Question Melted power plug, My PSU power plug melted... why??

[Brown Wizard]

My PSU power plug melted... I just noticed it today... probably started 2-3 days ago...

See photo here: https://pictr.com/image/0yjI7Y

My PSU is Thermaltake 1200w, I have one Nvidia Geforce GTX 1080 Ti inside my build... the rest are just pretty standard items...i7, RAMs, SSD, etc.. (the PSU is overkill for my setup but that is for another thread)...

Anyway, I connected that power cable to a Belkin extension. That Belkin extension powers a few other items such as my monitor, phone charger, and a fan... I don't believe any of these items can cause the PSU cable to melt... those are pretty standard low voltage items...

The PSU power cable I (the one that melted), is rated for 13A and 250v... which is pretty standard... this should be good for 3250w... my PSU is only 1200w.. even then it is not drawing that much 1080 Ti at peak is only 250w...

So why?? Right now I have replaced the power cable with another one... so far no heat or anything like that as far as I can tell... so why?? why??

 

[jonnyguru]

Probably a short inside the plug head.

Did you pop open the fuse compartment on the plug yet? Is there even a fuse in there?

 

[AllanGH]

Weak contact tension inside the plug strip, poor solder or crimp joint inside the mains lead cap, poor plating or conductivity of the cable cap contact finish, all can cause the problem you have had. If your PSU mains lead is in conformity with UK regulations, there is a 13A fuse inside the lead cap, which means that you aren't drawing too much current through that contact.

Replacing the PSU mains lead was the right initial approach. I hope that you have also replaced the Belkin plug strip?

If not, do so, as this is likely the root cause of your issue.

 

[Brown Wizard]

Probably a short inside the plug head.

Did you pop open the fuse compartment on the plug yet? Is there even a fuse in there?

Yes there is fuse inside... which seems completely intact... I think that fuse is still good and can be reuse....

 

[Brown Wizard]

Weak contact tension inside the plug strip, poor solder or crimp joint inside the mains lead cap, poor plating or conductivity of the cable cap contact finish, all can cause the problem you have had. If your PSU mains lead is in conformity with UK regulations, there is a 13A fuse inside the lead cap, which means that you aren't drawing too much current through that contact.

Replacing the PSU mains lead was the right initial approach. I hope that you have also replaced the Belkin plug strip?

If not, do so, as this is likely the root cause of your issue.

I have replaced both the Belkin power cord and also the PSU power cable... so far there is no heat and everything seems ok... will keep checking every day for a month or so...

The 13A fuse is intact and seems untouched by the heat... hopefully, this does not repeat and end up burning my PSU or components or worse me or my family...

 

[AllanGH]

You should be OK, then. I've had that happen on even high quality outlet strips (and Belkin is up there in quality), and it's usually weak contact tension on one of the outlets that gets things like that started.

Unfortunately, here in the USA, it seems to happen more often and, since we're running devices at the lower mains voltage, we draw more current to deliver the same power, and it's the current that heats things up.

With the shuttered live and neutral contact openings, you all fair better than we do, too, with less crap falling into the contact area. Giving it a look every six months is probably fine.

 

[Brown Wizard]

You should be OK, then. I've had that happen on even high quality outlet strips (and Belkin is up there in quality), and it's usually weak contact tension on one of the outlets that gets things like that started.

Unfortunately, here in the USA, it seems to happen more often and, since we're running devices at the lower mains voltage, we draw more current to deliver the same power, and it's the current that heats things up.

With the shuttered live and neutral contact openings, you all fair better than we do, too, with less crap falling into the contact area. Giving it a look every six months is probably fine.

I posted this same question in another forum... and they reached the same conclusion... weak contact point... when I plug something in that extension there was buzzing 'electricity sound' for a second... I just ignored it... didn't know it could cause for it to overheat... well... lesson learned I guess...

Thanks for the help.

 

[mbarnes86]

Minor point for UK use

the PSU mains lead probably should not have a 13A fuse unless the cable is rated at 13Amps and you have a 1kw or more PSU
so 13 A fuse is correct in this case. but not in a typical 300 to 750 Watt PSU .

The common cause of this sort of problem is probably the extension lead is faulty or a wall socket which is very old or has many plug insertions over a long period

In most cases the user blames the new electric heater connected to the mains plug not the mains socket

common fuse sizes in UK are 3A , 5A & 13A (1A and 10A can be found)

Unforunately there are a lot of poor quality & fake fuses which do not comply with the BS 1362 standard on the UK market so look for a recognised brand on the fuse

regards
Mike Barnes

 

[AllanGH]

...when I plug something in that extension there was buzzing 'electricity sound' for a second...

Ayup. Dead give-away of a weak contact and, yeah, that'll heat up fast.

Like you say, you know for the future.