View Full Version : The million dollar pump question. Sparky's welcome.;)
Creetin
11/07/2006, 08:43 AM
Why dont our pump companys use split phase ac motors? Why is it that DC pumps are more efficiant than our ac pumps when split phase ac motors are supiorior?
I know its more to produce, but not like its going to make the pumps too expensive.
Why is it that our name brand pump manufacturers wont do it?
Is there something i am missing? So what it cost $15 more to produce a superior pump that will burn way more efficiant than any pump we have to date.
Is there no company that would build them?
Creetin
11/07/2006, 08:54 AM
Or is it they are using split phase? I am not a electrical guy, But i was talking to my uncle and he was saying that any split phse motor will out produce DC motors. I thought of tunze, and hense this question.
Matrexz
11/07/2006, 08:56 AM
From my reading on single phase motors is that all of them are pretty much the same at running speed the only benefit from having the split phase is that it has a greated starting torque ability. That and they are about $15 more so mulitiply that by however many thousands a company makes a year that's how much more they would have to invest into making them.
Matrexz
11/07/2006, 08:58 AM
http://en.wikipedia.org/wiki/Electric_motor
Read this it goes into some good detail down below on the single phase motors.
RichConley
11/07/2006, 10:14 AM
<a href=showthread.php?s=&postid=8495008#post8495008 target=_blank>Originally posted</a> by Creetin
Or is it they are using split phase? I am not a electrical guy, But i was talking to my uncle and he was saying that any split phse motor will out produce DC motors. I thought of tunze, and hense this question.
Tunzes being more efficient has nothing to do with being DC, and everything to do with them being prop pumps, and not impellar pumps.
Creetin
11/07/2006, 10:34 AM
What about red dragon? Arent they DC?
RichConley
11/07/2006, 11:21 AM
No, most of them are AC. Theyre so efficient because 1, theyre like the sequence dart taken to an extreme...just can not handle pressure, and 2), theyre built to extremely fine specifications. Most pumps are built in such a way that if an impellar is slightly larger than its supposed to, etc, the pump still runs fine. They make allowances for poor parts. The red dragons dont do that.
There is a new pump that Royal Exclusive is working on thats DC though.
Darroll
11/07/2006, 04:54 PM
Can split phase AC motors be speed controlled?
BruiseAndy
11/07/2006, 08:30 PM
<a href=showthread.php?s=&postid=8498152#post8498152 target=_blank>Originally posted</a> by Darroll
Can split phase AC motors be speed controlled?
Yes, as long as it is inverter rated. If its not dont expect it to last more that 6-12 months.
Creetin
11/08/2006, 12:45 PM
Hmm a speed controlled closed loop. That sounds promising!
You can easily control the speed of an normal AC 110V motor...
With a conventional "Varifan", a rpm controller for fan in cows farms. You just have to respect the hp rating on the varifan.
Dark
BeanAnimal
11/08/2006, 01:15 PM
Most of your larger pumps ARE split phase. Some are Cap Start, others are PSC... Few are Cap Start, Cap run.
Smaller pumps/powerheads are not... why? They do not have a starting torque problem.
AC motors need to be speed controlled by a VFD if you want them to run smooth, quit and cool. Using rheostats or other voltage regulation is hard on the motors and generates extra heat and noise.... the larger the motor, the worse this gets. The MORE EFFICIENT the motor, the harder it is to speed controll via voltage (it does not like to slip behind the phase angle...)
The big question is why you would want to speed control a closed loop.
Bean
Darroll
11/09/2006, 12:57 PM
For feeding fish and shrimp.
control over wave action and vary the strength of currents in sync with moon phases/position
douggiestyle
11/09/2006, 01:19 PM
can all single phase motors be controlled with a vfd?
douggiestyle
11/09/2006, 03:15 PM
<a href=showthread.php?s=&postid=8503997#post8503997 target=_blank>Originally posted</a> by BeanAnimal
The big question is why you would want to speed control a closed loop.
Bean
to better replicate wave action. if you had a vfd connected to a plc. you could raise and lower the motor speed creating a varied enviroment for the tank.
hmmmmmm
Absolutely, but I don't know the long terms effects on motor who are'nt specially made for this application. I personally don't worry, but it' my opinion, and my pump, my $$$...
With an impeller pump, the possibilitis are various, like a wave maker, feeding options, day/night variables, etc...
Dark
BruiseAndy
11/09/2006, 06:24 PM
<a href=showthread.php?s=&postid=8512686#post8512686 target=_blank>Originally posted</a> by Dark
Absolutely, but I don't know the long terms effects on motor who are'nt specially made for this application. I personally don't worry, but it' my opinion, and my pump, my $$$...
With an impeller pump, the possibilitis are various, like a wave maker, feeding options, day/night variables, etc...
Dark
I'm thinking for the application you are describing you'd be better off using a 3 way valve and varying that instead of trying to vary pump speed. Would have to be closed loop though.
Don't know that kind of valve... Like Hydraulics one?
Dark
BruiseAndy
11/09/2006, 09:48 PM
Some are hydraulically actuated but you can buy the valves for $15-$25 usually. It would have one in and two outs. The more flow one output gets the less the other gets. Think about putting a Tee in your discharge line and piping the tee into the tank and into the pump return. now put a valve in the Tee that would change flow from tank to return and vice versa. Now put actuator on Tee and set up a timing circuit and stops on actuator to move it back and forth. Just a thought.
http://www.plumbingproducts.com/images/pvcvalve-locking-3way.jpg
I see... UI prefer my VF method, but it's a great idea, a nice DIY project! Did you try it already? Does an actuator is expensive? I'd never had a project with actuators yet.
Dark
marm64
11/10/2006, 02:38 AM
I believe that you can run a VFD on any AC motor, you do have to be careful that you have enough frequency to keep the speed and torque up so you do not generate too much heat. I have been looking for a reasonable single phase VFD but so far have struck out.
douggiestyle
11/10/2006, 09:32 AM
http://web6.automationdirect.com/adc/Overview/Catalog/AC_Drives_-z-_Motors/GS1_(120_-z-_230_VAC_V-z-Hz_Control)
these are priced well
Creetin
11/10/2006, 11:36 AM
Thats nice!! I thought this thread died. Now a closed loop ran off one of those would be cool. Just think a dart or bigger ran off one would be killer.
marm64
11/10/2006, 02:06 PM
<a href=showthread.php?s=&postid=8516918#post8516918 target=_blank>Originally posted</a> by douggiestyle
http://web6.automationdirect.com/adc/Overview/Catalog/AC_Drives_-z-_Motors/GS1_(120_-z-_230_VAC_V-z-Hz_Control)
these are priced well
This is what I was looking for but unfortunately like all the VFD single phase one that I looked at it does not do single phase output. From the website. So far I have not found a reasonable priced single phase input and single phase output VFD.
GS1-10P2 - GS1 AC micro drive, 0.25 hp, 120 V single phase input, 230 V three phase output,[/B]
douggiestyle
11/10/2006, 04:54 PM
missed that three phase output. good eye. got all glazed over when i saw single phase. ooops
what about getting the pump assembly and adding a three phase motor?
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