vacuum pump on thermostat

[Alex Davies]

Hiya,

I'm thinking of wiring my laval 77 dairy vacuum pump through a thermostat so that it turns on automatically above freezing, then shuts off again at freezing. Anyone else doing this?

I haven't started looking yet, but are there any brands/models of thermostats that folks are using and recommending for this?

Many thanks!

[Shaun]

Most thermostats will not be rated high enough for the current of the motor. I built one using an inexpensive PID controller and a contactor with a higher amp rating. It takes a little work to put it together ,but a fun project. You can use something like this maybe.

https://www.amazon.com/Packard-C230B-Pole-Contactor-Voltage/dp/B07C1X6SHD/ref=lp_306574011_1_3?s=industrial&ie=UTF8&qid=1550412339&sr=1-3

[BAP]

We used to use these all the time on vacuum pumps. You just wire one leg through the thermostat. They are designed for refrigeration. You can also get digital versions for more precision. You want one that will shut off colder than the start up temperature so it sucks all the sap out of the lines as it is freezing up.
https://www.amazon.com/Emerson-1609-101-Refrigeration-Temperature-Control/dp/B003U4N7AI/ref=mp_s_a_1_7?crid=3KARTXY29ZX4C&keywords=refrigeration+thermostat&qid=1550421709&s=gateway&sprefix=refridgeration+thermost&sr=8-7

[Alex Davies]

We used to use these all the time on vacuum pumps. You just wire one leg through the thermostat. They are designed for refrigeration. You can also get digital versions for more precision. You want one that will shut off colder than the start up temperature so it sucks all the sap out of the lines as it is freezing up.
https://www.amazon.com/Emerson-1609-101-Refrigeration-Temperature-Control/dp/B003U4N7AI/ref=mp_s_a_1_7?crid=3KARTXY29ZX4C&keywords=refrigeration+thermostat&qid=1550421709&s=gateway&sprefix=refridgeration+thermost&sr=8-7

Thanks BAP.

This items weighs 33.6 lbs... Wow.

It looks like it's fairly straight forward to hook-up? It's the right price anyways. There's not too much product information on the amazon site... I'm running an 8 awg gauge wire to the vacc pump... Do you know if this unit will be able to handle heavier load/wire size of a 5 hp pump?

Thanks!

[Alex Davies]

Most thermostats will not be rated high enough for the current of the motor. I built one using an inexpensive PID controller and a contactor with a higher amp rating. It takes a little work to put it together ,but a fun project. You can use something like this maybe.

https://www.amazon.com/Packard-C230B-Pole-Contactor-Voltage/dp/B07C1X6SHD/ref=lp_306574011_1_3?s=industrial&ie=UTF8&qid=1550412339&sr=1-3

This looks to be a little above my capability with my limited electrical knowledge... Maybe I'll just go the manual route...

Thanks