The problem with the block high temperature switch is the thermal inertia of the block.
If the seawater flow stops, as from a bad impeller or debris in the suction line, the first thing to get hot is the rubber exhaust hose. If the flow is completely stopped, as from a piece of impeller in the little pipe that sprays water into the exhaust elbow, the hose may be burned up before the block high temperature switch shuts down the genset. I know this from personal experience. The way to avoid this is to install a shutdown switch on the rubber exhaust hose as outlined in my email of yesterday or so. While you are at it, add the strainer downstream of the seawater pump, and add a shield around the seawater pump shaft to keep seawater from spraying into the alternator when the pump's seal fails. Do the same for your main engine, but connect the exhaust temp switch to an alarm instead of a shutdown. Further, it is a Good Thing to have mechanical gauges on the engines (genset and main engine(s)) themselves so you can see what is going on while at the engineside. It would be a good idea to have indicators to show which shut-down switch but that has not been needed so far on my vessel. I have never had a problem with any crankcase oil. Once the nut on the output shaft of the main transmission loosened up and allowed some transmission oil to escape causing some slippage of the clutches noticed by surging of the engine rpm. I went to idle immediately and upon inspection found a spray line of oil in the plane of rotation of the propeller shaft coupling. I added oil and tightened up the coupling nut when I arrived in port (Norfolk). The usual problem is fuel or cooling. A cooling problem will indicate an overheat condition on the temp gauge. If not there, then it is a fuel problem. Of course you have an electric fuel boost pump and fuel pressure gauges on the fuel system to troubleshoot. (see my archived message "Bandersnatch's Fuel System". Norm S/V Bandersnatch Lying Julington Creek FL 30 07.72N 081 38.4W > [Original Message] > From: Philip J. Rosch <[EMAIL PROTECTED]> > To: TWL2: <[EMAIL PROTECTED]> > Date: 1/4/2008 3:30:50 PM > Subject: (T&T: & TWL2:) Re: & TWL2:) Re: onan 8kw gen monitoring > > > I've never exercised the low oil pressure shutdown on my ONAN, but I can > tell you from much experience the high temp shutdown covers belt and > impeller problems like a breeze! There is a point where one needs to avoid > the angst of backup systems to backup systems and go cruising. I'm pretty > anal, but decided ONAN has it covered. > > Regards.... > > Phil Rosch > Old Harbor Consulting > M/V "Curmudgeon" MT-44TC > Currently Lying Bond Creek, NC. > > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of > george > Sent: Friday, January 04, 2008 11:52 AM > To: [EMAIL PROTECTED]; badornato; TWL2: > Subject: (T&T: & TWL2:) Re: & TWL2:) Re: onan 8kw gen monitoring > > > How can you detect when/if one or the other is NOT working? How do you > check that? If that sensor goes bad, the generator could blowup before you > are warned. > > ----~------~----~------~--~--- > > > --~--~---------~--~----~------------~-------~--~----~ > To UNSUBSCRIBE or change your email from live to digest or web board only, please send a request to Andina at [EMAIL PROTECTED] > POST messages in an email to [EMAIL PROTECTED] > View the live board at http://www.yandina.com/TWL2 > -~----------~----~----~----~------~----~------~--~--- _______________________________________________ Liveaboard mailing list [email protected] To adjust your membership settings over the web http://www.liveaboardnow.org/mailman/listinfo/liveaboard To subscribe send an email to [EMAIL PROTECTED] To unsubscribe send an email to [EMAIL PROTECTED] The archives are at http://www.liveaboardnow.org/pipermail/liveaboard/ To search the archives http://www.mail-archive.com/[email protected] The Mailman Users Guide can be found here http://www.gnu.org/software/mailman/mailman-member/index.html
