CVA-24 actuated valve problem.

[Dingoboy]

HI All,

I'm new to be forum thing so please bear with me. I have an automated pool filtration system that uses two CVA-24 actuated valves to switch between the pool and spa modes. Late last year, one of the valves failed and I was able to dismantle it and locate the problem. It was two of the metal gears that had lost some teeth. I was able to get replacement gears (~$50) and reassembled the actuated valve to get it working again. Initially, I had issues with the alignment between the micro-switches and the actual valve position, but was able to work out that the plastic "cam-rings" on the shaft could be independently adjusted. Once I had that worked out, it all functioned well. I tested the system by switching between pool and spa modes and watched the valves move correctly.

Last night I tried to tun on the spa and went outside a few minutes later and the spa tub was empty and the main pump running dry. The same actuated valve had moved to a odd position and pumped water back to the pool. Re-examining it again today and switching between pool and spa modes I found the following problem. Intermittently, the problem valve was turning in the wrong direction to it's normal operation. This caused the cams to activate the micro-switches from the opposite side and stop the valve in the odd positions. After working with it for a while, I was able to get it back in line and working normally. But for how long before it screws up again? My fear is that it may occur when I'm not home and burn out a pump (or worse).

My primary question is what is the faulty part of the valve? Is it the circuit board attached to the selector switch? Or maybe one of the micro-switches? Any thoughts would be greatly appreciated.

 

[Jimrahbe]

Dingo,

Welcome to TFP... A Great resource for all your pool questions.

Most likely an intermittent micro-switch. It is a pretty common problem.

If you use the search box in the upper right of your screen you can find tons of threads like this... https://www.troublefreepool.com/threads/99985-Pentair-Valve-Actuator-Fix-New-Switches?highlight=CVA-24%20microswitch&p=935342#post935342

Thanks for posting,

Jim R.

 

[gary300]

The motor in the CVA-24 actuators is a pancaked stack of two AC syncronous motors, one for each direction the actuator turns. Look at the motor and you will see it actually is in two sections, one on top of the other with seperate leads from each section. This type of motor requires a capactior to phase shift the AC voltage to the motor to get it to start rotation in the required direction.
Without the capacitor, the motor will start in a random direction, depending on the phase angle of the AC power applied to the motor at the instant the power is applied. If the big mylar capacitor inside the actuator is weak or has a bad connection, the motor might not start in the same direction each time.

In may experience with the CVA-24 actuators, the problem I always had was when, say for instance I turned on the spa the valves would turn normally and the spa would actuate. When done with the spa and tried to return to pool operation, one of the valves would not turn to return to pool mode. After investigation it always turned out to be that one of the micro switches in the actuator had become "stuck", that is that the plunger in the micro switch had be guncked up and would not release to the open position there for preventing the actuator from reversing direction. Replacing the micro switches fixed that problem.

I have never had an actuator go the wrong direction, unless someone has accidentally changed the position of the toggle switch on the back of the actuator. That is why I presented the unlikely scenario in the first paragraph.

Hope I have been of some help, good luck.