Application Note

Fluke 430 series features
The two most unique features are
AutoTrend, which records every-
thing on the screen automatically
without setting a trigger, and
System-Monitor, a quick diagno-
sis of system performance against
user defined limits. Other features
include:
•
Viewing stored data while
continuing to record.
•
Switching back and forth from
digital display to trend without
interrupting the recording.
•
Optically isolated so you can
record while downloading
information to your PC.
•
High resolution, color LCD
for viewing multiple parame-
ters and multiple phases
simultaneously.
•
Waveform capture lets you
test for interaction between
phases or between voltage
and current.
•
Triggering on envelope — or —
trigger on rms voltage or
current.
•
Screen cursors allow you to
pinpoint problems, quickly.
•
Capturing transients and
waveform disturbances with
5 µs resolution.
•
Toggling to phase or display at
any time for a quick check of
phase sequence.
Together these features help to
quickly diagnose problems and
build b
enchmark
s for predictive
maintenanc
e. The follow
ing case
study provides one such example.
Case study: Three-phase
motor failure
F
or three years in a row, a partic
-
ularly large three-phase motor
would fail twice a year. The facil-
ity maintenanc
e manager called
in both the electrical contractor
and the motor manufacturer, who
pointed fingers at each other but
failed to resolve anything on site.
The facility was left in the mid-
dle, w
ith no c
orrective action,
cyclical motor repair costs, and
lost production from the repeated
dow
ntimes
.
2 Fluke Corporation Logging and analyzing events with FlukeView® Forms Software
Tired of what was clearly a
pattern failure, the facility
manager hired an independent
consultant. The consultant told
the facility manager he would
perform a complete power quality
survey of the electrical distribu-
tion system feeding the motor,
determine its operating character-
istics and work from there to
solve the problem.
Measurements
The consultant connected his
Fluke 434 Three-Phase Handheld
P
ower Quality Analyzer to the
c
ircuit supplying energy to the
motor and pushed the View
Config button
. The diagram con-
firmed that his connections were
proper and that the power type
was three-phase Delta.
From there, he pushed the
Scope button and looked at
waveforms and numeric values for
all three phases. Judging by the
differences between the magni-
tudes at the top of the screen,
there appeared to b
e a balanc
e
problem between the phases.
To gather more information, he
switched to the numeric readout
on the Voltz/Amps/Hertz screen.
The current reading there was
even higher and still unbalanced.
Switching to the Unbalance
screen, he checked the voltage
and current values as well as the
phase diagram, to see if the
motor was operating within
acceptable limits.