Forum Discussion

mbopp's avatar
mbopp
Explorer
May 14, 2014

12V Macerator Pump Power

It's a long story but I ended up with a NIB 12V macerator pump off Craigslist. I wanted 12V power by the sewer outlet for it and this is what I came up with:

There was an unused 12V fused circuit on the converter. I got some 12ga flexible speaker wire from the local stereo shop, stripped and tinned the pair on one end, and tied it to the converter and ground buss bar.

On the other end, the pump had a flat 2-pole connector on it and I happened to have a mate for it from another project. I soldered and shrink wrapped it to the power cable and fished it out the hole for the outside shower hose. I have enough slack to pull it 3' out of the hole, and I just stuff it back inside when I'm done with it.

I figured this was easier than running a cable through the enclosed underbelly from the batteries.
  • wmoses's avatar
    wmoses
    Explorer
    May 15, 2014
    mbopp wrote:
    There was an unused 12V fused circuit on the converter. I got some 12ga flexible speaker wire from the local stereo shop, stripped and tinned the pair on one end, and tied it to the converter and ground buss bar.

    I have a FloJet macerator and I agree with the other posters who suggested that the 12ga speaker wire is inadequate. Instead I got a nice outdoor grade extension cord of the right length and 8ga 3 conductor wire from Home Depot (cheapest way to get the right length of heavy duty wire). Chopped off the ends and used that as my direct fused connection to the battery. I elected to put an inline 15A fuse in the positive lead from the battery and then I ran the wire under the trailer back to the sewer connector. This way the power is always available to the macerator without having to mess about with the converter.
  • SCVJeff's avatar
    SCVJeff
    Explorer
    May 15, 2014
    Make DARN SURE that pump has all the current it needs to do its job. IMO- 12ga for anything longer than a few feet from the battery is looking for trouble.

    You're gonna have a very unpleasant surprise when a big wad of TP gets in the shreadder and stalls the pump.
  • Lantley's avatar
    Lantley
    Nomad
    May 15, 2014
    mbopp wrote:

    I figured this was easier than running a cable through the enclosed underbelly from the batteries.

    It may have been easier however, I don't believe you have the proper wire or fuse. I would be concerned that the macerator may overload the circuit
  • Fishinghat's avatar
    Fishinghat
    Explorer II
    May 14, 2014
    Like the other posters, the use of speaker wire had me a little alarmed as these macerators can draw 20 amps or more. Twenty amps requires 12 gauge wire. For safety's sake, I installed a 30 amp fuse on 10 gauge wire to the macerator I had in my boat. I never had any problems and it worked just fine. Maybe my installation was a bit over capacity, but it made me feel safe.

    Using a wire that is too small can cause the wire to get hot and burn the insulation, and/or cause the voltage to drop which could damage the motor to the macerator.
  • mbopp's avatar
    mbopp
    Explorer
    May 14, 2014
    2oldman wrote:
    If that works, great. Some mac's can require beaucoup power.

    Yeah, the pump has a 20A fuse in its switch.
    I checked, the WFCO is rated for 20A per circuit on the 12V side. Hence the 12ga wire.
  • 2oldman's avatar
    2oldman
    Explorer II
    May 14, 2014
    If that works, great. Some mac's can require beaucoup power.
  • Bumpyroad's avatar
    Bumpyroad
    Explorer
    May 14, 2014
    I was lucky. my sewer hookup was in a compartment next to my generator and I just tapped onto the two leads there.
    bumpy

About DIY Maintenance

RV projects you can tackle on your own with a few friendly pointers.4,352 PostsLatest Activity: Dec 11, 2017