Application Story–Consolidated
Papers
 Consolidated
Papers of Wisconsin Rapids, WI has converted one of its subsidiaries
into a hydro-generation power company now called Consolidated
Water Power Company. They converted nine of their synchronous-motor
pocket wood grinders, formerly used for making paper, into
hydro-electric power generators. The grinder cutters were
removed and the grinder water wheels are now used to drive
the motors as 2,300-volt generators, each delivering 500 kilowatts
of power.
During periods of low water flow some of the generators are
shut down, which can lead to dangerous moisture build-up on
the stators. The company installed Motor Guard™ automatic
insulation-resistance testers to automatically and continuously
test and monitor equipment when it is not running.
The automatic insulation-resistance testers continuously
monitor leakage to ground by injecting fully rated DC voltage
into the windings. This provides immediate indication of unit
readiness.
When all hydro generators are operational, they supply 6%
of the mill's electrical energy requirements. The savings
in utility bills show up in Consolidated Paper‘s bottom
line. This kind of preventive maintenance keeps the savings
coming.
Application Story–De
Pere Wastewater Treatment Plant
 It's
only a matter of time before critical-duty electrical motors
experience a failure, often with little advance warning. Operators
at the De Pere Wastewater Treatment Plant in De Pere, WI came
to this conclusion after a survey of their motors revealed
numerous potential problems that had previously gone undetected.
To solve this problem, the De Pere plant has installed Motor
Guard™, automatic insulation resistance testers from
Meg-Alert™, to monitor all critical-duty motors. When
off-line, motors used for wastewater handling and biomass
aeration are continuously monitored to detect moisture and
contamination build-up as well as other potential causes of
motor failure.
With Motor Guard, declining insulation resistance is spotted,
the rate of decline can be logged, and maintenance can be
scheduled accordingly. The benefits are no tripping of circuit
breakers upon motor startup, avoidance of motor-winding burnout
and assured availability when needed. With this system, the
operators at De Pere have added a new level of monitoring
and protection to ensure their critical motors will start
and run properly.
Application Story–Entergy/Gulf
States Utilities
 The
Entergy/Gulf States Utilities Nelson Plant in Westlake, LA
must be able to start critical motors at a moment's notice.
Any malfunction in a critical-duty motor could keep a unit
offline for hours. In this region, high humidity causes moisture
build-up to occur in the windings of idle motors. To combat
this danger, the Nelson plant installed Motor Guard™,
automatic insulation testers from Meg-Alert™, on 83 of
their critical-duty motors. Blowers were also installed to
automatically turn on when a moisture problem is detected.
Motor Guard testers automatically and continually test and
monitor motors when they are not running. When it detects
winding insulation breakdown, Motor Guard alerts the staff
that a motor is unsafe to start. This preventive measure has
significantly reduced motor failure at the plant. Since using
Motor Guard, Entergy/Gulf States Utilities has developed a
planned program of motor reconditioning resulting in significant
savings. Repair or replacement of a large 4160 V motor can
cost up to $140,000, depending on size and application. By
contrast, reconditioning motor insulation before a major problem
occurs can be accomplished for about $15,000, even on a large
motor. The time and money saved using automatic testers instead
of having maintenance staff conduct manual testing with a
megohmmeter is another bonus to using the Motor Guard.
Application Story–San
Diego Gas & Electric Co.
 At
San Diego Gas & Electric Co. (SDG & E), now part of Duke Power,
medium-voltage motors are critical to their operation and
cost $20,000 to $40,000 per motor to rewind. Maintenance Electricians
needed a way to continuously monitor them and prevent motor
failure.
SDG & E decided to retrofit all medium-voltage motors on
each generating unit with Meg-Alert's Motor Guard™, an
automatic insulation resistance monitor. Motor Guard measures
current leakage to ground when motors are not running and
triggers an alarm if a motor is at risk of failure. Because
the test is automatic the need for hand megohm testing by
electricians is eliminated, greatly improving
personnel safety.
The staff at SDG& E were so pleased with the results they
installed additional testers for the remaining motors in the
plant. Today they have more than 100 automatic insulation
testers installed and operating.
Application Story–Town
of Tonawanda
 The
Town of Tonawanda wastewater facility just north of Buffalo,
New York is one of the nation's most up-to-date facilities
of its kind. Modernization and improvement are important at
the plant because they are always looking for ways to cut
energy usage and reduce maintenance and repair costs. One
of their most recent improvements is the $800,000 Sawyer Avenue
sewage lift station, which uses three 100 HP explosion proof
submersible motor/pump units.
These units are continuously monitored by Motor Guard™,
automatic testers that measure the dielectric strength of
the motor insulation. The device will detect any insulation
weakness and either trigger a warning alarm or lock out the
motor's start circuit, preventing a motor failure. Repairs
on these motors can cost thousands of dollars, so the Town
of Tonowanda feels that prevention is well worth the effort.
"We believe that if the insulation tester prevents just one
motor failure, it will have more than paid for itself," Robert
Morris, Town of Tonawanda.
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