I found two great deals, Sunny Island 6000 W and a Magnum 4400 W, can't decide !

Solarbaby

Hello everyone, same old question : )   

Wich inverter should I chose ?

Awesome deal on the SMA, but it's 120 V only so I need to purchase an autotransformer to power 240 loads and there is not much info on forums and youtube about this inverter. Huge surge rating and reliability seems extreme.

The Magnum is 120/240 V but can I use the full power on one line only to power one big load (mortar mixer) or would I need an autoformer anyway to balance loads ?

Also, I have seen many issues recently about temperature sensors ans control failure in the Magnum MS4448-¨PAE.

Any moral/tech/philosophical input highly appreciated.

softdown

I'd go for the 120/240 myself. I could use 240 volts, I never need over 3000 watts. A large well pump can have huge surge demands but they are 240 volt.

Smaller inverter should use less power when idling. Pretty universal rule - much like larger car engines.

My next system will be 1500 watt inverter unless the well is too deep. Using 3648 watts now - it uses too much energy for my needs unless the well pump is running - I think.

mike95490

Well engineered inverters use little power when idling.  (XW series =23W for a 6.8kw inverter)

Look for the Load Imbalance spec to see what your inverter choices can stand

Autotransformers, if you want them to manage a surge load, need to be sized to the surge.  Once the core of a 3kva transformer is saturated, it can't pass any surge current, so you may need the 240V inverter and use a smaller autotransformer to provide balance.