March pump control question.

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Brewmoor

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I am looking at different options to control the flow out of my march pump. I would like to find a way to control the flow without using more ball valves. Space on my rig will be tight and the less valves hanging around the better.

Is it possible to control the speed of the march pump with a pwm or other controller? I know it should be possible to control the speed. I guess what I am asking is will it cause priming issues or other issues if I slow down the pump?

Is there anybody doing this in their system?

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UPDATED:
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I would like to thank Boerderij_Kabouter, kladue and Bkloos for helping with this topic. I have decided to use a motorized ball valve to control the pump flow remotely from my control panel. The valve is a 12v floating position valve. I will have two switches on the panel. One for open and one for closed. They will be momentary on switches. Here is a video of the new valve. It was acquired from a manufacturer in China.

[youtube]http://www.youtube.com/watch?v=JiW9xDc-Jko[youtube]
 
I have been looking at getting the DC version of the March Pump and using a PWM controller from the model train world to control the speed. It would allow it to slow down without changing the torque of the motor drastically. You can even get a frequency module to change the frequency of the PWM so that you dont have to hear the hum that it can make at 400Hz.

http://www.bakatronics.com/shop/item.aspx?itemid=581

or for two pumps:

http://www.bakatronics.com/shop/item.aspx?itemid=688

And a power supply that doesn't cost an arm and a leg (you could even get two pumps off of this one.

http://www.frozencpu.com/products/8...ry_Power_Supply_SE-600-24.html?tl=g30c105s190

I was actually thinking about posting this and getting feedback, so any thoughts are welcomed.
 
I have been looking at getting the DC version of the March Pump and using a PWM controller from the model train world to control the speed. It would allow it to slow down without changing the torque of the motor drastically. You can even get a frequency module to change the frequency of the PWM so that you dont have to hear the hum that it can make at 400Hz.

http://www.bakatronics.com/shop/item.aspx?itemid=581

or for two pumps:

http://www.bakatronics.com/shop/item.aspx?itemid=688

And a power supply that doesn't cost an arm and a leg (you could even get two pumps off of this one.

http://www.frozencpu.com/products/8...ry_Power_Supply_SE-600-24.html?tl=g30c105s190

I was actually thinking about posting this and getting feedback, so any thoughts are welcomed.

That should work really well. However I would not spend that much on a power supply. Check ebay. You can get pretty much the same supply for about $20.

I still wonder if it will cause priming issues or other flow issues. Will it harm the pump itself?

My issue is that I ordered the 120v pump. I had a brain fart when ordering. I could send it back and get the DC version but that will mess with my time frame. Hopefully I can come up with 120v speed controller that will work with the pump. Given that it will not destroy it or cause me problems.
 
I thought most people used a ball valve on the OUT from the pump which is the right way to restrict the flow of a Mag-drive pump like the March
 
I think the strength of the PWM DC supply is that it will allow you to maintain torque (head height) while changing the flow rate of the pump over the range. In addition, they have a module that can accept a 4-20mA signal and allows you to change the speed through computer controls.

The only way that I can think of to control the speed of an AC motor would be a variable frequency drive. You might have a look at the link below. It might be something that would work, but I have not looked into it thoroughly at this point.

http://www.factorymation.com/s.nl;j...e3eSc3aPaxmLe34Pa38Ta38Mahz0?sc=2&category=13

Joshua
 
I saw this posted on an electronics forum. I can tear it out of the box and integrate it into my control panel.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=43060

Can you see any issues in harming the pump.
I thought most people used a ball valve on the OUT from the pump which is the right way to restrict the flow of a Mag-drive pump like the March

I don't have that option directly with my system. The pump will be hard plumbed and behind an enclosure.
 
for your application I think it would work, and I dont think it would hurt the pump, but I think a cheap VFD would do a lot more for you. Most of them would also allow more control options down the road.
 
I have been looking at getting the DC version of the March Pump and using a PWM controller from the model train world to control the speed. It would allow it to slow down without changing the torque of the motor drastically. You can even get a frequency module to change the frequency of the PWM so that you dont have to hear the hum that it can make at 400Hz.

http://www.bakatronics.com/shop/item.aspx?itemid=581

or for two pumps:

http://www.bakatronics.com/shop/item.aspx?itemid=688

And a power supply that doesn't cost an arm and a leg (you could even get two pumps off of this one.

http://www.frozencpu.com/products/8...ry_Power_Supply_SE-600-24.html?tl=g30c105s190

I was actually thinking about posting this and getting feedback, so any thoughts are welcomed.

If you order a PWM from them get the MXA067, it has fixed 100Hz (I metered out as 93 Hz) plus the variable frequency control of 400 to 3KHz. This is a 30 amp unit, also a MX068 in 50 amp. Made by Maxx Tronic. I'm using the MXA067 as a fuel injector pulser for flushing and balance flow checking 96 injectors. With thousands of dollars in injectors $44.17 total cost for this PWM is nothing. later it will drive the yeast starter and other wild ideas. Use the small pin power sockets on the different items makes for simple transfer and hookup.
For AC motors you want VFD, AC/DC with brushes like Milwaukee power tools a PWM will work. I use a 30 amp Powerstat for 0-140 VAC output. Great for big Milwaukee porting grinders. Shaded pole or brushless AC motors will lose torque big time and get hot, a no go with that idea. A small VFD would work. Why not add two more ball valves not like adding 10 more? Keep it simple and keep the cost of a VFD out of the picture. JMO.
 
Why not add two more ball valves not like adding 10 more? Keep it simple and keep the cost of a VFD out of the picture. JMO.

I might have to. I just don't have a good location for it. I guess I could build one into one of my hoses. Then I would just use that hose when sparging. It just doesn't really flow with my design. I will need to think about my design a bit before I start the plumbing.
 
I saw this posted on an electronics forum. I can tear it out of the box and integrate it into my control panel.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=43060

Can you see any issues in harming the pump.


I don't have that option directly with my system. The pump will be hard plumbed and behind an enclosure.

Most Router manufacturers will not honor the warranty if they find out their product was used with a Router Speed Controller because the devices can do damage to an AC motor. The march pump is a magnetic which is designed to have its OUTPUT restricted. All the router Speed Controller will do to your pump is help it to fail prematurely.
 
Most Router manufacturers will not honor the warranty if they find out their product was used with a Router Speed Controller because the devices can do damage to an AC motor. The march pump is a magnetic which is designed to have its OUTPUT restricted. All the router Speed Controller will do to your pump is help it to fail prematurely.

Good thing I don't own a router with a warranty:D

I contacted March about this. I will post what they have to say on controlling flow. I know most people are controlling the output with a ball valve. I get it. I am just trying to weigh all the options. In my opinion the less valves I have to deal with the easier my setup will be to use.

I think I will end up integrating some sort of valve into one or two of my quick change tubes. That way the valves can be used where they are needed.
 
Ok here is the reply I got from March:


Operating the motor on anything other than standard voltages (this includes speed controllers) will void the warranty on the motor....Slowing down the motor will not harm the pump, however the reduction in speed will not lead to a linear reduction in flow and pressure.
 
I am interested to see how this works... March pumps are not positive displacement, they are centrifugal. This is why the flow decrease will not be linear with speed if you control it with PWM.

I would sell your pump and trade up for a 24vDC version for this. I can't remember why, but I do remember from school running loads with PWM on VAC is complicated. SHould be pretty straight forward with a DC pump.

Will it kill the pump... I don't know. Is it worth a $130 gamble to avoid putting a ball valve in line somewhere? The valve does not have to be at the pump, it could be on the receiving vessel or at the end of a tube (i.e. anywhere downstream of the pump).... just some ideas.
 
I am torn. I am not sure what i will do yet. I will probably stay away from decreasing the voltage. I don't want to mess with the warranty on the pump.

My setup is going to have a plumbing panel much like a commercial skid brewing system. There is going to be 9 outlets on the front panel and I am going to use "jumper" tubes to direct the flow where I want it to go.

I think I am going to try putting a valve inline on one of the jumper tubes and see how it goes. If it is a pain I might consider more valves on the vessels. I just don't think I want to experiment with $130.
 
Depending on your budget, you could find an electronically controlled variable valve and mount that int he box. Then you could control the flow out of the pump via your panel. Would be sweet but likely more than double the cost of the pump.
 
Depending on your budget, you could find an electronically controlled variable valve and mount that int he box

I like this idea too... I've been thinking about how to control my pumps and was stuck at the external router control. With a variable/controllable valve, we could set it and forget it!

Do such valves exist int he hobby world and are they affordable? How about the controller?

Thoughts?

BK
 
I have seen people use the round light dimmers before. My buddy has one on his march pump and it works fine, he says no problems. I have heard that only certain dimmers will work. Keep searching the forums because I know I have read it before here which will work and which won't work. I use a ball valve, which would be no different than turning a light dimmer.
 
The ideas are starting to flow now. These are all great things to start thinking about.

How would the pwm make the valve stop in a certain position? Would a certain voltage only take the valve so far? I would like to see this idea work. My brain is spinning now.

I have seen people use the round light dimmers before. My buddy has one on his march pump and it works fine, he says no problems.
Does it create suction issues or priming issues? Is it possible he is using a DC pump and a residential volume control knob?
 
I use a ball valve, which would be no different than turning a light dimmer.

No. Your ball valve increases the pressure thereby reducing the flow volume out of the pump. The March pump is a magnetic drive and is designed to "slip" under back pressure conditions such that a user may throttle flow as you are doing. Your friend is sending a lower voltage to the motor windings essentially slowing how fast the motor and therefore the pump turns. March voids the warranty for this practice because it is outside of the spec and can be detrimental to the electronics of the motor. I would really recommend against this idea. It may work, but so did eating off lead plates for several centuries. Just because an idea works in the short term does not make it a good idea int he long run.

How would the pwm make the valve stop in a certain position? Would a certain voltage only take the valve so far? I would like to see this idea work. My brain is spinning now.

The PWM valves operate full-on full-off but at varied timing (that is what Pulse-Width-Modulation is basically). The ratio of on-time to off-time changes to average flow through the valve so you can reach your desired flow rate.
 
The PWM valves operate full-on full-off but at varied timing (that is what Pulse-Width-Modulation is basically). The ratio of on-time to off-time changes to average flow through the valve so you can reach your desired flow rate.

I wonder how the valve would hold up in this environment. I assume the valve is designed with a max cycle frequency... If so, would PWM exceed this and cause damage to the valve?

I've done some preliminary searches and can find the ASCO proportionals for about $450.... To rich for my blood. I'll keep searching and look for some alternatives.
 
The Belimo brand ball valves have low voltage actuators in either proportional or floating control (power to open, power to close, holds position when power off). These pop up on Ebay often priced between $10 - $50, just remove plastic flow limit device and you have a nearly full port ball valve.
 
What?! $450 is too rich for your blood?

Unfortunately yes;)

I like to think the PhD after my name stands for "Poor Hungry Doctor", while my father tells me it should stand for "Pile it Higher and Deeper."

Seriously though, I just spent close to that on solenoids, and SWMBO will have my balls in a vice if I blow another chunk of cash like that any time soon.

I need a cheap solution for my system.

I'll look into the Belimo's....
 
Ok so if I got a momentary on-off-on switch I could us it to make that valve open manually? If so

I can live with that. That is just as easy as using a potentiometer to dial it to the desired flow. I think I might pull the trigger and try it. It is not over the top expensive. I need to think about it a bit more but I think this might be the way to go.
 
The floating and proportional control actuators will take 90 seconds to go from closed to full open so a center off toggle switch should work fine. If you get to the point that you need to go 2-10 volt proportional control, just remove center screw in handle and swap actuators with the proportional model. Without a spring return the actuator will stay where it was when the power was turned off. To power these floating actuators a 20 VA 24VAC transformer or a 24VDC wall wart with 500 Ma or greater capacity will work.
When you get one of these valves you need to remove the internal snap ring and plastic flow setting disk for the higher flow, lower back pressure needed with the march pumps.
 
Thanks for all your insight for this. This helps a ton. I am pretty sure I am going to order one. I found a honeywell floating control valve for $36 I just need to make sure the specs are the same. If not $55 is not that bad.
 
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