neal@mnopltd.UUCP (03/18/90)
I couldn't find any other more or less appropriate group for this query....
Thunderstorm season is nearing, and I have promised myself that I will not
spend another spring unplugging my Xenix 386 machine and hiding under the
desk every other afternoon when the thunderstorms happen. I have a surge
protector on the cpu and modems...
So, I can put one of those 500 watt 15 minute standby UPS systems on my
processor. This should ride out a sag or a short drop out. I can even put
my surge protector in front of the UPS. BUT I figure a nearby strike can
still take out the surge protector, the UPS, and my cpu.
Should I put a ferro-resonant transformer in front of the whole mess? What
are general experiences on this? My goal is to be able to keep working and
ride out a blackout of up to ten minutes.
Post or mail answers, yer choice. I WILL (really really) summarize mail.
Except for lame comments from wimps in parts of the country that don't get
any *REAL* lighting strikes....
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Neal Rhodes MNOP Ltd (404)- 972-5430
President Lilburn (atlanta) GA 30247 Fax: 978-4741
uunet!emory!jdyx!mnopltd!neal Or uunet!gatech!stiatl!mnopltd!neal
------------------------------------------------------------------------------pricked@vax1.acs.udel.EDU (Jenn-Ming Yang) (03/18/90)
In article <169@mnopltd.UUCP> gatech!stiatl!mnopltd!neal writes: }Thunderstorm season is nearing, and I have promised myself that I will not }spend another spring unplugging my Xenix 386 machine and hiding under the }desk every other afternoon when the thunderstorms happen. I have a surge }protector on the cpu and modems... } }So, I can put one of those 500 watt 15 minute standby UPS systems on my }processor. This should ride out a sag or a short drop out. I can even put }my surge protector in front of the UPS. BUT I figure a nearby strike can }still take out the surge protector, the UPS, and my cpu. } }Should I put a ferro-resonant transformer in front of the whole mess? What }are general experiences on this? My goal is to be able to keep working and }ride out a blackout of up to ten minutes. You might(better!) want to protect against brownouts also. -- pricked@vax1.acs.udel.edu (or pricked@192.5.57.1, pricked@192.5.57.129)
kabra437@pallas.athenanet.com (Ken Abrams) (03/19/90)
In article <169@mnopltd.UUCP> gatech!stiatl!mnopltd!neal writes: > >So, I can put one of those 500 watt 15 minute standby UPS systems on my >processor. This should ride out a sag or a short drop out. I can even put >my surge protector in front of the UPS. BUT I figure a nearby strike can >still take out the surge protector, the UPS, and my cpu. > A battery powered UPS is probably the best you can do. All the rest is probably overkill (except a surge protector ahead of the UPS might save the UPS from damage on a minor hit). If you think you can save yourself from a direct lightning strike that occurs within a couple of hundred yards of your location, you are fooling yourself. NOTHING will prevent damage in that case except having the system disconnected from ALL external wiring (grounds included). Lightening is nasty stuff and doesn't follow any rules. If you MUST keep working during a nasty lightening storm, have a good backup and insurance (on both the system and your BODY). -- ======================================================== Ken Abrams uunet!pallas!kabra437 Illinois Bell kabra437@athenanet.com Springfield (voice) 217-753-7965
root@rdb1.UUCP (Robert Barrell) (03/21/90)
In article <319@pallas.athenanet.com>, kabra437@pallas.athenanet.com (Ken Abrams) writes: > If you think you can save yourself from a direct lightning strike that > occurs within a couple of hundred yards of your location, you are fooling > yourself. NOTHING will prevent damage in that case except having the > system disconnected from ALL external wiring (grounds included). > Lightening is nasty stuff and doesn't follow any rules. As an illustration of Ken's point, let me relate something which actually happened to my boss's home machine. My boss's house is located at the top of a hill, in semi-rural surroundings (a prime target for lightning strikes - his sattelite dish has already been hit twice). He is aware of the proper procedures for preventing lightning damage, and always disconnects all power cords during a storm. A year or so ago, a particularly bad storm arose a few hours after I had just installed a new, external modem for him. At the time, I had been short by one wire , so I had not been able to leave the modem connected to the phone line. In keeping with common practice, though, I did set the phone on top of the modem before I left. When the storm started to approach that night, my boss disconnected all the power cords to the modem, external tape drive, computer, terminals, etc. Since the modem was not connected to the phone line, there was nothing to disconnect there, yet. He did NOT, however, disconnect the PHONE from the phone line. Sure enough, THAT'S what got hit by the lightning. That would not have been too bad, but the brand of modem we had just connected (SmartLink - a Hayes look- alike) had a metal case. The lightning arc'ed from a rivet in the foot of the phone, into the case of the modem. Of course, the case was part of the ground connection, so the strike quickly blew-out (and arc'ed through) the filter capacitors for the RS232 lines. From there, it proceeded directly into the computer's serial board, melting two IC's and exploding two others. It also fried a terminal which had been attached to the second serial port on the same board, and also managed to fry the primary hard drive (but, oddly enough, NOT the controller, nor the secondary hard drive). All of this happened on a machine where all external connections HAD been removed, and only the spark-gap between a telephone foot's rivet and a modem's metal case remained. BTW, the NEW modem (another brand) has a plastic case, as does the new phone, and *ALL* connections (including the phone lines) are removed during a storm. -- Robert Barrell | ...!cbmvax!gvlv2!lock60!rdb1!root | Cody Computer Services Milo's Meadow BBS | root@rdb1 CIS: 70575,1312 | 55 East High Street login: nuucp or bbs |-----------------------------------| Pottstown, PA 19464 (215) 323-0497 | Business and Police Dept Software | (215) 326-7476