Wiring Diagram Review

[Trebor English]

Just so I get this right...
It goes Battery -- Switch -- 20A Fuse -- Fuse Block
Any recommendations on a switch for my setup?

No, at the battery is where you want the fuse.  Anything between the battery and the fuse needs to be able to sustain the 1000 cranking amps the unfused battery can put out.  

Smaller fuses have more resistance, more voltage drop, than bigger fuses.  Use the biggest fuse that is safe for your wire.  Actually it isn't much difference but if it doesn't matter don't use wire so big.  According to wikipedia #6 wire is good for 55 to 75 amps depending on insulation temperature rating.  
https://en.m.wikipedia.org/wiki/American_wire_gauge  

Your fuse block may get more stuff added later.  A smaller fuse will need to be upgraded.

 

[dgshelto]

I'm ditching the switches, I didn't even think about pulling a fuse if I want to work on some part of the circuit. I want to keep this simple and not introduce potential faults by adding non-essential items. I replaced the 6AWG with 12AWG based on my loads + buffer + close proximity to the battery (at least that's what the Blue Seas chart recommends...).

If there is anything else that seems to be a major no-no let me know, otherwise the (attached) diagram is what I intend to go with. I tried to incorporate as many recommended changes as possible.

 

[Canine]

DC likes to arc. Pulling fuses for a 5 amp device is no big deal. Pulling a fuse on a 100 amp device while 100 amps is flowing through it will give you quite a spark.

 

[tx2sturgis]

That's a LOT of wiring coming to and from the battery.

You can simplify things by using the fusepanel as your central 'tie-point', instead of the battery terminals. Assuming that is a typical BlueSea fuse panel, it should be rated at least 100 amps.

Then you only need 4 conductors to the battery, (2 for the feed to the panel, 2 for the inverter, or none for the inverter and only 2 wires to the battery) and 2 (or 1) fuses near the battery, instead of the 7 or so plus 3 fuses that you now have, and you can use one of the fuses in the fusepanel as a 'feed' to the controller, assuming you have some extra positions. 

As has been stated, more stuff means more resistance, and more things to go wrong.

Other than the larger inverter, your planned system is quite similar to mine. 

Of course, if this causes a ripple in your plans and you prefer it complicated, then by golly, carry on!

 

[Canine]

I used this to minimize the number of leads on one terminal:

https://www.amazon.com/Blue-Sea-Sys...020&sr=8-4&keywords=blue+sea+system+fuse&th=1

Is there an ANL fuse block that has two fuses on it? Or maybe a T fuse that does the same thing as the link above?

 

[John61CT]

Just so I get this right...

It goes Battery -- Switch -- 20A Fuse -- Fuse Block

Any recommendations on a switch for my setup?

No Fuse is closest to the batt, ideally just a few inches. Sized for the wire, 20A seems very low to me.

Also protect the top of the batt from shorting.

Blue Sea simple ON/OFF

 

[dgshelto]

I used this to minimize the number of leads on one terminal:

https://www.amazon.com/Blue-Sea-Sys...020&sr=8-4&keywords=blue+sea+system+fuse&th=1

Is there an ANL fuse block that has two fuses on it? Or maybe a T fuse that does the same thing as the link above?

How does that work exactly? I assume it is mounted onto my positive battery post and the fuses inside the cases are sized to whatever I need and then I run my individual cables to them?

 

[tx2sturgis]

Just tossing a wrench in the machinery here....

I took your drawing and re-worked it a bit to show you how mine is wired.

Apologies in advance since I am less talented at computer imaging and PDFs.

The primary thing to notice is the fewer cables that tie in around the battery...this is always where I have issues with corrosion, loose cables after many miles, access to fill caps, working around all the connectors, etc, etc.

So, on my my current and previous two builds, I tied the solar controller into the fuse panel.

In some installations, we physically install the fuse panel somewhere in between the batteries and the controller...not always, but often. 

Think about routing cables directly from the controller down to the battery, OR... passing thru the fuse panel on the way to the battery.

Same thing, with fewer connections at the battery to deal with. 

I'm not presenting this as THE correct way for every installation, just an option for modest systems. 

 

[Trebor English]

I took your drawing and re-worked it a bit to show you how mine is wired.

Mine is arranged the same way.  My fuse sizes are different and there are several chassis minus connections but the plus wiring is the same.  

My battery is also the engine starter battery.  After subtracting all that van stuff what's left is the same.

 

[Weight]

The inverter is small enough to be wired through a blade fuse. But my objection would be that there are 8 connections on the positive inverter cable.
One at the battery, two on the inline fuse, one on the fuse block feed, two on the blade fuse, one at the fuse block inverter feed, one more at the inverter.
But, my refrigerator is wired similar to that with a MRBF on the battery terminal instead of a inline fuse.

 

[dgshelto]

I'll pick up one of those dual MRBF battery terminal fuse blocks, seems easier and a more system efficient choice than the 2 inline fuses I have for the inverter & CC. Anyone have a link to the fuses they accept?

Since I have multiple leads coming off the neg battery post is there something similar to the MRBF battery terminal fuse block to help organize my wires (obviously not fused)? Or should I not worry about it and leave it as it is?

 

[Canine]

I assume it is mounted onto my positive battery post and the fuses inside the cases are sized to whatever I need and then I run my individual cables to them?

Yes, exactly. Although, it will increase the height of your battery bank about 1 1/2 inches if the connections are flat and on top of the battery. It is rated for 300 amps. I put a 250 amp fuse on one terminal for my 3000 watt inverter. That is too small if I were to use the inverter at its 3000 watt capacity. Since I will never use that full capacity, I downsized the fuse to protect the fuses inside the inverter. Inverter fuses are harder to change, more expensive, and harder to find. For the other terminal I used a 100 amp fuse for the Blue Sea Systems fuse block. That means it has 350 amps of fuses on a 300 amp limit fuse block, so I had better not go over the rated limit of that dual fuse terminal.

 

[Weight]

First Rule. Fuses protect wire.
There are a number of places to buy those fuses. Here is one; https://baymarinesupply.com/wiring/fuses/blue-sea-mrbf-fuse.html
I used bus bars for both positive and negative connections to my battery. Like this or larger.; https://baymarinesupply.com/wiring/wire/bus-bar-4-stud-250-amp.html
Second Rule. Fuses add resistance.

 

[CoraDias]

Hi...i am a new user here. As per my experience you should have the switch between the charge controller and the battery. Because when disconnecting power the solar needs to be disconnected first. When the solar panels are disconnected, the charge controller will still be on because it has power from the battery.

 

[tx2sturgis]

As per my experience you should have the switch between the charge controller and the battery. Because when disconnecting power the solar needs to be disconnected first. When the solar panels are disconnected, the charge controller will still be on because it has power from the battery.

Maybe you meant to say there should be a switch between the PV panels and the controller?

:huh:

Otherwise, according to your statement, the switch getting flipped to 'OFF' does leave the solar connected.

All solar controllers are happy with battery power connected, with or without solar input.

 

[dgshelto]

Yes, exactly. Although, it will increase the height of your battery bank about 1 1/2 inches if the connections are flat and on top of the battery. It is rated for 300 amps. I put a 250 amp fuse on one terminal for my 3000 watt inverter. That is too small if I were to use the inverter at its 3000 watt capacity. Since I will never use that full capacity, I downsized the fuse to protect the fuses inside the inverter. Inverter fuses are harder to change, more expensive, and harder to find. For the other terminal I used a 100 amp fuse for the Blue Sea Systems fuse block. That means it has 350 amps of fuses on a 300 amp limit fuse block, so I had better not go over the rated limit of that dual fuse terminal.

What kind of fuses do these blocks take? Got a link?

 

[Canine]

What kind of fuses do these blocks take? Got a link?

Click on the link in post #45, scroll down to where it says, "Frequently bought together", and you will see a link for the fuses themselves. Remember to click on one of Bob's links before you do so he will benefit from the purchase at no cost to you. I have an Amazon link of his bookmarked for that purpose so I don't have to keep looking it up.

 

[Scout]

Just tossing a wrench in the machinery here....

I took your drawing and re-worked it a bit to show you how mine is wired.

Apologies in advance since I am less talented at computer imaging and PDFs.

The primary thing to notice is the fewer cables that tie in around the battery...this is always where I have issues with corrosion, loose cables after many miles, access to fill caps, working around all the connectors, etc, etc.

So, on my my current and previous two builds, I tied the solar controller into the fuse panel.

In some installations, we physically install the fuse panel somewhere in between the batteries and the controller...not always, but often. 

Think about routing cables directly from the controller down to the battery, OR... passing thru the fuse panel on the way to the battery.

Same thing, with fewer connections at the battery to deal with. 

I'm not presenting this as THE correct way for every installation, just an option for modest systems. 

I asked this before but it got deleted when the forum changed.

Could someone explain hooking the cc to the fuse panel?
Isn't there charging power from the solar  going one way and battery power running the controller going the other way? Is it whatever has the highest potential that determines which way the power flows? Im assuming it cant flow both ways at the same time. I guess it would work the same if hooked to the battery.
I hope my question makes sense. I'm trying to figure out how this works. It would help alot if i could do this with mine.

 

[Weight]

I recommend any charge sources, such as solar controller, be connected as directly as possible to the battery, both positive and negative. I use my first heavy bus bar. The solar doesn't produce all that much power that we can afford to lose any to voltage dropping resistance. There must be a fuse at the positive battery connection, or bus bar. Direct current flows from the highest voltage to the lower voltage. If the battery is 12.9 and the CC is 14V, there it is.

 

[John61CT]

Isn't there charging power from the solar  going one way and battery power running the controller going the other way? Is it whatever has the highest potential that determines which way the power flows? Im assuming it cant flow both ways at the same time.

You need to be clear what terminals you're talking about.

The battery charging output should go directly to the House battery bank, short thick wiring with a fuse at the bank.

If you mean Loads output with LVD protection, that can be input to a small distribution / CP box, but that is usually very limited in the current level, and doesn't always support all consumer device types.

The power needed to power the SC from the battery is miniscule, and once the panels come online their input will be much greater.

If the power being drawn from the Load terminals is greater than what is provided from the panels, then the bank is discharged to make up the difference.

Personally I hardly ever use the SC load terminals, power to the distribution boxes goes through a load buss fed directly from the bank.

The charge sources can be connected to a separate charge buss bar, but most people combine those.