Re: electric power cables

Gordon (hlg@pacbell.net)
Sun, 8 Nov 1998 17:26:40 -0800


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West Wight Potter Website at URL
http://www.lesbois.com/wwpotter/
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>Regarding electric power cables,
>
>As you know you want to keep the total ohms just as low as reasonably
>possible ! Not wanting to spend a fortune on 4 ohm marine cable...I
>went to my local auto supply store and bought a set of EXTRA HEAVY DUTY
>jumper cables. I forget the ohms...but the stuff is REALLY heavy and low
>total ohms. I cut the pig tale of power cable that came with my electric
>motor and soldered [ soldered REALLY GOOD !!! ] the jumper ' extension "
>cable. This was for use on my old P -15 wherein I had the battery up
>just behind the anchor rode locker bulkhead. I then dressed the cable
>through the cabin hatch....attached it with velcro strips to the port
>cockpit rail and thence to the motor. Worked great. I do not know how
>long the cable must be in a P 19. I guess it should be about 19 feet ?
>I don't know anything about P 19s dimensions..
>
>Good luck
>Bill Zeitler
>A potterer at heart..but now in a modified Bay Hen.
>Wilmington, Delaware

The difference between the high-priced Ancor marine cable and the auto
cable is that the copper strands of the marine cable are tinned. The bare
copper auto cable is subject to corrosion in the marine environment.
Because my MinnKota uses 45 A at max speed I went overboard to minimize
voltage drop and resultant loss of max power.

The AWG 4 Ancor battery cable was about 2.29 a foot at West Marine, which
does add up. I also used Ancor tinned heavy-duty terminal lugs. The first
two I installed by soldering, using a torch, then added heatshrink. I don't
know if that is the proper soldering method but I couldn't think of any
other way to do it. I used electrical type rosin core (NOT acid core)
solder of course. In addition to insulation, the heatshrink seals the
connection so moisture is less likely to wick up the cable strands.

Then I poured another 20 bucks in that famous hole in the water to buy the
Ancor crimping tool that you have to beat with a hammer or clamp in a vise.
It works very well and is easy to use. The rest of my connections are
crimped, soldered, and heatshrink enclosed. Ancor advised me that either
crimping or soldering is satisfactory, but another source recommended both
crimping and soldering.

My cabling is out of sight until it emerges in the cabin. It's routed
inside the cockpit seats. I put a 60 A fuse in the +24 V circuit, mounted
on the side of the cabin. For the connection of the motor cables to the
boat cables, I have a pair of 3/8-inch-diameter stainless bolts with
wingnuts mounted in a varnished board behind a transparent Beckson access
plate in the lower vertical face of a cockpit seat. I used a staggered
arrangement of terminals so If I accidentally disconnect and drop the
positive lead coming from the battery it won't short out on the negative
lead. I've got a neat way of routing the motor cables from a hole in the
quarter to the junction box, but I won't go into that because it would
probably only be applicable to a first generation Potter like mine. This
custom junction box looks great and works beautifully and very easily. I'm
pleased with it.

Unfortunately, the contrast of the new motor and expensive wiring on my
rough and funky 1967 Potter makes it more obvious how ratty looking my boat
has become. But the 70-lbf-thrust electric motor was an experiment I just
wanted to do, realizing it would be expensive and quite possibly not very
practical. Messing about with boats, you know.

Regards,
Harry Gordon
P14 #234, Manatee
Mountain View, CA