Pump Speed Control

[Yorg]

I can't seem to get a consistent answer in my searches.

Can you control the speed of a March Mag drive pump safely, for the pump and you with:
a/ Light dimmer?
b/ Ceiling Fan speed control

???

 

[oldbugman]

hand valve on the outlet.

 

[tdh]

I've never needed to slow the speed down, it's never fast enough for me!

Did you realise that you can throttle the output? Always keep the input flooded though.

tdh

 

[mika]

Only way to do it safely electronically is with a Variable speed/frequency drive, you'll freak when you see the price.

Go with the Old chap, throttle the OUTLET with a valve of some kind. Not a fan of valves, crimp the hose with a pair of multi-grips.

 

[domonsura]

We debated this a while ago Yorg, the general consensus was that it wasn't worth the risk of killing the pump with a dimmer switch, or light dimmer because of the way that the cheap dimmers reduce the current (some clever type please insert correct electrical terminology here.....), but there are ways to do it properly. I think it was Tony that had the proper gear for the job.....

Edit: Where'd my sig go? weird .........

 

[domonsura]

uhhhh...yeah..and I forgot, you can just throttle the pump output....

 

[Wortgames]

Thread is here if anyone is interested:

http://www.aussiehomebrewer.com/forum/inde...showtopic=14865

 

[Yorg]

Thanks folks.
Yes. I'm aware of the outlet throttle.
Some advocate a bypass back to the inlet to lessen load on pump, when throttling back.
Wouldn't this mean that even with the throttle fully open, a substantial percentage would be cycling through the bypass, given some resistance in the system of plumbing/or head?
If I did use a bypass would it be then be best to make the bypass of a smaller diameter pipe to compensate?

 

[Tony]

the "corect geat" i have doesnt work so i stuck with throtling the outlet

cheers

 

[Ross]

Edit: Where'd my sig go? weird .........

Signature only ever shows on your last post in a thread

cheers Ross

 

[mika]

The pump at flow flow is only pulling a couple of amps, decreasing load on the pump really isn't an issue. The March pump is specced as a hot water system pump and I'm sure the duty cycle in that application is a lot more demanding than the occasional weekend use we're subjecting it too.
A Bypass may assist with priming the pump...maybe.
But lets not forget the principles of the universe, energy is lazy so will take the path of least resistance, thru the hose and up over the edge of the pot ? or unrestricted into the low pressure suction ? Think you'd end up with the bypass closed right up to get any sort of reasonable flow out of it.
My 2c.

 

[ausdb]

Only way to do it safely electronically is with a Variable speed/frequency drive, you'll freak when you see the price.

Go with the Old chap, throttle the OUTLET with a valve of some kind. Not a fan of valves, crimp the hose with a pair of multi-grips.

Variable freq drives will not work on single phase motors :-( The small single phase input variable speed drives actually output artificial three phase! (just about any inverter I know of driving a variable speed motor outputs three phase)

Like everyone else says, just throttle the output.

 

[ant]

Variable freq drives will not work on single phase motors :-( The small single phase input variable speed drives actually output artificial three phase! (just about any inverter I know of driving a variable speed motor outputs three phase)

Like everyone else says, just throttle the output.

...is the warp core about to blow? Are we in danger??? :blink:

 

[vlbaby]

Thanks folks.
Yes. I'm aware of the outlet throttle.
Some advocate a bypass back to the inlet to lessen load on pump, when throttling back.
Wouldn't this mean that even with the throttle fully open, a substantial percentage would be cycling through the bypass, given some resistance in the system of plumbing/or head?
If I did use a bypass would it be then be best to make the bypass of a smaller diameter pipe to compensate?

Hi Yorg,
i haven't tried this on a march pump, but I know that it is normal for a centrifugal impeller pump to draw more current with an unrestricted outlet than a fully closed one. If this it true of the march pump, then your bypass would actually have the effect opposite to that which you were looking for.

cheers

vl.

 

[mika]

Variable freq drives will not work on single phase motors :-( The small single phase input variable speed drives actually output artificial three phase! (just about any inverter I know of driving a variable speed motor outputs three phase)

Like everyone else says, just throttle the output.

DOH ! .... of course...forgot about the single phase thingo. So used to 3phase motors. Oh well, then you're really stuffed.

Throttle it !

 

[Yorg]

But folks,
Let me have one more stab at this - the notion of a pump going flat knacker non-stop, when the temperature drop in the insulated cooler is on such a gentle gradient to only require a few boosts over the duration of the mash just seems way too agricultural.

Why wouldn't a router controller like these work?:

http://www.houseoftools.com/product.htm?pi...&catid=1885

http://www.mlcswoodworking.com/orderstatus...s/speedcon.html

SURELY routers don't have 3 phase motors!? Do they?

Oh, and Tony, what happened to that Syntron controller you posted about in March? How did that go?

 

[ausdb]

But folks,
Let me have one more stab at this - the notion of a pump going flat knacker non-stop, when the temperature drop in the insulated cooler is on such a gentle gradient to only require a few boosts over the duration of the mash just seems way too agricultural.

Why wouldn't a router controller like these work?:

http://www.houseoftools.com/product.htm?pi...&catid=1885

http://www.mlcswoodworking.com/orderstatus...s/speedcon.html

SURELY routers don't have 3 phase motors!? Do they?

Oh, and Tony, what happened to that Syntron controller you posted about in March? How did that go?

Router controllers will only work on brush type motors like that used in routers, electric drills and angle grinders . Your march pump has an induction type motor on it and running it off a router type speed control will burn it out sooner rather than later, feel free to try if you like h34r:

Why are you so hung up on throttling the flow of the pump? as long as the motor has enough cooling which it will as you are not slowing it down there is no problem in throttling it back. It is often done in industrial situations with bigger motors pumps. It is not quite as energy efficient as having an optimal sized pump but it works.

 

[kook]

Why not just email March? I'm sure they'll be more than happy to help.

I know in the past they've told other members that it is fine to throttle the output, as we're not dealing with any significant pressure in homebrew.

I presume you're not trying to transfer highly pressurised wort or water?

 

[Andyd]

The pump at flow flow is only pulling a couple of amps, decreasing load on the pump really isn't an issue. The March pump is specced as a hot water system pump and I'm sure the duty cycle in that application is a lot more demanding than the occasional weekend use we're subjecting it too.
A Bypass may assist with priming the pump...maybe.
But lets not forget the principles of the universe, energy is lazy so will take the path of least resistance, thru the hose and up over the edge of the pot ? or unrestricted into the low pressure suction ? Think you'd end up with the bypass closed right up to get any sort of reasonable flow out of it.
My 2c.

The bypass is unlikely to help in priming unless it has a opening to the atmosphere somewhere - you need to force all that air out of the lines, and having a closed bypass will only trap it.

Guys, Karl at Process Pumps would more than likely be happy to put this one to bed once and for all, one way or the other. He really knows his pumps (not just march pumps) and is involved in pump installations beyond anything we could imagine. If he can't give us an answer, I don't know who can.

Regards,

Andy