Application Note

6 Fluke Corporation Power quality recording and analysis: techniques and applications
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:
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©2006 Fluke Corporation. All rights reserved.
Printed in U.S.A. 4/2006 2646555 A-EN-N Rev A
Fluke. Keeping your world
up and running.
•
Don’t jump right into record-
ing. Gather as much informa-
tion as you can with spot
measurements of voltage level,
voltage waveform/distortion,
current, unbalance. These may
point you to the problem or
give you some insight as to
where to go next.
•
Check your connections. If
the instrument has a phasor
or scope display, use it to
verify that the connections are
correct.
•
To twist the old saying: set
twice, measure once. If you
are trending, double check
your recording interval. If you
are using event or transient
capture, recheck your limits.
Before you push the RECORD button
•
Consider doing a short run of
an hour or so, before leaving
a monitor for a longer period.
This will help you work any
bugs out of your setup, and
you may get lucky and find
what you’re looking for!
Quality of service
In some cases, utilities agree to
provide power that complies with
predetermined specifications. The
specifications may be laid out in
contracts or may take the form
of regulations, like EN50160. In
these agreements, details of the
recording techniques, tolerances
and recording duration may be
spelled out. Standard EN50160,
for example, specifies tolerances
for a 1-week recording and refer-
ences standard IEC 61000-4-30
for measurement and recording
techniques. If you believe that
the power your utility is provid-
ing does not meet the agreed
upon specifications, test it.
Load studies, power
quality studies, and
commissioning
These types of recordings are
generally done to assess the
power prior to installation or
operation of equipment.
A load study is performed to
determine the existing loads on
a system, prior to adding more
loads. This may be required by
local authorities and local norms
or standards dictate the required
measurements, intervals and
durations. For example, the US
National Electrical Code specifies
current or power measurements
average over 15 minute intervals,
taken over 30 days. In addition to
satisfying the authorities, taking
recordings prior to significant
system modifications can help in
debugging the system later.
Power quality studies and
commissioning studies try to
answer the questions: “Is this
system healthy?” The strategy
in these applications is to cast a
wide net and record as much as
possible. Ideally we would record
voltage, current and power
trends, transients, and event logs.