Homebrew electrical layout and shopping list

[GreyDawg]

This is the umpteenth pass at my electrical layout for Ridley, a home-brew Transit. Time to go public for feedback.

Ridley is entirely 12V – no 110 V. Initially, the house batteries will be charged by an ACR. Later, if needed, I will add solar.

I am a total newbie at 12V but I have been reading forum posts and blogs until my eyes cross. I learned a lot from FarOutRide.

So …. deep breath …. here is my high-level layout.




Are there glaring errors of omission/commission?

Next step – assuming the layout is OK or close to OK – is to make an Amazon list.

For the on/off switches (Blue Sea Systems 350 Amp E-Series Battery Switches) do I need the simple on/off switch, or the switch with AFD (whatever that is?)

Blue Sea ACR: 7610 or 7611? And how about being able to jump the van battery from the house battery if needed .... is that just a frill?

Should I use on/off switches plus a fuse, or use a circuit breaker which could act as an on/off switch? I want to use whichever is safer, not cheaper or easier.

Are 150A bus bars sufficient?

How do I size the fuses (or circuit breakers) show in the diagram? For example, FarOutRide used a 40A fuse before their 12V fuse box so that they could use 10-14AWG wire rather than heavier wire to their various 12V loads.

And, in anticipation of a future solar system (that sounds so Neil DeGrasse Tyson), do y’all have advice on which battery monitor to select? Should I decide now about a particular brand/model of solar controller and match the monitor to it? Or does it really matter?

So many questions.... I apologize, but I suspect annoying y'all is better than electrocuting myself....

[Scalf77]

Looks pretty good from a starting point.

A couple of things, with a 230 Amp alternator go with Blue Sea 7622 , the 7610 & 7611 are rated for alternators up to 125 Amps.

Based on your drawing 150 amp bus bars would be OK, the question I have is do you plan on a shore charger and/or inverter/charger? Typically they one of the biggest current users.

I typically only use breakers where I expect the possibility of overloading.

As it stands cut off switch going to bus-bar cut-off to fuse panel would be redundant.

Fuse for fuse panel should be located close to the source, not the terminating point.

instead of going from ACR to Battery , I would go to the bus bar.



-greg

[larrie]

I agree with Greg’s comments. Along with taking the ACR to the bus bar the bar is also a good place to connect the solar input.

One thing you might consider is installing a set of Andersen Power Pole connectors at your batteries. Makes for an easy way to disconnect the batteries.

Be sure to have some spare circuit locations on the fuse box. I have found that there is always one more electrical load to add.

In our rig we used a Progressive Dynamics 120V to 12V converter so that we can plug into shore power at home to keep the batteries charged when not in use.

[GreyDawg]

Thanks! The comments make sense. I guess I am actually beginning to understand some of this stuff!

I will hire someone to do this high-zoot wiring (I will run the 12V loads from the from the 12V fuse box) but I want to understand, and I certainly want to make sure I get the right parts. The fellow I have lined up to do the wiring later this month has not yet offered to give me a parts list -- and he is pretty slammed with work so I better figure it out.

[Bbasso]

Self jump starting is not a frill.
When one of my starter batteries crapped out I was able to get started by pushing the button on my 7622 and get to work. After work I was had the battery replace under warranty.

[Scalf77]

Took the liberty to make some changes. Your expected loads (40 Amps) is pretty low. The 230 Amp Alternator does cause some issues, but going with larger wire to cover the alternator current (Max Rating) actually aids in emergency jump start conditions. So if you go with 1/0 gauge from battery to battery you kind of cover it all and have a good base. Obviously, you can choose to go a different gauge, just need to make sure that you keep your fusing in line with wire size.






If looking for good DC disconnects the Blue Sea M-series 6006, would be a good choice. If you wanted a Battery Disconnect switch put it between Class T fuse and busbar ( move power connection for 7622 and battery monitor to the bus bar (or bus bar side of switch) to eliminate any draw from those devices when switched off.



-greg

[GreyDawg]

Thanks. I had thought I was beginning to understand this topic but it will take me a while to study this updated diagram and understand it.

It looks like getting the Heavy Duty alternator and the dual van AGMs has opened up a can of worms that the regular alternator and single battery would not have opened.

[86Scotty]

Greg, I'm not sure if you know this about Transits but they are sold with CCP's (customer connection points) on the left of driver's seat (battery is under driver's seat) for people to add power accessories, inverters or the like. I actually bypassed mine but read up here on a post Graydawg made awhile back. It may clear up some things. If I'm thinking correctly she could easily just jump off a 60 amp fused CCP and skip the heavier wiring, T fuses, etc. just using about 4 or 6 gauge and an additional breaker for a disconnect. This would also make the 7610 a go saving a good bit of money.

This solves everything but the combine/jump start idea but couldn't that be more simply done with one of these snazzy new lithium battery jump starters? There are posts under the hood for jumping.

CCP questions and confusion - Page 2 - Ford Transit USA Forum

[GreyDawg]

Good point, Eric.

Yes, my van has 3 CCPs, each fused with 60amps, for the dual starter AGMs . It appears that, if one desires, they can be combined. This blog post (and the link to the discussion in the Ford Transit forum) gives a bit more information.

Or one can just connect to the batteries as Eric (and many others) did/do, bypassing the CCPs. (If you do a blow a CCP fuse, they are the very devil to replace).

Since I don't plan an inverter or any heavy draws (a 12V chest fridge, Maxxair roof fan, some LEDs, maybe a sink pump and/or stove ignition, and some charging points), perhaps scaling everything to 250A is not necessary.

Combine/jump start was just an idle thought a I read some of the ACR model descriptions ....definitely not a "must"

[Scalf77]

You are correct, I am not entirely up on the Transit.

You can certainly wire up a less robust system, and with your loads it would probably make sense. The size of your loads and battery capacity probably means that you will never see you use the full capacity of your alternator. Lowering the wire size capacity is an option, as long as you properly fuse for that wire size.

The alternator is capable of that output, but needs the applicable load to drive that output, so something has to go wrong (which fusing would protect) for your application to drive that output

I have yet to use my house battery to jump my starter in 14 years. I agree going robust to cover that option may not be a priority.

Going with 150 amp bus bars, and 2 gauge wire (150 amp fuse/breaker) would be still a very robust design. I believe your run from the starter to the house would be much shorter than in a an E-series.

Sorry, if I side tracked the discussion. My intent was to throw that out there to drive the discussion, there is no one correct answer.

-greg