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  • #78981

    Philip Swofford
    Participant
    Vessel Name: Blue C's
    Engines: Twin Cummins 370B's
    Location: Orange Beach, AL
    Country: United States

    I’m going to install two (One for each engine) emergency shutoff switches in my tower. These would be used in conjunction with the redundant alarm panel I have mounted there, so I can shut the engines down quickly in an alarm situation. These would be normally closed/momentary open switches which I purchased at Seaboard. I plan on putting them in line on the”hold in” coil circuit for the fuel shutoff solenoid. They would be energized any time the ignition key switch is turned on. The run for the wiring will be about 30 feet.

    What gauge wiring would be recommended to prevent any voltage drop issues?

    Additionally, am I missing an easier way to do this?

    Engines are Cummins Model 6BTA5.9-M3, SERIAL NUMBERS: 46070643 and 46050850, CPL: 2208

    Thanks!

    Philip

Viewing 6 replies - 1 through 6 (of 6 total)
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  • #79371

    Rob Schepis
    Forum Moderator
    Vessel Name: Tenacious
    Engines: 6BTA 5.9 330's - "Seaboard Style"
    Location: Long Island, NY
    Country: USA

    Very nice and good move in pairing the 190F switches with the 160F tstats.

    #79354

    Philip Swofford
    Participant
    Vessel Name: Blue C's
    Engines: Twin Cummins 370B's
    Location: Orange Beach, AL
    Country: United States

    Sorry Rob. I haven’t had a chance to look at this forum in quite a few days.

    Thanks for the photo! I’ll take a look at my setup. I don’t have the Cummins control panel in my boat, but I’m sure I can locate that wiring harness.

    My original plan was to make the tie in at the solenoid on each engine with spade connectors in such a way that if I had a malfunctioning switch in the tower, I could disable that circuit and re-enable the lower helm circuit so I could get home.

    I have an Aqualarm panel at the lower helm that alarms on low oil pressure, high engine coolant temp and loss of seawater flow via a Seaboard temp sensor on my exhaust elbow. All the sensors came from Seaboard and I recently changed out my engine coolant alarm switch with the lower temp 190F switch and the 160F high flow thermostat. In talking with Aqualarm, I just have to run jumper wires from the lower helm panel to the upper helm panel.

    If you see any flaws in my thinking here, please let me know. I’m always open to better ideas!

    Thanks!

    Philip

    #79025

    Rob Schepis
    Forum Moderator
    Vessel Name: Tenacious
    Engines: 6BTA 5.9 330's - "Seaboard Style"
    Location: Long Island, NY
    Country: USA

    See attached – This may be old news to you but worth sharing.

    What redundant alarms did you setup on the tower? Custom panel? What are you monitoring?

    #79013

    Philip Swofford
    Participant
    Vessel Name: Blue C's
    Engines: Twin Cummins 370B's
    Location: Orange Beach, AL
    Country: United States

    Thanks Corey and Justin!

    I also thought about a relay, but I also thought that might end up too complicated and more failure prone than this scheme.

    #79001

    Justin Riege
    Moderator

    Voltage drop

    Those solenoids actually have a decent sized coil. Although they don’t require a ton of current to hold position, about an amp. They use a lot for the initial stroke during cranking.

    According to tonys tips the suck in wire, white wire uses 20-30A and the red wire, the hold wire, uses about 1A.

    Fuel Shutoff Solenoid Wiring 101

    Looking at an engine in the shop floor, the wiring harness looks like roughly a 12 gauge wire. For the white wire, the suck in wire for the initial stroke, Assuming 20A at 3 feet this would yield a voltage drop of about 0.2 volts. That same wire at 30 feet would yield a voltage drop of about 2 volts. Probably a bit excessive?

    However, if you put this NC Momentary open in a 30 foot loop on the red wire, the hold wire, 1A would be no problem

    Although some of the others may have a better way to do it. Electrically speaking, its fine to run 1A that far on a 12AWG wire, it will yield about a voltage drop of about 0.095. Go up to a 10AWG and your really good with a voltage drop of 0.0599 V at 1A for 30 a foot loop.

    Aside from the obvious additional failure point, it seems okay.

    You could also do it with a relay, but that would add even more complexity and failure points.

    #78998

    Corey Schmidt
    Forum Moderator
    Vessel Name: Rebel Belle
    Engines: Cummins
    Location: Oxnard, CA
    Country: USA

    All you need to do is run the engine IGN through a N.C. switch just like an engine stop button… typical wire size for e mechanical engine would be around 12 AWG for that long of a run although you could probably get away with 14 AWG if you had to.

Viewing 6 replies - 1 through 6 (of 6 total)

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