Logo
FULL SITE MENU

Doing a complete rewire on my 37 Sedan...part question

R

russ_scotchandiron

New member
Hey everyone, this is my first post here but I have been lurking for a while. I recently bought a 1987 Silverton 37C sedan on the cheap, that I am doing a full interior refit on with ultimate plans to live on it full time.

The electrical was working fine until corrosion started to put gremlins in the system, so I decided it was time to do a full wiring rework.

The electrical in the boat was a total mess. Years of incompetent work with wires stuffed into other breakers, dead wires in the harness, butt connectors and tons of duct tape. I've since invested maybe 20 hours into chasing all the useless wires and removed 2 5-gallon buckets worth.

I've been doing as much research as I possibly can before I decide on the best battery setup that meets my needs and budget. I think I have settled on a three battery setup (twin engine) using two Blue Seas switches and two ACRs. I have a generator but contemplating getting rid of it because I don't like the idea of gas gen running for an extended period especially at night. I might just go with a large inverter and bulk up the house bank.

I found something in the system that is baffling me and I am sure its something very simple. Attached after the battery switches and before the starters was a solenoid. There are two small wires attached to it that appear to go to the helm. I assumed this was the starter relay but was just confused because there's a starter relay on each engine near the 50A breaker.

Just looking for some clarification on this main solenoid. (it serviced both engines)

Image upload here isn't working for me for some reason

https://1drv.ms/u/s!AmKlLTW8z0jJvwIwws2NN83O-OBg

https://1drv.ms/u/s!AmKlLTW8z0jJvwVfjKu08TQj6ysZ



s!AmKlLTW8z0jJvwIwws2NN83O-OBg
 
I think I might have just answered my own question. It would appear that solenoid is the parallel battery solenoid coming from the switch at the helm.

Still looking for clarification....
 
.............................
russ_scotchandiron said:
I've been doing as much research as I possibly can before I decide on the best battery setup that meets my needs and budget. I think I have settled on a three battery setup (twin engine) using two Blue Seas switches and two ACRs. I have a generator but contemplating getting rid of it because I don't like the idea of gas gen running for an extended period especially at night. I might just go with a large inverter and bulk up the house bank.

By nature Inverters are Amp Hour hungry and they are inefficient at producing 120 vac from 12 vdc.
Regardless of size, you will not want to bring the HLBB (house load battery bank) down below 50% of full charge.
At 50% discharge, you will want to bring the HLBB back up ASAP.
For this......... you will want to have an O/B generator and a good shunt resistor style battery monitoring system that tracks Amp Hours, not voltage alone.
You will greatly shorten the life of your HLBB if not.

I found something in the system that is baffling me and I am sure its something very simple. Attached after the battery switches and before the starters was a solenoid. There are two small wires attached to it that appear to go to the helm. I assumed this was the starter relay but was just confused because there's a starter relay on each engine near the 50A breaker.
If this relay was triggered by a momentary helm switch, it may have been there to join battery banks during starting.
If so, this is what we call a poor man's combining system..... but, it can work very well.

Just looking for some clarification on this main solenoid. (it serviced both engines)
How did it service both engines?


s!AmKlLTW8z0jJvwIwws2NN83O-OBg
Click to expand...
 
Last edited:
I’m aware of the issues presented with inverters. If I go the inverter route I’ll be getting lithium batteries and solar panels to keep them topped off and allow for a deeper discharge.

The soledoid had one side wired to the port starter and the other the starboard.

everything in this boat was done to mid 80s spec and certainly poor mans spec when compared to today’s options hence why I pulled it apart.
 
Last edited:
........................
russ_scotchandiron said:
I’m aware of the issues presented with inverters. If I go the inverter route I’ll be getting lithium batteries and solar panels to keep them topped off and allow for a deeper discharge.

The solenoid had one side wired to the port starter and the other the starboard.
Whether connecting this style solenoid "combining" feature, or using an ACR or VSR, I find it best to connect directly to the appropriate terminal of each MBSS.
(MBSS = main battery selector switch) This makes the runs short and eliminates unnecessary cables to/from the engine area.

FYI and FWIW......, I always make certain that the MBSS(s) are NOT mounted in the engine bay. I have always mounted them so that the selector knobs area accessible from outside of the engine bay.
Reason: should there be a major issue with the 12 vdc system (electrical fire, etc), you can quickly shut off the 12 vdc power without the need to open the hatch.
A good captain will still open the engine bay hatch for an inspection prior to an outing and initial start-up.
Your call on that.
Click to expand...
 
Agreed. I’m planning to mount the MBSS up near the main panel in a storage cabinet.

I commented on a post you made in an older thread where you posted a wiring diagram for a three battery setup with two cranking starboard batteries and 6v bank of port / HLBB batteries.

Im just a little confused on where is best to place fuses and your diagram didn’t include them.

Should i have fuses at the battery and also at the MBSS?
Fuse before and after the ACR?

Thanks
 
By nature Inverters are Amp Hour hungry and they are inefficient at producing 120 vac from 12 vdc.

I would disagree...I have a 3000Watt Pure sine inverter in my boat and six 300watt solar panels running through two Morningstar controllers (3 panels to each controller) and each controller then goes to a house battery (2 onboard-Big Red Surrette 275AH ) I can run everything in my boat including an 18Cu AC Fridge for 3 days with no sun to recharge the batteries. Naturally,everything possible in my boat is LED.

Between the twin 350s is a 8KW Westerbeke that is normally only used for Air Conditioning but can be used to run all electrics in the boat.
I have never run the Genset at night and never would.

And.....very unfortunately..due to "The Admirals" medical condition ......the boat is for sale.
 
Willow, do a search re; the inefficiency of 12 vdc to 120 vac Inverters.
Depending on the 120 vac load, you will see anywhere from 10% to 50%.
 
Willow that sounds like my plan down the road. I just want to get away from using the gen at all cost. Although not ideal I think a small portable gen could fit my needs if I ever found myself with totally flat batteries but honestly with conservative use of
power, LEDs lights and good solar power, I think the gen would almost be just wasted space and weight.
Ideally I’d like to get a small BTU A/c unit for the vberth area that’ll run off the batteries at night and I’ll also have the other main cabin AC for use when plugged into shore power.
 
RicardoMarine said:
Willow, do a search re; the inefficiency of 12 vdc to 120 vac Inverters.
Depending on the 120 vac load, you will see anywhere from 10% to 50%.
Click to expand...

I don't want to get into a urinating contest about the efficiency of inverters but here is just one source for a quote....

[FONT=&quot]This is due to the efficiency of the inverter. These days, quality inverters are between 90-92% efficient.

[/FONT]Lets just leave it with.....
I am very happy with my 3000watt pure sine wave inverter, I consider it very efficient and it runs my 18Cu 120VAC fridge with no problem. The trick in selecting an inverter is to read all the specs and then select one with about 50% more output than you calculate you need so that you can add a few more items without loosing the efficiency of the inverter.

russ.scotchandiron

I have always carried a Honda 2000ei inverter as my backup...and my security blanket :D
 
willow said:
I have always carried a Honda 2000ei inverter as my backup...and my security blanket :D
Click to expand...

Agreed... there are several reasons why I want to ditch the gen...the biggest being at the moment it is broken haha. The boat sat for a few years in salt water and it had its way with a lot of stuff in the boat. The gen actually starts an runs great but the cooling water flow is clogged up inside the head. I've looked to replace it or have it rebuilt and I am looking at minimum $5,000.

I figure for $5000 I can get a stack of lithiums, charger, inverter, and then add the solar down the road.

Not to mention the massive space I will free up in the rear deck when I remove the old gen. I can think of several things that would fit better in that space namely a combo washer dryer unit.

Would you by chance willing to share the components you used for your solar setup?
 
Would you by chance willing to share the components you used for your solar setup?

Well I was lucky...One of my best boating buddies is a sail boater(yeh, I know, stick boater:eek:) but he is also a master electrician and if you have a plan, as I did, he made suggestions on how to improve upon it.. He also has solar on his sailboat.

The six panels are just like any 6 solar panels, each at 300 watts, and I designed the rack that would hold them over top of the aft sundeck. The wiring of the panels was no big deal. I bought all the wire and connectors required on EBay. I bought two Morningstar controllers and routed each 3 section of solar panels, after they were wired together down a single pipe which ended up in my aft cabin just above a dresser. I bought "On" and "Off" rotary switches in order to turn the solar off prior to going into the controllers and another two switches after each controller so that I could control the batteries ..that is whether they got solar or shore power (through a Zantrex 40 amp charger) in the engine room. The Big Red batteries were hooked in parallel and a + and - cable ran from the top battery (they are stacked), through the appropriate fuses, (bought on EBay), and into the 3000 Watt Inverter. Two large electrical cables were hardwired into the inverter and they run through a raceway to two main distribution panels at the helm.
I have a remote panel to turn the inverter on/off and I bought the "extra" digital readouts that are incorporated in the MorningStar controllers. Each battery also has a temperature wire running to the Controller.
I did have a Zantrex meter prior to the solar installation so put that in the system as an easy readout display to see what was going into and out of the batteries...The MorningStar digital panels have the same info but I have to press a button to light up the LCDs in the controller so this is easier to see. I have two house batteries, each engine has its own start battery, the stern thruster have two batteries in series as does the bow thruster and I have voltage gauges and a separate charging system for all the thruster batteries.

Rather than use the hosts bandwidth, I could send you photos via email of some of the gear and the pics may enhance my explanations.

 

Attachments

  • IMG_0235.jpg
    IMG_0235.jpg
    63.3 KB · Views: 30
Back
Top