ahmet erkan wrote: > Hi Jim, > Next time keep some cognac in your boat, it may not keep you warm but > at least > you will have a smile on your face when they find you :-) > Anyway, getting back to the failure mode analysis : > I am glad you determined the root cause of the heat pump failure. > Actually you found two root causes, the open 7.5uF capacitor and the > dead battery > at the thermostat. > If you ever need to test your 7.5uF capacitor again, I recommend > you connect the > capacitor across your AC source and measure the current through it. > I recommend you short the terminals of your series ammeter as you > connect the capacitor > across the line and then open the meter terminals, this way, the > initial current surge will > not take out the fuse in the meter. > (Wear rubber gloves and eye protection or be very carefull, or ideally > do both during testing) > The 7.5uF cap across 120Vac at 60Hz should have about 340mA current > through it. > The equation for a 1uF capacitor getting discharged by 100k in > 0.063 seconds et cetera > has some major errors, I recommend you use to the current measurement > described above. > All the best, > Ahmet > sv8827 > > > Date: Wed, 2 Feb 2011 18:04:12 -0500 > > From: [email protected] > > To: [email protected] > > Subject: Re: [Liveaboard] Motor start capacitor. > > > > Jim Lynch wrote: > > > Ben Okopnik wrote: > > > > > >> On Tue, Feb 01, 2011 at 07:25:00PM -0500, Jim Lynch wrote: > > >> > > >> > > >>> > > >>> > > >> The general rule of thumb is that you should replace those caps with > > >> their exact replacements, or at least stay within 10% of the original > > >> capacitance. In my experience, as long as the voltage rating is > the same > > >> or higher and the capacitance value is somewhere in the same universe > > >> with the original one (-50% - +100%), it doesn't seem to make > much of a > > >> difference for start caps (not true for run caps, though.) Don't > ever go > > >> below the original voltage rating, though; the fireworks can be > pretty > > >> impressive. I know _all_ about it. :))) > > >> > > OK just as a followup. The cap was bad however when I replaced it the > > motor only ran for a few seconds. I called Mermaid in Florida and > > talked with Brian. Now it turns out Brian is a sales geek, not a > > support fellow. He instructed me to remove the thermostat and twist > > some wires together. Hm, so the blower IS working. He then said the > > thermostat was bad. I looked at it critically and realized the 2AA > > batteries were not 100%. In fact one of them was leaking a bit. I > > replaced them and ...........It works! I'm not basking in warmth. > > Well, it didn't hurt that the temp here got to 67 today, but the > > A-C/heat pump works again. > > > > Jim. > > _______________________________________________ > > Liveaboard mailing list > > [email protected] > > To adjust your membership settings over the web > http://liveaboardonline.com/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.liveaboardonline.com/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 > ------------------------------------------------------------------------ > > Thanks for the tip, however my meter does measure capacitance but does not measure AC current. Oh and I don't have insulated gloves on the boat. :)
Jim. _______________________________________________ Liveaboard mailing list [email protected] To adjust your membership settings over the web http://liveaboardonline.com/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.liveaboardonline.com/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
