Feedback Requested from the Electrical Gurus - Ford Transit USA Forum
 10Likes
Reply
 
Thread Tools
post #1 of 24 (permalink) Old 05-17-2017, 04:09:PM Thread Starter
Junior Member
 
Join Date: Mar 2017
Location: Southern California
Posts: 26
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Feedback Requested from the Electrical Gurus

Hi all,

Been working on my build, and am ready to start installing electrical. I am a complete novice in this department, but have put together this draft schematic based on all of the research I have done so far. Was hoping a few of the more experienced electrical folk here might be able to provide some feedback.

Here is a general overview of my thought process on this design:
1. I wanted to keep it as simple and cost-effective as possible. This will be an all DC system. The occasional AC needs (some computer charging and maybe charging tool batteries) would be serviced by plugging a small inverter (300-400W) into one of the 12V DC outlets.

2. No plans to spend a lot of time at campgrounds. So the only two charging sources are solar and alternator (no shore power hookup).

3. I understand that deep cycle lead acid batteries prefer a multi-phase charge profile. I plan to do this with a proper solar charge controller. The auxiliary/backup charging source will be the van alternator via ACR. I understand this isn't optimum for battery health long term, but I figure if I need it in a pinch to get me up to 80% SOC, I can generally get the rest of the way when the sun is out.

4. I did my best to estimate wire gauge and fuse sizes based on load, but ultimately some of that may change as I get a better idea of the true length of the wire runs and circuits. But for now, they are sized relative to the max charging input or load draw.

5. For reference, I have the single, flooded starter battery, not the double AGM pack. System is designed with that limitation in mind.

I think that's all for now. Really appreciate anyone who has a chance to look and give their thoughts.

-Andrew
Attached Files
File Type: pdf Electrical Diagram_Draft#1.pdf (365.8 KB, 57 views)
70sqftToFreedom is offline  
Sponsored Links
Advertisement
 
post #2 of 24 (permalink) Old 05-17-2017, 09:02:PM
Senior Member
 
oscarvan's Avatar
 
Join Date: Nov 2016
Location: Eastern PA, USA
Posts: 300
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 72 Post(s)
Looks pretty good. I'll answer one question:

Yes, a large fuse in the cable between the battery and the bus bar, as close to the battery as possible.

I would also put a disconnect in the feed from the solar panels..... Just so you can shut them off in case the controller goes nuts.

Based on your loads your wire gauges look pretty reasonable.

Someone will correct me......soon.
70sqftToFreedom likes this.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
oscarvan is offline  
post #3 of 24 (permalink) Old 05-17-2017, 09:45:PM
Senior Member
 
Join Date: Jan 2014
Location: Occidental, Ca.
Posts: 3,082
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 1112 Post(s)
I used a Blue Sea circuit breaker between the positive bus and the fuse block. Protection and a switch in one unit.
70sqftToFreedom likes this.

2015 high roof 148" WB 3.5 Ecoboost 3.31 LS rear cargo.
orton is online now  
 
post #4 of 24 (permalink) Old 05-17-2017, 09:53:PM Thread Starter
Junior Member
 
Join Date: Mar 2017
Location: Southern California
Posts: 26
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Quote:
Originally Posted by oscarvan View Post
Looks pretty good. I'll answer one question:

Yes, a large fuse in the cable between the battery and the bus bar, as close to the battery as possible.

I would also put a disconnect in the feed from the solar panels..... Just so you can shut them off in case the controller goes nuts.

Based on your loads your wire gauges look pretty reasonable.

Someone will correct me......soon.
Thanks Oscar. For the disconnect, assume your mean between the solar panels and the solar controller?
70sqftToFreedom is offline  
post #5 of 24 (permalink) Old 05-17-2017, 09:54:PM Thread Starter
Junior Member
 
Join Date: Mar 2017
Location: Southern California
Posts: 26
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Quote:
Originally Posted by orton View Post
I used a Blue Sea circuit breaker between the positive bus and the fuse block. Protection and a switch in one unit.
Thanks Dave. Regarding circuit breakers vs fuses, are there any downsides to breakers? (Other than cost)?
70sqftToFreedom is offline  
post #6 of 24 (permalink) Old 05-17-2017, 10:47:PM
Senior Member
 
Join Date: Jan 2014
Location: Occidental, Ca.
Posts: 3,082
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 1112 Post(s)
Quote:
Originally Posted by 70sqftToFreedom View Post
Thanks Dave. Regarding circuit breakers vs fuses, are there any downsides to breakers? (Other than cost)?
Cost difference is minor. I have read that a fuse will trip faster than a CB. A CB is reusable.

I also used a CB between the panel and the MPPT controller.
70sqftToFreedom likes this.

2015 high roof 148" WB 3.5 Ecoboost 3.31 LS rear cargo.
orton is online now  
post #7 of 24 (permalink) Old 05-17-2017, 11:54:PM
Senior Member
 
Join Date: Apr 2016
Location: mississippi
Posts: 1,194
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 337 Post(s)
evidently some of the DC breakers only work right when they are wall mounted, and do not work when they are floor mounted! (i have a 700 dollar mini-magnum distribution panel that is used with Magnum Dimensions inverters, that has a 250 amp DC breaker that only works when mounted vertically!)
no worries, i have a used $3,000 Square-D 3 pole 250 amp DC circuit breaker that will operate upsidedown if i wanted to mount it that way.
do not let the high DC breaker prices scare you, these are for special use or industrial applications. there are many lower cost DC breakers, just read the instructions/specifications for recommended mountings!
70sqftToFreedom likes this.

2016 transit cargo 250 MR, LWB, 3.5 eco, 3.31 limited slip

Last edited by Michael Ophus; 05-18-2017 at 12:04:AM.
Michael Ophus is online now  
post #8 of 24 (permalink) Old 05-18-2017, 12:59:AM
Senior Member
 
Hein's Avatar
 
Join Date: Nov 2014
Location: PacNW
Posts: 438
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 174 Post(s)
Have you considered a shunt based state-of-charge meter? Or at least a Ctek battery sense so you can track the condition of your batteries?

You do need another 50A fuse on the house side of your ACR connection. I would consider 4 gauge on those runs to reduce voltage drop while charging from alternator. Especially if the runs are long. (where are your batteries relative to the CCP.)

You also need a large main fuse/breaker on the house bank as mentioned. Remember that fuses/breakers protect the wire/cable so main ones should be close to each voltage source. Using a 50-60 A breaker at your CCP will combine protection and disconnect in one device.

I bypassed the OEM 60A CCP fuse because it is very difficult to service. When it blows you won't get any charge from the alternator just when you need it most. (when house bank is down) To replace it safely you need to disconnect the chassis battery or risk shorting the tools you are using to remove the fuse. Not something I would want to do out on a trip.

House to chassis ground should be as large as the cable going to the positive buss so more 2 gauge as you have it shown. You don't have any large loads (any plans for inverter? if so, how big?) so the largest current will likely be when you are charging off the alternator when the house batteries are down. You have limited that to 50A with your breaker but you could have some peaks higher than that. Common DC thermal breakers need some time to heat up before they trip so not as quick as an automotive fast blow fuse. So current peaks could blow the CCP fuse before the 50A breaker trips.
70sqftToFreedom likes this.

Last edited by Hein; 05-18-2017 at 01:15:AM.
Hein is online now  
post #9 of 24 (permalink) Old 05-18-2017, 06:52:AM
Member
 
Join Date: Mar 2017
Location: in the moment
Posts: 41
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Hello,

Is it possible, and/or practical to bring AC off an alternator and rectify it locally at the house battery bank with the goal of reducing cable mass requirements?

Thank you.
mister T is online now  
post #10 of 24 (permalink) Old 05-18-2017, 09:37:AM Thread Starter
Junior Member
 
Join Date: Mar 2017
Location: Southern California
Posts: 26
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Quote:
Originally Posted by Hein View Post
Have you considered a shunt based state-of-charge meter? Or at least a Ctek battery sense so you can track the condition of your batteries?
I would love to have one of these. The solar chargers I am considering seem to have some degree of "system monitoring" included, although I'm not sure how accurate they are. For a system/SOC monitor, would that mean installing a shunt in between the house battery negative and the negative bus bar, and then wiring the battery meter to the battery and both charging sources? I know each model is slightly different, but that's my general understanding of how they work.

Quote:
Originally Posted by Hein View Post
You do need another 50A fuse on the house side of your ACR connection. I would consider 4 gauge on those runs to reduce voltage drop while charging from alternator. Especially if the runs are long. (where are your batteries relative to the CCP.)
Should that fuse go before or after the positive bus? I know it should be as close as possible to the battery, so should it actually go between the positive bus and the house battery positive terminal?

I haven't made a final decision on the battery location. It looks like at 50A, 6AWG has me covered up to 15 feet. If I end up approaching that length, I will probably just go to 4 gauge.

Quote:
Originally Posted by Hein View Post
You also need a large main fuse/breaker on the house bank as mentioned. Remember that fuses/breakers protect the wire/cable so main ones should be close to each voltage source. Using a 50-60 A breaker at your CCP will combine protection and disconnect in one device.

I bypassed the OEM 60A CCP fuse because it is very difficult to service. When it blows you won't get any charge from the alternator just when you need it most. (when house bank is down) To replace it safely you need to disconnect the chassis battery or risk shorting the tools you are using to remove the fuse. Not something I would want to do out on a trip.
When you say "main" fuse/breaker on the house bank, which side? Or is this just the additional 50A fuse you mentioned above that was missing from the charging side of the house bank?

I agree with you on bypassing the CCP fuse. I installed the upgraded CCP so I would have the three fused 60A terminals; what a nightmare! Never want to have to go in there again! I figured having the three gives me the ability to just switch over to another one if the fuse blows, but I can only do that twice. I will install a 50A fuse or breaker between the CCP and the ACR.

Assuming this protection should be as close to the CCP as possible?

Quote:
Originally Posted by Hein View Post
House to chassis ground should be as large as the cable going to the positive buss so more 2 gauge as you have it shown.
That actually raises another question. I selected 2 gauge to connect the two batteries in parallel, thinking that should be enough to handle any current moving between them. But I wasn't sure if that size was needed to connect the charging sources to the battery. Since those are already fused upstream at a max of 60A, would 4 or 6 gauge be sufficient to connect the positive bus to the house batteries? (and also from the house batteries to the chassis ground?)

Quote:
Originally Posted by Hein View Post
You don't have any large loads (any plans for inverter? if so, how big?) so the largest current will likely be when you are charging off the alternator when the house batteries are down. You have limited that to 50A with your breaker but you could have some peaks higher than that. Common DC thermal breakers need some time to heat up before they trip so not as quick as an automotive fast blow fuse. So current peaks could blow the CCP fuse before the 50A breaker trips.
If I use an inverter, it would probably be no larger than 400W. So the loads would be relatively small. If I'm thinking about this right, a 50A circuit at 12V should be able to safely handle 600W, right? So 400W (with some room for surges) may be ok without risking blowing the fuse?

That's good to know about the difference between breakers and fuses. It seems that a fuse may be a better option for protecting the CCP if my goal is to avoid ever having to take that **** fusebox apart again. I can still get a separate disconnect switch.
70sqftToFreedom is offline  
Reply

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



  Similar Threads
Thread Thread Starter Forum Replies Last Post
Need advice from electrical gurus... BabyBuffy Electronics, Audio, and Lighting 8 05-06-2017 02:38:PM
Feedback On Electrical Plan mrgf Camper Vans and Conversions 32 04-22-2017 07:34:PM
Wood Floor Feedback morey Camper Vans and Conversions 63 02-07-2017 01:44:AM
Bed Platform Feedback Request morey Camper Vans and Conversions 33 11-04-2016 09:25:PM
Pic's requested USMC Vet Off Topic 14 04-24-2015 09:20:PM

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off