Automatic starters

[sgsommers]

Does anyone have any experience with different types of automatic vacuum pump starters and if so what preferances or opinions do you have. I believe ther are several types on the market and not all are thermostatically controlled.

One is controlled by flow, if the flow of incoming sap meets or exceeds a preset flow then the vacuum system starts.

Another system I believe monitors the transfer pump, meaning that if the transfer pump has to pump sap out it then starts the vacuum system but if the transfer pump does not run again for a preset time the system shuts down.

The the temperature controlled system is in ther to.

Maybe there are more systems available with different configurations.

Any info would be helpful..

Steve

[Parker]

In Hill I have a dairy tank thermostat set at 30 deg,,if it is 30 or above the pump is on,,origanilly the thermostat would turn on the cooling system for the bulk tank to keep the milk cool,,,,now it triggers a magnetic starter and that starts-runs the pump,,,,,,,on our tour of large producers in northern vermont this spring I talked with a lot of producers about their vaccum systems,,,they all seemed to prefer the systems that were started by sap flow into the releaser,,,as they pointed out,,, with varrying topograhphy there are microclimets in every orchard,,,just cause it is not warm enough for sap to run where the theromstat is dose not mean sap is not running in the woods somewhere,,,,,also if it gets really hot and the sap stops running,,my pump is still chugging away unless I go up there and shut it off.......

[sgsommers]

I also like the idea of the switch being controlled by the flow. There has been times that my thermostat is not kicking on the pump but the sap has been running for some time.

[powerdub]

I may be in the minority on this one but it has to be freezing hard before my pump shuts off. I think my pump comes on at 29 and off at 26. It always come on before the sap flows and shuts after the sap freezes. If you have the time you can pattern your sap flow and guess most of the time the temps. If you subscribe to thier way of thinking it is no different. At some point the sap started above first and when it finally thawed at the dumper it could have been running an hour. Now you have to build vacuum to catch up. I am trying to anticipate the run short of leaving my pump on 24/7. I know someone who does that by the way, with great success.

[emericksmaple]

Ok here is an electircal question for those who know electric. I am going to put our new vaccum pump on a theromstat to start it. In a farmtek magizine I have, they have a digital Thermostat in that ranges from -50 to 212. It also Says 120/208/240VAC input 50/60Hz. If I buy this is this all I would need to make it work or Would I need a magnetic switch as well????

[Fred Henderson]

I think that the stat will have to control the coil in a magnetic starter. That is a lot of line current to got thru the stat.

[powerdub]

I don't see why you couldn't run right off the stat. It has a 30 amp capacity if we are looking at the same thing.

[brookledge]

First question is what is your vac. pump going to use for electricity? What voltage, What current and how many phases? First of all most all are going to be single phase but there is a possibility that if you have purchased a used unit it could be three phase. If you have access to three phase and your motor is capable of three phase then I'd recommend going that route because three phase is the most efficient and will save you money in the long run.
Next is to determine the voltage. most motors are able to switch the voltage by switching two wires inside the motor you just need to have the wiring diagram.
The current(amps) will change depending on your voltage. Look on the motor for the specs.
Again 220 will operate a little more efficient than 110 in the long run and will draw half the amps. Ie. motor running on 220v might use 15 amps at 110 the same motor will use 30 amps.
So once you determine what your motor draws for amps. then you can go to the switch you are looking at to see if it can handle it. You stated it is rated at 120/240/208 but don't say the amperage rating.
If the switch will not work with it then you have other options such as the magnetic switch.
Sorry for being long winded.
Keith

[emericksmaple]

ok, I am going with 220 single phase. The pump calls for 20.2 amps. The theromstat says it will handle 30 amps. Do this still sound ok????

[powerdub]

I would err on the side of safety, or at least care. Your amp draw at start up could be a lot more for a few seconds and then fall back to 20 amps. That stat may take that for a while and it may be built to take it for a long time. In dealing with the unknown at this point I would recommend a contactor. You could always call them and get more info on it. The other thing with a contactor is they have heaters in them rated for your motors horse power and it provides motor protection. Just a breaker is not really good motor protection.

[sugaring42long]

There are two different ratings for switches and relays. One is for resistive loads such as heaters or lighting and is in amps and the other is for inductive loads such as motors or solenoids and is usually in hp at a certain line voltage.

That 30 amp rating is likely for resistive loads and and would probably fail after a few cycles with an inductive load. Look for a hp rating on the stat.

[emericksmaple]

Where can i find a magnetic switch for doing this??

[Parker]

Page 377 of the Grainger catolog,,,mine is part # 4DD96,,,I also got a thermal unit part # 1H623,,,,

[brookledge]

You can go to an electrical supply or order from grainger or McMaster Carr. Most all midsize and large air compressor use these so that they don't burn out the pressure switch.
Keith

[oneoldsap]

Eric you do need a mag switch. We run that same Farm Tec Therm switch that you have. Works like a charm once you get it set.

[danno]

What's the differance between "inductive amps" and "contact rating resistence"?

I want to put a thermostat on my Delaval 75 which is runnong at 230 volts, 12.5 amps and a mechanical releaser. Thermostat I'm looking at is rated at inductive - 240/8 amps; contact rating 240/22 amps?

Will this work or too small? How about with a magnetic starter?

[danno]

Wow, I'm dizzy after looking on line for thermostats. Can anybody refer me to a themostat that will run a 230 volt/12.5vamp pump?

[Parker]

I just got the new FARMTEK catolog,,(www.farmtek.com) 1-800-327-6835,,Now keep in mind someone ealse set up my system for me and I got the parts through Grainger (expensive) BUT I think everything you need is in this catolog for much less,,,I AM NO ELECTRIC PRO,,by any sterch BUT on page241 item #102720 is a thermostat that looks to fit the bill (I could be wrong),,,on page 256 there are moter starters for most applications,,if this stuff is not right I can give you the part #'s from Graingers but they are ALOT more expensive,,,,,,this catolog has all kinds of stuff that can be used in sugaring,,we have had good luck with them in the past