Pentair Actuator acting strange

[PowderDay]

I have a 12 year old pentair actuator (CVA-24T) on my suction side that controls if the water is coming from the pool or the spa. Recently the actuator has not been alternating moving back and forth like it is supposed to. What I mean by that is the pool is running and I'll turn the spa on, it will rotate from one side to the other and stop. Then when I switch back from spa to pool mode, instead of rotating back, it will keep rotating the same way and turn the valve to block all water from the pump! Sometimes it rotates back and forth like it's supposed to and other times it keeps rotating the same way and goes around blocking the pump to the other side. It almost seems random which way it chooses.

The first thing I did was replace the 2 micro switches on the inside and make sure the cams were tight. That didn't seem to make a difference.

Does anyone know what causes the actuator to know to switch directions when the control board switches from pool to spa or vice versa? I'm trying to avoid having to spend $150 on a brand new actuator and I'm not even sure that will fix the issue. Thank you.

 

[ajw22]

Something in the micro-switches or cam is worn out. The microswitches stop the motor rotation and change the direction.

Electrical schematic for the CVA-24T actuator

I just found this forum! Do you guys know where I can find an electrical schematic for the CVA-24T actuator? Mine quit working (stuck in the off position. I took the cover off and fooled around with the wires, switches, and the 3 way switch and finally got it to move to the on position. I...

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Replacing with a new actuator will fix it.

 

[setsailsoon]

Based on your description it sounds like your cam is worn and needs replacement. To verify here's how I test actuator internals:

Find the switch that's supposed to actuate based on the cam position. Follow the cam/switch test below. Then repeat for the other side by changing the control position or the toggle switch on the actuator.

Cam/Switch Test
Take the connectors off on each limit switch and touch them together. Does this make the actuator move back to the opposite position? If so the problem is either the limit switch or the cam is worn out and not actuating the switch. Put the connectors back on and manually actuate the switch when it is in the position the cam should actuate it. Then use a small screw driver to push in the switch lever. If this makes the motor turn the actuator the cam is bad and needs to be replaced.

If the problem is the cam it's pretty expensive. The micro switch can be found from an electrical supply cheap. If the cam is messed up you might be able to add some material to make it stick out but I wouldn't mess with it on a 12 year old actuator unless budget was extremely tight. Time to replace.

I hope this helps.

Chris

 

[Jimrahbe]

P,

The way an actuator works is that the automation sends 24 VAC down one of two wires.. If the voltage is on one wire the actuator will move one way, until it opens the microswitch which makes it stop.. When the automation puts the 24 VAC on the "other" wire, the actuator will move the other way until its microswitch opens and stops it.

Since your actuator intermittently does not stop.. I can't see the problem being anything but a bad actuator.

If I had a 12 year old actuator that was giving me problems I would just replace it, as my time is worth more to me than the cost of an actuator..

Thanks,

Jim R.

 

[PowderDay]

Thanks for all the replies!

The actuator always stops on each side. When it starts to move again, it randomly goes either direction. Usually it goes the opposite way but other times it keeps going the way it was the last time it moved.

I'll take the box off the actuator today and look at it closely as I shift it back and forth.

Is there any harm in not replacing the actuator? We don't use the spa more than a few times a year and I have the heater come on automatically for 10 minutes a week just to help preserve it. I'm thinking of just using the manual handle for the valve.

 

[ajw22]

It is fine to adjust the valve with the manual handle. Remove the bad actuator and put the handle on.

 

[PowderDay]

I did the cam/switch test. When I touched the connectors together the actuator moves. When I separate them it stops. Then when I touch them again it either keeps going in the same direction or it reverses. This is the random part I can't figure out. I believe it's always supposed to reverse directions when the connections touch again, right?

 

[peterl1365]

Thanks for all the replies!

The actuator always stops on each side. When it starts to move again, it randomly goes either direction. Usually it goes the opposite way but other times it keeps going the way it was the last time it moved.

I'll take the box off the actuator today and look at it closely as I shift it back and forth.

Is there any harm in not replacing the actuator? We don't use the spa more than a few times a year and I have the heater come on automatically for 10 minutes a week just to help preserve it. I'm thinking of just using the manual handle for the valve.

I had a very similar problem develop with my 14-year old actuator. Works in one direction, but doesn't stop in the other direction. I'm pretty sure that the problem is a bad microswitch. This video is a good resource for how to fix it. You might want to try this before replacing the whole actuator. The switches are linked in the video description and are very cheap.

 

[peterl1365]

I did the cam/switch test. When I touched the connectors together the actuator moves. When I separate them it stops. Then when I touch them again it either keeps going in the same direction or it reverses. This is the random part I can't figure out. I believe it's always supposed to reverse directions when the connections touch again, right?

Can't really know without a schematic. The reversing relay may be distinct from the switches themselves. So the direction may be determined by the relative state of each switch at the time the contacts are made. When you touch the the connectors together, you may be closing the Normally Open circuit, while the Normally Closed circuit is already made, thus the logic might be getting confused.

 

[PowderDay]

I had a very similar problem develop with my 14-year old actuator. Works in one direction, but doesn't stop in the other direction. I'm pretty sure that the problem is a bad microswitch. This video is a good resource for how to fix it. You might want to try this before replacing the whole actuator. The switches are linked in the video description and are very cheap.

I saw this was a common problem and replaced both micro switches. Unfortunately that didn't fix the problem. I'm assuming the new ones from Amazon are good.

 

[PowderDay]

Can't really know without a schematic. The reversing relay may be distinct from the switches themselves. So the direction may be determined by the relative state of each switch at the time the contacts are made. When you touch the the connectors together, you may be closing the Normally Open circuit, while the Normally Closed circuit is already made, thus the logic might be getting confused.

I'm not really sure I understand what you are saying. Can you explain more?

Out of curiosity, I did the same test on my other actuator that is working correctly. Each time I touched the wires on one side, the actuator keep rotating the same direction. I did the test on the other side and it always rotated towards the wires. So I'm thinking the bad actuator shouldn't have reversed directions on the same wire touching and un-touching. I don't have a strong understanding of how to test the actuator though and exactly what each set of wires is supposed to do. Mainly, how does it know which direction to turn the actuator. I understand how the micro switches stop the rotation.

 

[peterl1365]

I'm mostly guessing about how the switches work, but I suspect that the power to the actuators does not actually flow through the switches. I'm probably biased because I work on automation equipment for a living, and it would normally be considered dangerous to route power through limit switches. However, given the very low power of the motor, it is certainly possible.

The problem is that a limit switch generally cannot be used to kill power directly because you have the problem of moving off the switch. In other words, if the switch interrupts the power circuit, how do you then restore power while you're still on the limit switch? Therefore, you normally use the limit switch to signal another device to start or stop power. Additionally, the combination of switch inputs will tell the control circuit which direction to turn the motor. I don't know if the motors run on AC or DC power, but generally speaking reversing the polarity will reverse the direction of rotation.

Each switch has a Normally Open (NO) and a Normally Closed (NC) contact. If one contact is connected to the Common (power) connector, then the other contact is automatically disconnected. When you manually touch a wire to the common, then it is possible that you are simultaneously triggering both the NO and NC. The control circuit may not know how to deal with this situation since it should never occur in normal operation. These switches generally cannot close both contacts simultaneously unless there is a catastrophic failure involving a massive spark that welds the contacts together. You can google "Form C" contacts to get an idea of how these switches work internally.

There are probably many ways to design this circuit, so without a schematic from manufacturer, the best we can do is guess. If you've replaced both switches and the problem is still occurring, then I'd suspect something wrong with the controller circuit or the reversing relay.

 

[generessler]

I have JVA 2444's, which look similar to what you have. Their circuit looks like this:



I'm focusing on you saying that direction is the problem. There's no "reverse relay." The only thing that affects direction of rotation is whether 24VAC is connected between blk and red or blk and wht input wires. The micro switches don't affect direction. They only stop rotation. The only other thing in the direction-determining part of the circuit is the manual/reverse switch. If you are not touching that, then the only explanation I can see for what you reported is that 24VAC is arriving at the valve _on the wrong wire_. This means a sticky relay or other problem in the control box.

It's not a bad idea to replace the limit switches anyway. It sounds like they may also be intermittent.

If you have even a cheap Harbor Freight style meter, you should be able to check what's coming from the control box to verify whether the above is right. If that makes sense: 24VAC switches between red/white as expected, then check what's arriving at the limit switches does the same. That would let you rule out weirdness in the manual/reverse switch.

 

[peterl1365]

To further elaborate on the possible logic, each switch has two states which I will call ON or OFF. Since there are two switches, there are four combinations of SW1 ON/OFF and SW2 ON/OFF. The control circuit will look at the combination (and possibly how one combination changes to another combination) to determine the motor rotation direction and when to start or stop.

 

[peterl1365]

I have JVA 2444's, which look similar to what you have. Their circuit looks like this:

View attachment 170835

I'm focusing on you saying that direction is the problem. There's no "reverse relay." The only thing that affects direction of rotation is whether 24VAC is connected between blk and red or blk and wht input wires. The micro switches don't affect direction. They only stop rotation. The only other thing in the direction-determining part of the circuit is the manual/reverse switch. If you are not touching that, then the only explanation I can see for what you reported is that 24VAC is arriving at the valve _on the wrong wire_. This means a sticky relay or other problem in the control box.

It's not a bad idea to replace the limit switches anyway. It sounds like they may also be intermittent.

If you have even a cheap Harbor Freight style meter, you should be able to check what's coming from the control box to verify whether the above is right. If that makes sense: 24VAC switches between red/white as expected, then check what's arriving at the limit switches does the same. That would let you rule out weirdness in the manual/reverse switch.

I'm not sure I understand your circuit. During rotation when neither switch is open, both the red and white terminals are connected to black.

 

[generessler]

I'm not sure I understand your circuit. During rotation when neither switch is open, both the red and white terminals are connected to black.

I'm not sure where you're seeing that. Red and white go through the reversing switch to the motor. The only connection to black is through the motor windings. For example, if 24vac is present between black and red, then one motor coil sees that directly, and the other sees it through the capacitor. That sets the direction of rotation. If 24vac is between black and white, it's the same, but with the capacitor feeding the opposite winding.

 

[peterl1365]

I'm not sure where you're seeing that. Red and white go through the reversing switch to the motor. The only connection to black is through the motor windings. For example, if 24vac is present between black and red, then one motor coil sees that directly, and the other sees it through the capacitor. That sets the direction of rotation. If 24vac is between black and white, it's the same, but with the capacitor feeding the opposite winding.

I suppose you're right. I'm not very familiar with cap start motors. I normally work with DC and VFD/servo drives so I never deal with caps for motor rotation.

 

[swiedom]

Did you ever figure this out? I'm having a similar issue and would appreciate some direction on troubleshooting. I have swapped limit switches with a good actuator and switched the connector on the board. The issue followed the swap telling me it isn't the actuator but something on the board. Did you end up finding something similar?

 

[Mike_d_s]

@swiedom,

Woke up this morning to a partially drained hot tub, so I've been doing a little research on actuators this morning. I have a couple of issues one of which appears to be limit switch related (valve is only turning about 170 degrees) and one is gears as I notice the valve stops turning for a second then starts again and I can feel a little gear grinding if I put my hand on it.


Did you get your problem fixed yet? In my case, since I figured I'd need to do limit switches and gears, I was looking at $60-$70 in parts maybe and I found Jandy actuators on sale at PoolSupplyWorld for $99 shipped, so I just ordered a replacement actuator. The price was right so I figured I'd pass on the info.

FYI, you're close to me as I'm in North Fort Worth.

Mike

 

[mknauss]

FYI --- for repair/maintenance of valve actuators.

CVA24-T Actuator Details

I forgot to account for inertial reference frames in non-Newtonian space-time. Good catch. :goodjob: Here is the debug error information. "debug_error": { "errorCode": "api.invalidparam", "errorMessage": "An error occurred. Please try again later.", "wA": "GENERIC_WITHOUT_LINK"...

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