RIzu (Customer) asked a question.
Controlling a contactor with an overload relay and DL06.
I'm trying to control a power outlet through a contactor and an overload relay connected to the PLC. I've figured out the circuit diagram. I need to supply 24 V from the PLC output (say Y1) every time I turn it on, to the NC contact of the overload relay.
I have a DL-06 PLC with sinking outputs. Can somebody help me to figure out how to supply the required voltage every time I turn on an output on the PLC please?
Attached is the Circuit diagram I'm using. The part I'm looking to implement is circled.
In my experience, it's difficult to get a contractor to do much of anything, including control a power outlet. I've found contactors to be much more useful for this application.
That being said, if you have a sinking output module, you can't control the contactor directly as shown. You'll either have to use an interposing relay or wire the PLC output between the A2 coil and TB13. In general, an interposing relay is probably a better approach. Also, why are the V+ and COM wire colors the same?
Thank you for your reply. Sorry for the typo. I'm using the diagram from our system integrator that built our other machines.
I have sinking output PLC and I have the NC (95) contact on the overload relay connected to the output on PLC that supplies +24 VDC and the NC (96) to A1. A2 is connected to the common (0 V).
When I turn on the output on the PLC, It supplies 24 VDC the the NC 95 and 96 of the overload relay only when I have the 96 disconnected from the A1 side of the coil. Once I connect the 96 to A1 side of the coil, the voltage at A1 shows 2V. Do you know what I'm doing wrong here? Looks like I'm doing everything right but not able to turn on the contactor. I'm confused. Also When I remove the 0 V from A2 and keep the A1 connected to 96, I get 24 V at both A1 and A2.
Your wiring is not correct. Can you provide a drawing/diagram of your plc outputs? You might possibly be shorting your PLC output. Are you sure you have a sinking output? The other outputs shown on your diagram are showing sourcing or relay.
Thanks for your reply. As you can see in the picture, It says It's a sinking output PLC. Since the diagram is for sourcing output PLC, do you think if I connect the plc output between A2 and TB13 it will work? Right now I have A2 connected directly to TB13 (Comm).I don't have an interposing relay.
Sinking output means the output will be supplying 0V. Following the OEM's diagram (but considering yours is a sinking output PLC) terminal 21 should wire to 0V (minus terminal of a DC power supply). Terminal 23 should go to 95, and 96 to A2. The A1 terminal of your contactor should go to +24V (plus terminal of a DC power supply).
I followed your advice and now When I turn on the output of the PLC, I have +24 V DC between A1 and Common and +24 V DC between A2 and Comm and +24VDC between 96 and Common. 95 is connected to the PLC output and the +V on the plc is connected to 0V Comm as you advised (please see picture). The contactor didn't work. I don't know what else I'm doing wrong :(
Is there anything else in the PLC wiring, I need to do to complete the circuit? Do you know if I need to connect the C0 output (right now I don't have it connected to anything) of the PLC to +24V DC?
Really appreciate your help.
It worked! Thank you so much for your help friend! Can you answer just one more question for me? Why do we need to supply 24V to +V output of the plc even though we are only supplying 0V from the outputs of the PLC to the contactor (sinking output PLC)?
Because solid state outputs, unlike relays, need to be connected to both sides of your voltage supply to operate.
Thank you for your reply. Your help cleared a lot of confusion. Is that the same for magnetic contactor as well as electromechanical relays?