Grid tie and battery together

[SunEagle]

Arc flash.jpg

Yep. I have been there and witnessed that type of arc flash. Although it was 480v AC.

I have also seen smaller devices arc on DC voltages or Hi Voltage AC (138kv) in a substation. All of them are pretty but none are safe.

[Tired sparky]

Ampster, yes it has islanding protection. I tested this by switching off the mains to inverter fused spur unit and the inverter shuts down. It also has a nifty feature where you put a sensor on the incoming mains Live cable and it knows how much power you are drawing from the mains. It then will only let up to that amount of power into the house mains from the panels!! It’s so you don’t go exporting any extra back into the grid and giving the power company free electricity.

[jturner777]

From an experienced electronics technician, your relay is fine for your application. I would suggest you perform 2 items to increase the longevity of contacts though.
1) Parallel connect the 2 "gangs" of contacts so that the current is shared between the 2 contacts. Thus you have 80 amps capacity instead of 40 amps. And only 8 amps thru each contact instead of 16 amps thru one contact.
2) Connect a .1 mfd to .5 mfd 50 VDC capacitor across the paralleled contacts. This will greatly reduce the spark when then contacts open or close and increase contact life. Think of your old cars points and capacitor ignition system. Good luck!