Power Supply - Breaker Tripping

[LtRyan5184]

Hello All,

I just moved in to a University Apartment. I set up my desktop and powered it, by itself, on. It ran for about 30 seconds and then tripped the breaker for the room. I called maintenance who came and reset it. Once again I attempted to turn it on and about a minute later it tripped again. Maintenance swears up and down that the breaker is good and that it must be the desktop.

My machine was build in 09 with the following parts: 

Sunbeam PSU-H680-REV-US-BL 680W ATX 12V 2.0 Power Supply
GIGABYTE GA-EP45-UD3R LGA 775 Intel P45 ATX Intel Motherboard
Intel Core 2 Quad Q6600
4GB DDR2 RAM
90 GB SSD
350GB 5400RPM HDD

My question is that is it possible for the PSU to degrade to the point of over drawing? Theoretically it should draw a MAX of around 6 amps. Much lower than the 15-20 amp threshold of the breaker.

I've powered up everything else including an Xbox 360, TV, and a MacBook Pro running on wall power / charging; and no issues.

Thanks again.
John

[Calum]

If the PSU is faulty, it can certainly trip a breaker, regardless of how much it should draw or what is connected to it.  I've had several PSUs blow fuses/breakers when connected to just a power supply tester, meaning almost no load at all.
I would say in all probability your power supply is toast - the only other possibility is a bad power cable, worth a shot but it's unlikely to be that.

[LtRyan5184]

Thanks!

Ive replaced the cords and surge protector so it must be that then. Kills me to buy from Best Buy but I need it for class, So ill run over there and grab a new one.

I'll post my results later today.

[Salmon Trout]

My question is that is it possible for the PSU to degrade to the point of over drawing? Theoretically it should draw a MAX of around 6 amps. Much lower than the 15-20 amp threshold of the breaker.

Yes it is possible. That theoretical current draw would be based on a simple Watts = Volts x Amps calculation, and would be what you would expect once the computer is up and running and drawing a steady current. However all PSUs draw a larger current at the moment of powering up. With a good 600 Watt PSU the switch-on surge is unlikely to hit 20 amps but one that is failing could draw a bigger surge. If other items are connected to that circuit and drawing current your PSU could be the final straw for the breaker. Some breakers are more sensitive than others. That is, if the breaker is a simple over-current type. If it is a ground leakage or arc sensing type these are much more likely to trip on a slight overcurrent, and in fact your PSU could have developed a small leak to ground which would trip that type of breaker. You could try the PC on a different circuit, and if it didn't trigger a trip that could point to an abnormally sensitive breaker feeding your room, but it might be a hard job convincing the maintenance people of that. Also a quick survey of PSU comments on modders and overclockers forums suggests that Sunbeam make cheap PSUs not noted for reliability. Words like "junk" appear often. I found a terrible review of a Sunbeam 580W PSU on a hardware reviews site.

[Calum]

Salmon - sorry, on my mobile so quote isn't available. The Sunbeam 580 is terrible, yes, but the 680 appears to be a rebranded OCZ - so not fantastic, but it could be a lot worse. Sunbeam, like Rosewill and a few others, is a very variable PSU brand, they rebadge some utter junk, some half decent stuff, and some amazing units too, so research is key.
Just wanted to add that in case it comes in handy sometime in the future.

[Salmon Trout]

Thanks, Calum. Yes, Sunbeam are rebadgers as you noted. I believe the core of the OP's query is "Is it possible for a PSU to degrade in function to the extent that it trips a 20 Amp breaker?" and the answer has to be a definite "Yes, it is possible", whatever the brand. A failing or out-of-spec  PSU can trip a GFCI (ground fault circuit interruptor) or AFCI (arc fault circuit interruptor) even if the current is within overcurrent limits, so determining the breaker type and trying the equipment out on another circuit might be a good idea. I see that since 1999 (USA) and 2002 (Canada) wiring codes have mandated the use of AFCIs to feed any circuit in the "bedroom" of a "dwelling unit". I would guess that a university apartment might well use protection that is very much to code.

 

[Calum]

I'm sorry if I gave the wrong impression with my post, my intention wasn't to take anything away from your quite correct reply.  As we've both stated, it's very possible for a failing PSU to trip a circuit breaker regardless of whether the PSU's nominal maximum draw would be able to do so, and regardless of the PSU's quality or lack thereof.  You obviously know a lot more about electrical circuits, breakers, and standards than I do, hence my statement was a lot more general.
I merely wanted to add that Sunbeam don't solely rebadge bad units, but some half-decent and some better ones too - not that it has any bearing on the topic as regardless of the quality, the PSU in the OP isn't working properly (or the circuit has an issue, which admittedly I hadn't considered).  Apologies for going slightly off topic, it wasn't important.

[patio]

I'll just stray a bit off topic on this and state i'm pretty dissappointed with some of the stalwart names of the PSU industry doing more and more re-branding...
Names mean literally nothin now.

[Calum]

Unfortunately it's inevitable when there are only a few PSU manufacturers, of which fewer still sell units under their own names.
I agree though, in the last few years some previously good brands have started rebranding worse and worse units - Corsair to name a major offender.

[Salmon Trout]

I'm sorry if I gave the wrong impression with my post

I didn't see anything wrong with your post...

[Calum]

I must be having one of those days then heh, no harm done