[C38] Wiring Diagram

[Les Howell]

Hi, Everyone,

    Some important points about the electrical systems.  First, note that 
the DC system is only grounded to the engine.  This means that our entire 
12V system is isolated from the ocean, except through the transmission, 
coupling and shaft.  We replaced the engine, transmission and shaft in JACE, 
and the new coupling is isolated which I think is supposed to reduce noise 
(note supposed !!!).  Now JACE 's DC is totally isolated to ocean ground. 
This will impact your use of RADAR, VHF, and SSB radios.  AM/FM stereos and 
TV's use a different means to generate their reception, but they, too will 
benefit from a good ground.  I don't have a fixed GPS so I can't comment on 
that.

    The 120VAC system is totally isolated from ocean ground.  I don't know 
if this is good or not, but you are relying on the condition of the earth 
ground at the dock to help prevent electrolysis and electrocution.  Check 
your shore power cable at least annually.  I installed a galvanic isolator 
in JACE, but when I added an inverter I didn't know what to do for safety 
ground.  I am still looking into that.  If you know any real good electrical 
types, who have solved this, please let me know.

    If you just need to solve the radiation ground, you can add copper 
inside the hull (4 square feet or more should do the job).  But lightening 
protection may require something different.  In any event, I would recommend 
finding out if your coupling is providing electrical ground for you, and 
also checking leakage with the battery isolated (switches off).  This will 
help you check for any possible sources of electrolysis.  Changing your 
zincs often will help as well.  We put new through hulls in JACE, all 
Bronze.  We were told to leave them isolated because having some connected 
and some isolated is potential for electrolysis to eat up the zinc from the 
bronze.  Your engine through hull is probably already bronze (ours was), 
because of the constant rush of water and flexing of the hoses due to engine 
movement, it was fully isolated and had no electrolysis evident.  You should 
periodically check that they are not showing pink (bronze tends to look pink 
if you scratch it when it loses zinc.)

    The charging path originally in the boats was from the alternator to the 
panel, through the ammeter, and back to the starter solenoid, where the 
system was wired to the power panel.  Newer systems don't do this because it 
is a weak link in the charging system, and because it can potentially burn 
the wiring harness to the engine, so they put a voltmeter and tie the 
alternator directly to the starter solenoid.  The panel gets its power from 
this point as well.  You will notice that the wire from the engine to the 
switch and back to the engine is 10 or 12 AWG.  This is because it carries 
the current for the solenoid and the engine heaters or the heater solenoid 
depending on how your engine is wired.

    If you have a multi bank battery charger, read its manual CAREFULLY. 
After noticing that my batteries were not fully topped off, I finally 
re-read mine and discovered that it required any unused outputs to be 
strapped to one of the used ones to get the charger to full output.  I did 
that and gained about 15% more of my battery capacity.  Since I notice that 
many people talk about batteries not being fully charged, I am suspecious 
that I am not the only one that missed that one line in my charger's paper 
work.

    I replaced the original wire from the solenoid to the panel in JACE as a 
safety precaution (it wasn't tinned).  It needs to be between #0 and #2 wire 
to carry the current required to start the engine.  The switch in the panel 
changes the source for engine starting from battery 1 to battery 2, so the 
leads from the batteries to this switch also need to be heavy cable as well. 
The original house battery run in JACE went through the bilge, under the 
floor, up through the back of the chart table behind the drawers to the 
power panel.  There were no clamps that I could find anywhere on this run. 
I ran the new cable the same way, but I don't like it, so re-routing it and 
adding clamps is on the to-do list.  When replacing wire, use marine wire. 
It is finer, and the strands are tinned.  This will help prevent sea water 
and salt air from corroding the wire, and because the strands are thinner, 
it is more flexible, meaning it will last longer in the flex of the boat. 
Standard recommendation is strapping wire every foot or so to help prevent 
unnecessary flex.

    The runs from the power panel to the mast go through a plastic hose on 
JACE, I don't know if this was standard or not.  However I haven't found the 
entrance to the hose.  I suspect it is inside the liner behind the chart 
table.  I am planning on rewiring JACE sometime soon, so I will know more 
later.

    The run from the solenoid to the power panel goes across the roof of the 
engine space, down the starboard side of the door, through the area in the 
forward end of the quarter berth, up through the liner to the inside of the 
power panel.  Once I realized I would be redoing this I ran a messenger line 
from the power panel down to the quarter berth area of nylon small stuff and 
tied it to a 6" piece of wood which I leave in place.  It is long enought to 
let the line go three times through this area so I can tie wires to it and 
run them up to the panel.

    One of the worst bits on our boats are those riveted 3 way splices.  I 
have replaced most of mine with butt joints big enough to hold two wires on 
one side and ensured the wires were well joined prior to insertion.  I seal 
all my butt joints with some Marine Goop.  easier than heat shrink and I 
don't have the opportunity to check out my fire extinguishers in sealing the 
joints (clumsy man with a lighter or matches oft gets burned).  I also 
bought one of the ratcheting crimping tools.  Get one, it is cheap and does 
a much better job than the one pressed from steel.

    During the past several years I have replaced many bits of the wiring 
with better bits, and eliminated several joints in each wire.  Along with 
that I have removed a considerable amount of old electrical tape.  In the 
years since our boats were built new materials make it easier to create 
better joints and have better seals.  I recommend that any "erratic 
circuits" you have be investigated and rewired.  It may save your boat.  The 
connections from the panel, under the engine, and over to the port side are 
suspect because I know that I found three of those wonderful riveted 
connectors in the house wiring.

    At least one 38 had AWG 10 in one part of the AC circuit and AWG 12 in 
another part between the inlet for shore power and the panel.  It had some 
burn points in the cable when it was replaced.

    The DC wiring is almost all AWG 16.  going to AWG 12 or 14 will improve 
your lighting and make things easier, although it is a bit more expensive. 
For those of you overseas, You will have to check the metric conversion.  I 
don't know the sizes in metric.

    As I get the physical routing all figured out, and figure out how to 
strap the new wiring in place, I will post all that as well.

Good luck.

Regards,
Les H
Les Howell Technical Specialist, Teradyne (retired) hlhowell at pacbell.net IM: 
OldETC (Yahoo) Professional Profile
----- Original Message ----- 
From: "Charles Finn" <charles at finn.ws>
To: "Catalina 38 Listserve" <listserve at catalina38.org>
Sent: Wednesday, June 14, 2006 6:55 PM
Subject: Re: [C38] Wiring Diagram


>I have uploaded the Wiring Diagram to our website.  You will find it in
> C38-Specs.  Thank you Bill Ferrara!
>
> Charles Finn
> Mighty Quinn  #114
> Webmaster
>
> _______________________________________________
> Listserve mailing list
> Listserve at catalina38.org
> http://catalina38.org/mailman/listinfo/listserve_catalina38.org
>