How to wire a 24V Actuator with reverse polarities across motor to PLC

[MorphuisOGrady]

I just tested one. There is 5 cores going to actuator. 2 for motor/coil and NO/NC/COM for limit switch.

So there is only one limit switch?

SO should I use 2 relays and PLC outputs?

Sample logic
XIC Open_Cmd XIO Sts_Opened OTE Open_OP
XIC Close_Cmd XIX Sts_Opened OTE Close_OP

Sts_Opened being the limit switch.

Is this the idea or is one realy only necessary?

 

[brucechase]

I just tested one. There is 5 cores going to actuator. 2 for motor/coil and NO/NC/COM for limit switch.

So there is only one limit switch?

SO should I use 2 relays and PLC outputs?

Sample logic
XIC Open_Cmd XIO Sts_Opened OTE Open_OP
XIC Close_Cmd XIX Sts_Opened OTE Close_OP

Sts_Opened being the limit switch.

Is this the idea or is one realy only necessary?

One limit switch will be a problem. How will you know when you reach the end of stroke in either direction?

Your spec sheet says switches in one place (implying more than one switch) and switch in another. Run the actuator to the end of travel while looking at the limit switch contacts and see if they change states only when extended or retracted or see if they change states both when extended and retracted (which I highly doubt). If you don't already have the 50 of them, you can see if they make a system with 2 switches in it.

Otherwise, you will need some feedback to tell you when you are at the fully open or fully closed position so you can turn off the motor. If you can add an external sensor, you can still wire it up as shown in post 23.

 

[MorphuisOGrady]

Reply from Manufacturer:

There is a micro switch inside the actuator. When the actuator is all the way in. The BLACK wire and the BROWN wire is make connection. When the actuator is all the way out. The BLACK wire and the WHITE wire is make connection.

This to me suggests 2 contacts/switches? Agreed?

 

[bernie_carlton]

What is the state in the middle of the extension? And does 'make connection' mean the associated wires are open or closed? Normally a 'limit' will go 'open' when at the limit.

 

[OkiePC]

Reply from Manufacturer:

There is a micro switch inside the actuator. When the actuator is all the way in. The BLACK wire and the BROWN wire is make connection. When the actuator is all the way out. The BLACK wire and the WHITE wire is make connection.

This to me suggests 2 contacts/switches? Agreed?

Yes, but it's more like a form "c" contact, since the black wire is common to both end limits. Sounds like they used normally open switches that close when the actuator reaches the end limit, and wired them together internally so that they share a common black wire.

Back to the original subject, I would not drive these motors directly with any kind of PLC output (even though I saw no spec for power or current requirement), instead I would use two interlocked relays, one for forward and one for reverse. If you can't squeeze in mechanically interlocked relays, then interlock them electrically. If you don't you will short your supply someday, and let the smoke out of something.

I did this with a power window motor in a Suburban once, and it toasted the window motor, costing me four hours and $100 and nearly two fingers to replace it!

 

[Clay B.]

Reply from Manufacturer:

There is a micro switch inside the actuator. When the actuator is all the way in. The BLACK wire and the BROWN wire is make connection. When the actuator is all the way out. The BLACK wire and the WHITE wire is make connection.

This to me suggests 2 contacts/switches? Agreed?

Yes, you would need 2 switches for that to happen. Downside is you say the switches close when you reach the end positions. This means you circuit will have to be a bit more complex to invert the signal. You will need atleast 2 more relays to make this work. You could do it with 2 relays but you would need a manual bypass if you lost power in the middle of the stroke. I am suprised that the Limit switches do not have normally closed contacts also. I would ask if you could order them with this option. It would make your circuit alot simplier.

 

[MorphuisOGrady]

Yes, you would need 2 switches for that to happen. Downside is you say the switches close when you reach the end positions. This means you circuit will have to be a bit more complex to invert the signal. You will need atleast 2 more relays to make this work. You could do it with 2 relays but you would need a manual bypass if you lost power in the middle of the stroke. I am suprised that the Limit switches do not have normally closed contacts also. I would ask if you could order them with this option. It would make your circuit alot simplier.

I tested it and there is no doubt that each switch closes at either end.

You mean if I had both NO and NC contacts for both directions?

So now I need to use 4 relays per actuator to make this work?

 

[MorphuisOGrady]

What is the state in the middle of the extension? And does 'make connection' mean the associated wires are open or closed? Normally a 'limit' will go 'open' when at the limit.

Hi Bernie,

Just tested and to answer your question there is no middle as such.

When I extend or retract at about halfway I can actually here the microswitch clicking and then both switches change state

 

[bernie_carlton]

So one pair is closed for about one half of the travel and the other pair for the other half? I would expect 'limit switches' to go to their unique state only at the 'limit' of the travel. That makes it even more complex.

 

[iant]

Your PDF says it is a 12V Dc Actuator - You could use 2 12V dc Supplies with a floating (0 Vdc)(-12 - 0 - +12)
then 1 relay per output 1 for fwd 1 for REV.
Not mush different to what has been suggested but easier to wire

I Know you said 24 V dc but I still need confirmation.
The PDF shows a 12 Dc actuator is this correct

 

[OkiePC]

Also, apply voltage to the LS common black wire, and bring the two position signal wires back to the PLC as inputs. Two interloacked relays (driven by two PLC outputs) and two PLC inputs for position monitoring.

 

[Lancie1]

When I extend or retract at about halfway I can actually here the microswitch clicking and then both switches change state.

Please verify whether or not the limit switch switch point is adjustable. If so, then adjust the first limit to open at one end, and the second limit switch to open at the other end or travel.

 

[MorphuisOGrady]

I Know you said 24 V dc but I still need confirmation.
The PDF shows a 12 Dc actuator is this correct

Yes you are correct. They are 12V actuators. They are available in 24V ones too. I thought I would need the 24V ones if using a Micrologix but as I'll be using relays this wont be an issue.

 

[MorphuisOGrady]

Please verify whether or not the limit switch switch point is adjustable. If so, then adjust the first limit to open at one end, and the second limit switch to open at the other end or travel.

The limit switches are not adjustable.

 

[MorphuisOGrady]

Is this not a single microswitch with a NO/NC contact?