The single largest application for these sensors
is to transmit operational status of motors, lights
and air systems back to central computers and PLC's.
The energy management systems in new buildings require
many such sensors.
An increasing number of air conditioning contractors
are using the sensors in lieu of differential pressure
and air-flow switches to confirm operational status
and detect broken belts. Though the sensors cost more
than DP switches, the difference is more than made
up by less installation time, shorter wiring runs
and much higher reliability.
A pump manufacturer controls the sequencing of backup
pumps, using current sensing to indicate increasing
A machining company reduced tool breakage by monitoring
a rotary indexer for jam-ups resulting from sputtered
metal coming from the spot welding operation.
Many panel builders use the units to monitor the
integrity of heating elements. A large number of these
are in use along the Alaska pipeline. In addition,
Ground-Fault Sensors are now required by code in some
jurisdictions to monitor unsheathed heating elements.
A major electric tool manufacturer uses the sensors
to test the life of flexible cords, noting the drop
in current as the strands of wire begin to break.
A water company monitors the output of 3-phase convertors
and telemeters the status back to their offices.
In winter, Montana mining operations are crippled
if trucks happen to freeze during the night. By monitoring
the current in each engine dip-stick heater, the night
guard immediately spots burned-out heaters.
A heating system manufacturer uses the sensors to
ensure that heaters go off when commanded. Sticking
relays were causing the large heaters to burn out.
Sensors automatically start the lubrication system
for pumps driven by variable speed drives.
A small machine shop uses a current sensor to drive
a counter to count the number of parts cut off by
a band saw.
A major fuse manufacturer uses the units to signal
the start of test current and the time to fuse rupture
in their ongoing test and quality program.
A power company uses the sensors to monitor tower
lights, causing automatic switch over to the backup
light and auto-alarm when the primary lamp fails.
A machine shop uses a current-operated switch to
interlock a surface grinder with its magnetic chuck,
preventing operation unless the chuck is energized.
A large communications company uses the sensors to
turn on their backup diesel generators automatically
whenever their Uninterruptible Power System comes
The sensors detect undercurrent in large pumps and
initiate shutdown to prevent running while dry.
A machine shop uses a sensor to turn on the shop
exhaust system when any one of 8 grinders turns on.
Similarly, gas stations are installing sensors which
automatically turn on the vacuum system when any of
numerous pumps come on-line.
A plastic pipe company uses these sensors to warn
operators of plastic grinding machines that a critical
overload point is being reached. Since motor rewinding
was costing $1500, the sensors were very cost-effective.
A tomato processing in California uses the units
to prevent crushers from operating unless the feed
conveyors are running.
An Alaska airport uses a current sensor in each hanger
for billing purposes. Their central computer monitors
the length of time engine dipstick heaters are plugged
104 motors are monitored and status signals are sent
back to a central computer controlling nd automating
a tomato processing plant.
Several bulk-mail centers use current sensors to
detect jam-ups in their high-speed automatic handling
A major electrical appliance company uses the sensors
in their manufacturing test line to determine correct
The U.S. Coast Guard uses these units to signal (1)
lamp degradation and (2) lamp failure in ocean buoys
A manufacturer of hydrogen-burning furnaces uses
the sensors to detect burned-out heaters whose purpose
is to burn off safely any hydrogen which may escape.
A major power company monitors 7000 HP motors, using
current sensors, to note the number of times they
turn on, how long they run, and the time between operations
as a condition for determining when the motors must
be pulled for rewinding.