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SanDiegoChip 01-27-2012 01:41 PM

Connect two different sized wire together?
Any suggestions on how to connect two different sized wire together?
We are installing an Air Breeze wind generator.
Sunny San Diego!
We have the mast up and have ordered 8 awg wires for the run to the batteries as they run is over 30.

This conforms to the Air Breeze specs.

The wires coming from the Air Breeze look to be #10 or# 12.

I think the neutral and ground get connected together and then the natural and battery negative get run to the batter positive and battery negative.
We were thinking that putting a #10 eye solder less term end on the Air Breeze and then the same on the 3 8 awg cable. Then bolting the wires together. This does not seem ideal. They are running down an aluminum pole and will have about 8 of slack inside the pole so they could be against the side. We could put a hose over the connections and other insulation methods but again this seems less than ideal.

Some new eyes on this and any idea welcome!


donradclife 01-27-2012 02:06 PM

Solder and tape. For the smaller crimp fittings I double over the smaller wire inside the crimp, but in this case the #10 wire is probably too thick to do this well.

SanDiegoChip 01-27-2012 02:25 PM

Never even considered solder. This may well be the solution to this.

cb32863 01-27-2012 02:56 PM

Wirenuts and tape? Twist the wires together, tape them, add wire nut, tape over that. Or Solder too..... could always do a small bus bar type deal too.....

PaulfromNWOnt 01-27-2012 03:04 PM

Strip about 3/4 to 1" back on each wire.
Add 1" piece of self gluing heat shrink tubing to one end.
Fan the ends of both wires.
Wrap each end around the opposite wire.
Tug gently to seat.
Cover with heat shrink and heat it.

No solder necessary.

Alternatively, use heat shrinkable butt connectors sized to the larger wire, and strip double the length on the smaller wire and fold it back on itself.
Heat and shrink the covering to seal.

btrayfors 01-27-2012 04:00 PM

The wire sizes (AWG8 vs. AWG10 or 12) aren't all that different. One approach that might work well for you, providing a strong, solderless, water tight connection, is based on the use of good adhesive heat-shrink butt connectors plus additional adhesive heat-shrink tubing.

1. Use high quality yellow butt connectors, like the Ancor ones sold at West Marine;

2. With your wire strippers, carefully pare down the AWG8 to AWG10 size (which the yellow butt connectors are designed for);

3. Slip some appropriate sized adhesive heat shrink tubing over one wire;

4. Crimp on the butt connector using a proper crimper for heat-shrink type connectors (which don't damage the heat shrink);

5. Shrink the connector; and

6. Slip the additional heat shrink tubing over the entire connector and wire ends, and heat shrink.

This will provide a strong water tight connection.

The use of solder probably isn't a good idea as solder will likely increase the propensity of the wire to break due to wire movement. With very few exceptions, electrical connections on a boat should not be soldered. Good crimps are way better.


bljones 01-27-2012 04:26 PM

I am surprised we haven't heard from Mainesail on this.
cb, i am gonna pull your sailor card! Wire nuts??!!?? On a boat??!!!???

I've seen reducing butt connectors on smaller gauges, but not larger than about 10 Gauge. If it was me, i think I'd use a distribution block.

kd3pc 01-27-2012 04:39 PM


some of these ideas to snip the 8 down in size and to make a somewhat physical connection are dangerous if you hope to pass any amount of current across that marginal connection. It will become a high resistance (hot) short and will impede the current flow.

How are you going to know that the strands you cut away on one end are still in use on the other end? You need an electrical connection that is made of a physically stout connection that is not loose, impaired or faulty by design.

buy the appropriate "bug" or "lug" dependent on the size wires or a terminal strip for that wire you want to use and do it correctly. Anything else is going to fail in short order and you will spend a lot of time,money and blame trying to find where the problem is.

cb32863 01-27-2012 04:48 PM


Originally Posted by bljones (Post 822331)
cb, i am gonna pull your sailor card! Wire nuts??!!?? On a boat??!!!???

Hey, I figured it fit the question...... ;) If I buy the rum can i have it back?

JRA1968 01-27-2012 04:50 PM

First off if you want it to last do it right the first time. List of materials , soldering iron or torch , solder, glue or melt type shrink wrap , ox_gaurd (never do marine wiring without it can get it at any hardware store). To answer your ? on wire sizing the larger gauge is to make sure proper current is supplied to wind gen as the wire run maybe have a drop in current due to length . Cheers and strong winds

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