Why no fuses in a PSU?

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Barrymore

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My son's PSU died. Cause - load shedding. Most appliances have fuses that can blow from a power surge.
Can anyone explain why PSU,s do not have fuses built in?
 
greed, cost, take your pic. I have seen ones with a fuse though, but not recently
 
Most of the PSUs I've opened up had fuses integrated. They were all soldered in though, so not easily removable. In cheap power supplies, the fuse is the last thing to fail. Normally it's a capacitor which leaks.

A side note... STAY AWAY FROM RAIDMAX. Almost had to replace the motherboard of a PC because one of the main capacitors had leaked so badly that I initially thought the PC had been water damaged.

The PSU was less than a month old when this happened. :mad:
 
Claim from your supplier - municipality or Eskom.
 
They used to. I know this because a fuse in a buddie's PSU blew. We didn't have a replacement so we pushed a concrete nail into the fuse slot and subsequently tripped his house. Ahhh, the good old days of being an idiot ...
 
Totempole said:
Most of the PSUs I've opened up had fuses integrated. They were all soldered in though, so not easily removable. In cheap power supplies, the fuse is the last thing to fail. Normally it's a capacitor which leaks.

A side note... STAY AWAY FROM RAIDMAX. Almost had to replace the motherboard of a PC because one of the main capacitors had leaked so badly that I initially thought the PC had been water damaged.

The PSU was less than a month old when this happened. :mad:
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Nope raidmax is pretty good, pending which raidmax you get, I have raidmax made by the oem andyson the K series, one of their better PSU's. Been running 24/7 for the past year and a half, with zero issues.Had a corsair PSU fail on me with in 6 months, coolermasters of yester year which were pretty decent fail with in a day replaced it with thermaltake TR 2 made by FSP over 10 years old still running a Pentium dual core rig 24/7.

Corsair failing is sad, but just proves the point of shiite happens, doesn't necessarily mean they are outright bad.
 
rakabos3 said:
greed, cost, take your pic. I have seen ones with a fuse though, but not recently
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OK


I had a PSU in a gaming rig Years ago...It was a Silverstone 1000w.

It had like a tripswitch built in.

A fuse does not protect from surges. A fuse protects from fire in case of a short.
 
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This is why I turn things off before the lights go out, and only back on after the lights have been back on for a while.

But now this makes me wonder about a few things:

How effective are those surge protector plugs, you, the ones that Ellies supply for instance? And do they need replacing if there was a surge, or do they have some sort of reset button after being tripped?

And then, if you invest in a decent UPS, that should then protect your PC and other components, but what about the UPS itself, what happens to it when there is a power surge?
 
Some PSU's will have fuses in them depending on the design. A fuse does not always protect a circuit againts surges. It is there to prevent excessive current being drawn during a fault condition. If the fuse blows its most of the time due to something else that broke.

All power supplies are also supposed to have surge protection in them but the surge protection has a limited life i.e. it can only withstand a certain amount of surges. The more powerful the surge, the shorter the life of the protection.
The surge protection plugs will be of a similar design to the protection that the PSU has but might be a bit beefier and take longer to stop working.
 
Thanks! Will most likely get a few of these surge protection plugs just as an extra precaution.
 
And the surge protectors have an indicator light that shows it is still operating effectively. When LED is out change to a new protector.
 
Barrymore said:
Can anyone explain why PSU,s do not have fuses built in?
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I am sure it has a fuse, as fuse protects against fire. There are in various forms, sometimes inside round plastic enclosure. Look at components marked 'F1' or similar. If you still can't find it, you can trace a path between outlet pins and rectifier diodes (usually on the hot wire). But don't hold our breath, a blown fuse indicate that something else is faulty.
 
sajunky said:
I am sure it has a fuse, as fuse protects against fire. There are in various forms, sometimes inside round plastic enclosure. Look at components marked 'F1' or similar. If you still can't find it, you can trace a path between outlet pins and rectifier diodes (usually on the hot wire). But don't hold our breath, a blown fuse indicate that something else is faulty.
Click to expand...
True, fuses normally don't help for surges because generally fuses are 'slow blow', meaning they only blow in long overload conditions. Surges are normally quicker, and are suppressed using MOV's or similar...however, many times this type of protection is either left off, or underspec for our dodgy supply here.
 
Fuses blow for a reason - if not due to a surge, then you have bigger problems. Most likely some of the components from the switching side have been fried.
 
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