• Creator
    Topic
  • #58687

    Luke Nelson
    Participant
    Vessel Name: Southern Image
    Engines: QSC 8.3 540hp
    Location: Perth
    Country: Western Australia

    Hi Guys,
    Does anyone know the temperature the attached temp switch activates at? It it sitting on the exhaust mixer.Basically the engine has done 2 impellers in a month and not shut down. The shut down circuit is working and tested, I am not sure on the temp switch. I could have been that it was seen with no water just in time both times. The engine has not visibly overheated.

    Short of just replacing what else can be done?
    It does not seem to have a coolant sensor unless it is hidden on the side of the engine against the bulkhead?

Viewing 5 replies - 1 through 5 (of 5 total)
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    Replies
  • #58862

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

    The ones we use are normally open (when holding it in your hand) and they close on rise to complete the simple alarm circuit. Yours could be normally open (N.O.) or normally closed (N.C.) (and open on rise) depending on the type of circuit. Figure that out for testing the system. You tested the switch per Justin’s instructions, now take it a step further and re-install the switch and test the system. If it’s N.O. you jump the leads to test, if it’s N.C. you pull a lead.

    What about the impeller? Install a new (not old new) one and lube it up good and see how it does? My lube of choice is KY Jelly and I would think it is available worldwide..

    #58851

    Luke Nelson
    Participant
    Vessel Name: Southern Image
    Engines: QSC 8.3 540hp
    Location: Perth
    Country: Western Australia

    Thanks Justin,
    Heat gun worked for the test a bit of peace of mind that ot will shut done if it gets hot.

    Luke

    #58718

    Justin Riege
    Moderator

    I am not sure about that one but the one we sell trips at 180.

    If you suspect it isn’t working you could swap it out or test it.

    Since it looks like you have it off it would be pretty easy to test if you have a multi-meter, heat source and thermometer. Just carefully and slowly warm it up til it trips. A heat gun works great, or very carefully with a small propane flame. Heck even a lighter might work.

    On ours you don’t even really need the multi-meter, you can hear it click. But probably best to check it for continuity.

    #58700

    Luke Nelson
    Participant
    Vessel Name: Southern Image
    Engines: QSC 8.3 540hp
    Location: Perth
    Country: Western Australia

    Thanks Rob,
    The 2nd impeller apparently may not have been new and only lasted 3 weeks or a few trips. I pulled the left overs out of 2 out of the heat exchanger as the it was almost totally blocked with rubber.

    The intake is clear and the genset is pumping water well out the exhaust. Internally the pump looks ok and has not had a lot of use <1000 hours.

    #58699

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

    So basically it’s “eating impellers” ?
    What’s the condition of the pump internally ? the cam ?
    Has the seawater intake been 100% verified as to zero restriction ?

Viewing 5 replies - 1 through 5 (of 5 total)

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