Application Note

4 Fluke Corporation Basic power quality measurements on the go with the Fluke 345
Fluke Corporation
PO Box 9090, Everett, WA USA 98206
Fluke Europe B.V.
PO Box 1186, 5602 BD
Eindhoven, The Netherlands
For more information call:
In the U.S.A. [phone] or
Fax [phone]
In Europe/M-East/Africa [phone] or
Fax [phone]
In Canada (800)-36-FLUKE or
Fax [phone]
From other countries [phone] or
Fax [phone]
Web access: http://www.fluke.com
©2006 Fluke Corporation. All rights reserved.
Printed in U.S.A. 10/2006 2722823 A-EN-N Rev A
Fluke. Keeping your world
up and running.™
Power measurements
Power measurements—Watts, VA, VAR, Volts, Amps
and Power Factor—are the mainstays of any system
analysis. The Fluke 345 reads these parameters
in both single-phase and balanced three-phase
power systems. Taking these measurements will
help determine circuit loading, so you can judge
whether it’s safe to add more load or if a new cir-
cuit is required. These parameters are essential for
investigating and correcting low power factor, the
culprit behind high utility bills.
Inrush current
Sometimes, after performing a power test, the cir-
cuit breaker will still open when a load starts up.
Usually, that means there is a momentary current
surge, called inrush. When that happens, use the
Fluke 345 to measure the peak value and duration
of the inrush current during load start. With that
information, you can determine whether to move
the load to another circuit or make other appropri-
ate changes to the existing circuit.
Logging
Very often problems are intermittent—for example
a circuit breaker opens occasionally or it looks like
a wire has overheated but it isn’t hot now. What to
do? Use a tool that logs data over a period of time.
The logging function on the power quality clamp
meter allows it to be set up and left to discover the
problem over a couple of hours or several days.
Then, upload the logged data to a computer and
use the Power Log software to view your findings
in graphical format, analyze the information, and
generate reports.
Power quality clamp meters like the Fluke 345
offer the ease of use, portability, and flexibility
needed to solve most problems in a commercial,
industrial and residential setting. With this kind
of tool, you can make everyday voltage and cur-
rent measurements as well as evaluate harmonics,
power, inrush current, view waveforms, and log
measurements when the standard testers don’t
provide the answer.