POWER PLAY - PART 3 |
| by Wayne M. Krakau - Chicago Computer Guide, October 1997 |
|
| In this final installment of the trilogy, having already covered the
basics of bad electric power from both outside and inside, Ill conclude with one
last real-world example and some possible defenses. |
| A couple of years ago, I was lucky enough to be referred to a client
without a network. (Its rare for me to find one. Usually I meet new clients who need
an existing LAN fixed.) I sold the client a 10-user NetWare LAN, including all of the
hardware (server, workstations, etc.), all of the system software (NetWare, DOS, Windows,
shared fax system, various utilities), and most of the applications software (contact
manager, database, word processor). |
| In addition, since the clients system administrator had little
computer expertise, my company became, in effect, their computer department. This
situation is common for my company and imparts a great sense of responsibility for the
clients welfare. |
| The first problem was a report of defective monitors. Some monitors
were frequently blurred to the point of unreadability. We replaced those monitors. That
didnt help. The new ones were also blurred. That led me to suspect some underlying
power problem. The system administrator vehemently denied any possibility of a power
problem. The building was only about two years old and he completely trusted the very
experienced electrician who wired it. |
| Then the administrator reported malfunctions of the internal modem
within their shared-fax machine (Essentially it was a nondedicated fax server - a
configuration which I didnt like, but the client demanded). The mode would
completely lock up and even turning the computer off and on didnt always revive it.
It would remain locked up for random lengths of time ranging from a few minutes to several
hours. Again I suspected power issues. |
| At the administrators request, I replaced the fax computers
modem, then the motherboard, then the power supply, and finally the I/O card (which was
also the disk controller). Nothing helped. Simultaneously, I began consulting with the top
troubleshooters at APC (American Power Conversion, West Kingston, RI, 800-800-4APC). The
file server (which had no problems) was protected by an APC UPS (Uninterruptible Power
Supply) and the workstations, including the modems phone line, were protected by APC
surge suppressors. |
| The APC engineer (and I do mean "engineer" as opposed to
"technician") agreed that there were power problems. Even as I described the
situation to him over the phone, I was receiving reports of random boot-up problems with
other workstations on the LAN. He suggested that I try putting a UPS on the fax computer.
The district manager for APC lent me a small UPS for this test. Even that didnt
help. |
| Meanwhile, I was examining the system under the direction of the APC
engineer. Through trial and error experimentation with electrical devices, I found that I
could upset the display of several monitors by turning on a freestanding fan. I also found
that the desk light in one cubicle prevented another computer two cubicles away from
rebooting! |
| Based on my description of the wiring, the APC engineer noted several
NEC (National Electric Code) violations were apparent, and that an improper ground was
preventing the UPSs and surge suppressors from doing their jobs. After talking to the
engineer, the administrator finally agreed that there were electrical problems. He
declined the engineers offer of a Power Audit, in which APC would send someone to
this site with the appropriate test equipment to fully analyze the power problems and work
with the client to see that they were fixed. The client said the Power Audit would cost
too much and stated that he trusted his electrician to fix things. |
| A month later, I was called upon by the same client to inspect more
allegedly defective PCs. The client had spent $3,500 on rewiring the building and was sure
that the power system, including the ground, was now perfect. He took his
electricians word for this. Now, all of the workstations worked perfectly - if they
were turned on individually. If all of the workstations were on, the last couple that were
turned on wouldnt boot. The administrator couldnt run all of them at once. At
least one, and sometimes two, had to remain off. |
| The physical position of the malfunctioning PCs wasnt an issue.
The order in which they were turned on was the only deciding factor. The last one or two
turned on invariably malfunctioned. |
| Although I replaced several PCs, retested all of their LAN cabling, and
spent several days (and many hours on the phone with the APC engineer) trying to find a
way around these problems, the administrator dropped my company as a vendor, accusing me
of having cheated him. Through all of this, I had spent over 100 hours of my time on
debugging their electrical problems, all without charging them. Oh, well - I guess there
are some situations in which you simply cant prove you are ethical. (By the way, the
last I heard, they still cant run all of their PCs at once.) |
| This episode leads me to my primary suggestion for attacking mysterious
power problems. Arrange for APC to do one of their Power Audits. I have heard rumors that
other companies may start offering similar services in the future, but, so far, I am only
familiar with APCs offering. Also, I have had several years experience using their
products and accessing their technical support, so I know that they can get the job done. |
| In a Power Audit, APC personnel are sent to inspect the clients
site and test the power system based on the NEC, the IEEE and other industry and
government standards for wiring and cabling. They use |
| equipment like harmonic analyzers, branch circuit analyzers, and
various power monitoring devices to test the power system. Best of all, they use their
experience to visually inspect each component of the power system, looking for standards
violations. |
| Most of the time, they find multiple standards violations, including
violations of the NEC, which, as I stated in Part 2 of this series, was issued in the
1930's and is the main code on which electricians base their work. I have no idea if
these violations are caused by extreme cost-cutting in building and remodeling projects,
by a lack of skill on the part of electricians, or if the same type of uncaring attitude
that is the curse of the computer industry has affected electricians, or if theres
some other reason. |
| I just dont have the background to comment in any serious way on
the causes of these code violations. All I know is that some of these violations are
safety related. It would be interesting to know the legal ramifications of an
electrocution or death by fire traced back to this type of violation. Im sure the
personal injury lawyers would have a field day. (This is all, of course, in addition to
any loss due to either downtime or inaccurate data from a malfunctioning power system.) |
| The main objection that Ive heard against an APC Power Audit (or
the equivalent service provided by some other company) is the expense. The cost varies so
much depending upon the exact situation that I cant quote exact numbers, but it is
expensive to send a professional out into the field with a pile of fancy equipment. I have
heard a rough estimate in the $3000-$4000 range for one 25-user LAN, but that was an
off-the-cuff estimate specific to one particular client, so I wouldnt be willing to
budget based on that estimate. |
| Another, admittedly limited, option is to purchase a Perfector UPS from
International Power Technologies (Orem, UT, 800-944-0356). It is a 1500 Volt-Amp digital
on-line UPS. It runs completely without reference to a ground. It can take any voltage
from 60 through 270 volts and can output your choice of any voltage from 90 to 270 volts
at either 50 or 60 Hertz. It is the perfect choice for systems that are out in the field
running off portable or otherwise nonstandard power systems. |
| At a $2,995 list price, its a bit expensive for day-to-day office
use, but for situations where the underlying power infrastructure is not adequate, it
could be just what you need. There are limits to its usefulness. First, you usually
dont find out about bad power until after you have already purchased a
"normal" UPS. You would have to discard the old UPS or put it to use elsewhere. |
| Also, it can only protect up to 1500 Volt-Amps worth of equipment. If
your whole buildings power system is inadequate, you might have to buy a lot of
these Perfectors to run your business. I still havent figured out how to get around
the network communications problems inherent in having multiple independent ground
references from all these Perfectors. In the long run, it may be cheaper (and safer!) to
just fix your power system. |
| Now, pardon me, while I check out this loose wire behind my computer.
Ill have to crawl under my desk and stretch out to reach it. Hmm, I wonder if
its carrying any current. Ill be right back to finish this article.
Zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzt! |
| ©1997, Wayne M. Krakau |