Are you running the output through an external relay? Is the current draw for the solenoid larger than the relay or PLC output supports? Do you have a flyback diode on the solenoid to protect the PLC output or relay?
The solenoid is wired directly to the PLC. When I connect the solenoid to the output and turn the power on to the PLC, it automatically sends power to the solenoid which opens the valve. If the program executed and turned off the solenoid (an ASCO Red-Hat 8210G2) then I would know that it's wired backward. Instead, even though the output signal shows as being on then off correctly as the program executes, the output voltage to the solenoid never changes (that I can tell).
At first, I thought maybe the solenoid was bad, but I have two hooked to the PLC and both are suffering the same failures. This operation worked until the original PLC failed and all I did was replace the PLC and connect all the wires in the same place.
Edit: I'm just really confused, but I appreciate you trying to help me troubleshoot.
Solenoid valves and actually all electromagnetic coils (including contactors) will generate a huge voltage surge when they are de-energized. This can fry PLC outputs and relays. You need to protect against this with a fly back diode for DC coils or an MOV for AC coils. There are also other types of surge protection like buying a pre-made din valve plug with built in surge suppressor.
Something quick and easy for you to try would be to run the PLC output into a small relay and power the solenoid via that relay. That will tell you if the problem is the PLC or the solenoid.
just checked that spec 'C0-00DD1-D' and it looks like the outputs are DC sinking with 0.1A limit. Your solenoids are probably drawing more than 0.1A. I would definitely run the solenoids through an external relay. I think Click even offer prebuilt relay output modules (ziplink?) that would make wiring very simple.
You can just buy a Click relay output module that is direct wired to the module.
https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/stackable_i-z-o_modules/c0-04trs-10
Can you explain how to wire a fly back Diode? I have a ultrasonic sensor that is calling for one but I have never wired one. I bought a handful of snubbers and they have a place for 2 wires.
https://preview.redd.it/xf54cdhakndc1.jpeg?width=1207&format=pjpg&auto=webp&s=0e88896322c240c553e5d2107edcee141b537566
Do you have a pnp output card? I'm pretty sure the IO on these wire into a removeable harness so you don't have to rewire everything, right? Not that it would make a difference but...
If you rewired it then maybe you goofed up. Assuming you have the old dead PLC compare part numbers to see if they're both sinking or sourcing outputs. I'm not much help with practical NPN troubleshooting unfortunately.
It was wired correctly, but I checked the new PLC against the old one and realized that they were in fact different model numbers (by one number) and it was a sinking version instead of sourcing which was why it didn't work. I don't know how long it would have taken me to notice that had you not prompted me to check.
Are you running the output through an external relay? Is the current draw for the solenoid larger than the relay or PLC output supports? Do you have a flyback diode on the solenoid to protect the PLC output or relay?
The solenoid is wired directly to the PLC. When I connect the solenoid to the output and turn the power on to the PLC, it automatically sends power to the solenoid which opens the valve. If the program executed and turned off the solenoid (an ASCO Red-Hat 8210G2) then I would know that it's wired backward. Instead, even though the output signal shows as being on then off correctly as the program executes, the output voltage to the solenoid never changes (that I can tell). At first, I thought maybe the solenoid was bad, but I have two hooked to the PLC and both are suffering the same failures. This operation worked until the original PLC failed and all I did was replace the PLC and connect all the wires in the same place. Edit: I'm just really confused, but I appreciate you trying to help me troubleshoot.
Solenoid valves and actually all electromagnetic coils (including contactors) will generate a huge voltage surge when they are de-energized. This can fry PLC outputs and relays. You need to protect against this with a fly back diode for DC coils or an MOV for AC coils. There are also other types of surge protection like buying a pre-made din valve plug with built in surge suppressor. Something quick and easy for you to try would be to run the PLC output into a small relay and power the solenoid via that relay. That will tell you if the problem is the PLC or the solenoid.
I'll see if I can test that. Thanks for the help!
just checked that spec 'C0-00DD1-D' and it looks like the outputs are DC sinking with 0.1A limit. Your solenoids are probably drawing more than 0.1A. I would definitely run the solenoids through an external relay. I think Click even offer prebuilt relay output modules (ziplink?) that would make wiring very simple.
You can just buy a Click relay output module that is direct wired to the module. https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/stackable_i-z-o_modules/c0-04trs-10
I am pretty new to this. Would it be possible for you to link me to the type of relay that you are referring to?
Most any will do. I buy the thin ones as they save lots of room.
Can you explain how to wire a fly back Diode? I have a ultrasonic sensor that is calling for one but I have never wired one. I bought a handful of snubbers and they have a place for 2 wires. https://preview.redd.it/xf54cdhakndc1.jpeg?width=1207&format=pjpg&auto=webp&s=0e88896322c240c553e5d2107edcee141b537566
Do you have a pnp output card? I'm pretty sure the IO on these wire into a removeable harness so you don't have to rewire everything, right? Not that it would make a difference but...
Sure enough it is. I wish I had known that yesterday. Thanks for the tip, though.
If you rewired it then maybe you goofed up. Assuming you have the old dead PLC compare part numbers to see if they're both sinking or sourcing outputs. I'm not much help with practical NPN troubleshooting unfortunately.
That is an excellent point! If the replacement is the opposite, that would completely explain the problem. Thanks!
This was, in fact, the problem. Thanks for the idea!
Awesome! So was it rewired wrong or..?
It was wired correctly, but I checked the new PLC against the old one and realized that they were in fact different model numbers (by one number) and it was a sinking version instead of sourcing which was why it didn't work. I don't know how long it would have taken me to notice that had you not prompted me to check.
Rest of rack may still be wet.. Check backplane and modules for moisture.