
Originally Posted by
valveman
You should be worried about pump and motor life. Cycling on and off is the biggest killer of pump systems. When the CU301 controller is working as it should, it will turn on the pump when you need water, and adjust the motor RPM to produce the exact amount of water you are using. So when a shower is turned on, the pump stays on, for as long as the shower is running. The problem is that the CU301 is no more dependable than any other computerized system. Your saving grace is that this type pump will still work as a normal type pump, even without the CU301 controller. Most other variable speed pumps will not do this. If you had any other brand, you would be replacing the controller on a regular basis, or you would have to replace the entire system, including the pump.
Without the CU301 controller, and working with a pressure switch and small tank, the pump could cycle on and off 50 times or more while you take a shower. You really have two options.
(1)You can install a large pressure tank. This will decrease the number of cycles but, does not eliminate the cycling. A large enough tank will still probably cycle the pump 3 or 4 times during a shower, which can still add up to hundreds or thousands of cycles per month.
(2) You can install a Cycle Stop Valve. This will work with a small tank. The CSV controls the flow from the pump to exactly match the usage, without varying the speed of the motor. This will eliminate cycling, and the pump will run as long as the shower or sprinklers are on.
You can verify what I am saying by turning on a shower, and watching the pressure gauge. You will see that the pump cycles on and off every few seconds the way you have it now. This will get you by for a day or two but, will soon destroy the pump. Not to mention the huge and continuing variations in pressure that can be very annoying. This variation in pressure will only be slowed down if you install a big pressure tank. The pressure will remain constant while the shower or sprinklers are running, when controlled by a Cycle Stop Valve.
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