Question RE: Electric motor
Texas Wellman
Solar Expert Posts: 153 ✭✭
I have a simple question: Does anyone make a std. electric motor for solar that will fit a 56J type frame?
I am wanting to obtain a DC/Solar motor to power a water pump that would normally be used with a A/C electric motor. There is not many options out there for me to accomplish this.....this is a special application.
The current motor is a 56-J frame, .5 HP at 3450 (but I don't need to run full rpms).....
I am doing some testing and I need options.
Thank you for all replies to this solar newbie.
I am wanting to obtain a DC/Solar motor to power a water pump that would normally be used with a A/C electric motor. There is not many options out there for me to accomplish this.....this is a special application.
The current motor is a 56-J frame, .5 HP at 3450 (but I don't need to run full rpms).....
I am doing some testing and I need options.
Thank you for all replies to this solar newbie.
Comments
Will this be attached to solar panels directly, or will there be a battery bank involved?
VFD (Variable Frequency Drives) are pretty nice as they give you soft start and the ability to slow the pump motor down if you do not need full RPM.
You would need a 3 phase motor or single phase motor with external start capacitor to use a VFD controller.
-Bill
Have you inquired of SunPumps? They make lots of DC power pumps and AC to DC conversions (at least they used to).
Some of their "conventional" pumps: http://www.solar-electric.com/sucesosupu.html
Company web site: http://www.sunpumps.com/
Directly to Solar Panels, using a controller of course. No batteries, it runs when the sun shines (or the tanks full)
So you're saying I can use a regular A/C motor with start cap (they already have a start cap) in conjunction with a VFD and it will work with solar?
What do you think the approx. cost is for a 1/2 HP motor? Any suggestions would be welcome and truly appreciated. I'm over my head on all this stuff so please forgive any ignorance. I am very interested in solar applications and hope to get this project off the ground soon.
I have checked into Sun Pumps. They are the only company that makes what I am looking for but they are pricey for what I need. I only need the motor to go with my pump, and of course the controller. I have not checked to see what frame size their motor is. Also I wonder if I can use any controller to use with their motor?
Thanks for your quick replies, if I get the information I need I will post up the results.
The VFD's, typically, are for use with 120/240 VAC power--and make the pump motor much friendlier for use with inverters+battery bank (reduced surge current, run at slower speeds/reduced power if needed, etc.).
I have found one VFD which was designed to work with solar panels and pumps directly (included MPPT and then ran a three phase pump motor). However, it looked like that vendor may have gone out of business/disappeared.
With VFD's, they need poly phase motors... Either Three Phase or a single phase with externally accessible starting windings (call it two phase?).
The VFD can also be used with poly phase synchronous Permanent Magnet Motors. By using PM motors instead of induction motors (the AC / non-brushed common motors we use almost everywhere today), I guess they can save another ~20% power usage over induction (no need to generate the magnetic field in the armature as done for induction motors).
I have no special insight to VFD/Motor manufacturers... If this was battery+inverter, I would call a couple VFD manufacturers/distributors and see what they could do for me.
For pure solar--You have two major ways to go... A brushed universal motor + linear current booster (brushed motors work well, but don't have very long life in continuous operation; LCB, sort of, does the MPPT function to match high voltage/low current from solar panels during morning/evenings and match it to the low voltage/high current need to run DC motors at lower speeds with high torque).
I believe Dankoff uses Brushed DC motors--I have heard of (in general) brushed motors lasting 6 months in continuous operation before needing new brushes. Perhaps for seasonal solar pumping, you can get 2-4 years? And their pumps are north of >$1,000 (bare motors are probably not cheap).
You can try calling our host NAWS and see if they have any ideas/sources.
-Bill
Thanks BB. No, I am looking to keep it simple. Adding an inverter/VFD etc only adds cost and complexity, which I am trying to avoid.
The problem is that everybody makes a solar pump, but nobody makes a decent shallow well small diameter solar pump.
Yea, we recommend avoiding batteries for pumping--if that can be done.
-Bill
So there is no catalog of motors (DC or similar) that I could look through to find the motor I need?
You have to go to the pump Mfg's catalogs/websites. Our forum host has a web store with a section of pumps: http://www.solar-electric.com/sodcwapu.html
SunPumps Dankoff Shurflo Grundfos all make DC pumps, and therefor, use DC motors.
If looking for a bare DC motor, you may have to look at NEWARK, Grainger or some other electric supplier. There are brushless motors that need a fancy controller, there are eBike motors with their own style of controllers.
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