Troubleshooting a PLC Output

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Күн бұрын

Пікірлер: 71

@tektonelec4695 Жыл бұрын

Great video and on point. During my time in electrical industrial maintenance the most common PLC module we would find failed were both SLC relay output cards as well as Compactlogix. The relay outputs would typically be failed in the closed position especially on power open, power closed valves. Something to keep in mind is that 120V Triac outputs commonly leak current in the off state and can mimic almost full line voltage to a voltmeter with the output in the off state without a load attached.

@KletteTech Жыл бұрын

Well said! And Great advice. Thank you commenting and sharing your knowledge.

@Simple_But_Expensive 5 ай бұрын

@@tektonelec4695 It is not just SLC and Compactlogix that suffer this. I was working with PLCs my entire career (earliest was a Goulds), and I never found any relay output cards that didn’t suffer this problem. I trained all my guys to always leave spare points when designing PLCs, so you could move a wire and get back to running right away (power plants only willingly shut down during scheduled maintenance outages), and to always use an interposing relay with a flyback diode to mitigate this problem. We used this method even with a 24 volt card powering a 24 volt circuit. It took up more real estate and cost more, but it greatly reduced the failure rate. We weren’t a professional PLC company, we were custom designing PLC control systems for the combined cycle power plant we worked at, so there was nobody to tell us it cost too much. Given the cost to our customer for down time, estimated at $250k/hour, we were able to show that doing it this way raised our run time from 95% to 97% in one year, netting out customer several million in increased profits, and us a nice increase in contract revenue. Of course myself and my techs only got a slight one time increase in our incentive bonus, but we expected that. The true value to us was pride in our work.

@EthanMiller-h6g 22 күн бұрын

This video makes troubleshooting PLC outputs so clear! If you ever need hands-on electrical troubleshooting, Johnson Electric and Controls in California is the team to call. They’ve helped me out of more than one tricky situation. Highly recommend!

@jluke6861 2 күн бұрын

Thank you for the Great Video.

@bicoolelectricaladventurist 7 күн бұрын

Very clear and informative. Thank you

@renzonieves4156 8 ай бұрын

Thank you so much; A very clear and slow explanation. Easy to understand, step by step.

@tjwiltube Жыл бұрын

Nice job, Pat!

@KletteTech Жыл бұрын

Thanks T-Dog.

@muscleman4799 2 ай бұрын

Really good plc troubleshoot thank you for your time man

@LidzDJ9864 5 ай бұрын

Is the pls short circuit protection on on the output side?

@maintenancetoronto1095 4 күн бұрын

5:44, The NO in the diagram should be connected between DC1.VAC and OUT1.

@naimhasan2877 8 ай бұрын

Very good explanation. I like it. Thank you so much for your informative tutorial.

@theelectricianguy 8 ай бұрын

Good job sir, exactly how I would have done it. I’ve actually ran into this out in the field several times, had 2 output cards with bad relay terminals not putting out voltage. You don’t see it much but I always like to add circuit breakers on my outputs when I build and wire control panels, a lot of times the output in the field could possibly take out the output it’s attached to. Good video!

@Randylongoria81 4 ай бұрын

Could you check for another output on the plc? And how would you program that?

@alexzhitomirets5864 Жыл бұрын

Is it common to wire 120V load through the PLC outputs or better to wire a low voltage relay first? Let's say I have an air solenoid valve (120V).

@scoutsx_d4441 Жыл бұрын

solenoid valves are inductive loads which will generate back emf. Typically the solenoids come with built in diode protection, but it is always good to put an interposing relay to separate the output from the load. Cheap solution and much safer.

@alexzhitomirets5864 Жыл бұрын

Thanks, that's what I was thinking.

@KletteTech Жыл бұрын

Agreed. For simple pilot lights and other low current devices you can wire through the PLC

@deeperloveforphysics9513 7 ай бұрын

This is one of my best videos. Thank you so much. Please, help and make more videos on plc troubleshooting. If you've link to other topics on plc troubleshooting please , share with me. Thank you again.

@KletteTech 4 ай бұрын

Glad it helped!

@jkim5595 5 ай бұрын

I think the internal relay contact on the wiring diagram should be shown between DC1 and Out1 to check yellow light.

@maintenancetoronto1095 4 күн бұрын

I have the same comment as well.

@gechoemiru9931 8 ай бұрын

Is it possible to attach the manual to see it clearly. It will be more clear for me if I can see the wiring diagram.

@emiliohuerta2658 9 ай бұрын

thank you so much im between a tech 2 and tech 3 at my profession and had a little hard time understanding this. Now if i may adk a question so in this case if i dont have a laptop available, how do i force the button to stay on while i check?

@KletteTech 9 ай бұрын

I do not believe you can. You would have to know the logic that is in the program and activate the inputs

@ramya2255 27 күн бұрын

In what/which software are you running/using the plc programming ?

@KletteTech 26 күн бұрын

RSLogix 500

@deeperloveforphysics9513 7 ай бұрын

I had 6 outputs from a plc, these are nozzles that were opening accordingly as programmed. However, after some times the began to operate inappropriately. Instead of opening and closing sequencially as programmed, they began to open and close in a wild manner, what could be the cause, any idea on what i should do?

@brianfirth5435 Ай бұрын

If the PLC code has not been changed, then most likely you have a PLC input with a loose termination or a faulty input device.

@jordanneville7112 3 ай бұрын

Great video, How often do you see a PLC go bad particularly the relay type Mitsubishi plcs ?

@KletteTech 3 ай бұрын

Depends on how much current is flowing through it

@lifevideo7628 4 ай бұрын

Thanks, I got a new and easy system to find out trouble

@KletteTech 4 ай бұрын

Glad I could help

@ShujahHaider-b6y 8 ай бұрын

So Super informative video thanks for nice shearing sir 🇵🇰💖

@juliogomez8636 3 ай бұрын

Hello what kind the Plc Do you have

@gechoemiru9931 8 ай бұрын

That is great. Thank you

@thumbsup9208 5 ай бұрын

What about if you do not have access to the PLC to put force on the terminal, how can continue the troubleshooting./

@enstad7258 5 ай бұрын

Then you need to activate the inputs that activate the output you are troubleshooting

@Simple_But_Expensive 7 ай бұрын

What if it was wired with wetted voltage? If the output is sinking, the power goes to the bulb, and then to the output contact.

@vishnunath5202 9 ай бұрын

Great video. 👍

@KletteTech 9 ай бұрын

Thanks 👍

@street282 7 ай бұрын

Thanks 👍🏻

@mw3blackopsglitches 11 ай бұрын

Great video!!

@KletteTech 11 ай бұрын

Thanks!

@BurRun-kt3tf 2 ай бұрын

Thank អរគុណ👏

@makiseCpenebas 4 ай бұрын

what happen when u wrong insert power terminal on 1743-aent allen bradley mean u swap the +/- position

@k50159 9 ай бұрын

Thank you so much

@KletteTech 9 ай бұрын

You Welcome

@wmdavis9101 4 ай бұрын

I'm confused on how exactly how the PLC output is bad. If your able to activate on the software wouldn't that imply it's still good. In other words how is the software able to activate the output if it's broken?

@Cesar-kc5un 4 ай бұрын

No the plc true is just showing how it should be turned on .

@wmdavis9101 4 ай бұрын

@@Cesar-kc5un At 6:40 he forces output zero "on", then takes measure and it is producing 120V. How is the program able to force it on while the button is unable to?

@SolaniSibanyoni 4 ай бұрын

Just like your phone.. You can switch the torch on and not get any light... The plc software can be 100% but the hardware maybe faulty

@donnellbaxter8050 5 ай бұрын

Thanks sir make more videos.

@KletteTech 4 ай бұрын

Will do

@garrettsmith6679 9 ай бұрын

So you activated the output manually and it’s not coming on so you know it’s not the trigger signal or input to activate that output. But which input is suppose to active that output?

@KletteTech 9 ай бұрын

That is determined by the logic that is programmed into RSLogix 500

@garrettsmith6679 9 ай бұрын

@@KletteTech so the plc receives data from whatever that light is referencing to? Also how do the inputs work, do they correlate directly with a certain output or do you program any input to whatever output you want? Thanks for the responses

@daveb9370 8 ай бұрын

@@garrettsmith6679you can program any input to any output. Another quick test is to use a jumper wire from the correct voltage source, in this case 120 vac, from the input to the output terminal, and if the device works, you know the output is bad.

@garrettsmith6679 8 ай бұрын

⁠@@daveb9370right!!

@garrettsmith6679 8 ай бұрын

@@daveb9370 right!!

@ryanpate6215 7 ай бұрын

Report back to the bosses lol that had me laughing my ass off! Just move the output to another open spot or just add another 120v output card. PLCs lose Inputs and output all the time. Don't make a bigger problem than it really needs to be. If you know the bulb is good, go straight to the output and check it there.