Valve Actuator: Current Draw & DIY Automation

[PhiDeck]

Regarding a Jandy Valve Actuator (JVA), Model 2444 (or equivalent):

My inference is that the JVA only draws ~0.75 A from its relay-switched 24 Vac supply while it is moving. That once it finishes rotating to the cam-defined angle, a microswitch opens the current path to the motor. Is that correct?

Assuming I am correct, then it would seem to follow that one can size the 24 Vac step-down transformer to provide just 1 A, as long as one can guarantee the automation controller will only activate one JVA at a time.

However, since there is no positional feedback from JVAs, the controller is oblivious to their position upon power-up. The work-around would seem to be:
- non-volatile state variables
- a master relay switching 24 Vac to the common of the JVAs’ relays
Upon power-up the individual JVAs’ relays would be set to their last position before turning on the master 24 Vac relay.

Unfortunately, that does not account for:
- initial installation
- manual operation of the valves while the controller is off
- a JVA being in mid-rotation when power failed
- failure of a JVA microswitch

Is there a solution to this problem, or must I resign myself to supplying enough 24 Vac to operate all JVAs simultaneously?

 

[Jimrahbe]

pd,

I am not sure what it is you are trying to do, but these valve drivers are normally at one end of there rotation or the other. Upon initial start up, (the first time used after set up) if the valve is at the wrong end of the rotation then there is a small switch on the side of the actuator that you can reverse which will drive the valve to the other limit of travel.

You are basically correct on how the valve will drive one way until the limit switch removes the power. To move the valve back to the original position, you have to apply power to the other input lead.

Thanks for posting,

Jim R.

 

[PhiDeck]

Jim,

I’m designing my own automation controller, and trying to keep the cost reasonable. I am appalled by the price of higher wattage step-down transformers, and am trying to figure out if there’s a way to get away with a 20 VA transformer, despite having multiple JVAs.

Thanks for confirming my assumption about how a JVA works.

Philip Decker

 

[cjpwalker]

.

How much are you looking to spend?

 

[PhiDeck]

View attachment 70441.

How much are you looking to spend?

Forgot to mention I was looking at DIN Rail mount transformers.
Was hoping to implement entire controller with DIN Rail modules.
However, making an exception or two may be prudent. In which case the middle transformer in your screen-cap would work.
Thanks.

 

[Jimrahbe]

Jim,

I’m designing my own automation controller, and trying to keep the cost reasonable. I am appalled by the price of higher wattage step-down transformers, and am trying to figure out if there’s a way to get away with a 20 VA transformer, despite having multiple JVAs.

Thanks for confirming my assumption about how a JVA works.

Philip Decker

Phil,

When switching between the Pool Mode and the Spa Mode, it is normal for the Intake valve and the Return valve to move at the same time.

I suspect there are other cases where the pool owner might want to program more than one valve to move at the same time.

Thanks,

Jim R.

 

[PhiDeck]

Phil,

When switching between the Pool Mode and the Spa Mode, it is normal for the Intake valve and the Return valve to move at the same time.

I suspect there are other cases where the pool owner might want to program more than one valve to move at the same time.

Thanks,

Jim R.

I don’t have a Spa.
My JVAs are:
- Solar heat
- Pool cleaner
- Lower water level (after Florida déluge)
I don’t see a need to operate them concurrently.

 

[Jimrahbe]

I don’t have a Spa.
My JVAs are:
- Solar heat
- Pool cleaner
- Lower water level (after Florida déluge)
I don’t see a need to operate them concurrently.

Phil,

I had "assumed" that you were building something more universal and not something just for your pool...

That's what happens when you assume...

I need an emoji for that...

Jim R.

 

[PhiDeck]

I am a retired engineer (BSEE, MSCS) doing small electronics projects for fun. No interest in dealing with mass production (or UL), nor with providing tech support.

 

[cjpwalker]

Forgot to mention I was looking at DIN Rail mount transformers.
Was hoping to implement entire controller with DIN Rail modules.
However, making an exception or two may be prudent. In which case the middle transformer in your screen-cap would work.
Thanks.

DIN rail mounting sure does make for a clean looking panel. Seems like everything is more expensive, though - contactors, relays, all of it...

 

[PoolGate]

Maybe the smart JVA control board will offer some insite?

Jandy Smart JVA Assembly