Motor Control

[Kevin in Alberta]

Hi, first post, just ordered my first control a 16 channel. Im building a Fountain that will blast water and control lights with the lor controller. I have the lights and the water blasting figured out. But i need to be able to control some AC water pumps and i need them to be variable. so i can fade the water stream up and down.



any ideas on how to do this? i found a pfd from light-o-rama that says digital i/o boards can be used but i have no idea on how to do this.



any help is greatly appreiciatated.

thank you

Kevin

[Victory402]

Kevin, I'm not an expert on this, but it seems to me you will need to control the speed of your pump to control the rate of flow for the water. Which means your pump motor will need to be a variable speed motor. As for the control of this type of motor through LOR you will have to wait for the pros here to chime in. You have an awesome project going there...very intriguing. I'm interested in some variable motor speed control, so i'll be watching your post. Thumbs up!

[-klb-]

Different types of motors require different methods for speed control. AC synchronous motors are the most difficult to do, and the LOR controllers currently on the market aren't suitable.

Take a look at item 4 in the first post in this thread:

http://lightorama.mywowbb.com/forum76/16635.html

I think that is what you will be looking for.

Here is some information on the controller.

http://www.lightorama.com/Documents/MLC-100.pdf

[Dr. Jones]

take a look at this thread

http://www.constantlychristmas.com/forum/showthread.php?t=3772

I believe Art specs which motors he used

[Paul C]

Hello Kevin,

At my work and at other industrial sites, we use VFD's (variable frequency drive) to control the speed of our motors. The one in the attachment will run on 120 vac and put out 3 phase 208 vac. ACTECH has many different style's, you might look for 220 single phase vac in and 3 phase out as the amount of running cost (current)will be cut by 1/3 or so. Anyway the thing increases and decreases the frequency and voltage going to the motor, controlling how fast it spins according to the amount of load applied.

Ok how do we control our VFD: This VFD has an 0-10 vdc input 0 = 0% 10 = 100% output. If you use a dc controller card from LOR, you'll be able to control the VFD. Using a meter, test the LOR board to see what amount of fade is required to achieve 0-10vdc. You may want to use a .05 amp fuse in this curcuit, oops factor.

The even more expensive part: The motor that is on your pump I'm guessing is 3 phase, it will probably smoke if you really start testing it with low frequency's lower than 20 hertz, or frequency's above 60(oh yeah you can over speed the motor) and fast ramp ups. So you will want to get a Baldor FQ series motor or equivalent, that will handle that kind of abuse.

I say less than 20 Hz on a conventional motor do to cooling, you will loose cooling if the fans spins to slow. Even in Alberta.

We also use valves to control flow, but that causes disturbed flow that will need straightening. Also if you build a system that blocks total flow, provide a way for a small amount of water to bypass your fountain when all the nozzles are shut, so you do not dead head the pump. This will cause premature bearing and seal wear.



Attached files

[Kevin in Alberta]

thanks for all your response's



question about the VFD's i have been looking around and i can not find one with output of 110v single phase, can i hook up a single phase pump on a 3 phase vfd?

it surprises me that i cant find one considering lor's fountain board will be controling 110v single phase pumps. (i called and asked and it will not be ready for when i need it in the first part of july)

[Paul C]

Sorry no, they are three phase only. What kind of pump do you have? what HP.

[Kevin in Alberta]

Hi Paul



I thinking of using Jebao water pump with asynchronus motors. they are 225W 110v single phase. 4200gph.



I found a VFD for single phase 110v motors i think it will work, my plan is to hook up a 200v 8 amp bridge recitfier to a lor chanel and then vary the output of the lor to give me a max of 12 volts to control the speed on the VFD. I also will put a fuse after the rectifer so i dont burn out the VFD.

here is the link for the VFD. http://www.controlres.com/stratus.php

let me know what you think.



Thanks

[Paul C]

Cool, I'm glad you found something that will work. The rectifier idea will work good, we did that to a VFD at work and it worked real good. Just watch your pump temp, it could get high if you have it running slow for a long time.

• 
  
• Input Power: 115 & 230 VAC ±10%
  47-64 Hz
  Single Phase
  
• Output Power: 1 kW load rated for three-phase output
  800 Watts load rated for single-phase @ 240 VAC
  400 Watts load rated for single-phase @ 120 VAC
  
• Fixed 20 kHz PWM rate
  
• 0 to 400 Hz output frequency
  
• Overload current protection
  
• Controls fan/motor speed based on:
  
  • 
    
  • 4-20 mA control signal
    
  • 2-10 VDC control signal
    
  • Remote temperature sensor (thermistor)
    
  • 0-18 VDC transducer (powered from Stratus)
    
  • Modbus communication link
    
  • Dual control option (i.e. temperature and humidity)

  
  [*]Storage Temperature: -40°C to 125°C
  [*]Ambient Operating Temperature: -20°C to 40°C

These are really good stats, I especially like the 0-400HZ range. you could give your pump bursts of say 100HZ for a large shot. Cant wait to show the guys at work. Modbus communication link oooohh nice. Fixed 20 kHz PWM rate,if you wondering what this is, it will not make that freaked motor sound wing,wing,wing. most vfds start at 2 kHz for tork reasons, you loose as you go up they say, but I set the mixers in our 400 gal kettels at 12 and sew no change in the load. So cool have fun.