CD 25 Re-wiring question..

[Stuart]

Hi all,
I am in the process of rewiring a CD25 and I need some help. I did a load sheet, and electrical schematic and showed it to a marine electrician. He suggested that I put a 50 amp fuse between the battery isolation switch and the panel. I thought that the fuse should be close to the battery as possible. Where does it belong?

Also, he suggested that I should run a wire(sized to the total load) from the negative bus bar to the dynplate for a common ground. Since I am not running any radios, etc (Loran, gps) to the plate, is it good practice to use the dynaplate as a ground? Thanks to all-

Perplexed in Maine,
Stuart
S/V Yankee Cowboy



st1975@yahoo.com

[John R.]

Hi all,
I am in the process of rewiring a CD25 and I need some help. I did a load sheet, and electrical schematic and showed it to a marine electrician. He suggested that I put a 50 amp fuse between the battery isolation switch and the panel. I thought that the fuse should be close to the battery as possible. Where does it belong?

Also, he suggested that I should run a wire(sized to the total load) from the negative bus bar to the dynplate for a common ground. Since I am not running any radios, etc (Loran, gps) to the plate, is it good practice to use the dynaplate as a ground? Thanks to all-

Perplexed in Maine,
Stuart
S/V Yankee Cowboy

Closer to the battery is where it should be. I'm not sure how he came to the 50 amp fuse rating, that rating depends on the bank capacity and wiring AWG. If your boat has an inboard engine the common ground point should be a buss bar or stud and that should be wired to a good ground on the engine and another wire leading from there to the ground plate. That is assuming you don't have a flexible coupling or drivesaver on your shaft. If you do you will need to bridge the coupling with wire braid or similar to make sure the conduction gets to the shaft. If you don't have an inboard go straight to the ground plate as he recommends. As always make sure all wiring is of appropriate gauge, all terminals should be soldered, stud or bolt points should be clean, tight and suitable in size for a good ground.

[Stuart]

Hi all,
I am in the process of rewiring a CD25 and I need some help. I did a load sheet, and electrical schematic and showed it to a marine electrician. He suggested that I put a 50 amp fuse between the battery isolation switch and the panel. I thought that the fuse should be close to the battery as possible. Where does it belong?

Also, he suggested that I should run a wire(sized to the total load) from the negative bus bar to the dynplate for a common ground. Since I am not running any radios, etc (Loran, gps) to the plate, is it good practice to use the dynaplate as a ground? Thanks to all-

Perplexed in Maine,
Stuart
S/V Yankee Cowboy

Closer to the battery is where it should be. I'm not sure how he came to the 50 amp fuse rating, that rating depends on the bank capacity and wiring AWG. If your boat has an inboard engine the common ground point should be a buss bar or stud and that should be wired to a good ground on the engine and another wire leading from there to the ground plate. That is assuming you don't have a flexible coupling or drivesaver on your shaft. If you do you will need to bridge the coupling with wire braid or similar to make sure the conduction gets to the shaft. If you don't have an inboard go straight to the ground plate as he recommends. As always make sure all wiring is of appropriate gauge, all terminals should be soldered, stud or bolt points should be clean, tight and suitable in size for a good ground.

John R.,
Thanks for the response. I have an outboard engine with charger option. The battery is a 80 Ah capacity and the total panel load is around 30 Amps. The feed line is 8 Guage to the panel from the battery. I thought 50 Amps was a little high for a fuse with my load. What do you think? Go lower?

Also, you think soldering is the way to go over crimping? It does seem like a more solid connection (both phyiscally and electrically).


Thanks,
Stuart



st1975@yahoo.com

[matt cawthorne]

Stuart,
It is not common to put fuses in the starter motor circuit of larger boats and the ABYC does not require it. They add resistance and reduce the ability to start large diesel engines. The panel is not designed for the type of currents that a starter motor draws. To protect the panel and keep the full current going to the starter two wires are normally taken off of the common post of the battery selector. One heavy wire goes to the starter and a second, smaller wire goes through a fuse or breaker to the distribution panel. If your 25 Does not have a starter or it draws less than 50 amps I would suggest installing a fuse as near to each battery as possible. Given the smaller size of your boat and your use of the word battery (singular), your battery slector is just an on-off correct? In that case, one fuse near the battery as possible.

Matt



mcawthor@bellatlantic.net

[Tom]

Hi all,
I am in the process of rewiring a CD25 and I need some help. I did a load sheet, and electrical schematic and showed it to a marine electrician. He suggested that I put a 50 amp fuse between the battery isolation switch and the panel. I thought that the fuse should be close to the battery as possible. Where does it belong?

Also, he suggested that I should run a wire(sized to the total load) from the negative bus bar to the dynplate for a common ground. Since I am not running any radios, etc (Loran, gps) to the plate, is it good practice to use the dynaplate as a ground? Thanks to all-

Perplexed in Maine,
Stuart
S/V Yankee Cowboy

Stuart,
I too have a CD25. I have a dynaplate but this year I plan on eliminating it from the ground circuit. I have an electric start outboard and I think because the outboard was grounded and the dynaplate was too I had a circuit going on and the outboard being aluminum it wasn't too healthy for it. The zinc didn't last the season. I think you only want one ground in the circuit. I'm no expert so I would like to hear what the thinking is out there.

Tom



tomb5050@aol.com

[Joe Mac Phee]

Stuart,

You are correct, the ABYC code does tell you to put the fuse(breaker) as close to the source (battery) as possible. However, there are some other issues that may require compromise on just how close. The primary issue is the current required for the starter motor for the engine (if there is one). The starter requirenment is usually very high and not fused. If the starter is wired to the load side of the battery switch, the fuse for the rest of the load is usually after the battery switch.

The suggested size for the fuse is about right for 8 gauge copper wire. Remember that the fuse is there to protect the wire, not the load (each load item is usually individually protected).

The issue of soldered versus crimped connections could go on forever. The NASA soldering school tells you that solid wires should be soldered and stranded wires should be crimped (not to be confused with the fact that marine wire is usually solder plated whether solid or stranded). The reason that stranded wire should not be soldered is that the solder wicks up the strands under the insulation creating a rigid area that will break when flexed, defeating the usual reason for using stranded in the first place. NASA trained technicians have heat sinks to be used for each size of wire to prevent the wicking phenomenon. A crimped connection, done with the right tool, is a gas tight connection. Depending on the depth of your paranoia, you can also use crimp connectors that have a shrinkable sleeve on the fitting that has adhesive inside. Heat applied to the sleeve will shrink the sleeve and melt the adhesive to provide even more protection and sounder sleeping.

Hopefully this is more illuminating than confusing. I believe that your electrician is giving you sound advice.

Do not touch anything that would jeopardize your brilliant future.

Joe Mac Phee
S/V Iolanthe
CD-30/K



jvmacphee@aol.com

[wayne grenier]

Hi all,
I am in the process of rewiring a CD25 and I need some help. I did a load sheet, and electrical schematic and showed it to a marine electrician. He suggested that I put a 50 amp fuse between the battery isolation switch and the panel. I thought that the fuse should be close to the battery as possible. Where does it belong?

Also, he suggested that I should run a wire(sized to the total load) from the negative bus bar to the dynplate for a common ground. Since I am not running any radios, etc (Loran, gps) to the plate, is it good practice to use the dynaplate as a ground? Thanks to all-

Perplexed in Maine,
Stuart
S/V Yankee Cowboy

One evening after a delighful solo sail-I was motoring in with my CApe Dory 28', The temp gauge began climbing so I limped back to the mooring and changed the raw water impeller. I started the motor and stuck my head into the engine compartment to check for leaks when a tremendous amount of smoke began pouring out. I shut off the motor and batteries and dumped a fire extingusher onto the engine. For one minute I considered jumping as it appeard the boat was going to burn to the water line. The yacht club launch pulled up and offered me their big extinguisher but the smoke appeared to be settling down. Then the volunteer fire dept who happened to be practicing turned up in their boat and several guys with work boots bega climbing all over my boat. They wanted to tow me to the dock to conduct an "investigation". I respectfully declined and physically disconnected both batteries. The battery cable from the switch to the started had burned and melted. I replaced the cable, switched on the switch and instantly the engine block became hot to the touch. Assuming there was a prblem with starter I took it home and bench-tested it and it worked fine-put it in the boat it was shorted out to the block-I replaced the starter for $600 and solved the problem. I had the old started checked out and was told the solenoid was shorted out-no kidding-no one that I knoe of has ever had this happen before-did I cook the solenoid when the engine began running hot? I don't know-as far as fuses in the battery cable your in trouble either way-as everyone suggest startes draw a tremendous amount of amps and if you are in an emergency sitation and blow the fuse what happens? I thought about using a fuse like everyone has described-(they do sell them) but I have not done so as it appears I experienced a "one in a million" situation. It was easily the scariest thing that's ever happened to me on a boat-the moral is-keep your fire extinguishers up to date and easily accesible and a battery shut off switch is a necissity-I ended up replacing the cable and the switch and some wires that were tied to the battery cable-damage was very light but I re-wired the whole boat that fall-Mine is a 1974-hull #13 and to say the wiring was inadequate is being more than kind-I just thought it was interesting the starter would work out of the boat but was shorted out when mounted to the block-confused the heck out of me-(and some other people who make a living doing mechanics).



grenier@ma.ultranet.com

[Scott Ritchey]

As Joe correctly points out, the fuse is there to keep the wire from overheating and catching fire. Size the fuse (amps) based on the wire size. The West Marine catalog and the ShipShape site (as well as many books) give the capacity of various wire sizes. Recommend you consider a circuit breaker vs a regular fuse. West Marine caries a line made by Blue Sea that range from 25-150 amps (about $40). That way you can safely reset the breaker after you think you fixed the problem. I have these breakers (one on each battery) about a foot from the battery terminal. That was the closest I could mount them. I also agree with Joe on crimping. It's a lot faster to crimp and all your wires should be stranded, anyway. Besides, the solder flux seems to promote corrosion.



RitcheyVS@aol.com

[John R.]

Hi all,
I am in the process of rewiring a CD25 and I need some help. I did a load sheet, and electrical schematic and showed it to a marine electrician. He suggested that I put a 50 amp fuse between the battery isolation switch and the panel. I thought that the fuse should be close to the battery as possible. Where does it belong?

Also, he suggested that I should run a wire(sized to the total load) from the negative bus bar to the dynplate for a common ground. Since I am not running any radios, etc (Loran, gps) to the plate, is it good practice to use the dynaplate as a ground? Thanks to all-

Perplexed in Maine,
Stuart
S/V Yankee Cowboy

Closer to the battery is where it should be. I'm not sure how he came to the 50 amp fuse rating, that rating depends on the bank capacity and wiring AWG. If your boat has an inboard engine the common ground point should be a buss bar or stud and that should be wired to a good ground on the engine and another wire leading from there to the ground plate. That is assuming you don't have a flexible coupling or drivesaver on your shaft. If you do you will need to bridge the coupling with wire braid or similar to make sure the conduction gets to the shaft. If you don't have an inboard go straight to the ground plate as he recommends. As always make sure all wiring is of appropriate gauge, all terminals should be soldered, stud or bolt points should be clean, tight and suitable in size for a good ground.

John R.,
Thanks for the response. I have an outboard engine with charger option. The battery is a 80 Ah capacity and the total panel load is around 30 Amps. The feed line is 8 Guage to the panel from the battery. I thought 50 Amps was a little high for a fuse with my load. What do you think? Go lower?

Also, you think soldering is the way to go over crimping? It does seem like a more solid connection (both phyiscally and electrically).


Thanks,
Stuart

The fuse sounds appropriate based on your specifications. Yes, from the years in the marine industry and witnessing the quality (or actually lack of quality) in the typical crimping process performed by boat owners and shockingly some marine electricians it leaves soldering as a preferred connector attachment method. Use high quality rosin flux and high tin content or high silver content solder. heat the fittings not the wire. Use pre-tinned wire to facilitate easier soldering. I understand full well the idealistic world NASA subscribes to as mentioned in another post but simply put most folks don't have a clue how to do a proper crimp and don't have the right tools to do the crimp even if they knew how. Soldering is dependable and quite to the contrary inhibits corossion if done properly whereas a typical crimp terminal is plagued with corossion due to the wicking of moisture up into the spaces between individual strands of wire. Of course that can be minimized by proper fabrication and maintenance techniques. If a wire is properly secured the stiffness associated in the very ends of a soldered conductor is of no detrimental consequence. On a high speed powerboat with much vibration special considerations to the securement of small soldered conductors would be prudent technique.

[Mark Yashinsky]

Take a look on the Blue Sea site, under technical. They have reproduced part of teh ABYC section on electrical and offer other information on applications based on the ABYC specs. They briefly talk about soldering connections and how the soldered section is to be handled differently, but they do say, "Solder cannot be the only mechanical connection in any circuit." You still have to crimp the connection!!!
As for the battery connections, the charging and battery switch connections could be split and CB's put on the alternator output, if you dont want to have a CB on your master switch supply (starter current).

[Stuart]

Thanks to all for the advice and links...I appreciate it.


Stuart

Hi all,
I am in the process of rewiring a CD25 and I need some help. I did a load sheet, and electrical schematic and showed it to a marine electrician. He suggested that I put a 50 amp fuse between the battery isolation switch and the panel. I thought that the fuse should be close to the battery as possible. Where does it belong?

Also, he suggested that I should run a wire(sized to the total load) from the negative bus bar to the dynplate for a common ground. Since I am not running any radios, etc (Loran, gps) to the plate, is it good practice to use the dynaplate as a ground? Thanks to all-

Perplexed in Maine,
Stuart
S/V Yankee Cowboy

st1975@yahoo.com

[Joe Mac Phee]

Stuart and John,

John is correct. There are many bad crimp connections out there. In addition, if I had a nickel for every cold solder joint I have encountered in the last 40 years, I would own a much larger boat.

Both soldering and crimping seem simple, but are not. Crimping is a welding process and soldering is an alloying process.

A crimp connection, done with the correct tool, is actually a cold weld. This is why a crimp can only be done on stranded (copper) wire. A cutaway cross section of the joint would show that all of the strands have been deformed into a homogeneous mass. This gas tight connection will not corrode inside the joint. John is right, anyone who attempts this joint without the correct tool is doomed! The slip joint pliers in your tool box is not adequate.

A solder connection done with the correct solder and flux and an iron with the correct temperature actually forms an alloy between the solder and the copper. This is why it is so important to have a scrupulously clean connection before soldering. It is getting more difficult to get eutectic (37/63) solder because of sensitivity about lead and its fumes. Non-eutectic solders have a larger plastic range putting a premium on the iron temperature and a strong mechanical connection before soldering. If the joint moves within the plastic range, the joint is ruined. It is vital that the iron be temperature controlled at the temperature required for the solder being used. The iron should not overheat the joint (and the adjacent wire insulation) and have sufficient mass to not be cooled by the joint. In addition, the flux should be removed after the joint is completed to prevent further corrosion (even rosin flux).

So, both processes should be well understood before using. Neither is rocket science. John is correct, there are many hackers out there, some masquerading as professionals . Look in your professionals tool box. If all you see is a hammer and a screwdriver, find someone else!

p.s. I have been rewiring the batteries on Iolanthe. The crimp tool has 26 inch handles and deforms 1/0 wire!

Happy connections,

Joe Mac Phee
S/V Iolanthe
CD-30/K



jvmacphee@aol.com

[Mark Yashinsky]

Alloy generally implies two or more different different metals being melted together and combining, while in this molten state. Soldering and brazing is melting a metal, that has great affinity to the other metals being joined, onto another metal that is not melted. Kinda like glueing the parts together. The affinity of the solder is what draws the solder up into copper plumbing joints. Welding you DO melt the all the metals together.
As for the crimper, one can also get an impact (hammer) crimper for battery battery terminals.