Electrical help needed - valve actuators.

[borne]

I have a 24 VAC transformer powering two Jandy pool valve actuators. I have both hooked up to a single pole, double throw switch. Flip the switch one way the the actuators move until limit switches inside turn it off. Flip the switch the other way, and it puts power to a different lead to the actuators and they move the opposite direction until the other limit switch shuts them off.

One of the valves goes 90 degrees and the other 45. Problem is, when the one gets to 45, it does not switch off but instead oscilates back and forth switching directions until the 90 degree one stops. Works OK, but I'm afraid I'm going to cause damage. I looked at the manual and it specifically says not to double lug the switch leg wires as I have done. That I should get a double pole switch. However, I can't figure out why it should make a difference. My switch is far away, so hooking it up the recommended way would require a run of two additional wires which I'd prefer to avoid.

Here is the internal schematic - in section 7.1 and how it should really be wired up. Any alternatives?

[N8N]

I didn't look at teh schematic, but are you sure the limit switch on the second valve is working?: Do you have the limit switch on the first valve killing power to both valves? Seems to me like you need a limit switch on each valve.

nate

[Jeff The Drunk]

So you prefer to avoid wiring it per specific instructions provided by the manufacturer?

[Bill]

You are getting voltage "backfed" from a wire on one actuator to the wire on the other actuator.

The wires need to be isolated per the directions.

You can use relays for this at the actuators and not need to run any more wires.

Power one relay and they go one direction. Power the other relay and they go the other direction. You could use 24 volts AC (VAC) relays which are DPST (Double Pole Single Throw).

Search google.com for the words...

How relays work

...and there will be many different pages explaining the basics of relays.

And search for relays (contactor same thing with mounting brackets)...

24 ac contactor dpst

[borne]

Each valve has two limit switches and they are working correctly.

[borne]

Yes I would if I can come up with a way to make it work as intended. Sure I can run two more wires and be done, but if its really not hurting anything or if I can figure a way to make it work by rewiring the actuators inside, then I will do that.

[Tony Hwang]

Ever heard of counter EMF in a coil? It acts like fly wheel. Don't try to cut the corner. Instruction for wiring is there for a reason.

[Tony]

OK, you actually read the instructions, NOW FOLLOW THEM!!!!

[gfretwell]

These are really stepper motors that use a capacitor to give you the step (phase shift). I suspect you are "seeing" the capacitor in the other motor and causing it to step backward.

I agree with the relay idea or just use a 2 pole switch.

[borne]

Thanks. I have some relays on hand already. Or maybe I'll just end up running the extra wires as I also have a DP switch I can use.

[bud--]

I agree. As a specific, if the red wires are powered, the white wires are connected between the 2 valve drivers and connect to motor on both.

You could test this by disconnecting one of the white wires when the red wire is driven (and vice-versa).

I also agree that relays could be used.

One of several possible connections uses a single DPDT relay

red ----------------------------NO-----------red | | contact | | | coil | | | | zone | black--------------------------------black motor | | | | | | white----------NC---------white | | | contact | | | | | | | | | red black white zone motor

[borne]

Yes, but the instructions were written for the everyday electrician who just goes and wires things up. I like to dig deeper and learn as much as I can, especially if it can save me some physical labor and/or money.

So I contacted an engineer at Jandy who was very helpful and confirmed what I already knew - that my two valves will work on a single pole switch, but will have that chatter in the one unit until the latter one gets to its position. I asked if I was doing any damage, and he said that the only problem (and the reason they say not to do this in the manual), is that the motor can overheat if the valves are run for a long time. Since mine travel 45 and 90 degrees (about 10 seconds) and are operated about twice per week, he thought there would be no problems.

So problem solved - I had no real problem to begin with, and now I don't need to crawl in the attic space and add additional wire runs, double pole switch, etc.

[Twayne]

1. Do you know for certain the limit switch works? Pull the wires off and manually make the connections. Does it fix it?
2. Is the switch you're using a "make before break" type? You would need a "break before make" type for that application. If it's make before break then you're momentarily applying power to both valves at the same time, which could cause damage to the switch or even one of the solenoids. You might even have created a partial weld inside the switch where partial power is being applied to both when you select the one valve. Test it manually, without the switch.
3. If it were an approved method to not use the other two wires, wouldn'tyou expect the directions to say so?

Assuming you can test both the switch and valves to operate normally when you remove the switch and manuall connect the wires, AND they test perfect,

0.0 ohms and inifinity on the proper pins, then run the extra two wires above ground and see if it works right. I think it will, but I'm betting you have to replace the switch first. Or possibly a valve but a non-working limit switch doesn't explain all that's going on. Just be sure to check both. And next time, follow instructions. Cutting corners almost never works.

Twayne

[Twayne]

Good thinking! As long as the intent of the instructions are met, it'll work fine; relays would make it possible without running the other two wires, I think. Depends on the specific requirements but that sounds workable. If it's done right and you don't cut corners again.

[Twayne]

The switch should be break before make, remember. Make before break will still cause problems down the road.

[Twayne]

It's amazing sometimes what people will go thru simply in order to not have followed instructions in the first place. Your engineer friend has probably helped you out; but not entirely if that's all he said.