I have a 48v Mecer 5kva inverter that has been connected up to solar panels. Up until recently I have not had the possibility of grid power.....but just now got it! So now I want to connect the house to grid power and use my solar system as a backup. My question.....can I connect the main grid utility directly to the inverter? I believe the answer is "yes." So, then my next question has to do with switching between grid power and solar. Is there an automatic transfer switch within the inverter that will take care of this? Final question.....if I connect up the grid power to the inverter, will it charge up my batteries to keep them topped up....thinking specifically for cloudy days and at night. Thanks!

10 hours ago, Stefan Kern said:

Up until recently I have not had the possibility of grid power.....but just now got it! So now I want to connect the house to grid power and use my solar system as a backup.

Heh. Many people that have had grid access all their lives want to get rid of it and go off-grid. It will be interesting to see how your view changes over the years, if at all.  Is grid power going to be affordable?

Also consider that you might want to set up your system to use the grid sparingly, basically mainly as a backup.

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My question.....can I connect the main grid utility directly to the inverter?

Yes. There is a set of terminals called "AC input". That's where you connect the grid to.

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So, then my next question has to do with switching between grid power and solar. Is there an automatic transfer switch within the inverter that will take care of this?

Yes, all Axperts have this built in. For a 5 kVA model, the current limit is 40 A. So if you acquire some very heavy loads (large air conditioner, large geyser, stove/oven) these might have to connect directly to the grid, not the AC-out of the inverter. So in the event of a blackout, you won't be able to use those appliances.

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Final question.....if I connect up the grid power to the inverter, will it charge up my batteries to keep them topped up....thinking specifically for cloudy days and at night.

Yes, you can set up the maximum utility charge current, and you can set it up to charge from the grid if needed and available, or from solar alone. I have mine set up so that it only ever charges from the grid between 10pm and 7am. I use a small computer to send commands to do this.

Edited December 4, 20195 yr by Coulomb

Brilliant! Thanks so much for the responses. Is there a way to set up the grid/solar charging times on the inverter itself or does it need to be done through a computer?

 

11 hours ago, Stefan Kern said:

Is there a way to set up the grid/solar charging times on the inverter itself or does it need to be done through a computer?

To absolutely forbid grid charging at certain times requires a computer. However, you can set it up so that most of the time solar power will charge the battery, and grid power will only be used when needed. Basically, put sensible values into settings 12 and 13 (back to grid and back to battery settings, respectively). Any time that an Axpert MKS inverter-charger is in battery mode, it can't charge from the grid, so keep it in battery mode by charging the battery from solar. When there isn't enough solar power, then the inverter-charger will go to line mode, powering the loads from the grid, and charging the battery from whatever solar power there is plus grid charging (at the rate set by setting 11, Maximum Utility Charging Current).

Edited December 4, 20195 yr by Coulomb

To my knowledge when I used this type of inverter.

There is one drawback when switching from pv to mains and vice versa that is not seamless (there are small delays when switching) with this mercer (axpert) 5kva.