Anyone Know About Surge Protection/Dissipation Built Into PSU's?

[Dave Perry]

Hi guys,

I posted a message similar to this on General Hardware but my question became a bit more technical so I thought I'd ask it here. Does anyone know about what modern (a year or two old) ATX PSU's usually have for built-in surge protection?

I had a particular kind of spike/surge take out my Dell ATX PSU. It was caused by a bad grounding on the incoming power line and the result of that is that voltage crossed over from one house circuit into another, resulting in a surge of up to 240v for maybe 0.5 up to 2 seconds. What appears to be a MOV (like in a surge supressor) inside the PSU popped like a fire cracker but I see no other damage inside the PSU and can't tell if the fuse blew. No expolded caps or other scorched components. The PSU is totally inoperative, though.

My question is this: should the PSU most likley be designed to eat up that kind of surge (since it's nowhere near a lightning strike level) and then render itself inoperable? In other words, if it ate a 240v surge, is it supposed to have shut down then to protect the PC and is that probably why it doesn't work now? Two people on the GH board thought the MOBO, et. al. was probably okay, but I'm wondering if it's normal for the PSU not to work after something like this and the MOBO to still have not been affected.

Thanks for any input you have!

Dave

 

[stevty2889]

Most modern good quality PSU's have built in surge protection. Since it wasn't from a lightning strike, I'd say most likely your motherboard and all other components are safe. Obviously once it blows it's circuit, it will be inoperable to prevent any damage to the rest of the system in case another surge were to occur.

 

[Dave Perry]

Thanks for the reply. I guess my question arose from the fact that the run of the mill surge supressor power strips will go on passing current (at least mine did) after a big jolt but the surge supression has basically been "used up". But then they don't have fuses per se so I guess maybe the fuse blew on the PSU and that's what killed it.

So, in a lightning strike, is it possible for the PSU fuse to be breached, allowing excess juice to still get into the PC?