We have not divulged the names of the customers in the following case
studies in order to protect their privacy.  But each event happened, 
as is documented in our files.

POWER QUALITY MONITORING 
AT A MAJOR PUBLIC
SANITATION FACILITY

This customer had experienced bouts with malfunctioning equipment
suspected of being influenced by poor power quality.  Included in the
vast array of equipment at the facility were numerous soft-start 
motor controllers and variable speed drives for large loads.

The preferred monitoring equipment would have to sample waveforms at
a high rate, perhaps fast enough to measure the 60th power harmonic. 
It would also have to be able to capture waveforms under a variety of
circumstances and triggered by numerous events, sometimes external,
sometimes internally determined.  

Manufacturer reputation and local support were also important factors
for the facility to consider.  This was going to be a major procure-
ment for the department, management was reluctant to spend that much 
money on one piece of diagnostic equipment, and there was no room for
error.  

After reviewing power monitoring and analysis systems for over a year,
the customer chose the Power Measurement 7700ION and Pegasys.  The 
local (Hanover Technical) sales rep instructed facility personnel in 
the configuration and operation of the monitor and companion analysis
software.

One particularly pesky soft-start controller on a large pump had been
a source of considerable irritation.  It had never performed to spec-
ification since installation, and various means of remedy provided by
the manufacturer had failed.

The 7700ION monitor was configured to capture waveforms for voltage 
and current at the instant of startup.  Status inputs would allow the
triggering by closure of a controller dry contact, or current inrush
at a predetermined threshold could be used to trigger it as well. 
The waveforms showed that during startup, two of the three phases were
not firing 120 degrees from each other, but were in sync.  The 
controller was returned to the manufacture to have the malfunctioning
circuitry replaced and the problem was resolved.

YOU DON'T HAVE TO ENDURE THE COST AND AGGRAVATION OF POOR POWER
QUALITY OR EVEN MALFUNCTIONING EQUIPMENT AS THIS SITUATION SOMEWHAT
SURPRISINGLY TURNED OUT.  HANOVER CAN PRESCRIBE THE RIGHT MONITORING 
AND ANALYSIS SYSTEM FOR YOUR SITUATION.


COMPUTER SCREEN FLICKER
MAKES WORKERS SICK
TO THEIR STOMACHS

In the world of power quality, very little is ever as simple as it may
seem.  A multi-branch banking firm was referred to Hanover Technical
Sales by one of our other customers.  At one of their branches, they
experienced periodic and somewhat predictable situations wherein the
computer screens in one part of the building showed a most disturbing
trait.  

When the building was occupied during the normal course of the day, 
the images on computer screens would shift back and forth about an
eighth of an inch at a frequency of about three times per second.  
After trying to work at their computers for more than a few minutes at
a time, employees complained of feeling sick to their stomachs.
A rep from Hanover visited the site and confirmed the phenomenon.  It 
was very annoying to try to concentrate, to say the least.

The bank's technology troubleshooter was perplexed.  He suspected that
there was a power quality problem, but the utility indicated the power
to the building was AOK.  If there was a problem, it had to come from
within.  No indication was given as to whether or not the utility had
indeed tried to find the problem for the bank and failed.

An electrical testing firm was brought in by Hanover Technical Sales 
to try to identify the problem.  Harmonics on the internal power lines 
would be the first suspect, but no appreciable levels could be 
recorded.  Subsequent power monitoring showed nothing that would 
point the finger at the flickering screens so noxious to all.

Discounting the possibility of supernatural forces, the test firm then
brought in test and measurement equipment not normally associated with
a power quality investigation.  A thorough analysis determined another
physical phenomenon was playing a role in the flicker.  It wasn't 
power quality, per se', but an improper wiring procedure that caused
the flicker.  The result was a magnetic imbalance in part of the 
building that was strong enough to affect the path of the particle 
beam in the computer monitors.  It's a rare occurance in the world of unusual
power phenomenon, but it happened.  Flat screened laptop computer 
monitors would not be affected, by the way.

No, we're not going to tell you how we were able to arrive at that
determination.  We don't believe in giving away the milk.  It makes it
more difficult to sell the cow if you do.  But if you have problems
you suspect may be caused by power quality, give Hanover Technical 
Sales a call.  We can put you in touch with people who have both the
right equipment AND the experience to make it work.


1000 KVA TRANSFORMER
FAILS IN A HOSPITAL

A 1000 KVA dry-type transformer failed, leaving the hospital without 
power in one of its critical care areas for a short while.  Fortunately,
the transformer was part of a double-ended unit substation, and after
switching over to the other side, power was restored.
Trouble was that the second transformer was equally old, of the same
design and brand and feared to be the next to fail.  While it could 
indeed last for years, that was a risk to be avoided. A replacement 
for the failed unit was needed as soon as possible.

An electrical testing firm was called in to survey the damage and 
effect a remedy.  They were given a turnkey purchase order to 
complete the replacement.  They, in conjunction with Hanover Technical 
Sales, measured the transformer containment, acquired all necessary
technical data and ordered a replacement core and coils (upgrading 
from aluminum to copper)from a local transformer manufacturer.  The 
switchgear and transformers were on the second floor level and 
embedded deeply within the utilities room.  A very limited space was 
available within which to force the new core and coils in, and the 
old ones out.  Tearing out equipment and support beams was out of the
question.

A rigging firm was contracted to hoist and move the assembly.  An
electrical contractor was engaged to handle the installation details.
Upon installation completion, the system was thoroughly tested and
determined it to be fit for energization.

All went smoothly, within budget, on time and without the need for an
outage.  The project leader also took responsibility for cleanup and 
disposal after the job was completed.

When your back is against the wall, call Hanover Technical Sales, Inc.
We can team together with the right firm to arrive at the right 
solution for your critical power delivery emergency.


HANOVER TECHNICAL SALES, INC.


email sales@hanovertechnical.com
Phone 757-357-2677
P. O. Box 70
Battery Park, VA  23304
United States

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