Converting pump to vfd

[madmapler]

Back again with yet another question. I just bought a sihi 2 stage pump that has no motor. It had been run with a 10 hp. Is it possible to set it up with vfd without too much hassle? Has anyone converted their pumps over? Thanks in advance.

[maple flats]

I think that is often done with 3 phase power, I don't know if you can do it with single phase. I'll bet someone will chime in. With 3 PH you can set it for a certain vacuum level and the pump will run at the RPM needed to get that.

[Amber Gold]

If it has no motor, then you can put whatever you want for a motor. With that big of a pump, I'd definitely go three phase. The motor's cheaper to buy and far cheaper to operate. You will spend a lot on a VFD, but I think it'll be worth it. Also, you'll easily be able to soft start it w/out overloading your electrical system.

[lpakiz]

For a VFD converter, check out Factorymation.com. They also have a live chat feature, which is MOST helpful. As far as auto-controlling the speed, not sure where to get that transducer or how to program it.
My Vfd Single-to-three phase converter for 1/2 HP was $122 plus a reasonable shipping fee. You can program the acceleration and deceleration, plus a whole lot more.

[madmapler]

I saw a vfd on ebay that serves as a phase converter as well. We're fortunate to have electricity around these parts let alone 3ph. I'm wondering how to get it to auto regulate with the desired vacuum.

[Mark]

I saw a vfd on ebay that serves as a phase converter as well. We're fortunate to have electricity around these parts let alone 3ph. I'm wondering how to get it to auto regulate with the desired vacuum.

Most VFD's from what I have been told is you can put single phase in and run a 3ph motor. You have to get a VFD rated for double the hp if you are using 1ph input. You would then need a pressure tranducer to measure the vacuum. I am putting a VFD on my 20hp 2 stage Sihi for next year and have been talking to a supplier. The motor should be rated for inverter duty because they can heat up at slower speeds. The fan on the end of the motor may not cool enough at slow speeds. Best to find a good supplier and have him set you up with everything you need.

[madmapler]

Thanks guys. This gives me a direction to move in. Your help is really appreciated.

[brookledge]

Marks post answered your question well. The only thing I'll add is when programing the drive unit you will need to know the operating range of your vacuum pump. Meaning how slow can it operate and still maintain vacuum. On mine it is a nash pump and low speed is 1100 rpm and wide open is 1800. you have a liquid ring and it needs to maintain a higher rpm to keep the vacuum seal than other style pumps. The transducer will maintain the desired vacuum you have it progamed for. My drive is a 10 HP running a 5 HP motor
I'm very happy with mine. I can just look at the drive unit digital display to see the rpm and tell if I have any problems in my sugarbush. Then if I do I can begin to isolate the mainlines and save myself a lot of time
Keith

[madmapler]

Thanks neighbor.

[TheMapleMoose]

I think I've read even if you've got access to 3ph it's cheaper to have a 1ph service and convert 1ph to 3ph using VFD than it is to get hooked up 3ph at the service. I'm sure someone has more insight, just food for thought

[lpakiz]

The VFD I got from Factorymation is able to be programmed for low and high limits. I have mine on my arch blower set to go no higher than 80 HZ and no lower than 40. I was worried that someone would want to see how fast the blower would go and then explode the direct-drive impeller. The unit will go from 0 (not very likely to be set this low) to 120, which would double the speed of your motor.

[Big John]

I recommend a world wide 10hp 3ph motor. and a 20hp cerus titan P series VFD. fairly easy to install they come with a cheat sheet. We also run transducers or{pid} in the vac line so as to sense the vacuum needed. that tells us when the system is really tight. versus just hg on the gauge. for exaple i try to maintain. 27.25-27.75 inches as that is all I can do at my elevation. to do that my set point on the drive for forward speed is 54-54.75 hz when the vac is all tight. it will run about 37.5-38 hz And the feed back from the trasducer will be higher than my set point. 55-56 hz meaning the vac is super tight and trying to make 28 inches. but yet I draw 20 amps. with my nash elmo i can only go as low as 36 hz and then there is liquid ring issues. And there is never a need to go to 60 hz because you can't make 30 hg ever. So you should do it and save electricity. and make more syrup Win Win.