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#59329 - 12/01/05 10:08 PM Surge suppressor and loose neutral  
Edward  Offline
Joined: Dec 2002
Posts: 308
Will a surge suppressor protect computers against a loose neutral on a three wire system ?

my guess is it will not. But i like to hear you as well.



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#59330 - 12/01/05 10:24 PM Re: Surge suppressor and loose neutral  
yaktx  Offline
Joined: Feb 2003
Posts: 288
Austin, Texas, USA
I don't think so. I wouldn't bet my computer on it, anyway.

#59331 - 12/01/05 11:15 PM Re: Surge suppressor and loose neutral  
JoeTestingEngr  Offline
Joined: Nov 2005
Posts: 791
Chicago, Il.
It would probably offer you some protection but it wouldn't be doing quite what it was designed to do. If the leg you were on made excursions close to 240VAC because of a heavily loaded opposite leg, the MOV H-N in the suppressor might start clamping the sine wave. The MOVs would be dissipating energy for repetitve mS instead of infrequent uS or nS, as they are designed for. It would be a race between the MOV to blow or the overcurrent protection to trip. If the the MOVs clamp higher than 240VRMS, the suppressor would be of no use.

#59332 - 12/02/05 03:22 AM Re: Surge suppressor and loose neutral  
e57  Offline
Joined: May 2003
Posts: 2,876
I can tell you.... NO PROTECTION WHAT SO EVER!

Surge strip fine, computer power supply TOAST!

See this thread....

Mark Heller
"Well - I oughta....." -Jackie Gleason

#59333 - 12/02/05 08:44 AM Re: Surge suppressor and loose neutral  
gideonr  Offline
Joined: Dec 2004
Posts: 161
Edinburgh, Scotland, UK
If your computer power supply is a wide range input type, typically 90 to 240 volts, then it should survive. Most recent ones here in europe are this type, especially as they now must have power factor correction built in.

#59334 - 12/02/05 10:43 AM Re: Surge suppressor and loose neutral  
renosteinke  Offline
Cat Servant
Joined: Jan 2005
Posts: 5,316
Blue Collar Country
Funny, my experience says "yes." I once made a poor neutral connection, and during the night fried a stereo power supply, a couple ballasts, two UPS units, and several surge suppressors; the computers that had the power strips before the UPS (or computer) came through undamaged.

#59335 - 12/02/05 06:54 PM Re: Surge suppressor and loose neutral  
JoeTestingEngr  Offline
Joined: Nov 2005
Posts: 791
Chicago, Il.
e57: I can tell you.... NO PROTECTION WHAT SO EVER!

renosteinke: Funny, my experience says "yes."

Well, I can certainly see how you both could be right, depending on the selection of MOVs or TVSs(Transorbs) inside your surge suppressors.


#59336 - 12/02/05 11:19 PM Re: Surge suppressor and loose neutral  
sierra electrician  Offline
Joined: Feb 2005
Posts: 219
North Fork, CA USA
I once broke the nuetral feeding a strip type surge suppressor...POW!!! It sounded like someone fired a pistol. The suppressor blew up, but the computer that was plugged into it was fine. Go figure.


#59337 - 12/03/05 01:15 PM Re: Surge suppressor and loose neutral  
gfretwell  Offline

Joined: Jul 2004
Posts: 9,143
Many years ago one of the computer trade rags did a story on this. Thier conclusion was a good strip would protect you if the on strip O/C device opened up with the MOV overload.
A lot still depends on the threshold and current capability of the MOV.

Greg Fretwell

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