[SOLVED] PSU power cord burnt. Is it the PSU's or the cord's or UPS's fault?

[jacobquinn]

Hey guys,

The PSU's power cord burnt which was plugged into UPS. The UPS was plugged into a powerstrip and powerstrip into the wall socket.

The thing is, the UPS was turned off 6 hours before the cable caught fire. How can the cable burn when the UPS is turned off?

The CPU is working fine though. But what do you think caused this? Is it the PSU or the PSU cable or UPS? What should I replace to fix this?

The cord burnt in two different places on the cord.
Here are images of burnt power cord:
https://imgur.com/a/Ko2WzH8

Here are some details written on the components:

PSU: Zebronics AC 230V
PSU power cord: 10A 250V
Power strip: 6A 250V AC

Thanks in advance

Edit: The power strip was ON but the UPS that was plugged into the strip was off

 

[jay32267]

So it melted just in that one spot?

If so.....I think there was a fault in the cord.

As far as the UPS being off when this happened....it could not possibly have been totally off.

If everything works OK....I would just replace the cord.

 

[jacobquinn]

Clarification:
The power cord burned in to different places on cable.
The two images in the URL are two different burns on the cable.

 

[jay32267]

Is it possible that cable was damaged before it burnt.....or is it possible that it was damaged and burnt at the same time?

 

[grimfox]

I think it's highly likely that the cable was damaged. It was either pinched (may rolled over with a chair or a pet took a taste of it.) and thus any current through the cable would have exposed the short and caused it to burn. It's hard to tell from the photo but the wire gauge looks pretty thin for the rating you reported.

Sometimes the cables can smolder slowly for a long time. It wouldn't take much current to burn the cable once it's damaged. Count your blessings that the cable did not burn worse than that or catch something else on fire or damage the system. Dispose of that cable get a new one and look for what potentially damaged the cable. Maybe look at getting a floor conduit or some other sort of cabling protection so it doesn't happen again.

 

[rgd1101]

MERGED QUESTION
Question from keithroy : "PSU cable burnt"

I had my UPS plugged in an extension cord which was plugged in wall socket. Monitor and CPU (PSU cable) were plugged in UPS.

The extension cord also has router and mobile charge plugged in. I turned of the UPS, but not the extension cord. So the router and phone charger were on.

Few hours later, in the middle of PSU cable, it became warm and caught fire slowly.

What might be the cause? because the UPS was turned off.

Should I change the UPS as well apart from the PSU cable? Could it be the UPS that caused this?
The specs are:
PSU: AC 230V
PSU cable: 10A 250V

I used another PSU cable (7A 125V) to check if the CPU is working (It is working). Can I use this cable (7A 125V) with the current PSU (AC 230V)?

Pls help.

MERGED QUESTION
Question from keithroy : "PSU cable caught fire"

I had my UPS plugged in an extension cord which was plugged in wall socket. Monitor and CPU (PSU cable) were plugged in UPS.

The extension cord also has router and mobile charge plugged in. I turned of the UPS, but not the extension cord. So the router and phone charger were on.

Few hours later, in the middle of PSU cable, it became warm and caught fire slowly.

What might be the cause? because the UPS was turned off.

Pls help.

Do you know what gauge wire the extension cable was?

The first thing that went wrong here is that if power going to the PSU cord was indeed shut off by the UPS being off, then something must be mis-wired with hot and neutral inverted, which would lead to neutral getting broken by switches instead of hot.

The second thing that must have gone wrong is that your power cord was either damaged/defective or of grossly inadequate quality. If you got it from questionable sources, you may have gotten a cord made of under-sized copper-plated aluminum wires. These may be marked as 16AWG but actually contain something closer to 24AWG.

Do you know what gauge wire the extension cable was?

The first thing that went wrong here is that if power going to the PSU cord was indeed shut off by the UPS being off, then something must be mis-wired with hot and neutral inverted, which would lead to neutral getting broken by switches instead of hot.

The second thing that must have gone wrong is that your power cord was either damaged/defective or of grossly inadequate quality. If you got it from questionable sources, you may have gotten a cord made of under-sized copper-plated aluminum wires. These may be marked as 16AWG but actually contain something closer to 24AWG.

Should I change the UPS as well apart from the PSU cable? Could it be the UPS that caused this?
The specs are:
PSU: AC 230V
PSU cable: 10A 250V

I used another PSU cable (7A 125V) to check if the CPU is working (It is working). Can I use this cable (7A 125V) with the current PSU (AC 230V)?

Thanks

A defective UPS wouldn't cause the PSU cable to blow up, only a defective/damaged or improper/fake rating cable would. You need to get a proper quality power cord, replacing one crap quality cord with another won't prevent the same problem from occurring again.

As for the live-neutral inversion, you need to get an outlet tester that does polarity and ground checks to determine whether the live-neutral inversion is in the building wiring/outlet, the extension or the UPS. Changing the UPS won't help you in any way if the miswiring is elsewhere.

 

[rgd1101]

Please stick with 1 thread/1 user.

 

[jacobquinn]

Edit: Also I have been using the PC for almost a year.

I mean, how can the cable burn when there's no current flowing through it. (The UPS was turned off 6 hours prior).

 

[InvalidError]

I mean, how can the cable burn when there's no current flowing through it. (The UPS was turned off 6 hours prior).

As I wrote in the other thread: miswired outlet/building, cable or device.

If hot and neutral are swapped upstream from whatever switch is in the circuit, then neutral on the cord will be always hot and can short to ground.

So you probably have a miswired building or extension cord on top of a defective, damaged or fake spec'd power cable.

 

[jay32267]

+1^^^^