power supplies burning out

[bwyllie]

A computer that is located behind a motor control center, with a wall in between the MCC and computer, in a waste water treatment plant keeps having its power supplies burn out. It only happens to this PC. Any suggestions on how to alleviate this condition(besides moving the computer) and what could be causing it?

Thanks for your input.

 

[al hildenbrand]

As stated, there is not enough information to look at either the line or the load side of the power supply.

Do you have access to any power quality monitoring equipment that could be used on the branch circuit that supplies the computer?

Did the power supply burn out with smoke, simply stop working, or some other set of symptoms?

 

[catchtwentytwo]

Is the MCC the source for the PC?s feed or is it from another source? You could try a mini-UPS or a shielded isolation transformer at the PC but be sure they are returnable, especially the UPS.

Just for curiosity sake: is the monitor ?rolling??

 

[ramsy]

..power supplies burn out. It only happens to this PC. Any suggestions ..?

Try opening the case and brushing out all the debris that accumulates in these PC's. It may not be location at all. Moist dust bunnies or a short can fry pwr supplies repeatedly.

If a peripheral was changed recently, remove it or plug the old board back in, or just try moving the PC elsewhere. If not possible, try running two PC's at the same location and see if both have similar failures.

If the location receptacle(s) are suspect, make sure the EGC impedance is under 1 Ohm. Adding an EGC to a 2-wire receptical fixed several outages on my PC. Don't know why, unless the Pwr strip's surge supressor was dumping spikes into the grounding prong on my PC's power cord.

 

[ramsy]

On 2nd thought, if the location receptacle(s) are suspect, voltage and frequency ranges may be easier to check first.

If your frequency meter is bouncing above 60 Hz, (H-N) then predominant harmononics could damage the pwr supply; catchtwentytwo's UPS idea would solve this.

If voltage is swinging out of nameplate ranges for those switch mode supplies, older units 108-132vac, newer units usually from 100-140vac, they tend to drop out or reboot, but shouldn't fail permanantly.

The meter logging idea shows current or voltage transients, if no surge surpressor or UPS is installed. These spikes can eventually damage the pwr. supply also.

 

[hardworkingstiff]

Is there a high ambient temperature with AMD processors?

 

[Pierre C Belarge]

Install a metallic shield on the wall that separates the MCC from the room with the PC screen. I am willing to bet all of Mike Holts money that it will eliminate your problem. If you read Karl Riley's book, Tracing EMF in Building Wiring, the 2nd Edition, he explains this situation much better than I could.

 

[ramsy]

Is there a high ambient temperature with AMD processors?

I think we killed this topic. Now if bwyllie finds his problem was not mentioned above, he can have my pay check from last week.

"I knew this was not going to be a quick task as the heat transfer was not upto the quantities of a normal frying pan. It was a tedious task waiting for the Egg to cook but 11 minutes later it was loverly." Frying an egg on the CPU of AMD's XP 1500