What time of day does your sap stop flowing?

[NTBugtraq]

Ok, I'm trying to figure out some guidelines that will help me decide when to turn off my pump that's on the main line. I can certainly stand at my storage tank for 10 minutes and listen, but there has to be more scientific methods.

I don't know what they are, but could it be that if I've been above 0c for x hours sap stops? Could it be if the temperature drops x degrees (above freezing) the sap stops? I know sap flows based on barometric pressure, so if it drops x amount, then sap stops?

My main line isn't unfrozen until about 11:00am, and sap seems to stop by about 6:00pm for me, but that seems to be unscientific, so looking to see if anyone has any better insights.

Cheers,
Russ

[CampHamp]

Russ,

I think the best method is temperature. You can find thermostatic switches on EBay for 120V and 12V - if you go that route, make sure their range includes temps you want and allows you to set the range between start/stop (not a fixed 2 degrees, for example).

What kind of pump do you have? Is there are concern about freezing (i.e. no releaser)? Do you have a screen before the inlet? These answers will help you figure out your temp settings.

I have a diaphragm pump with a screen to block ice and I set my shut down to BELOW freezing (-2.3C - it runs to -2C sometimes or the sensor is off) so that sap doesn't fill the pump while it's off. I start it up at 1C, knowing that my screen will stop ice at that point.

The only problem is when you get long lags at just below freezing (like -1C for 6 hours) then your pumps running for no reason -- I manually shut it down on those nights. I will be trying to setup a "delay relay" soon so that it will shut down 1 hour after freezing (or some other reasonable logic like that).

Good luck with it and let us know how it goes!

[NTBugtraq]

Thanks Jamie, stuff to look into. I have a self-priming centrifugal pump (which I manually power), in a wooden box with an incandescent light (which I don't turn off). Its directly attached to my main line at the lowest point. So far, no problems keeping priming fluid in the pump, but you're right, its running far more than it needs to (even when I turn it off over-night).

What's a releaser?

Cheers,
Russ

[CampHamp]

The Big Boys pull sap into a collection chamber using air suction and, when the chamber fills, it drops the sap all at once and closes again to start the cycle again. That way they can pull ice through and not worry about it hitting a pump and they get high pressure without any sap to keep the pump primed.

[markct]

Its by temp not time, sometimes it runs all night. we had a hard freeze then no freeze for 3 days and it ran around the clock got over 2 gal a tap each day.

[maple flats]

Most bigger operations run non stop unless there is an extended freeze.

[Burnt sap]

Every night at 11 o'clock. :lol: I know smart a@@ right. but the door was left open.