I've made a mistake..

[theripley]

I am currently working with a PLC having a power supply unit that accepts dual input voltage (the one that tells "short 110V, open 200V"). I must have been out of my mind because I plugged in the 200V supply on that termination instead of plugging it to the power supply termination. After a few seconds, smoke came out of the power supply unit - I definitely burnt it.

I take out the power, let it rest a while then plugged the 200V supply this time on the correct termination. To my surprise, the power supply unit, CPU and the rest of the gang are in run mode like nothing had happened.

My question - is it still safe to use this unit after what had happened? It may run now but I'm not sure how long will it run in good condition after smoke came out of it.

Please advise.

 

[RussB]

Sounds like you only let out the 110 volt smoke and there is still enough 200 volt smoke to run the PLC.

 

[theripley]

Hi RussB,

Are you suggesting that it is still safe to use this unit?

 

[kallileo]

Can you open the case and check which components are burned?

 

[Steve Bailey]

What is the PLC controlling? What are the consequences of sudden failure of the power supply while the PLC is controlling that process?

You have obviously wounded the power supply. What we don't know is whether or not the wound will prove fatal. The unit might work for a few more hours, a few more days, or even longer. I'd have a spare on hand if I were you.

 

[theripley]

Is it safe to assume that only power supply unit got busted? Is there a way to check if other units are still in good condition?

 

[rootboy]

I'd say that you are safe, as long as the power supply never gets used with 110 volts. What you need now is a SMT-mounted air freshener...

 

[NetNathan]

I would recommend replacing the power supply. It has definitely been affected, due to the smoke.

 

[James Mcquade]

+1 replace the unit.

Other damage could have occurred that will show up at the worst possible time. 2 am, you get the call to fix the machine and no spares are available.

regards,
james

 

[Donnchadh]

Hi

I would at least order up a spare and get one ready as the chances of it going are gone way up.
2am or 2pm is never a good time for this when you could have saved some downtime ,

Donnchadh

 

[shooter]

see if both coils on primary side are oke.
if ot the power supply is running on one coil only thus the voltage is only half.
check the supressors for peaks etc. if burned just cut hem out, o real need for them

 

[Firejo]

If you’re doing this for a customer then replacing the entire unit is a must. Having a system fail is bad enough but having a unit fail and take your reputation with it is almost as bad as it gets. You don’t know what kind of stress was put on the rest of the system and more than likely life has been taken out of at least the power supply. If this is for your work, only you can tell if you need to replace it. What’s going to happen if it fails (again, not just the system but your reputation). If this is something for yourself, see what happens.

 

[theripley]

I asked my technician to check the PSU (power supply unit). He founds out the huge capacitors connected on the dual voltage input termination is leaking. As per his findings all other components are in good condition.

What do you guys think? On my perception, I can still use the PSU as long as I don't short the dual voltage input termination. Do you agree?

 

[rootboy]

That sounds about right. Ask your tech to please wash the board down to get rid of the electrolytic (which should be a base, so distilled vinegar will neutralize it). Rinse it with distilled water, then rinse it again. Then dry the board, then dry it again, and then replace the caps and fire it back up.

I re-capped my Amiga 4000 and as part of the general repairs, I soaked my Amiga motherboard in distilled vinegar and used a toothbrush to clean off the gunk where the battery had leaked. I dried mine over the course of three days, and once it was all put back together, it fired right up.

 

[danatomega]

Much of this business is risk management. If you can afford the risk of leaving your customer with something other than new condition components, then go for it - continue with the 'damaged' unit. As previously stated, your reputation is at stake.

rootboy re-capped HIS Amiga 4000 (not his customer's).