Charger and Inverter loop?

[Zilcho]

Hey all I was wondering if someone might be able to help me out. I'm currently planning out the wiring for my camper conversion but I've run into a problem, when running on batteries with the inverter switched on a loop would be made as the charger is coming off the consumer unit which would charge the batteries which would feed the inverter which would then feed the consumer unit.

I only need the charger on when hooked up to mains and the inverter on when not so any ideas on a best solution? I was thinking a separate RCBO for the charger straight off the mains instead of through the consumer unit maybe.

Here's a quick simple pic to show the problem. View attachment 22334

Thanks a lot,
Mark

 

[funkyronster]

poss solution

I think I know what you mean…..you don't want your inverter in the loop when hooked up - neither do you want your inverter converting 12v to 220v feeding your batt charger and back to 12v!! aarrgghh!

Basically I use a mains operated multi-pole relay. In it's default position - ie not actuated, it is in "off grid mode" ie no hook up. The output from the inverter goes to the consumer unit and to the van. But the battery charger is connected to the hookup BEFORE the consumer unit.

When hookup mains is connected, the relay actuates, the battery charger starts working, and the mains is switched to the consumer unit.

So basically you have a relay that switches either the inverter or the hookup to the CU and thus the van…..and the relay is actuated by the hookup voltage. But you wire the charger directly to the hookup before the relay.

Now in my setup - when i'm hooked up, my inverter is still switched on - but it's 220v is going nowhere - because the relay is actuated. So it's just switched on doing nothing. Some inverters have control lines - mine doesn't.

It sounds complicated but it isn't - all vans have to have a circuit design that prevents this loop. A relay is the answer!

I don't have the software handy to draw you a diag - but if you need one I'll do it on paper and photo it…..

 

[Zilcho]

Thanks

Hey funkyronster sorry for the delayed response only just got back to sorting the electrics out, yea I think a relay would be the way to go with the charger wired on the mains intake before it. Thanks for the help.

 

[Teutone]

why don't you just switch the inverter off when on EHU? You won't need it anyway. I only switch the inverter on when I need it, it doesn't run constantly. Even without anything plugged in with 240V, you still use 12V and drain the battery for no reason with the inverter running idle.