auto temp sensor

[PATheron]

I think Id like to put a temp sensor at my shed for my vac pump. I live in a little dip on top of a big hill. My surarbush has roughly 100' of elevation difference with my shed being roughly in the middle of the elevation difference. What would you guys suggest my set points should be for the sensor? I want the pump running for sure whenever ANY of the lats could be thawed out and then once they ALL freeze I want it off. Dr. Perkins- Ive read your research paper on temp deviations in the sugarbush and I know things can be quite different at different points in a situation like mine. What would you suggest? Maybe on at 30 degrees and off at say 25? I dont care if it runs more than it needs to at all. I want to be certain that theres alway suck on thawed lines but at 10 hp it starts to get a little expensive around the clock for 3 months. Thanks Theron

[Thompson's Tree Farm]

Theron,
Could you get 2 or 3 of those thermometers that record the high and low for the past 24 hours? Put them all in one place so you can compare how they read, then place them out in different points in your bush to get an idea of what some of the temperature differentials really are. Then you would have some idea of where to set the switches. Just brainstorming here....
Doug

[PATheron]

Doug- Where do you buy them and how much do they cost? Theron

[DrTimPerkins]

Maybe on at 30 degrees and off at say 25? I dont care if it runs more than it needs to at all.

There is so much variation in temperature that it is impossible to be certain that lines are frozen in all parts of the bush from a single measurement. If you really don't care that it runs more.....leave it on all season, or only shut it off when the temperature drops and it is cold for a couple of days.

[jrthe3]

theron you should hook that pump up at the pole skip the meter

[danno]

Doug- Where do you buy them and how much do they cost? Theron

Radioshack, maybe Walmart. $20-$30.

[danno]

Theron - I don't know if you already have your sensor - but post 17 in this thread has a couple of links to previous threads on this issue with real good info on what to use, how to wire etc.

http://www.mapletrader.com/community/showthread.php?t=3855&page=2&highlight=temp+sensor

Quick question - I like to keep my vacuum on until everything freezes up to reduce bacteria back flow as well, but have had problems with the air vapor freezing in my vacuum regulator thus driving my vacuum levels to meltdown stage. Anybode else experience this or find a way to overcome this. I guess a heat source close to the regulator would resolve this.

[Thompson's Tree Farm]

Theron,
Try Farmtek. I get a catalog but they are online too. They have digital ones in the 24$ range and regular mercury ones for about $12. Problem would be determining the times of the highs and lows.
Doug

[PATheron]

Syrup Doc- Thats exactly how I did it last year. I think I figured out about what its going to cost me today. Looks like about .60 an hour or like 14 bucks a day. At that rate Ill keep doing what Im doing and just turn it off on the deep freezes. I thought it would be costing me more than that. I still think it might be a decent Idea though if I use pretty broad setpoints. Ill have to see how the time goes but now I know I wont go bankrupt at least while its running. Theron

[DrTimPerkins]

Syrup Doc- Thats exactly how I did it last year. I think I figured out about what its going to cost me today. Looks like about .60 an hour or like 14 bucks a day. At that rate Ill keep doing what Im doing and just turn it off on the deep freezes. I thought it would be costing me more than that. I still think it might be a decent Idea though if I use pretty broad setpoints. Ill have to see how the time goes but now I know I wont go bankrupt at least while its running. Theron

If you use very broad and conservative setpoints you'd likely be just fine.

The newest styles of pumps for maple use have variable frequency drives (VFDs), which ramp down the rpm of the pump motor to maintain a set vacuum level at the pump. If the system is tight, and the sap isn't running, they'll run very slowly and cost very little in electricity to operate, Much easier on the pump as well compared to running full-bore all the time. VFDs are costly little buggers though, but save in both electric cost and pump wear and tear.

[Brent]

I was up at my dealer's the other day and picked up a spile adaptor for a vacuum / pressure gauge.

On the way home it occurred to me that maybe you could put your pump on a switch sensing the vacuum / pressure in the tree. These guages show pressure during the day that often goes to the high teens in lb/ sq in and then decline at night and then go to vacuum as the tree tops freeze, then swing back to pressure the next day as it warms.

You might want to put the switch on a tree that is just under tapping size so the system vacuum wouldn't interfere.

[KenWP]

I have used VFDs for years for water for huge hog barns. You alwasy have the same water pressure instead of ups and downs. The ones I used had the directions in Dutch so we had to have them translated. Also used a submersible well pump that did the same thing and we finally had enough water to keep the farm going for a change.