On Wednesday 18 November 2020 12:49:21 Chris Albertson wrote: > How many watt hours does you motor burn if left running overnight? > Yes I know it depends on the load and the speed.
Cheapo induction motor, smart reprogramming of the vfd to hold up its torque at lower speeds. I ran it at 11 g's doing the motor mount cutouts for about 5 hours yesterday, brought the tank up to 36C, and the motor to 38C. But slow it to 4k, where my lf boost is kicking in and it will get hot. > If I did the math right and did not drop a decimal point, I think > roughly 1 WH will heat a liter of water 1 degree C. > > Let's say you have a 100W motor running 8 hours that is 800 WH and you > would expect to heat a four galon (16 liter) tank to 50C over ambient > enough to burn your fingers and soften plastic hoses. Convert 1hp to watts. The motor coming is a 2.2kw model but the vfd will limit it to less unless I reprogram it. If I have to do that, I'll likely get a 3kw vfd. But we'll see. > When I ran my > water cooler I used an old 50 gallon aquarium tank. Even with 50 gal. > it would heat up overnight. It is pretty easy to nearly boil a > bucket of water in 8 hours even with a small 100W heater. Even with > a 50 gal tank I use a fan to blow air over the top of the tank. A > primitive evaporative cooler. We were doing about 100 to 120 watts > with 8 to 12 hour runs. Others were using trash cans filled with water > but I just happened to have an old 50 gal tank. > > Do you have a water meter? I'd put one of those meters on the motor > and calculate water heating. > No meter. Just stick-on lcd aquarioum thermometers that top out at 40C. New motor is about a week away, stuck in CA customs north of the mack bridge I expect. > > I > > On Wed, Nov 18, 2020 at 7:34 AM Gene Heskett <ghesk...@shentel.net> wrote: > > Greetings all; > > > > Leaving it run at 4g's overnight wasn't quite the result I expected. > > > > Going out to check on it and work on the BS-1 project, I could feel > > the heat on my face from 3 feet away, but it was still humming along > > at 4g's. No smoke. But the hoses on top of the motor were melted, > > for about 3" away from the spigots on the motor. And the tank had > > lost 3 of its 4 gallons of water with no sign of where it went, > > nothing wet so it either came out as steam, or it melted the hoses > > quite early and its had time to dry. Shut it down. Tank is cold. > > Pump lost prime for lack of water at the intake. > > > > I think I can say that experiment was a failure. But the motor still > > runs whisper quiet. And it looks like I need to get another big coil > > of hose, or figure out how to pull at least 6" thru the cable chain > > to reach the motor with "good" hose again. Plenty of spare at the > > tank end of the run. Sigh... It, and the motor mounts, will have to > > await the arrival of the better motor. > > > > Cheers, Gene Heskett > > -- > > "There are four boxes to be used in defense of liberty: > > soap, ballot, jury, and ammo. Please use in that order." > > -Ed Howdershelt (Author) > > If we desire respect for the law, we must first make the law > > respectable. - Louis D. Brandeis > > Genes Web page <http://geneslinuxbox.net:6309/gene> > > > > > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
