Sunday, March 17, 2013

INSTRUMENTATION PROJECT PART 9: CONNECTIONS

The battery end of the project has been wired up with fuses and Anderson connectors. The helm meter panel like wise has been wired and tested. So the only thing that remains is to connect the two with wires. There are four meters each monitoring one of the four 12 volt batteries in the 48 volt electric propulsion string. I thought about individual wires in a harness, duplex wire and various other cable types. Happily I found what I needed in a trash bin that fit my needs perfectly.
    I was doing some freelance work in a building that was undergoing some renovation and found about fifty feet of E90298 cable made by National Wire about to be thrown out. It had ten 20 AWG wires inside a durable UV resistant cover.  It even had a shield around the bundled wires. The wires were also tinned making it perfect for the marine environment on board as it would be more resistant to corrosion than bare copper. Best of all I could not beat the price FREE! I love to recycle where I can and this cable instead ending up in a landfill  is perfect for the instrumentation project interconnection.

I love it when a plan comes together like this. Because I only needed eight wires to measure the four individual battery voltages it meant I had two spare wires that I might use down the road for something. The only issue I thought might be a problem is each of the 10 wires in the harness were different colors. Which could be confusing down the road in trying to figure out which wire was positive or negative when connecting or trouble shooting. But this was easily solved after I first assigned the color coded wires to each battery:

Because of the various colors used to connect the batteries I decided to cover each wire with two different colored heat shrink at the battery end. Red for the wires that went to the positive battery terminals and black for wires that went to the negative battery terminals. These would help avoid confusion and mis-connections even though the Anderson Powerpole connectors where color coded. It just adds helps eliminate confusion. It would also add another layer of protection for the wires:

.I also put on some  General Purpose 1/4-inch Braided Cable Sleeve over the heat shrinked wires. This not only kept the wires together making for neater wire runs but, also added another layer of protection to the wiring harness:

All I needed to do now was crimp on the Anderson Powerpole pins and insert them into the proper color coded powerpole housing and the battery end of the instrumentation project was done:

 For the helm end of wire I chose to enclose each pair of wires in white heat shrink:

and connect them to the helm panel meters box:

After an operations check out the project was just about complete. All that I needed to do was to add a little sealant to the back of the Anderson Powerpole connectors to water proof the wires and also inside and outside of the meter enclosure box where they connect up. I used Marine Goop. Once that was done it was time to move on to wiring the battery current meter.


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