Mind's exploding, would love some help!

[mikexavier]

Hey all, I've been at this for a while now... I have no background in electrics so it's a bit of a mind-bending exercise for me. Here's where I'm at so far (attached PDF). I'd love some general feedback on this system for an RV/Campervan if it all looks "correct", safe, efficient etc.

I'm stuck on wire size/fuse sizes and locations and if I need a relay between the BMS and Battery protect - I had seen one of Will's videos where he mentions using a relay with a 24-12v transformer but not sure if I need to use one or not.

Thanks for the help, really appreciate it!

Mike

 

[Picasso]

attach the img can't read text on your post , might want to mark it as an RV/camper I was looking at the Driving try to work out what that was. Most call that the starting and the other house bank.

 

[mikexavier]

attach the img can't read text on your post , might want to mark it as an RV/camper I was looking at the Driving try to work out what that was. Most call that the starting and the other house bank.

Thanks, @Picasso I've updated the image and attached it as a PDF.

 

[SCClockDr]

@mikexavier
Is it your intention to NOT measure your inverter draw? It needs to connect on the ground end of the shunt vs three battery end if you wish to monitor its draw.

 

[mikexavier]

No, that wasn't my intention... thanks for letting me know! I've updated the schematic, does that look right to you now? Thanks @SCClockDr

 

[SCClockDr]

EDIT: Dup post.

 

[SCClockDr]

Two more things.
On your SCC's the PV wires appear reversed. Pos going in to Neg on both & the battery wires need to move left one terminal.

 

[mikexavier]

Like so? I checked the user manual on the Tracer BN SCC and it looks like it goes +- +- +- as you mentioned in the previous comment.

 

[SCClockDr]

Looks good to me. You might want to use orange (L) & gray (N) for clarity.

 

[mikexavier]

Great, thank you, and you don't feel there need to be any additional fuses? I still need to work out some of the wire sizes as well but I think there are some good online calculators for that kind of thing.

 

[mikexavier]

Do I need to have a 230v battery charger from the Automatic Transfer Switch (shore power)? Right now, I have it going directly into the battery bank, which doesn't seem right to me that a normal household power (230v in Switzerland) would go directly into a 12v battery bank? or is that fine?

 

[SCClockDr]

Based on version 3 your 230V goes to the inverter. I therefore presumed it was an inverter/charger. It now dawns on me the inclusion of a dedicated transfer switch might render my presumption in error. If you indeed need a converter/charger it needs to be separate from the inverter 230V output as that would create a loop.

 

[mikexavier]

The ATS has outputs for "output", "inverter" & "battery", and that gives me another confusion point. Are the provided for you to choose which is the best way to go in your system, or so that it can monitor/manage where the power should be directed and all should be connected?

 

[SCClockDr]

You have manual for the transfer switch?

 

[mikexavier]

Not yet, and I can't find one online. I should have the unit in about a week. I've attached the only wiring diagram I could find for this particular ATS. It seems to me that it will detect which needs power and adjust accordingly?

 

[SCClockDr]

I believe the battery DC terminals on the ATS are for contactor control & internal power.

 

[mikexavier]

ok, so then I'd need to figure out how to power the 12v items in the van (when connected to shore power), if the other cables are running 230v to the inverter and 230v appliances.

 

[SCClockDr]

That would be your 12v fuse block near the top middle.

 

[mikexavier]

Which is run from the 12v battery bank, so when on grid power how would it receive power unless I was sending power from the ATS to the battery?

 

[SCClockDr]

In order to charge the battery from the grid/generator, you need a device that converts grid power to battery charging voltage. Some inverters do this as well as invert DC to AC, they usually have their own ATS. If your inverter lacks the charge function then a converter/charger is needed to convert grid power to battery charging voltage. I'd look for a unit capable of multiple battery profiles.