DC Primary System Upgrade

[Ward H]

With the help of many on the forum I've pretty much settled on my 93 C30 primary DC system upgrade.
I was planning on doing it in stages, keeping cost down as much as possible. The more I looked at it the more I realized that doing the complete upgrade now would be much simpler.

My upgrades include:
GC2 6v 230Ah house bank. Grp 24 aux bank.
Replace all 4 Ga SAE wire with 1/0 AWG wire. Crimp my own connections.
New 30A charger,
SI 120A ACR
90A alternator ( I just couldn't put that rusty old 50A back in after these upgrades)
Positive and Negative Bus Bars
Proper battery, charger, ACR and alternator fusing.
I will follow Maine Sail's suggested best practices for wiring runs and connections where ever possible.

I've studied many other's diagrams, have read many threads and Maine's articles. Parts are arriving and I have a plan.

Many thinks to Maine Sail for his detailed posts. He also spent some time with me on the phone explaining some things that were easier talking rather than writing about.
I've sourced my alternator, charger, ACR, MRBF terminals w/ fuses and wire from Maine.

I'm starting next week. Timing is good as my wife will be thoroughly consumed by the winter olympics and won't miss me a bit.

The fist pic is of the original wiring layout. The second is my plan for the upgrade.

 

[jssailem]

Nice post @Ward H. Like that you bit the bullet and went for the 90A alternator. That will serve you well. You’ll have many days and nights out on the water.

Might as well put the down time to good purpose while the weather works towards spring. Besides even in the cold, time on the boat is better than sitting at a computer or in front of the TV.

 

[LeslieTroyer]

100A fuses for charger and always on, both on 6ga wire seems high. Think about using 60A - size the fuse for the wire used.

Other than that look at Main’s 1,2 Both + switch wiring method. One additional switch a a small bit of wire for more flexibility

Be sure a post pictures when done.

Mahalo

 

[Ward H]

100A fuses for charger and always on, both on 6ga wire seems high. Think about using 60A - size the fuse for the wire used.

Other than that look at Main’s 1,2 Both + switch wiring method. One additional switch a a small bit of wire for more flexibility

Les,
Ampacity for 6 AWG is 120A. (using genuinedealz.com chart) Per Maine, he likes to fuse to about 80% of ampacity. That would be 96A.
I think I am using Maine's battery use switch method. I also have the alternator disconnect, a mSeries On/Off battery switch, shown.
Not sure what I am missing. Can you elaborate?

Might as well put the down time to good purpose while the weather works towards spring. Besides even in the cold, time on the boat is better than sitting at a computer or in front of the TV.

Nothing beats messing about with old boats. And I got the message when my wife asked when i was going to start on the project. I said it was a bit cold to start now. She went shopping and came back with a small electric heater.

 

[SG]

Why only a 30 Amp charger?

I'd go much larger?

 

[marchem]

100A fuses for charger and always on, both on 6ga wire seems high. Think about using 60A - size the fuse for the wire used.

Other than that look at Main’s 1,2 Both + switch wiring method. One additional switch a a small bit of wire for more flexibility

Be sure a post pictures when done.

Mahalo

I agree with Leslie about the isolated starting system (and am doing the same thing with our Catalina 310 starting today): Run the wire from the starter to #2, instead of C. Take the wire you've got going from start battery to #2 and run it to a 300A disconnect, then to the starter. Here's a picture that shows it better>

Let's both post pictures as it goes.

 

[jssailem]

She went shopping and came back with a small electric heater.

Got to love that wife. She is a keeper. Tell her so from me.

 

[LeslieTroyer]

@Ward H while the wire can go to 120 A the 5025 is only rated at 100A. While you could use do the 100’s you might as well protect the equipment if it doesn’t hurt. The 60’s were twice the anticipated flow on either of those wires so seemed like a good number. I didn’t look up the ampacity of #6 before posting, my bad. And I just contradicted my self about fusing for equipment/load rather than the wire. Your design is so much better than 99% of the boats it’s nitpicking and personal preference at this point.

Mahalo

 

[Ward H]

I agree with Leslie about the isolated starting system (and am doing the same thing with our Catalina 310 starting today): Run the wire from the starter to #2, instead of C. Take the wire you've got going from start battery to #2 and run it to a 300A disconnect, then to the starter.

I see the advantage of adding the isolated starting system if I was worried about instrument drop out during start but I'm not. My plan is to never combine banks so no fear of a failed house bank affecting the aux bank.
I will use the house bank for house loads and starting. The aux is only for use if the house bank fails or is drawn down too low to start the engine.
Of course, it will be easy to add if I change my plan but for now it is an option.

 

[Ward H]

@LeslieTroyer
Thinking like you, I originally did plan with 60A fuses on the circuits. But I've read enough posts by Maine Sail about sizing fuses to protect the wire, not the device, that I plan to change to the 100A fuses.

 

[marchem]

I see the advantage of adding the isolated starting system if I was worried about instrument drop out during start but I'm not. My plan is to never combine banks so no fear of a failed house bank affecting the aux bank.
I will use the house bank for house loads and starting. The aux is only for use if the house bank fails or is drawn down too low to start the engine.
Of course, it will be easy to add if I change my plan but for now it is an option.

Sounds good!

 

[Ward H]

One concern I have is having enough of the 1/0 AWG, attached to the battery switch, to flex when swinging down the distribution panel. That and the weight of the wire hanging off the back of the switch.
I'm now thinking of installing a new battery 4 position battery switch on the white panel under the distribution panel. That should resolve my concerns and remove a lot of bulk from behind the distribution panel.
That also removes the issue of the existing switch, which passes through "1 + 2" when moving between position 1 and 2.
Thoughts?
PS - The old radio is gone.

 

[Ward H]

Upgrade Update
I did a lot of prep at home mounting things on backing plates. That allowed me to make good progress Yesterday. I mounted things, ran some wires, crimped and marked some wires. Got 3 or 4 more 1/0 wires to run, a busbar to mount, wire runs to secure and neaten things up. Need to remember to run the negative connection for the ACR.

I thought I would have the charger done but mis-counted my 10 AWG ring terminals so still need to do the ground wire and jumper the outputs. Should finish that tomorrow.

Before I'm completely done I'll be sealing the bottom of the battery compartment. I'll also be adding some trim to hide/protect the wires on the charger.

Back to it tomorrow.

 

[Maine Sail]

That also removes the issue of the existing switch, which passes through "1 + 2" when moving between position 1 and 2.
Thoughts?

And what "issue" would that be?

 

[Maine Sail]

Upgrade Update

Looking good!!

 

[Ward H]

And what "issue" would that be?

My switch positions are, left to right, 2 - Both - 1 - Off.
When I wrote that I thought that if battery 1 was bad or dead, it would be bad to combine them while moving through the Both position to battery 2.
Since then I read where you said that combining them momentarily would not hurt.
So no issue there.
I also discovered that you were right, with better wire management running the 1/0 AWG to the battery switch did not cause a problem with swinging the door down.
A battery switch not on the panel would be better but not worth the work to change out.

Looking good!!

Thanks. It helped to have a lot of good photos to give me ideas.

 

[LeslieTroyer]

Looking very clean. Very nice

Mahalo

 

[dlochner]

Looks good. Do you hire out?

 

[marchem]

Upgrade Update
I did a lot of prep at home mounting things on backing plates. That allowed me to make good progress Yesterday. I mounted things, ran some wires, crimped and marked some wires. Got 3 or 4 more 1/0 wires to run, a busbar to mount, wire runs to secure and neaten things up. Need to remember to run the negative connection for the ACR.

I thought I would have the charger done but mis-counted my 10 AWG ring terminals so still need to do the ground wire and jumper the outputs. Should finish that tomorrow.

Before I'm completely done I'll be sealing the bottom of the battery compartment. I'll also be adding some trim to hide/protect the wires on the charger.

Back to it tomorrow.

View attachment 146771 View attachment 146772

Very nice!! Congrats.

 

[Ward H]

Do you hire out?

I used the cheapest labor I could find. Me.