Automatic switching between incoming AC Mains and DC Solar power

[digimart]

My solar-inverter has an in-built AC battery charger ( 220V, 50Hz) as well. Specs of Inverter are 2000 Watts, 48vDC.
I have installed Panels of 1200Watts @ 48VDC

During day-time, some days are such that my power consumption compared to Solar Energy being made is low, and my batteries are charged in full.

But at other days, my power consumption is more than Solar Energy being produced, and it drains the battery bank bit by bit. In such situation, I manually switch ON the in-built AC Mains battery charger of the inverter, to charge the batteries using AC Mains supply, till they reach at 52VDC. At that point I manually Switch OFF the AC Mains battery charger of the inverter.

Please comment on the following idea / solution for automatic switching On/ Off for the AC battery charger of Inverter :

If I install a Relay switch so that in case the battery bank voltage drops to 48VDC, the switch should start the AC battery charger on the inverter, and once the battery bank voltage reaches 52VDC , it should cut the AC mains. In this way I be able to use Solar for maximum possible time, and be able to have minimum possible use of AC Mains.

Is the above possible or not through use of a Relay Switch ? If yes, what type and specs of a Relay Switch would I be needing ?

Regards.

Omar

 

[Worcester]

Yes it's possible.

You need a simple control circuit that monitors voltage and triggers a relay on and off.

If you're handy with a soldering iron and a little bit of programming you could do that with a an arduino - check out Jeelabs (JeeLabs . net and The JeeLabs Shop - Welcome ) also you'll get a bunch of help here: Home | OpenEnergyMonitor with the code and design.

 

[digimart]

Unfortunately, I am not very technical in these circuits etc.
Am hoping to find something off the shelf

 

[Worcester]

Unfortunately, I am not very technical in these circuits etc.
Am hoping to find something off the shelf

In which case check these out : Morningstar Charge Controllers | Wind & Sun Ltd. Charge Controllers and Relay Driver

From the relay driver data sheet:
"In this application, the Relay Driver is used to send voltage alarms to a communications device provided by the user at the site. It also will monitor battery voltage and start a generator wh enever there is insufficient solar charging from the PV array. "