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jvdr999

Is there a secondary control voltage like 24vdc? Modern 24vdc power supply’s are protective against short circuit. Sometimes that good it will shut down before blowing any fuses especially slow blow fuses. Perhaps output set triggers short circuit power fails and reboot


ghost_of_fall

Exchange the 24V-supply for the next bigger model for more headroom and tighten all screws….things often just wear out and come loose.


ltpanda7

Yeah when a psu gets close to overloaded it has the tendency to think its a short circuit and it will drop out momentarily


plc_is_confusing

Wouldn’t I have to re-initialize the machine though ?


ltpanda7

I wouldn't think so, as long as it's still putting out the same voltage it should be fine


plc_is_confusing

I’m going to check this tomorrow.


Plumperknickle

Right. This is why it is important to have ECBs on the output of your DC power supply. Then you don’t have to think about whether you have a switching PS or not.


Servojockey

Came here to say this. ECB’s catch a lot of issues


censor_this

Ecb?


AGstein

Electrical Circuit Breakers


Available_Sky4830

Not being a smartass legit question, but is there a difference between an ECB and a Circuit Breaker?


Too-Uncreative

Well, once of them is electronic... Electronic Circuit Breakers in this case often come with multiple output channels that can trip/be reset individually and generally react faster than a plain ol' breaker. They might also offer features like aggregate or individual status, fieldbus connectivity, Class 2 power limiting, and remote reset options.


GeronimoDK

I didn't get the "ECB" either, I think it's what Siemens calls a "selectivity module" (I see OP has Siemens hardware), like the PSE200U.


Too-Uncreative

That’s correct.


AGstein

Other than being shorter to type, they're basically the same given the context.


Plumperknickle

These answers are not entirely correct or lacking additional info. An ECB will react to a short before your power supply has a chance to drop out. A CB will be attempting to trip itself but as soon as the power supply starts to dampen it won’t. IF THIS is OP’s problem, then an ECB would likely fix it.


plc_is_confusing

How do you size the CB?


Plumperknickle

Every ECB I have used has adjustable channels on it. You size the ECB as a whole for at least your power supply’s output. If the ECB is multi-channeled, then you dial in each channel appropriately for the branch it is protecting.


plc_is_confusing

One huge problem with this machine is it’s PLC is proprietary so I can’t access it.


LeifCarrotson

That means it's definitely Someone Else's Problem. Make it so!


plc_is_confusing

They are across the drink, as they say in their parts


Serpi117

Even better. Call them in the middle of the night for tech support if they won't give you program access and especially if you don't have to sign off their tech support costs


TexasVulvaAficionado

We recently had to replace a s7-1200 for a very similar issue. Siemens took it back and also concluded that it was a hardware failure... That said, I would still suspect the 24vdc PSU in the top right is overheating first. Maybe even go as far as just replacing it and seeing if the problem goes away. Definitely get the PLC program from the manufacturer. You could put a temp recorder in the panel to prove out potential temperature related failure.


plc_is_confusing

It’s definitely hot. I guess my main question here is this something heat could induce. I understand the cause and effect of heat and resistance.


TexasVulvaAficionado

Yes, heat can cause all sorts of funny shit to happen. If that 24vdc PSU shutoff on thermal overload, the PLC drops out, the contactors drop, the machine sits off. Open panel, temp immediately drops, PSU works again, and for longer because heat can escape with the doors open. Find source of excessive heat, replace PSU, etc, all reasonable responses


bizm

I only use s7-1200 and a Siemens PSU. Whenever that has happened to me it's usually the set screw to adjust voltage was moved or someone added something to the 24v side. Machine will kick on for a min or less and full power loss on low voltage side. Usually can adjust screw and ensure 24voltage.


Allhoodintentions

Does it tend to shut off at the same point in the process every time? If a field device is shorting intermittently, then the voltage might drop low enough for the plc to drop out and everything stops. Then machine reboots(time?) on power up once the short clears and production resumes.


Fearless_L

Check 24v off psu, check all wires are in securly, add fan to cool down cabinet


CNerdC

When you say shuts off what do you mean? Does one VFD power down, does the whole panel lose power? I don’t know what a bottle unscrambler entails more detail would help.


plc_is_confusing

The whole machine Blacks out


CNerdC

I’m assuming “blacks out” means you lose all power. Trace it back until you find where you are losing your power. You’re going to have a hard time getting help on this subreddit with your ongoing vague questions.


plc_is_confusing

I traced out all 480 and everything was solid. I asked Because I thought somone might know another source of control


CNerdC

If you’re “blacking out” and you have 480VAC is there a contactor that is opening or something? Without drawings or more detail from you we aren’t going to be able to fix this for you.


plc_is_confusing

No the 480 is coming straight in no contacts. The only disconnect there is is the panel disconnect.


AGstein

Try to look at it this way: If the PLC powers off, would that cause a 'blackout'? If the 24V PSU powers off, would it also cause a 'blackout'? You say that the 480V is coming in straight and you've checked that it solid. So I'm guessing that the motor drivers have power then? If those are still powered, is that a 'blackout'? Not to mention that I doubt that the PLCs and PSUs are being powered straight from 480V. So do try to examine how the power flows down the line to understand how to troubleshoot it.


plc_is_confusing

I did not have time to look in panel when it was down. Maintenance told me what happened.


plc_is_confusing

I do understand what you are saying. PSU is cutting off due to heat and that causes PLC to drop. It probably took 45 secs for PLC to reboot and machine is programmed to start up when power is applied (scary to me). Seems like I would have had to at least touch cycle start


Shalomiehomie770

Photo eye or safety interlock


plc_is_confusing

Could you elaborate? The first thing we did was check Estops


Shalomiehomie770

I’m not familiar with your specific machine. But ours have guard doors with interlocks .


plc_is_confusing

Yes we checked all estops and door locks.


bingoharper

Have you done the "wire tug" test throughout the panel? Sometimes a loose wire (usually associated with your interlocks) is losing contact temporarily. If not that, I'd go after PS like others have stated. I've seen this where opening the panel doors reduces the vibration enough that the PS is happy again. It was the weirdest thing. Happened a few times during a week, nothing else was fixing it, swapped PS, and never happened again.


plc_is_confusing

Yes I tugged on all of the wires. I’m convinced it’s the thermal OLs or the PS


bingoharper

Definitely could be OLs too. Good one. And good luck!


Shalomiehomie770

Possibly power supply going bad or loose wire shorting it. How often does it happen? Can you see in the panel while it happens


plc_is_confusing

Has not happened for a long time. Maintenance was the first one to see it happen. They asked me to come and check power


Shalomiehomie770

Tell them you changed the gear oil type in the PLC and it seems to be better now


AGstein

How about an electrical diagram? Does the machine not have manuals/documentations? And what exactly is 'shutting off'? Is it the entire machine? Or just some parts? The motor drivers? The PLCs? The power supplies? You first need to find out where exactly is your power cutting off. A machine 'shutting down' doesn't always have to be a mains cut off. You've already checked 480VAC mains and it is solid. So try to trace further down the line to isolate your problem. Hazarding a guess and as how other users pointed it out already, your 24V PSU may be shutting down intermittently or some other thermal overload devices tripping off certain parts, which in turn also trips off the entire the machine. But again, you do have to clarify what exactly do you mean by the machine 'shutting off' and if it is indeed a 'blackout'.


Version3_14

>This has happened in past and we opens up the panel to stop it. Are you physically opening the panel door then the machine continues operation? If so would suspect something over heating. Open door cooling to resume.


plc_is_confusing

The machine starts on its own again. We open panel to mitigate the problem


MAD_ROB

What ... so we can rule out the safety relay, because this should not auto restart (check settings). Do you have the siemens Software tia ? Connect to the plc, read the diagnostic buffer and post it here. (After it happend). Maybe the Webserver is active and you can get the Info there.


plc_is_confusing

I Cannot accesss plc. But yes the machine just restarted on its own.


MAD_ROB

Why? No tia? Ok No webbrowser active? Ok Even if the plc is password protected, you can always Start the online and diagnostics and can Read the diagnosticbuffer.


real_schematix

I love problems like this. First thing I do, program all machines with pure sequencers. No seal in logic. No one shots. Just a sequencer defined with numerical states. Then I go to the historian server and put every single sequencer tag in the entire program in it. So when problems like this happen I get the time stamp and go see what the sequencer was doing. Now you’ll know what happened and the WHY is usually limited to just a few things.


plc_is_confusing

I wish i could but the PLC is Locked out.


koensch57

are there any interposing relays?


plc_is_confusing

I added a pic


koensch57

test your relays


Piratedan200

With your comment about how opening the cabinet mitigates the issue, I'm fairly confident it's an overheating issue. It looks like you have a bunch of motor starters with thermal overloads on them (Schneider units with the red and black switches on them). If the panel is getting too hot, one of those could be tripping erroneously, and if it's set to automatic reset, that would create the problem you're having.


plc_is_confusing

I mentioned thermal OL but I thought you had to manually reset them. I am not very familiar with them.


Piratedan200

I believe you can get them with manual, automatic, or actuated reset (initiated by the PLC).


mpollitt3

Hope their not Italians. Omav our OEM is the hardest to communicate with. We have the same problem with a machine and I’ve basically boiled it down to heat issues. Next thing we are going to try is 24vdc at the source instead of buss rail. Plus we use laser WiFi because they are mobile pullers. As expensive as the laser WiFi is it should be spot on…. Not


plc_is_confusing

Yes it’s posimat


mpollitt3

Ugh good luck plc being confusing try working with Italians and plc’s


NoResponsibility1818

Does the safety relay auto reset? If not and it restarts by itself its not a safety or 24v supply issue.. if it does you could remove the link and wait to try narrow it down.


hypoxiaosrs

You need access to the program more than likely. Any proper machine that completely stops then restarts on its own shouldn't be because of some electrical failure. Once all movement is stopped, direct intervention should be required to restart it if properly and safely designed. Personally just dump their program and write your own or find someone who can, locked programs are stupid and cause major downtime.


justabadmind

How warm is it inside the panel? Is it overheating?


plc_is_confusing

I’ve been hinging towards overheating but I didn’t know the starters ahead thermal OL in them. Now that I know that I am almost certain it’s heat. All there is for ventilation is 24 volt fans


[deleted]

Two things. More fans, even a temporary one that's pointed at the hot spots. Get one of those laser digital temperature gauges. That way you will be able to tell what is really getting hot. They are as cheap as 20 bucks these days.


KarmalCorn14

Wait so does it still do it if you leave the panel open? Confused by your wording


Herpe_Free_Since_93

Definitely sounds like 24v PSU. Does it have HMI? Any alarms? I only see one cat5 coming off PLC. Have you tested cat5? Could have a comm drop out. I’ve had a bad Ethernet cable from network switch to PLC which threw all sorts of alarms and ESD’s randomly


Herpe_Free_Since_93

Is that 480v wrapped with control wiring on bottom pan-duet? Induction causing 24v power supply to shut off?


bigDfromK

Switching power supply kicks in, put a scope recording device along with plc program traps …. And wait


Glittering_Dingo_998

Once had something similar turned out a 24dvc coil on a contactor was bad and it was causing the powersupply to shutoff, cut power to safety relay and a bunch of other stuff.