line voltages/ psu voltages

Shadow250 · Post by **Shadow250** » Wed Sep 24, 2003 7:44 pm

ok my ac voltages taken at the outlett have fluctuated from 108v to 121v while the mobo reported psu voltages have remained the same. my question is can a malfunctiong psu correct this varied of a voltage range. or can it cause voltage drops in the line?

Post by **FlyingPenguin** » Wed Sep 24, 2003 8:30 pm

What do you mean by a "malfunctioning PSU"? That a typo or its there something wrong with the PSU?

Line voltage can vary dramatically depending on a lot of things. Most devices don't have a problem with it although extremely large variations can damage motors and electronics (motors are susceptible to both high AND low voltage damage).

Something you can't test easily without an oscilliscope or a frequency meter is the line frequency. North American power companies generally provide very stable line frequencies, but during brownouts the frequency can vary and that too can cause damage.

Normal voltage fluctuations of 10% are nothing to be concerned over - I'd be very concerned if your voltage varied by 20% or more.

A quality PSU will have no problems with normal voltage fluctations. A cheap one might. You should never skimp on the PSU.

A continous UPS will smooth the line voltage but these cost more than a cheap standby ups which only kicks in when the voltage drops (you're not going to find a continous UPS for less than $100).

Shadow250 · Post by **Shadow250** » Wed Sep 24, 2003 9:03 pm

ok let me explaian that better. i have a multimeter monitering my ac voltage. its reading range from 108v to 121v. at the 108v the lights dim and flicker but the computer stayed on,. also the mainboard
readings stayed the same. i wonder if a malfuncioning psu can cause drops in the ac voltage. note ive had the computer reset once tonight when the light flickered.

Post by **FlyingPenguin** » Wed Sep 24, 2003 9:22 pm

No, a malfunctioning PSU is not going to make the line voltage in your house fluctuate - not unless you have a short circuit in it and I think you'd smell and see the results of that soon enough.

It takes something drawing a LOT of current to do that. Likely culprits are your hot water heater, AC, refridgerator, washing machine, dryer, stove.

AC usually is the prime candidate. Lights always dim in my house when the AC kicks in.

A bad power transformer on the power pole can also cause line fluctations. If you're concerned, have the power company check it out.

If you still think the computer is causing it, unplug the computer from the wall. If the flickering continues it's not the computer for sure.

Shadow250 · Post by **Shadow250** » Wed Sep 24, 2003 9:48 pm

hey i found it, it seems this place uses (my gawd) old tyme screw in FUSES .thats right your eyes arent messed up. the one for this outlet had a load of crap dirt and junk in it. after cleaning it up it seems ok. im gonna get one of thos ups 's as soon as i can shell the cash out. i found one with replaceable batts and 45mins running at half load for 200 bux. is that good?

Pugsley · Post by **Pugsley** » Wed Sep 24, 2003 10:22 pm

dear god... update that pannel!!!

Once i went down here to work on the puter and half the lights in the house are dim... im wodering WTF is going on.. half the lights are normal and the otheres are all dim and pulsing... so after thinking for a few seconds i break open the pannel and get a meter out.. turns out one of the legs was reading 45V and the other was normal... luckly my puters were on the good leg. Power company comes out and does a few checks and comes back and says they need to cut power... so they do and an hour later a big truck shows up and they proceed to change the transformer on the pole. they got the old one down and it turns out that the bottom had rusted a hole in it and it was leaking oil. luckly it didnt explode or worse yet.. short out and feed the house 6Kv or whatever runs down the line.

Post by **FlyingPenguin** » Wed Sep 24, 2003 10:25 pm

Yup, I'm with Pugsley, I would STRONGLY recommend getting an electrian to replace that panel. Fire waiting to happen.

Meanwhile unscrew your fuses one at a time and check for corrosion and burn marks. Replace any that don't look good. A small squirt of WD40 in the socket will help to (don't over do it). NEVER reach into the socket to clean it - you can easily be electrocuted.

Shadow250 · Post by **Shadow250** » Thu Sep 25, 2003 1:50 pm

hell no i would'nt stick my hand in a fuse box they look like a light socket. i i used a peice of rubber gas line that was layin around to knok the crap out of it . no it never had gas in it. its up to the landlord to fix the fuses he thinks it works good nuff. so ill just get the conditioning ups for now. maybe later ill turn off the power and use a 12v batt to put some burn marks on the box so he'll change it. the ups im looking at is this you think it would do the job?