An AC unit takes a second to start, 86,400 seconds per 24 hours....you feeling lucky ?
A simple relay interlock on the thermostats would take care of this or wifi thermostats connected to Home Assistant.