Slowing down a Thomsen #4

[revnatscider]

(I run a cidery, not a brewery.)

I have a Thomsen #4 strapped to a Baldor 1 HP 3450 rpm motor. I would like to slow it down a bit, and wondering if I can just swap the motor with another I have. It's a Dayton 1/2 HP 1725 rpm motor. Both are 110/220. The shaft and bolt-down pattern look compatible. I don't need the amount of head I currently have, nor the volume. The pump is nearly always throttled down via a half-open valve on the outlet. I would prefer that the cider be treated more gently, and handling hoses with that much liquid shooting through them can be difficult.

Will I be really unhappy with the half-horse, half-speed motor on the Thomsen #4? I am transferring 2 bbls occasionally and 9 bbls regularly, the latter taking a couple minutes to transfer. I use the same pump for CIP, nearly always throttled.

[CraftBeerIndia]

Vfd

Have you considered using a VFD drive? It will cost you a few hundred dollars but you'll have the flexibility to run the pump at any speed. I think that restricting a discharge valve is a bad technique - although i'm sure many people are doing it.

[iscorice]

Alex
any recommendations on a brand or a particular model. we are mounting 2 pumps on carts and were discussing this as part of the cart fabrications.
Thanks
Porter

[CraftBeerIndia]

Vfd

The one that I used was a Danfoss VLT 2800...we had 1 installed in the control panel for the brewhouse pump, 1 for the mash tun rakes, and 1 in the cellar for the portable pump. You'll also want the LCP Remote kit, which allows you to toggle a knob (potentiometer) to adjust the speed...there are many other brands available such as Schneider, Eaton... but you'll have to decide on what works best for you, for your application and in your particular set of circumstances. Please do post what you find, $, supplier, and how it works for you!

[sopbeer]

Vfd

Take a look at Drives Warehouse, Hitachi x200s. We replaced the Danfoss as were not reliable or built to the quality for brew house usage (Chinese made). We haven't had any problems with the Hitachi (Japanese) and they work well, programmable and reliable.

Drives warehouse has the best prices I've been able to find to meet our needs. Make sure you get the correct size, I would over size to be safe as pumps pull a lot of amps.

Good luck

[revnatscider]

The Hitachi x200 looks good, priced right. I didn't mention it in the OP, but I am hoping to actually swap the Dayton and Baldor motors. The Dayton is on a machine that needs a larger, faster motor and the Baldor is on the pump I want slower.

So as to the OP, does anyone know if I'd hate myself and wreck the pump by running it slower and with less HPs?

[gitchegumee]

Throttling for CIP isn't an issue--pumps are properly throttled on the outlet all the time. And with a cider that you're not worried about protein foam formation, I wouldn't worry about the cider taking much of a hit either. You cannot use a VFD with single phase motors--rule that out with what you have. With a centrifugal pump, you reduce your head with motor speed--not so much for the flow. Sounds like what you want, no? Everyone that runs a brewery should learn to read a pump curve--there are online tutorials everywhere. This isn't a guessing game. Say for the sake of this example that you need 10 feet of head. And that you have the original, uncut impeller of 3 7/8 inches. According to Thomsen's 3450 RPM pump curve for this model you are running off the chart--even at 20 feet of head--quite a bit for a simple, small transfer. This means that you MUST add restriction or overload your motor. And it means you are using the wrong motor/pump combination for this duty. Now according to Thomsen's 1750 RPM curve with the same uncut impeller (which curve, by the way shows ONLY the possibility of 1/2HP motor), you will be pushing 37 GPM at the same 10 feet of head. Not bad, eh? Also note that you will only be able to push 16 1/2 feet of head at zero flow. So the combination is safe and sound. You will be just fine swapping motors. I'll bet a night of beers on it. It's less than an hour's job, and costs nothing--why not try it? Good luck!

[revnatscider]

... You will be just fine swapping motors. I'll bet a night of beers on it. It's less than an hour's job, and costs nothing--why not try it? Good luck!

Everything you say is golden! Next time you're in Portland or I'm in Micronesia, I owe you a night of beers.

[gitchegumee]

I won't hold my breath for you to get here, but before we have those drinks give the swap a try and prove it to yourself. And it would be worth it to pull off the pump head to measure the impeller diameter. Just so you know your equipment that much better and what you can expect from it. At the same time, inspect your mechanical seal. Cheers!

[CPESystems]

Nat,

Before you start taking your pump apart you can make sure it will fit the other motor by checking the frame size on the motor name plates. They will probably both be a 56C frame size.

[revnatscider]

One says 56, the other says 56C. From what I can tell on the googles, there should be no difference in dimensions but I may be wrong... ?

[CPESystems]

The "C" stands for the mounting flange on the front of the motor. So yes both are the same size. If it just says 56 and has a flange then some one added the flange later. A very common thing to do.

[Triptych]

How well does Hitatchi X200 work with single phase?

[CPESystems]

The x200 will accept single phase input if it is a model type S

ie. X200-003S not a X200-003L which is 3 phase input.

In both cases the motor MUST be 3 phase. You can not use a VFD on a single phase motor.

[Triptych]

Great thanks for the info.

One other possibly stupid question, is there some special way to interpret Thomsen model numbers? (i.e. the first number is the pump series, followed by something else?)

So if someone lists a 42521-GA, how do I figure out what series that pump is?