Application Note

2 Fluke Corporation Making watt-hour measurements with Fluke power quality analyzers
4. Press the record button and
select watts for reading #1.
Reading #2 is not required,
so you may select any of the
other items — VA (volt
amperes) would be a good
choice for reading #2 unless
you have some other need.
5. Selecting
record time:
•
If you do not know how
long you are going to be
making the watt average
measurements, then use
endless which has a 16-day
maximum. Be sure to keep
an accurate record of how
long the measurement was
made; longer is better to
keep timing errors to a
minimum.
•
If you know how long you
want to measure, then
select one of the preset
times (four minutes to eight
days). Use that time value to
calculate the watt-hours
unless you stop 43B record
mode before it stops itself.
In that case, record the
measurement time at which
you stopped the recording.
6. Start the recording.
7. Press the hold button to stop
recording unless you are going
to let it automatically
stop on
one of its preset values.
8. Before turning off the 43B or
disconnecting the voltage
leads and the current clamp,
write down the average watt
values or save the screen
information in one of the save
memories.
9. Convert watts to watt-hours as
described on page 1.
Fluke 43B rec
ording mode with record time
selections from four min to endless (16 days).
Glossary
Apparent Power In an ac circuit, the power value obtained by multiplying the current by
(kVA) voltage (P equals IE), with no consideration of the effects of phase angle.
Kilowatt 1,000 watts
Reactance The opposition offered to the flow of alternating current by
(X) pure capacitance, inductance, or a combination of the two.
Reactive Power The product of kilovolts and amperes in a reactive component of a circuit.
(kV
A
R)
Real Power
The apparent power multiplied by the power factor in an alternating-current circuit
(kWh) c
ontaining reactanc
e. Real power is the differenc
e between the apparent power and
the reactive power
. Actual radiated or dissipated power cannot exc
eed real power
.
Watt-hour A unit of electrical energy or work. It is defined as one watt of power sustained for
(W
H)
one hour
. A 1
3-watt lamp operating for 6 hours would c
onsume (13 W) x (6 hrs) = 78 WH.
A larger unit of measurement is the k
ilowatt-hour (k
wh), which is 1
000 W
H
.
For accurate measurement of short cycle loads, use a power recorder with high resolution capabilities.
Using the Fluke 43B
for average watt
measurements
1. Connect the 43B.
2. Connect the voltage leads
and current clamp before
starting the record mode.
3. Select the
power mode and
make sure the wattage read-
ings are correct.
Fluke Corporation
P
O Box 9
0
9
0, Everett, W
A USA 98206
Fluke Europe B.V.
PO Box 1186, 5602 BD
Eindhoven, The N
etherlands
For more information call:
In the U.S.A. [phone] or
F
ax (425) 446-5
1
1
6
In Europe/
M
-
East/
Africa (3
1 40) 2 6
7
5 200 or
Fax [phone]
In Canada (800) 36-FLUKE or
F
ax (9
05) 89
0-6866
From other countries [phone] or
Fax [phone]
Web access: http://www.fluke.com
©2004 Fluke Corporation
. All rights reserved.
Printed in U.S.A. 10/2004 2066287 A-US-N Rev B
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e
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