Connect a dimmer switch to a water pump???

Old 04-29-20, 03:07 PM
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Connect a dimmer switch to a water pump???

I would like to better control the flow of water being pumped within my swap cooler mostly based on the outside humidity level. I have a plastic MasterCool water pump 6000-7500 and would like to connect a dimmer switch or anything else which would allow me to control the flow of water from within the house. Does anyone know if I could connected a dimmer switch, have another idea or can direct me to a better resource?

I live in AZ and have found that I can control the flow by turning the water pump on and off say every 10 minutes and running the pump for about 2 minutes on most days.
Old 04-30-20, 06:20 AM
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I would contact the manufacturer and see if that motor's speed can be controlled. Generally you can't just put a "dimmer" on a AC motor because it's speed is controlled by the electricity's frequency and a simple dimmer will reduce the voltage which could cause the motor to overheat/burn out.

A better option would be to install a valve in the output side of the pump. You can partially close the valve to restrict/reduce the flow to the chiller. Or, you can install a diverter valve that would allow you to direct some of the pump's output back to the sump. This would allow you to control the flow to the chiller without restricting the flow through the pump.
Old 04-30-20, 07:42 AM
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How about something like this.

You might have to run a relay from this and then the relay contacts would control the motor.

Does not really control by humidity but at least automates what you are doing now.
Perhaps you can figure out how to place a humidistat in line with the relay to give some control by humidity.
Old 04-30-20, 09:01 AM
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You better look into your pump and how it's controlled before buying something random off Amazon, you could very well have a 220V pump and you dont want to try to install a timer for a coffee pot!
Old 04-30-20, 10:58 AM
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You could reduce the speed of that motor with a variable speed drive but they are extremely expensive. I would recommend following Dane's idea..... restrict the flow with a valve or add a bypass tee to recirculate the water back into the sump.

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