Thursday, March 07, 2013

INSTRUMENTATION PROJECT PART SIX: Choose to Fuse

So it's time to start thinking about the wiring the instrumentation project up. Since I'll be running 12 volts out to the helm from each of the 8A4D batteries in the 48 volt propulsion bank. Also since each battery is also rated at around 210 amps it is real good idea to have fuse in line with each of the meters.  On the Paktrakr meter there was a 1/4 amp fuse soldered in line with the power lead.  It was easy to blow it when hooking it up to the battery terminals. So I soldered in an  In-line AGC Fuse Holder so I could disconnect it or replace it easily.  It worked OK. but, the two pieces when disconnected easily separated and the contacts could be come exposed  if one was not careful. Since I would be using at least four fuses in the instrumentation project I wanted to use a better fuse holder. One that would not expose it's contacts or wander around in the confined space around the batteries.


I found what I needed with a In-Line Waterproof fuse holder made by Bussman. The waterproof aspect of these fuse was not that important in my application. Because if these fuses are ever under water I would have other problems to worry about. But, other qualities of these fuses are useful for this project.

For example the yellow color makes them stand out in the dark space where the batteries are located. Even more important is that when disconnecting the fuse the two pieces are connected together and don't separate.

 Also the contacts are securely crimped and not just tack soldered to the contact face like the in line fuse holder I used with the Paktrker.

This makes for a secure connection that will not easily pull apart. For the wire connecting the fuse holder to the battery I cut open some 16 AWG duplex marine wire with a box cutter and removed the red and yellow wires for the fuse connections:

The 16 gauge wire was a little hard to install into the fuse holder. So I spread a little dish washing liquid onto the wire insulation which made it much easier to push the wire through the opening:

At the other end of the wire I crimped on a closed marine lug and used some heat shrink on the crimped end:

So now that I had the In-Line Waterproof fuse holders connected to the batteries on one end. On the other end of the fuse I used a short piece of the 16 AWG wire and connected it to an Anderson 30 amp Powerpole connector. I'll explain why I chose to do this in a future Instrumentation Project post.


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