Solar Wiring Questions

[SirMarkofATX]

Strange. I uploaded an current version (VIAIR removed) in the original post: https://gdrvowners.com/forum/solar/1...8912#post18912

Howard

Howard,

I have noob questions for you or anyone on the forum that wants to advise. I am comparing "Hawsons Master Electrical Diagram" to my setup and am wondering if I have it right. The wires from my solar charge controller go to my "most" positive post on my 12 volt battery bank and the other goes to the trailer frame ground.

Your positive appears to go through a circuit breaker, then a fuse, then a disconnect switch, then to a power splitter (or distribution bar - not sure what it's called) and finally to the positive posts on the batteries.

First question: Am I safe just going straight from the charge controller to the positive post without any circuit breakers or fuses?

Second question: Your negative from the charge controller goes to the load post on the shunt and mine goes to the trailer frame ground. Am I messing up my readings on my BVM 712 Battery Monitor by going to the ground instead of the shunt?

I have zero electrical training or knowledge and am struggling up a steep learning curve with our new 310GK & factory Jaboni solar charging system.

Thank you in advance for your patience & advice,

Mark

[howson]

Mark,
I've moved your post to it's own thread so we don't intermix this conversation with the one ongoing in the "Cheap Solar" thread.

If you've read any of my posts you've probably already know my disclaimer but here it is again: I don't claim to be an expert--I'm still learning every day. There are many other, much more qualified individuals on this forum than myself. Hopefully they will chime in (like TucsonJim , Jkwilson , OffToHavasu ,etc).

With that out of the way, to your questions:

First question: Am I safe just going straight from the charge controller to the positive post without any circuit breakers or fuses?

Three reasons I suggest a circuit breaker between the positive and solar controller. 1) It provides a way to disconnect (turn off) the solar controller while leaving the rest of your system on without having to physically disconnect wires. 2) If something goes wrong, the weakest link in the system will be the first to go. Ideally, the circuit breaker will be that "weak link" so if there's ever an issue that drives the current to an unsafe level the circuit breaker opens. 3) Every circuit diagram you will find on AMSolar.com's DIY website will show a circuit breaker in that path. Those drawings were made by an electrical engineer. Below is a random example from https://drive.google.com/drive/folde...C1YbLzdNrrT32E that I clicked on and sure enough--there's a circuit breaker.

Second question: Your negative from the charge controller goes to the load post on the shunt and mine goes to the trailer frame ground. Am I messing up my readings on my BVM 712 Battery Monitor by going to the ground instead of the shunt?

Again, look at the example above. AMSolar shows the negative going directly to the shunt. Garret Towne (the engineer at AMSolar) makes it a point that all negatives must be connected to the shunt.

The trailer frame is connected to the battery negative, so assuming the trailer's ground goes through the shunt, power is (eventually) making it's way where it needs to go and is being counted by your BMV. If your trailer frame ground is connected directly to your battery, the BMV's shunt is NOT recording that current flow.

Another reason to not use the trailer frame is that it involves other connections and wiring that may introduce additional loss in your solar system. Ideally the wires coming from your solar controller to your battery (and shunt) are the largest copper strand wires your controller can utilize (and as short as possible).

I have zero electrical training or knowledge and am struggling up a steep learning curve with our new 310GK & factory Jaboni solar charging system.

Thank you in advance for your patience & advice,

Spend $15 and buy Will Prowse's book.


Everything in his book is available on his YouTube channel, website, or on other websites but I enjoyed sitting down in my recliner and being able to read (in a "real" book) all the different aspects associated with solar power.

I also recommend spending time going through Will's videos on Youtube. https://www.youtube.com/user/errolprowse/videos

Garret Towne's, too. https://www.youtube.com/channel/UCjs...nO47pAA/videos

Some of the info will actually conflict between the two sites--you'll discover that as you learn more about this subject!

I hope this helps.

Howard

[TucsonJim]

SirMarkofATX

Mark - You should always have some protection between the controller and the battery. You want a fuse to burn out or a circuit breaker to open if you ever get excessive current. If you don't have a fuse or a circuit breaker, the wire may become the failure point and cause a fire. I'm attaching a very simple diagram that shows where the fuses or breakers should be located.



As for my shunt. I ran one wire from my most negative battery terminal to the input on the shunt. On the other side of the shunt, I ran one wire to a terminal block and I make all my ground connection on the blocks. This ties all the grounds to a common point.

Jim

[OffToHavasu]

Generally, fuses have a tendency to blow quicker the a circuit breaker. Granted, you have to replace them vs reset, but they'll stop the bad stuff quicker.

[SirMarkofATX]

SirMarkofATX

Mark - You should always have some protection between the controller and the battery. You want a fuse to burn out or a circuit breaker to open if you ever get excessive current. If you don't have a fuse or a circuit breaker, the wire may become the failure point and cause a fire. I'm attaching a very simple diagram that shows where the fuses or breakers should be located.



As for my shunt. I ran one wire from my most negative battery terminal to the input on the shunt. On the other side of the shunt, I ran one wire to a terminal block and I make all my ground connection on the blocks. This ties all the grounds to a common point.

Jim

Jim,

Thank you for the diagram and the explanation. I was too hasty in posting the question. All I can see from the compartment where the batteries are is the last two feet of wire as it comes through the wall in a conduit. I need to trace the wire all of the way to the solar controller before jumping to any conclusions. It's a factory solar install so surely they included the proper fuses & circuit breakers? Investigating that is going to be a project for next weekend when I have the rig home from storage. I will keep you posted.

Mark

[SirMarkofATX]

Mark,
I've moved your post to it's own thread so we don't intermix this conversation with the one ongoing in the "Cheap Solar" thread.

If you've read any of my posts you've probably already know my disclaimer but here it is again: I don't claim to be an expert--I'm still learning every day. There are many other, much more qualified individuals on this forum than myself. Hopefully they will chime in (like TucsonJim , Jkwilson , OffToHavasu ,etc).

With that out of the way, to your questions:



Three reasons I suggest a circuit breaker between the positive and solar controller. 1) It provides a way to disconnect (turn off) the solar controller while leaving the rest of your system on without having to physically disconnect wires. 2) If something goes wrong, the weakest link in the system will be the first to go. Ideally, the circuit breaker will be that "weak link" so if there's ever an issue that drives the current to an unsafe level the circuit breaker opens. 3) Every circuit diagram you will find on AMSolar.com's DIY website will show a circuit breaker in that path. Those drawings were made by an electrical engineer. Below is a random example from https://drive.google.com/drive/folde...C1YbLzdNrrT32E that I clicked on and sure enough--there's a circuit breaker.





Again, look at the example above. AMSolar shows the negative going directly to the shunt. Garret Towne (the engineer at AMSolar) makes it a point that all negatives must be connected to the shunt.

The trailer frame is connected to the battery negative, so assuming the trailer's ground goes through the shunt, power is (eventually) making it's way where it needs to go and is being counted by your BMV. If your trailer frame ground is connected directly to your battery, the BMV's shunt is NOT recording that current flow.

Another reason to not use the trailer frame is that it involves other connections and wiring that may introduce additional loss in your solar system. Ideally the wires coming from your solar controller to your battery (and shunt) are the largest copper strand wires your controller can utilize (and as short as possible).



Spend $15 and buy Will Prowse's book.


Everything in his book is available on his YouTube channel, website, or on other websites but I enjoyed sitting down in my recliner and being able to read (in a "real" book) all the different aspects associated with solar power.

I also recommend spending time going through Will's videos on Youtube. https://www.youtube.com/user/errolprowse/videos

Garret Towne's, too. https://www.youtube.com/channel/UCjs...nO47pAA/videos

Some of the info will actually conflict between the two sites--you'll discover that as you learn more about this subject!

I hope this helps.

Howard

Howard,

Thank you for pointing me to these resources. I have ordered the book and watched a couple of Will's videos. He is a great presenter and is easy for me to understand. I can see where I will be learning a lot from him. I am planning to watch some of Garret Towne's videos this weekend and am looking forward to learning from him as well.

Mark

[SirMarkofATX]

Mark,
I've moved your post to it's own thread so we don't intermix this conversation with the one ongoing in the "Cheap Solar" thread.

If you've read any of my posts you've probably already know my disclaimer but here it is again: I don't claim to be an expert--I'm still learning every day. There are many other, much more qualified individuals on this forum than myself. Hopefully they will chime in (like TucsonJim , Jkwilson , OffToHavasu ,etc).

With that out of the way, to your questions:



Three reasons I suggest a circuit breaker between the positive and solar controller. 1) It provides a way to disconnect (turn off) the solar controller while leaving the rest of your system on without having to physically disconnect wires. 2) If something goes wrong, the weakest link in the system will be the first to go. Ideally, the circuit breaker will be that "weak link" so if there's ever an issue that drives the current to an unsafe level the circuit breaker opens. 3) Every circuit diagram you will find on AMSolar.com's DIY website will show a circuit breaker in that path. Those drawings were made by an electrical engineer. Below is a random example from https://drive.google.com/drive/folde...C1YbLzdNrrT32E that I clicked on and sure enough--there's a circuit breaker.





Again, look at the example above. AMSolar shows the negative going directly to the shunt. Garret Towne (the engineer at AMSolar) makes it a point that all negatives must be connected to the shunt.

The trailer frame is connected to the battery negative, so assuming the trailer's ground goes through the shunt, power is (eventually) making it's way where it needs to go and is being counted by your BMV. If your trailer frame ground is connected directly to your battery, the BMV's shunt is NOT recording that current flow.

Another reason to not use the trailer frame is that it involves other connections and wiring that may introduce additional loss in your solar system. Ideally the wires coming from your solar controller to your battery (and shunt) are the largest copper strand wires your controller can utilize (and as short as possible).



Spend $15 and buy Will Prowse's book.


Everything in his book is available on his YouTube channel, website, or on other websites but I enjoyed sitting down in my recliner and being able to read (in a "real" book) all the different aspects associated with solar power.

I also recommend spending time going through Will's videos on Youtube. https://www.youtube.com/user/errolprowse/videos

Garret Towne's, too. https://www.youtube.com/channel/UCjs...nO47pAA/videos

Some of the info will actually conflict between the two sites--you'll discover that as you learn more about this subject!

I hope this helps.

Howard

Howard,

I am trying to understand your statement "The trailer frame is connected to the battery negative, so assuming the trailer's ground goes through the shunt, power is (eventually) making it's way where it needs to go and is being counted by your BMV. If your trailer frame ground is connected directly to your battery, the BMV's shunt is NOT recording that current flow." so I went over to the storage lot last night and took these pictures of the wiring setup:


It looks like the battery negative is connected to the frame via the shunt because there is a wire from the load side of the shunt to the trailer frame. I believe therefore that the solar power (and the power from the other three wires on the frame ground) is being counted by the BVM. Is that correct? Would it be better for there only to be the one wire from the shunt to the trailer ground and the other four wires be attached to the shunt?

Mark

[315RLTSinPA]

Jim,

Thank you for the diagram and the explanation. I was too hasty in posting the question. All I can see from the compartment where the batteries are is the last two feet of wire as it comes through the wall in a conduit. I need to trace the wire all of the way to the solar controller before jumping to any conclusions. It's a factory solar install so surely they included the proper fuses & circuit breakers? Investigating that is going to be a project for next weekend when I have the rig home from storage. I will keep you posted.

Mark

Don't assume they included fuses with the factory install. Where circuit breakers come in handy, is if you need to disconnect the batteries for some reason. That way you can shut down power from the panels before shutting down power from the batteries. As in Renogy's instructions, always have battery power to the controller before applying power from the panels.

[howson]

...solar power (and the power from the other three wires on the frame ground) is being counted by the BVM. Is that correct? Would it be better for there only to be the one wire from the shunt to the trailer ground and the other four wires be attached to the shunt?

Mark,
From what I can see, the BMV is wired to account for the solar power.

Personally I would not have the solar controller output going to that trailer ground connection and the combining with all the other DC returns (on one wire) to the BMV.

The following is my opinion based on a lot of reading. I do not claim any special expertise. If someone else chimes in with a different perspective, please pay attention! (I learn from the folks here every day.)

OK , so my .02:

1) The battery negative from the solar controller should be wired directly to the load side of the shunt, not to trailer ground. The black wire from the controller (as well as the red, positive wire from the solar controller) should be the largest pure copper strand wire the controller can handle. I have 4ga with copper lugs connected to mine. Why? To minimize loss in the wiring. (See Will's video on the topic.)

2) The only returns on the trailer ground wire (from the screw to the load side of the shunt) should be what the OEM originally engineered it to carry. What does that mean? When your camper was new there was one wire that came off of the trailer frame that was connected to the battery negative. With the BMV, that wire moved from the battery negative to the load side of the shunt. On the "battery" side of the shunt a new wire should go and connect to the battery.

I hope that makes sense.

Bottom line: yes, what you have now is functional, but not (IMO) what it should be.

Howard

TucsonJim -- could really use some help here, Jim! Do you agree with what I've written?

[TucsonJim]

Mark,
From what I can see, the BMV is wired to account for the solar power.

Personally I would not have the solar controller output going to that trailer ground connection and the combining with all the other DC returns (on one wire) to the BMV.

The following is my opinion based on a lot of reading. I do not claim any special expertise. If someone else chimes in with a different perspective, please pay attention! (I learn from the folks here every day.)

OK , so my .02:

1) The battery negative from the solar controller should be wired directly to the load side of the shunt, not to trailer ground. The black wire from the controller (as well as the red, positive wire from the solar controller) should be the largest pure copper strand wire the controller can handle. I have 4ga with copper lugs connected to mine. Why? To minimize loss in the wiring. (See Will's video on the topic.)

Moving the controller ground wire to the load side of the shunt is okay, but not needed. On my rig, I set up a ground buss and all grounds are tied to it, including one to the frame and one to the shunt. This is working great for me.

As for the controller wire size. There are many charts that show the proper wire size based on the length of the run, the amount of current and the acceptable loss (in percentage). If you don't want to be concerned with interpreting these charts, you can't go wrong with using the largest wire size that will fit the controller.

2) The only returns on the trailer ground wire (from the screw to the load side of the shunt) should be what the OEM originally engineered it to carry. What does that mean? When your camper was new there was one wire that came off of the trailer frame that was connected to the battery negative. With the BMV, that wire moved from the battery negative to the load side of the shunt. On the "battery" side of the shunt a new wire should go and connect to the battery.

Exactly.

I hope that makes sense.

Bottom line: yes, what you have now is functional, but not (IMO) what it should be.

Howard

TucsonJim -- could really use some help here, Jim! Do you agree with what I've written?

Hi guys. I put my responses in "RED" above.

Jim

[SirMarkofATX]

Hi guys. I put my responses in "RED" above.

Jim

Thank you for the thoughtful feedback gentlemen. My plan going forward is to:
- Read the Mobile Solar Power book by William Prowse and watch the youtube videos that howson recommended.
- Trace each and every wire in my power setup and make a diagram so that I know and understand what I have.
- Add circuit breakers (and fuses if they are missing) as recommended by 315RLTSinPA.
- Verify the size & length of the controller wire size.
- Compare my wiring diagram to those provided by Howard and Jim to see if I want to add some additional fuses and circuit breakers to my system for safety and flexibility.
- I will probably add a ground bus per TucsonJim because, even if it is not required, it certainly appeals to my need for things to be neat and orderly
Stand by for more questions. As I get into this there will be more!

Mark

[TucsonJim]

Thank you for the thoughtful feedback gentlemen. My plan going forward is to:
- Read the Mobile Solar Power book by William Prowse and watch the youtube videos that howson recommended.
- Trace each and every wire in my power setup and make a diagram so that I know and understand what I have.
- Add circuit breakers (and fuses if they are missing) as recommended by 315RLTSinPA.
- Verify the size & length of the controller wire size.
- Compare my wiring diagram to those provided by Howard and Jim to see if I want to add some additional fuses and circuit breakers to my system for safety and flexibility.
- I will probably add a ground bus per TucsonJim because, even if it is not required, it certainly appeals to my need for things to be neat and orderly
Stand by for more questions. As I get into this there will be more!

Mark

Mark,

Here are a couple of photos of the buss bars I used for my +12V connections and my grounds. I purchased them on Amazon.





Jim

[SirMarkofATX]

Mark,

Here are a couple of photos of the buss bars I used for my +12V connections and my grounds. I purchased them on Amazon.





Jim

Jim, Yes! That is the way I want mine to look. It is easy to follow and understand. Everything is tied down and organized. There is a sense of pride in workmanship. You have set the bar pretty high but now I have a visual of where I am going with this project.

Best,

Mark

[Grammy&Grandad]

Thank you for the thoughtful feedback gentlemen. My plan going forward is to:
- Read the Mobile Solar Power book by William Prowse and watch the youtube videos that howson recommended.
- Trace each and every wire in my power setup and make a diagram so that I know and understand what I have.
- Add circuit breakers (and fuses if they are missing) as recommended by 315RLTSinPA.
- Verify the size & length of the controller wire size.
- Compare my wiring diagram to those provided by Howard and Jim to see if I want to add some additional fuses and circuit breakers to my system for safety and flexibility.
- I will probably add a ground bus per TucsonJim because, even if it is not required, it certainly appeals to my need for things to be neat and orderly
Stand by for more questions. As I get into this there will be more!

Mark

Mark - I know this was a post from a while back.
Cuirous to what you found. I have a 2021 380FL with factory solar. A truck wash employee recently stepped on and broke my panel MC4 connectors on the roof. Replacing connectors went fine. But now my Jaboni controller displays no input voltage from the panel. I've checked everything up top and panel is producing 37.4 v output that is not making it to the controller I guess. Jabioni customer service thinks I should check for any fuse that may have blown whenever the panel connections were severed. Did you find any factory installed fuse or circuit breaker between the roof and the controller? If so, do you recall what type? I want to be prepared when I open things up to look. Thanks for any help!

[howson]

Grammy&Grandad -- GD does not install a fuse or a shutoff between the roof connector and the wires going to the controller.

If you have a multimeter and know how to do a continuity test, that's where I suggest starting. If you need suggestions on how to accomplish the test, reply back and myself (or the many other very knowledgeable forum members) will be more than happy to explain.

Howard