Set point for vacuum thermostat control

[SandMan]

Question? I have a "new" vacuum set-up this year. Atlantic Fluids 3hp with a solid state starter controlled by a Johnson Controller thermostat. For those that have a thermostat on your vacuum system, what do you use as your "set-point" and why? I've had times in the past with bright sunny days and no wind that my tree's will run below 32 degrees, but generally they don't start up until the temp has reached the high 30's (this was on gravity).

Thanks in advance!

Mike

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[BreezyHill]

I set to 28 degrees. Last season I spent several mornings checking the lines to witness thawing of different ladder designs. On a sunny day the lines will be thawing a 29 degrees with the vac on. On a cloudy day you were at temps of 32 and 33 before you saw any movement in the lines.

The ideal situation is to have two temp units...one for cloudy and one for sunny days. I have a design for a unit to switch between the two but have yet to find the parts that will make the unit work as I desire.

While running the vac on a system that has no flow, it is often thought to cause micro leaks on weak connections. In my opinion, I will risk a few hours of this chance of leaks to have the system drawing down the vac as soon as the lines are clear in order to get peak production. I will find these leaks and they will be repaired.

I manage my system for profit. An expense that has no return is waste; but the expense of a few dollars in electricity over the season is off set by the production of a quart of product.

You must also look at your control units location in relation to your bush. My sensor must be set on the north side of the sugar house so that it does not get any sun light; but it is then open to a westerly breeze that flows down the brook bed. This location is typical to part of my bush.

This season we tubed part of our main bush that was never tapped due to tree size and the amount of tubing to bring 450 taps online. After close scrutiny this part of the bush has been found to be a great producer due to it is protect from the west winds that limited our production in 2014. This section of the bush runs 2-4 degrees warmer than the sugar house, but is still required to go thru the ladder lines. The summer of 2015 we will be renting a ladder lift to add another wet line to the current wet dry line system on the ladders to capitalize on the production of this section of the bush. On a mid season sunny day, the temp will rize from 28 to 29 in 20 minutes, while in early season it can take 2 hours.

When setting a temp unit consider: your bushes temp in relation to the sensor location on sunny and cloudy days, set it for the lowest temp you have had sap movement in the bush, install a sensor bypass switch that will allow quick turn on of the pump when the sensor is not set properly and you see thawing of lines or sap production, install a kill switch of those days that the temp only reaches 30 degrees for early season. No reason to have that pump running 24/7 when the temp is 30 degrees and the wind is whipping at 20 MPH.

It seems like a lot of extra switches on a control unit that was going to make your life easier; but $10 in switches can save you thousands of dollars over their life time in saved electricity, pump and motor wear. I saved the cost last season in oil changes on the pump. when you change the vac oil every 200 hours that is only 8 days of the pump running 24 hours on a 30 degree cloudy days with a breeze.

Ben

[SandMan]

Ben,

I appreciate your comments about "sensor location". Totally makes sense. Currently, the sensor for the vacuum is on the south side of the sugar house up under the eve (out of the sunlight)...still seems like it is reading a few degrees higher then a regular temperature sensor that is on the north side. And yes, I have two small sugar bushes that have different sun exposure. Will have to do some fine tuning once the season starts!

Advanced thermostat settings! I'm using a Johnson Control A419. It is currently set with cooling set-point "cut-in"...so when the the temperature gets to 29 degrees (if that is what I set the set point at) it energizes the line. It also has a "DIFFERENTIAL" setting which is the temp that de-energizes the line. The factory setting is 5. In other words, if you are using a cooling mode with a "cut-in" (energizing) at 29 degrees, the line won't "de-energize" until the temperature hits 24 degree which seems a little cold. I'm sure all the lines will be frozen long before then.

Question: For those that are using a sensor with both a set point and differential, how far below your set point do you set your differential?

Thanks,

Mike

[BreezyHill]

Mine is at zero. The sap freezes in the dark rather quickly, so I have cleared as much slush as possible and the warmer parts of the bush are frozen also by the time the set point is reached.

When you start working with high vac you will be amazed at what you bush does. The runs starts sooner last longer and the peaks are higher and longer. It is like giving your bush Viagra. Sorry couldn't resist that.

Nice pump set up!

The sensor under the eve is a poor location: heat on the building wall will rise up to the eve during the day and heat the area
it will be more protected from air movement on breeze days that will warm the bush on cloudy days
the building surface will buffer all increases and decreases of temperature.

I would Relocate to the north side as trying to find a good set point will be very trying and frustrating as it will be different nearly every day of the season.

Ben

[tuckermtn]

with our A419 we have it set to cut out at 31 and on at 34 (differential is 3)

also note that on a A419 you can set a delay of 1 min, 5 min, etc so that when the temp is right on the edge, you don't short cycle the pump.

[SandMan]

Good point Eric. I think the factory setting is 1, but a longer delay seems like it would be easier on the pump.

Mike

[MAPLE FARMER]

Ranco makes an awesome digital temp controll and u can pick it up on amazon for $47 it has a cooling and heating mode and u can set the differential up to 30 degrees apart. I use a 30 amp relay to start my pump which is around $20 on amazon as well (You would be amazed what you can find for sugaring on amazon and how much money you can save). I have my pump set so it will turn on at 34 degrees and shut off at 28 degrees as it takes sap a little longer to freeze at night then water. So the temp controll has a differential of 6. Just some food for thought.

[Beerclouds]

I bought an inkbird itc-1000 temp controller...cant quite figure out how to set my turn on number and shut off number....im also using a 30amp relay

[Lloyd'sMapleSyrupandSap]

I'm looking for a temperature controler that's web/wifi enabled to start and shut down vacuum pump. Any suggestions?

[Lloyd'sMapleSyrupandSap]

I would use two temperature sensors and monitor them both. One would be in the sun, the other would be in a shaded spot, so as to get true air temperature. Sometimes the sap will run if the sun is shining brightly, even if the air temp is below freezing. The temperature in the tree and in the lines is above freezing. Also later in the season, the tree is thawed completely through and takes a low temperature to freeze it back up. Monitoring the temperature remotely, aka cell phone, would make it possible to adjust to changing conditions. You might also want a third temperature sensor in a tree to monitor the temp there. i have internet on location, i have a wifi thermostat in my home that is web connected and i manage from my cell. problem is home thermostats don't go down to 25 degrees. I think i need a refrigeration thermostat, close on temp rise, for the purpose, i havent found one yet but I'm sure someone makes them.