what is the distance between the battery bank the engine. I want to install 1AWG wiring on pos and neg side, given the age of the wiring. Thanks very much
Cliff : I don't know the exact distance but I'll guess at 6-8 ft? But WHY are you planning to use such HEAVY wire!??! I rewired with #4 gage, but it was marine grade wire and I soldered all of the connections and have NEVER had a problem!!
A few thoughts
My boat is set up differently than stock, but perhaps this might help? Hope you can read it with current file resolution.
Quote from: crieders on December 06, 2023, 02:13:17 PM
what is the distance between the battery bank the engine. I want to install 1AWG wiring on pos and neg side, given the age of the wiring. Thanks very much
Cliff,
Distance for what? The ROUTING of the wire(s) is a critical part of the distance, since measuring voltage drop is based on the actual length of the wire, not a straight line dimension. Also, just where you leave the battery box and where you plan to connect at the engine end is important. That routing is impacted also on whether you intend to go UNDER the engine to get there (which I did when I rerouted my positive from the AO and supplemental negative).
Making the wire that big needs to be determined on the load. Absent an inverter, #1AWG is not necessary on a C34. With a reasonably sized inverter (1500W) it would be inadequate. Something is not in balance here.
Thank you all. 1 awg was recommended by a marine electric guy who is highly regarded in the Rock Hall Md area.
I did an extensive rewire on my boat several years ago and used 1AWG for the charging system. Very happy I did. I have a write up in the Tech WIKI if you're interested. As a word of caution each boat is slightly different so you can't use someone else's dimensions for anything but reference.
Cliff : As mentioned I used #4 gage wire from my alternator to the batteries circuit . I did upgrade to #2 wire for my starting battery wire circuit. All wire is tinned marine grade wire with crimps and solder.
A few thoughts
Quote from: crieders on December 06, 2023, 02:13:17 PM
what is the distance between the battery bank the engine. I want to install 1AWG wiring on pos and neg side, given the age of the wiring. Thanks very much
Good move Cliff.
The OEM #4 is waaaay too light for the starting cable. #2 or #1 is minimum depending on the distance but since it's a one-time purchase
#2 so #1 is better for not a lot more cash than
#1 #2.
2 AWG is smaller diameter than 1AWG. Did you mean 1AWG is better than 2AWG for a little more cash?
I used tinned and stranded marine grade wire/cable rated for 600V, 105°C dry and 75°C wet.
Duh!!!
Thx for rescinding my diploma, Jon!!!
No worries, you're still the professor :thumb:
Guys: SORRY, but my #4 marine grade wiring has work FLAWLESSLY for only 33 years with the original M25XP and the new M25XPB engines !!! So #4 size is Not "WAAAY TOO small"!!!! :thumb:
A thought
No 4 awg is plenty, unless owners give a flyin crap about ABYC standards and the maximum voltage drop on critical circuits. But who cares about that.
Guys : I scanned the ABYC E11 and didn't find that stringent about "voltage drop and minimum voltage drop on critical circuits!!" [/quote] "#4 awg is plenty unless owners give a flyin crap about ABYC standards and the maximum voltage drop on critical circuits. But who cares about that." [/quote]
The only critical circuit that I know of on my C34 is the Engine Starting. With my skimpy AWG #4 tined wire - I touch the glow plugs for 5 seconds, and the touch the starter for 1 second and the engine STARTS!! As I said before I made that wiring change in 1991? and have had NO problems since!!
So Guys if you want a heavier gage wire - go for it, but it really isn't necessary!! :shock:
A few thoughts
Guys : I scanned the ABYC E11 and didn't find that stringent about "voltage drop and minimum voltage drop on critical circuits!!" [/quote] "#4 awg is plenty unless owners give a flyin crap about ABYC standards and the maximum voltage drop on critical circuits. But who cares about that." [/quote]
The only critical circuit that I know of on my C34 is the Engine Starting. With my skimpy AWG #4 tined wire - I touch the glow plugs for 5 seconds, and the touch the starter for 1 second and the engine STARTS!! As I said before I made that wiring change in 1991? and have had NO problems since!!
So Guys if you want a heavier gage wire - go for it, but it really isn't necessary!! :shock:
A few thoughts
Quote from: Ron Hill on December 18, 2023, 02:58:35 PM
The only critical circuit that I know of on my C34 is the Engine Starting. With my skimpy AWG #4 tined wire - I touch the glow plugs for 5 seconds, and the touch the starter for 1 second and the engine STARTS!! As I said before I made that wiring change in 1991? and have had NO problems since!!
Ron can you clarify the point you are trying to make? Yes, starting would be one of the critical circuits, limited to 3% (or less) drop.
But, you said that you had
upgraded to 2 AWG -- This is consistent with what I said to Cliff: '
minimum #1 or #2 for the starting circuit[/u][/b].'
EVEN if 4 AWG on a
starting circuit has 3% drop the key is, what happens when trying to start if the battery is down a bit? That's when cable size becomes most important.
Remember that V drop is along the entire (positive and negative) length. @ 80a, a 4 AWG circuit with 5 feet of pos and neg cable is over 3% (not counting terminal loss.) 7 feet each of 2 AWG pos and neg cable is over 3%. 9 feet each of 1 AWG pos and neg cable puts you at 3%.
Certainly, 4 AWG is adequate for a separate
charging conductor to the bank.
E11 - 11.14.2.6 Conductors used for panelboard or switchboard main feeders, bilge blowers, electronic equipment, navigation lights, and any other circuit where voltage drop should be kept to a minimum shall be sized for a voltage drop not to exceed three percent.
Ken : The point is that even using the house banks #4 awg wire (no starting battery) - if I can just touch the starter button for 1 second and the engine springs to life; what ever voltage drop there is, doesn't bother the starter/engine one bit!!
The key is - marine grade tinned wire and GOOD connections!! :thumb:
A thought
i looked for the tech article and did not see it. any chance you could sent to me or post? last Sunday I looked over everything in prep for ordering what I needed and I was intimidated just figuring out where the new wires would hook to at the engine end and how to fish them to the location! But with all this good help, I intend to try.
Hi Cliff, If you're talking about my write up; go to the Tech WIKI on this website, scroll down to Projects by Boat/Author, then click on Della Jean, Jon Windt. This will take you to a list of my project write ups. The first one is 1987 Catalina 34 MK1 Electrical System Upgrade. Click on that and you'll be taken to the write up with step by step text, photos, and spreadsheets. There's also a link in the introduction to the original post on the message board with lots of questions, answers, graphs, etc. Last I looked it was 19 pages and 69k views.
Cliff
Note that if you have the OEM setup the Neg cable bolts to the bell housing. That's not the best location and should be moved to the starter bolt. Both are M8 bolts so you want a 5/16" lug on that cable end.
There is a diagram of the change to the Neg cable location here (bottom of the page):
https://groups.io/g/Catalina30/wiki/11336
The Pos cable is in the starter solenoid "B post" , which is also M8.
Of course, you need to also replace the cables to your battery selector switch.
Ken
Cliff : Look at the old Mainsheet tech note in the Nov 1996 edition. I list the electrical modifications made by 3 C34 owners. Apache, Bay Tripper and Wiskers! That should surely give you some ideas. Bay Tripper and Wiskers (as I recall) with for 4 Gulf Cart batteries while Apache did 3 group 27 Gel batteries.
Hope this helps, a few thoughts :clap