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.

For numerous case studies on power monitoring, analysis and control
solutions, visit PML 


POWER QUALITY
MANAGE IT OR ENDURE
THE CONSEQUENCES

In late 1992, a manufacture of instrumentation was concerned with 
power quality in an office full of computers, printers, and copy 
machines. It was suspected that line voltage transients and/or common
mode noise were causing program interruptions at PCs in the area.


To better understand the problems, measurements where taken. Voltage 
and current waveforms were collected at the distribution panels for 
each of the phase conductors feeding these circuits served by this 
switch gear. Similar data was collected at the panels. Neutral-to-
ground voltage at the panel, and the combined neutral current at the 
split point between the panels was measured. 
   
The system one-line diagram and specifications for the transformer 
and wiring was obtained from the facility’s electrical engineer, and 
this information was forwarded to Power Quality, Int'l, one of the firms
we represent. A single filter was purchased and installed in 
accordance with PQI’s recommendations. 

In this case, a panel 230 feet from the transformer and switchgear was
designated as the point of filter application for this demonstration.
Another panel 100 feet from the target panel is on the same circuit 
and serves the same office area. Total current load and transformer 
heating were not concerns in this case, since the circuit and 
transformer were operating well below rated capacity.
   
A  PQI HarMitigator(tm)  -  I0Filter(tm) was connected at the target 
panel by installing a three-phase breaker and making the neutral 
connection.  The installation of the  I0Filterâ was made without 
interrupting service to the computer loads and no adverse affects 
were noted when the filter was placed on-line. Zero sequence currents
from the adjacent panel were also drawn to the filter rather than 
returning to the distribution transformer. After about a month, an 
attempt to conduct further tests with the filter switched off met with
objections from the office manager because the group had experienced 
fewer computer problems after the filter installation and they didn’t
want to risk possible work stoppages.

How much more proof do you need?  Give us a call.  Let's discuss 
how Power Quality Int'l can help reduce power quality problems within 
your electrical system.



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.



IT ISN'T THE MONEY

At least it's not the direct cost of a product or service that moti-
vates some firms.  At least one company saw that the cost of electri-
city was minimal compared to it's overall cost of doing business.

It's just that when less than perfect power reliability disables a
workforce of hundreds or even thousands of people until power is 
restored, something had to be done.  This one in particular also
suffered the hidden cost of having to do rework in many cases.

One may argue that given sufficient quantity and large enough UPS 
units, virtually any business can be conducted without significant 
impact.  Truthfully, though, the direct cost of UPS units is further
biased by implementation problems that just add to power quality 
problems in many instances.

So this company decided to create a utility within their own
physical boundaries.  They realized that unless it was better than
what their present utility was doing for them, much better in fact,
that it would be a terrible waste of the company's time and money.

Optimizing the operation of such a utility would have to be the task
of some very smart device or devices.  Was cost a factor?  You can bet
not.  For them, the cost of electricity was less than a half percent
of annual sales.  But one power outage or one instance of poor power
quality could cost the company millions of dollars in productivity 
and sales.

This system had to operate around the clock, automatically, and at 
discrete points around the facility if need be.  It had to be able
to control the power flow.  To do so meant constant monitoring of all
the key power parameters.  To do so simply and flexibly required that
all the monitoring, analysis and control be contained within one 
functional device at any particular location.

The undeniably best solution was provided by Power Measurement.  Their
system incorporated monitor/analyzers with built-in programmable
control architecture.  The system is flexible enough to allow the
customer to reconfigure it if their needs or their energy strategy or
reliability philosophy changes.  And as the technology is advanced, the
flash memory utilized in the "smart meters" can be reprogrammed, while
in operation, to incorporate those upgrades.

The system, viewed thru Power Measurement's Pegasys software, was
brought into better focus than the customer expected.  As a result,
they were able to identify more distribution system problems than they
ever realized they had ... and resolve them earlier on, with better 
preparation, and perhaps at a lesser cost and with lower secondary
impact than they otherwise would have been able to do with more
conventional, but now outdated "smart metering" provided by others.



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 electricl testing firm was called in to survey the damage and 
effect a remedy.  They were given a turnkey purchase order to 
complete the replacement.  Then, in conjunction with Hanover Technical 
Sales, we 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.



HOW MUCH IS A
LIFE'S WORK WORTH?

Over half of the people involved in lost time accidents resulting from
accidental exposure to 480 volt circuits or short circuit flashes, etc.
never return to work.

Never!   Ever!

One company sought a means of reducing the risk of line clearing when
troubleshooting a piece of machinery in the factory.  They wanted a 
meter that minimized the number of settings, was auto-ranging on both AC
and DC, had a high input impedance to eliminate flashovers, an easy to
interpret display, and no way that the meter could, by itself, cause
a short circuit.

The solution, a TEGAM 110A hand-held safety voltmeter.  Its virtues 
include all these features.  10 megohms of impedance, 1 meg in each
lead alone, virtually eliminate the chance of a meter allowing a
significant current to flow or flash thru its circuitry.  It's either 
on or off.  The user merely needs to touch the probe tips to the c
ircuit to determine once and for all, whether the line has been 
cleared ... and we mean totally cleared ... no voltage whatsoever!

The 110A is a versatile line clearing voltmeter for circuits to 1000
volts ... and has been tested to 2,500 volts without damage to it.  It's
the best combined safety and productivity tool of its kind available.
The cost, less than $150.00 from Hanover Technical Sales, Inc.


Another company wanted a meter that could be used to troubleshoot 
electrical power and control circuits in an industrial, commercial or
utility setting.  Their simplicity and productivity needs were
similar to the first company, yet it also had to have some safety
features as well.  Not surprisingly, they also wanted to use the meter
for more than line clearing.  So it had to reject so-called phantom or
induced voltages displayed by typical high input impedance DVM's used
for electronic testing and troubleshooting.  You know the kind ... they
are sold by every Tom, Dick and Harry electrical distributor in the
phone book under the name of ... well, we aren't going to get into 
that.  And in the presence of harmonics found in most any non-lighting 
circuit these days, it had to read True RMS values, not just some 
averaged value at 60 hertz ... to 750 volts.   

The solution was TEGAM's 125 VOLTMAN TRMS hand-held safety and 
troubleshooting voltmeter ... it even auto-ranges when "volt-less" 
CONTINUITY is found ... priced by Hanover at less than $280.00.


Not everybody needs TRMS capability in a hand-held safety voltmeter.
That's why a third company chose TEGAM's new 122 meter available from
Hanover at less than $150.00 each.  The 122 provides phantom or induced
voltage rejection, auto-ranging to 750 volts like the 125 meter, and
sinle two-position switch simplicity.  Like the others, it's a two-
fisted meter that puts the technicians attention where it ought to be,
on the tested circuit.  And it has audible warnings to indicate AC, DC 
or CONTINUITY.  Blinking lights signify the presence of voltage.  It's 
a great little troubleshooting meter that every electrical technician
ought to have.


Certainly a workman's life and limb are worth more to your company than
$280.00.  And the productivity that TEGAM brings to your technicians
is well worth taking a second look.  Give Hanover a call today!


POOR POWER QUALITY
GOT YOU "UPS" THE CREEK?

Many computer centers rely upon UPS devices to protect critical  
electrical loads from power interruptions.  Several years ago, one co.
found that their UPS was switching into bypass for no apparent reason.
The total load was well below the nameplate capacity of the UPS. 
Because most of the loads connected to the UPS were single phase, 
non-linear (computer terminals, printers, modems and facsimile 
machines), harmonic distortion was immediately suspected as a possible 
cause. 

A detailed power quality audit confirmed high zero sequence 
harmonic currents (180hz) on the neutral conductors and excessive 
harmonic distortion of the voltage, well above the IEEE Standard-519-
1992 guideline of 5%. The company felt that while the IEEE Standard 
519-1992 guideline of 5% voltage distortion is acceptable for general 
commercial loads, a 3% voltage distortion guideline would be a more 
prudent goal for their data processing facilities. 

The immediate goal was to correct these problems and to provide 
operational and power quality protection for future expansion of 
critical loads.  One approach to solving this problem might have been 
the installation of a new service utilizing over sized neutrals and a 
K-Factor rated transformer (a standard industry solution that attempts 
to survive harmonic environments through oversizing). The company was 
aware of the fact that a K-Factor rated transformer would not improve
power quality and may even make the power quality problem worse. So 
they preferred a solution that would actually remove the harmonics 
from the system.				                    

It was decided to install a  PQI HarMitigator(tm) type I0Filter(tm). 
This ‘shunt’ filter  is unique in its ability to cancel zero sequence 
harmonic currents within its ultra low impedance windings.  Install-
ation of  the I0Filter(tm) would allow them to use all of their exist-
ing equipment while vastly improving power quality and system perform-
ance. They also wished to be able to load the UPS up to its full 
nameplate capacity.  The results obtained with the I0Filter(tm) 
installation were instantaneous. After the installation, the UPS 
automatically switched out of bypass. Total Harmonic Distortion of 
current was reduced by more than 65% and  Total Harmonic  Distortion 
of voltage was reduced from a high of 6.5% to less than 2%. As an 
added benefit, the  I0Filter(tm)  also acts as a phase balancer which 
has a very positive effect on the UPS.

Want to improve electrical power system performance?  Call us!  We're 
Your Empower Company.  Together with Power Quality Int'l we can help 
you reduce power quality problems within your electrical system.

(Special thanks to Power Quality, Int'l for their cooperation when we
drafted some of these case studies)


HANOVER TECHNICAL SALES, INC.

WE'RE YOUR EMPOWER COMPANY

email hanover@visi.net
Phone 757-357-AMPS
P. O. Box 70
Battery Park, VA  23304
United States




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