VFD vs. Rotory phase converter?

[gentlemanfarmervt]

Last season had a great first year with gravity system and looking to take tings a step forward. Recently purchased new vac. pump for this season which requires 3 phase power. Single phase is available on site. After alittle research im discovering there are a few options. 1st, the pump is a Busch Mink 1144BV 3-phase so how do i convert single to 3-phase? 2nd, does this pump need to be heated? i guess the real question is how should i set this thing up? Too many ?'s regarding vfd or rotory converter? just really need some help. Any assistance is apprecieated.

[Flat Lander Sugaring]

i have seen them both in use, I think I would go with the VFD and use a soft start to ramp the motor up to full capacity, GMP prices are not going to go down. Are you adding a meter to run the pump or sugar house? I see you said single phase is on site.

[optionguru]

In my garage I had the same issue and we were told to use a rotary phase converter to even out the power. It worked well to run my recycling and crushing equipment. I was told that the electronic converters should be oversized for your application ie if you need to run a 5hp motor you should get a converter rated for 10hp. This is all what my electrician told me so take it for what it's worth.

[lpakiz]

For a VFD, call the folks at factorymation.com.
Or go to their website and click on "live chat" and soon a typed message will appear, asking what they can help you with. Type back that you want info on a VFD. They will want to know all the particulars, such as input power source (110 or 220) size of motor, amp draw of the motor, etc. then they will recommend exactly which VFD to buy. Great people there. Products are reasonably priced and their tech support is the best.
I can tell you that the VFD I got for my 1/2 HP blower motor can run the blower from maybe 1/2 speed up to double speed. So for a 1750 motor, you could go as slow as 800 RPM (guessing here) to 3500, if you think the driven load would take the stress. You can easily set the cycles per second (HZ) as well as acceleration and deceleration rate, or even incorporate a brake in the deceleration rate. Neat devices.
Did I mention that they also convert single phase to three phase, but you may be somewhat short of full nameplate horsepower.

[DrTimPerkins]

We use a VFD with both of our Busch pumps to convert to 3-phase and to allow the system to ramp down when the vacuum reaches the preset level. Pump does NOT need to be heated, however when you fire it up it is best to turn on the VFD first and allow it to warm up for 15-min or so BEFORE you turn on the pump itself. If you don't do that you can burn out the VFD.

[BreezyHill]

25 years ago I bought up a feed mill. The motors were all 3 ph. We only had single from the grid. Researched rotary units and they can be a hassle if you are not running just one motor due to sizing. I would use a vfd as they have a lot of uses and energy saving options available. I had to buy generators to make our power. I have a 45 kw and a 100kw. These are great but as with anything there is maintance and repairs.
So get a VFD read the owners manual and start to look at ways to use it to cut your power useage. It will be a great investment!

[lpakiz]

Dr. Perkins,
Where can I find info on the device that tells the VFD what HZ to deliver to the motor, depending on vacuum level, and the level the operator is asking from the pump? Probably called a transducer, but understandable info is hard to find.

[batsofbedlam]

This is the 4th year I will be using a Busch pump with VFD drive. The savings on electricity are amazing and it is the quietest of the 3 sugar bushes we tap.
When setting it up, I called the manufacturer of the VFD and talked to one of their tech support people. I spent about two on my cellphone, but he walked me through every step in setting up the controls.
Basically, you set the Hertz after you reach the vacuum level you would like to attain, and you can easily change that level any time you wish.

[DrTimPerkins]

Where can I find info on the device that tells the VFD what HZ to deliver to the motor, depending on vacuum level, and the level the operator is asking from the pump? Probably called a transducer, but understandable info is hard to find.

It is all in the VFD manual.....if you read electricease. Or you could spend time on the cellphone with the VFD manufacturer tech support. Perhaps the company that sold you the pump and VFD can provide the proper settings. Other than that your options are to have an electrician install and program it for you, or find a maple producer with the same exact setup and go through the VFD settings step-by-step and write them all down.

Yes, you definitely need a vacuum pressure transducer. This is plumbed into the vacuum system, and then connects to the VFD. The VFD reads the vacuum pressure from the transducer, compares it to the settings in the VFD, and then adjusts the Hz appropriately according to its programming.

[Timberwolf]

A pressure transducer and properly configured VFD will help you save money as the transducer can tell the VFD when you are at the vacuum pressure you want and will slow the motor down saving you electricity and $$$. Though this setup may be more complex than really needed for some with added cost. If you check your vacuum level frequently you could adjust yourself based on vacuum pressure and save the added cost and complexity, though some savings would be lost and you may operate below optimal vacuum pressure.

As for setup if you understand them they are not that bad, otherwise try to find a good distributor in your area and purchase from them and get them to help you configure it. If you are not sure where to start anyone that sells motors and/or electrical supplies to industry/factories is likely able to help.

[BAP]

Find a good Dairy Milking Equipment dealer near you if you need help setting up a VFD. They have been used in milking systems for approximately 20 +/- years. We had one that we used for 15 + years 2x a day 365 days/year with no problems except for the one time we had a lightning strike. Using a soft start works better.

[gentlemanfarmervt]

We have absolutely no experience with vfd's and need to know how 208 single is converted to three phase 240? or is it 480? working with electrician now and we're pretty green with this... will this pump run on three phase 240? How are folks doing this? also we need a soft start and we have no idea what goes first or how to wire it. as I understand we come down pole to disconnect (100A) and lead wire to trailer (mobile pump house) to soft start, then into vfd? Finally into pump as 3 phase 240?

[GeneralStark]

Typically with a VFD you are taking single phase 240V, coming in from the grid to your meter, and digitally convert it to 3 phase 240V. Likely your pump can be run at 240V 3 phase so shoot for that. Higher voltage will mean less amperage, and the pump can be run at higher voltage, but you will be working with 240V. If you get the info off the plate of the motor and post it here we can confirm this, but that is likely. When using a VFD you don't need a soft starter as the VFD can be programmed to slowly bring the motor up to full speed. Programming the VFD is a bit too complex to post here, and will depend upon the model, but most electricians can figure out the basics.

Without knowing your exact situation it is tough to say how to do all the wiring. Is there a meter involved? Is the power coming in from a utility pole or from somewhere else. You should put the VFD on a breaker or disconnect of its own.

[sapman]

The best thing I ever did was talk with an electrician at a dairy I was working at. He came out and got the transducer all set up, and talked me through other settings and troubleshooting. An invaluable resource!

[lpakiz]

BAP, that is good suggestion. Guess I didn't connect that the same device was used in dairy as well as maple vacuum.
Thanks!
If you had the pump, motor and VFD, roughly how much $$ to add the transducer?

[arcticmaple8]

Hello gentlemanfarmervt,

All you need is a vfd sized for your motor and someone to program it. You do not need a soft start, a vfd will soft start your motor by programming the accel and decel times. A transducer is optional but pointless if you want maximum vacuum, you will get the most vacuum running your motor full speed (60hz). A transducer can save you money if you wish to set your vacuum level lower as your pump will run slower, you can also adjust your running speed manually on vfd programming. It is not a good practice to run a motor past 60hz even though a vfd will adjust to 400hz, it makes more heat in the motor. If you feed single phase 240v into a vfd the motor must be wired for low voltage(208-240) not high voltage(460-480). Good sorces for vfd's and help programming are electric motor shops, electrical suppliers, and the internet if you know what your looking for.

We stock ac tech vfd's if you cant find what you need or have any questions feel free to call 716-239-1540

[GeneralStark]

Hello gentlemanfarmervt,

All you need is a vfd sized for your motor and someone to program it. You do not need a soft start, a vfd will soft start your motor by programming the accel and decel times. A transducer is optional but pointless if you want maximum vacuum, you will get the most vacuum running your motor full speed (60hz). A transducer can save you money if you wish to set your vacuum level lower as your pump will run slower, you can also adjust your running speed manually on vfd programming. It is not a good practice to run a motor past 60hz even though a vfd will adjust to 400hz, it makes more heat in the motor. If you feed single phase 240v into a vfd the motor must be wired for low voltage(208-240) not high voltage(460-480). Good sorces for vfd's and help programming are electric motor shops, electrical suppliers, and the internet if you know what your looking for.

We stock ac tech vfd's if you cant find what you need or have any questions feel free to call 716-239-1540

Wrong. A transducer is absolutely not pointless. If you size your pump correctly, it should not have to run at 60 HZ to provide the cfms necessary at the vacuum level you wish to operate at. Just as an example, my 3 hp pump which can create 33 cfm at 26" hg is more than adequate for the 500 + taps I will have this season. I have installed more mainline than necessary to achieve 2-5 taps/lateral and am using the 50 tap/1cfm rule. I also am lifting 150 taps so 12-15 cfm should be adequate. I will have more taps on this pump in the future.

Anyway, the transducer allows the vfd to slow the motor down once your desired vac. level is reached and reduces wear on the motor and electrical consumption. Also, if running the pump 24/7 the pump will slow down when the lines freeze. Optional...yes. Pointless...NO.

[arcticmaple8]

hello lpakiz,

The cost to add a transducer to an existing setup varies depending on the transducer cost. For a good quality accurate vacuum transducer like we use on dairy systems your looking at $500, There are probably cheaper ones that would work fine as maple trees are not as sensitive as cows lol. The transducer is just 2 or 3 wires to the terminal strip and change some settings.

[arcticmaple8]

I doubt your 3 hp pump can create 33cfm at 26" of hg, as the vac level goes up your cfm will drop 33cfm is at open flow, I see what your saying and agree its not pointless but not necessary. How much slower does your pump run on transducer at 26"?

[GeneralStark]

I doubt your 3 hp pump can create 33cfm at 26" of hg, as the vac level goes up your cfm will drop 33cfm is at open flow, I see what your saying and agree its not pointless but not necessary. How much slower does your pump run on transducer at 26"?

Take a look for yourself: http://www.airtechusa.com/products/3av55.html

33 cfm is not at open flow. Not sure yet at what HZ the pump will run at 28" (desired vac. level) as I have not had the opportunity to test it yet.

[GeneralStark]

hello lpakiz,

The cost to add a transducer to an existing setup varies depending on the transducer cost. For a good quality accurate vacuum transducer like we use on dairy systems your looking at $500, There are probably cheaper ones that would work fine as maple trees are not as sensitive as cows lol. The transducer is just 2 or 3 wires to the terminal strip and change some settings.

You can generally find a Setra 209 on ebay for 35-55$ used (and new in some cases), or about 150-200$ new. Just be sure it is calibrated for vacuum (-14.7 psi).

[arcticmaple8]

Thanks for posting the link, I did not realize how efficient liquid ring pumps are with cfm at high vac levels. So a vacuum transducer is definitely not pointless and is an option that should be considered as it would probably pay for itself in one season. Thanks for the lesson

[lpakiz]

Thanks, all, for your contributions. Here I can learn in minutes what would take hours, days or weeks visiting dairy dealers, researching articles and catalogs or reading on the internet. What a forum!

[GeneralStark]

Thanks for posting the link, I did not realize how efficient liquid ring pumps are with cfm at high vac levels. So a vacuum transducer is definitely not pointless and is an option that should be considered as it would probably pay for itself in one season. Thanks for the lesson

No problem. We will see if the pump actually performs as advertised. I was quite surprised by the performance curve as well as the other LR pumps I have used don't provide cfms that high at high vac.