8kW Power-Meter HM8115-2
99 Washington Street
Melrose, MA 02176
Phone 781-665-1400
Toll Free 1-800-517-8431
Visit us at www.TestEquipmentDepot.com
Back to the Hameg HM8115-2 Page
8kW Power-Meter
HM8115-2
Manual
English
Contents
Deutsch
Français
Español
3
40
58
English
Declaration of Conformity
22
Power Meter HM8115-2
24
Specifications
25
Important hints
Symbols
Unpacking
Positioning
Transport
Storage
Safety instructions
Operating conditions
Warranty and repair
Maintenance
Line voltage selector
Change of fuse
26
26
26
26
26
26
26
27
27
27
27
27
Designation of operating controls
28
Basics of power measurement
Arithmetic mean value
Rectified mean value
Root-mean-square value
Form factor
Crest factor
Power
Active, true power
Reactive power
Apparent power
Power factor
How to calculate the Power factor
29
29
29
29
29
29
29
30
30
31
31
31
Concept of the HM 8115-2
32
Introduction to the operation of the HM 8115-2
Self test
32
32
Operating controls and displays
Connectors
32
34
Listing of software commands
37
Serial interface
38
Glossary
39
Subject to change without notice
23
HM8115-2
HM8115 2
8 kW Power Meter
HM8115-2
HZ815 Power adapter
Wide measurement range 1 mW…8 kW
Voltage range 100 mV…500 V, current range 1 mA…16 A
Frequency range DC…1 kHz
Simultaneous voltage, current and power display
RMS value
Display of apparent, effective and reactive power
Power factor display
Autoranging, simple operation
Monitor output (BNC) representing the instantaneous active
power
Active power
Suitable for measurements on frequency converters
Software for remote control and data acquisition included
Galvanically isolated USB/RS-232 Interface, optional IEEE-488
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176
24
Subject to change without notice
FAX 781.665.0780 - TestEquipmentDepot.com
Specifications
8 kW Power Meter HM8115-2
All data valid at 23 °C after 30 minute warm-up
Voltage
Ranges:
Resolution:
Accuracy:
Input impedance:
Crest factor:
Input protection:
Current
Ranges:
Resolution:
Accuracy:
Crest factor:
Input protection:
True RMS voltage measurement (AC+DC)
50 V
150 V
500 V
0.1 V
1V
1V
20 Hz…1 kHz:
± (0.4 % + 5 digit)
DC:
± (0.6 % + 5 digit)
1 MΩ II 100 pF
max. 3.5 at full scale
max. 500 Vp
True RMS current measurement (AC+DC)
160 mA
1.6 A
16 A
1 mA
1 mA
10 mA
20 Hz…1 kHz:
± (0.4 % + 5 digit)
DC:
± (0.6 % + 5 digit)
max. 4 at full scale
fuse, FF 16 A 6.3 x 32 mm (superfast)
Miscellaneous
Safety Class:
Power supply:
Power consumption:
Operating temperature:
Storage temperature:
Max. rel. humidity:
Dimensions (W x H x D):
Weight:
Safety Class I (EN 61010)
115/230 V ± 10 %, 50/60 Hz, CAT II
approx. 15 W at 50 Hz
+5°C...+40°C
-20°C...+70°C
5%...80% (non condensing)
285 x 75 x 365 mm
approx. 4 kg
Accessories supplied: Operator’s Manual, power cable, software
Optional accessories:
HZ10S/R Silicone test lead
HZ815 Socket adapter
HO880 IEEE-488 (GPIB) Interface
Active power measurement
Ranges:
8W
24 W
80 W 240 W 800 W 2400 W 8000 W
Resolution:
1 mW 10 mW 10 mW 100 mW 100 mW
1W
1W
Accuracy:
20 Hz…1 kHz:
± (0.5 % + 10 digit)
DC:
± (0.5 % + 10 digit)
Display:
4-digit, 7-segment LED
Reactive power measurement
Ranges:
8 var
24 var
80 var 240/800 var 2400/8000 var
Resolution:
1 mvar 10 mvar 10 mvar
100 mvar
1 var
Accuracy:
20 Hz…400 Hz: ± (2.5 % + 10 digit + 0.02 x P)
P = active power
Display:
4-digit, 7-segment LED
Apparent power measurement
Ranges:
8 VA
24 VA
80 VA 240/800 VA
2400/8000 VA
Resolution:
1 mVA 10 mVA 10 mVA
100 mVA
1 VA
Accuracy:
20 Hz…1 kHz:
± (0.8 % + 5 digit)
Display:
4-digit, 7-segment LED
Power factor measurement
Display:
0.00…+1.00
Accuracy:
50 Hz…60 Hz:
± (2% + 3 digit) (sine wave)
voltage and current › 1/10 of full scale
Monitor output (analog)
Connection:
BNC connector (galvanic isolation
to test circuit and RS-232 interface)
Reference potential:
protective earth
Level:
1 VAC at full scale (2400/8000 digit)
Accuracy:
typ. 5 %
Output impedance:
approx. 10 kΩ
Bandwidth:
DC…1 kHz
Protected up to:
± 30 V
Functions and displays
Measurement functions:
Range selection:
Overrange alarm:
Display resolution
Voltage:
Current:
Power:
Power factor:
Interface
Interface:
Connection RS-232:
Protocol:
Data rate:
Functions:
voltage, current, power, power factor
automatic/manual
visual and acoustic
3-digit, 7-segment LED
4-digit, 7-segment LED
4-digit, 7-segment LED
3-digit, 7-segment LED
USB/RS-232 (standard), IEEE-488 (opt.)
D-sub connector (galvanic isolation
to test circuit and monitor output)
Xon / Xoff
9600 Baud
control/data fetch
HM8115-2E/071108/ce · Subject to alterations · © HAMEG Instruments GmbH® · DQS-certified in accordance with DIN EN ISO 9001:2000, Reg.-No.: DE-071040 QM
HAMEG Instruments GmbH · Industriestr. 6 · D-63533 Mainhausen · Tel +49 (0) 6182 800 0 · Fax +49 (0) 6182 800 100 · www.hameg.com · [email protected]
Subject to change without notice
25
Important hints
Transport
Important hints
Please keep the carton in case the instrument may require
later shipment for repair. Improper packaging may void the
warranty!
Symbols
Storage
(1)
Symbol 1:
Symbol 2:
Symbol 3:
Symbol 4:
Symbol 5:
Symbol 6:
(2)
(3)
(4)
HINT
STOP
(5)
(6)
Attention, please consult manual
Danger! High voltage!STOP
Ground connection
Important note
Hints for application
Stop! Possible instrument damage!
Unpacking
Please check for completeness of parts while unpacking. Also
check for any mechanical damage or loose parts. In case of
transport damage inform the supplier immediately and do not
operate the instrument.
Check setting of line voltage selector whether it corresponds
to the actual line voltage.
Dry indoors storage is required. After exposure to extreme
temperatures 2 h should be allowed before the instrument is
turned on.
Safety instructions
The instrument conforms to VDE 0411/1 safety standards applicable to measuring instruments and left the factory in proper
condition according to this standard. Hence it conforms also
to the European standard EN 61010-1 resp. to the international standard IEC 61010-1. Please observe all warnings in this
manual in order to preserve safety and guarantee operation
without any danger to the operator. According to safety class 1
requirements all parts of the housing and the chassis are connected to the safety ground terminal of the power connector.
For safety reasons the instrument must only be operated from
3 terminal power connectors or via isolation transformers. In
case of doubt the power connector should be checked according to DIN VDE 0100/610.
Disconnecting the protective earth internally or externally is absolutely prohibited!
Positioning
As soon as the voltages applied to the INPUT terminals
exceed levels accepted as safe to the touch
all applicable safety rules are to be observed!
DC voltages must be disconnected from earth.
AC voltages shall be derived from a safety isolation
transformer and must also be disconnected from
earth.
Two positions are possible: According to picture 1 the front
feet are used to lift the instrument so its front points slightly
upward. (Appr. 10 degrees)
If the feet are not used the instrument can be combined with
many other Hameg instruments.
In case several instruments are stacked the feet rest in the
recesses of the instrument below so the instruments can not
be inadvertently moved. Please do not stack more than 3 instruments. A higher stack will become unstable, also heat
dissipation may be impaired.
Before the safety connectors on the INPUT terminals
are pulled off it must be assured that the
voltage has been switched off, otherwise there may
be danger of accident, even danger of life!
If instruments of protective class I are connected
to the OUPUT terminals
the protective earth PE
must be connected separately to the test object. If
this is not observed there is danger of life!
This instrument may only be opened by qualified
personnel. Before opening all voltages have to be
removed!
picture 1
picture 2
STOP
The safety connectors may become quite hot at
high current levels!
–
The line voltage selector must be properly set for the line
voltage used.
–
Opening of the instrument is allowed only to qualified personnel
–
Prior to opening the instrument must be disconnected from
the line and all other inputs/outputs.
picture 3
In any of the following cases the instrument must be taken out
of service and locked away from unauthorized use:
26
Subject to change without notice
Important hints
–
–
–
–
–
–
–
Visible damages
Damage to the power cord
Damage to the fuse holder
Loose parts
No operation
After longterm storage in an inappropriate environment ,
e.g. open air or high humidity.
Excessive transport stress
Operating conditions
The instruments are destined for use in dry clean rooms. Operation in an environment with high dust content, high humidity,
danger of explosion or chemical vapors is prohibited.
Operating temperature is +5 °C ... +40 °C. Storage or transport
limits are –20 °C ... +70 °C. In case of condensation two hours
are to be allowed for drying prior to operation.
For safety reasons operation is only allowed from 3 terminal
connectors with a safety ground connection or via isolation
transformers of class 2. The instrument may be used in any
position, however, sufficient ventilation must be assured as
convection cooling is used. For continuous operation prefer a
horizontal or slightly upward position using the feet.
Do not cover either the holes of the case nor the
cooling fins.
Nominal specs are valid after a warm-up period of min. 30 min.
in the interval of +23 °C. Values without a tolerance are typical
ofSTOP
an average production instrument.
STOP
Do not use alcohol, solvents or paste. Under no circumstances any fluid should be allowed to get into
the instrument. If other cleaning fluids are used
damage to the lacquered or plastic surfaces is possible.
Line voltage selector
The instrument is destined for opera-tion on 115
or 230 V mains, 50/60 Hz.
The proper line voltage
is selected with the
line voltage selector. It is
necessary to change the
fuse observing the proper values printed on the
back panel.
Change of fuse
The mains fuse
is accessible on the back panel. A change of
the fuse is only allowed after the instrument was disconnected
from the line and the power cord removed. Fuse holder and
power cord must not show any sign of damage. Use a screw
driver to loosen the fuse holder screw counterclockwise while
pressing the top of the fuse holder down. The top holding the
fuse will then come off. Exchange the defective fuse against a
correct new one. Any „repair“ of a defective fuse or brid-ging
is dangerous and hence prohibited. Any damages to the instrument incurred by such manipulations are not covered by
the warranty.
Warranty and Repair
Type of fuse:
HAMEG instruments are subjected to a strict quality control.
Prior to leaving the factory, each instrument is burnt-in for
10 hours. By intermittent operation during this period almost
all defects are detected. Following the burn-in, each instrument is tested for function and quality, the specifications are
checked in all operating modes; the test gear is calibrated to
national standards.
5 x 20 mm; 250V~, C;
IEC 127/III; DIN 41662
(DIN 41571/3).
Value
115 V: 200 mA slow blow
230 V: 100 mA slow blow
The warranty standards applicable are those of the country
in which the instrument was sold. Reclamations should be directed to the dealer.
Only valid in EU countries
In order to speed reclamations customers in EU countries may
also contact HAMEG directly. Also, after the warranty expired,
the HAMEG service will be at your disposal for any repairs.
Return material authorization (RMA):
Prior to returning an instrument to HAMEG ask for a RMA
number either by internet (http://www.hameg.com) or fax. If
you do not have an original shipping carton, you may obtain
one by calling the HAMEG service dept (+49 (0) 6182 800 500)
or by sending an email to [email protected]
Maintenance
The instrument does not require any maintenance. Dirt may
be removed by a soft moist cloth, if necessary adding a mild
detergent. (Water and 1 %.) Grease may be removed with benzine (petrol ether). Displays and windows may only be cleaned
with a moist cloth.
Subject to change without notice
27
Designition of operating controls
Designation of operating controls
1
5
2
3
7
6
8
4
9
Front panel
10
11
12
14
13
FUNCTION LED – Show function selected
POWER – Mains switch
INPUT – Input for test object
VOLT Display – Voltage display
FUSE – Fuse for measurement circuit
AMPERE Display – Current display
OUTPUT – Output to test object
FUNCTION – Display
Rear panel
MONITOR – Monitoring output
Connector (D-Sub, 9-pin) for serial interface
VOLT pushbuttons – Selection of voltage ranges
Mains voltage selector
VOLT LED – Show range selected
Mains input connector combined with fuse holder
AMPERE pushbuttons – Selection of current ranges
AMPERE LED – Show range selected
FUNCTION pushbuttons – Select function desired
15
28
Subject to change without notice
16
17
Basics of Power Measurement
Root-Mean-Square Value (RMS)
Basics of Power Measurement
The quadratic mean value of a signal is equal to the mean of
the signal squared integrated for a full period
_
1
x(t)2 = —
T
Abbreviations and symbols used:
W
active, true power P
VA
apparent power
S
var
reactiv power
Q
voltage as a variable of time
voltage squared as a variable of time
rectified voltage
rms value of voltage
peak value of voltage
Irms
î
rms value of current
peak value of current
T
T
∫x(t)2| ·
0
T
dt
Example:
If an AC rms signal of 230 V is applied to an incandescent lamp
(purely resistive at 50/60 Hz) the lamp will be as bright as powered by 230 V DC.
For a sine wave u(t) = û sin ωt the rms value will be 1/√2 = 0.707
of the peak value:
dt
U =
The arithmetic mean value of a periodic signal is the average
calculated for a full period T, it is identical to its DC content.
–
–
dt
The purpose of the rms value was to create a value which allows the use of the same formulas as with DC for resistance,
power etc. The rms value of an AC signal generates the same
effect as a DC signal of the same numerical value.
Arithmetic mean value (average)
∫x(t)| ·
0
1
—
xeff =
ϕ
phase angle between voltage and current
cos ϕ power factor, valid only for sine waveform
PF
power factor in general for arbitrary waveforms
1
x(t) = —
T
T
The rms value is derived by calculating the square root
u(t)
u²(t)
IÛI
Vrms
û
_
∫x(t)2| ·
0
1
—
T
∫ (û sin ωt)2 dt
0
T
û
= — = 0,707û
2
If the average = 0 it is a pure AC signal
If all instantaneous values are equal to the average it is
pure DC
Otherwise the average will constitute the DC content of the
signal
–
u2 (t)
Vrm
Useff
Rectified mean value
I_
1
IxI(t) = —
T
∫ Ix(t)I ·
T
0
0
t
dt
u(t)
The rectified mean is the average of the absolute values. The
absolute values are derived by rectifying the signal. In general the rectified mean is calculated by integrating the absolute
values for a period T.
Form factor
The form factor multiplied by the rectified value equals the rms
value. The form factor is derived by:
rms
rms = ———
——value
—————
F = V——
IûI
rectified value
û
For a sine wave the form factor is
0
π
t
HINT
—— = 1,11
2 2
Crest factor
IuI
t
0
The crest factor is derived by dividing the peak value by the rms
value of a signal. It is very important for the correct measurement of pulse signals and a vital specification of a measuring
instrument.
peak value
û
= ——————————
C = ——
Vrms
rms value
In case of a sine wave u(t) = û sin ωt the rectified mean will
amount to 2/π = 0.637 of the peak value according to:
I_
1
IuI = —
T
∫ Iû sin ωtI dt
T
0
2
= — û = 0,637û
π
HINT
For sinusoidal signals the crest factor is
√2 = 1,414
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176
FAX 781.665.0780 - TestEquipmentDepot.com
Subject to change without notice
29
Basics of Power Measurement
Please note that erroneous results will show if the
crest factor of a signal is higher than that of the
measuring instrument because it will be overdriven.
STOP
Hence the accuracy of the rms value measurement will depend
on the crest factor of the signal, the higher the crest factor the
less the accuracy. Please note also that the crest factor specification relates to the full scale value, if the signal is below full
scale its crest factor may be proportionally higher.
Form factors
Crestfactor
C
Formfactor
F
2
π
2 2
is calculated from the rms voltage and the real component of
the current as shown in the vector diagram above.
Defining: P
Vrms
Irms
ϕ
= active power
= rms value of voltage
= rms value of current
= phase angle
the active power is derived as follows:
P = Vrms · Irms · cosϕ
cosϕ is the socalled power factor (valid for sine waves only).
= 1,11
HINT
The instantaneous power is the power at time t
equal to the product of voltage and current both at
time t.
p(t) = i(t) · u(t)
For sine waves the instantaneous power is given by:
2
π
2 2
π
2
2
= 1,11
= 1,57
p(t) = û sin (ωt + ϕ) · î sin ωt
The active power or true power is equal to the arithmetic mean
of the instantaneous power. The active power is derived by integrating for a period T and dividing by the period T as folllows:
P
3
2
3
Power
Active, true Power (unit W, designation P)
As soon as either the source or the load or both contain inductive or capacitive components there will be a phase angle or
time difference between voltage and current. The active power
∫ î sin ωt
T
0
· û sin ( ωt + ϕ) dt
î · û · cosϕ
= ———————
2
= Ueff · Ieff · cos ϕ
= 1,15
With DC power is simply derived by multiplying voltage and
current.
With AC the waveform and the phase angle resp. time relationship between voltage and current have also to be taken into
account. For sine waves the calculation is fairly simple, as the
sine is the only waveform without harmonics. For all other waveforms the calculation will be more complex.
As long as the instrument specifications for frequency and crest
factor are observed the power meter will accurately measure
the average of the instantaneous power.
1
= —
T
HINT
The power factor will be maximum cos ϕ = 1 at zero
phase shift. This is only the case with a purely resistive circuit.
In an ac circuit which contains only reactances the
phase shift will be ϕ = 90° and the power factor
hence cos ϕ = 0. The active power will be also zero.
Reactive Power (unit VAr, designation Q)
Reactive power equals rms voltage times reactive current.
With the designations:
Q
= reactive Power
Vrms = rms voltage
Irms = rms current
ϕ
= phase angle between
voltage and current
a vector diagramm
can be drawn as follows:
The reactive power is derived by:
u
i
Q = Vrms · Irms · sinϕ
û
î
ϕ
ω
ωt
ϕ
U
Icos ϕ
I
HINT
30
Subject to change without notice
Reactive currents constitute a load on the public
mains. In order to reduce the reactive power the
phase angle ϕ must be made smaller. For most of
the reactive power transformers, motors etc. are
responsible, therefore capacitors in parallel to
these loads must be added to compensate for their
inductive currents.
Basics of Power Measurement
Example of power including reactive power
With DC the instantanesous values of voltage and current are
constant with respect to time, hence the power is constant.
If e.g. the current is rectangular while the voltage is sinusoidal the power factor will be P/S. Also in such case the reactive power can be determined as demonstrated in the following
example:
In contrast to this the instantaneous value of power of AC or
AC + DC signals will fluctuate, its amplitude and polarity will
periodically change. If the phase angle is zero this is the special
case of pure active power which remains positive (exclusively
directed from source to load) at all times.
If there is a reactive component in the circuit there will be a
phase difference between voltage and current. The inductive
or capacitive element will store and release energy periodically
which creates an additional current component, the reactive
part. The product of voltage and current will therefore become
negative for portions of a period which means that energy will
flow back to the source.
û = 325,00 V
î = 12,25 A
How to calculate the power factor (example):
rms voltage is:
û
Ueff = —— = 229,8 V ≈ 230 V
√2
The rms current is given by:
Ieff =
Apparent power (unit VA)
The apparent power is equal to the product of voltage and current. The apparent power is further equal to the geometric sum
of active and reactive power as shown in this diagram:
With the designations:
S
= apparent power
P
= active power
Q
= reactive power
Vrms = rms voltage
Irms = rms current
the apparent power is derived:
S = P 2 + Q 2 = Vrms x Jrms
P
PF = ––––
S
PF
S
P
= power factor
= apparent power
= active power
In the very special case of sinusoidal voltage and
current the power factor equals
HINT
1
î2
π
4π
= —— · [(π – —— ) + (2π – —— )]
2π
3
3
=
2
î 2 · ——
3
= î·
2
3
——
2
Ieff = 12,25 A · —— = 10,00 A
3
The apparent power S:
S = Vrms · Irms = 230 V · 10,0 A = 2300 VA
The active power is derived from:
π
π
1
û·î
P = ——π∫ û · î sin ϕ · dϕ = ——— [ – cos ϕ]π
π 3
π
3
û·î
P = ———
π
1,5
[(– (-1)) – (-0,5)] = ——
π
·û·î
1,5
= ——
π · 325 V · 12,25 A = 1900 W
Power factor
In general the power factor PF is derived:
2π
—— 0 ∫î 2 · dϕ
2π
The power factor thus becomes:
P
1900 W
PF = —— = —————— = 0,826
S
2300 VA
Obviously there is a reactive power component as the
apparent power exceeds the active power:
Q=
S2 – P 2 = (2300 VA)2 – (1900 W)2 = 1296 var
PF = cosϕ
Subject to change without notice
31
Concept of the HM8115-2
Concept of the HM8115-2
The instrument will automatically go into the active power
measurement mode, the LED located near “FUNCTION
“
and labelled “WATT“ will light up. The AUTO range function will
select the optimum ranges for voltage and current.
The HM8115-2 uses true rms converters for measuring voltage and current. The instantaneous power is measured using
an analog multiplier. The active power is derived by integrating the instantaneous power for a period T. All other values
are calculated.
The apparent power:
Operating controls and Displays
S = Vrms x Irms.
The reactive power
Q=
S2 – P 2
The power factor PF = P/S. This will always yield the correct
power factor because the cosj is only defined for purely sinusoidal signals. However, in SMPS, motor controls etc. nonsinusoidal signals are prevalent.
The instantaneous power can be taken off the rear panel terminal and shown on a scope. The HM8115-2 can be remotely
controlled via the serial interface, also all values can be read
via the interface. Measuring circuit, monitor output and serial
interface are isolated from each other.
Introduction to the Operation of the HM8115-2
ΠPower
This is the mains switch labelled “I“ = On and “0“ = Off.
After turn-on the LED display for “FUNCTION  “ will show for
a moment the number of the version of firmware installed , e.g.
“2.01“, then the baud rate of the serial interface, e.g. “9600“,
then it will go into the active power measurement mode. The
LED near “FUNCTION
“ labelled “WATT“ will light up. Autoranging will be active and select the optimum ranges for
voltage and current.
 VOLT display
This display will indicate the voltage on the output . Due to the
drop across the shunt this voltage will be slightly reduced with
respect to the input voltage. In case of overrange the display
will show blinking horizontal bars. In order to go to the appropriate range the righthand VOLT pushbutton Å must be used
or the autorange function selected.
Ž AMPERE display
This displays shows the current. In case of overrange the display will show blinking horizontal bars. In order to go to the
appropriate range the righthand AMPERE “ pushbutton must
be activated or the autorange function selected.
Please read the instruction manual carefully.
At first time operation please observe the following recommendations:
–
–
–
–
has been set to the correct
The mains voltage selector
voltage, and the correct fuse has been installed inside the
mains connector
Proper connection to an outlet with safety ground contact
or an isolation transfomer has been made.
There are no visible damages to the instrument
There are no loose parts floating around inside the instrument.
 FUNCTION display
The FUNCTION display will indicate the measurement result
of the selected function.
These function can be chosen:
–
–
–
–
Active power in watts
Reactive power in voltamperes reactive
Apparent power in voltamperes
Power factor PF
The function desired can be selected using the FUNCTION
Self Test
After turn-on with power switch Œ the 3rd display  for the
FUNCTION will show the nuber of the firmware implemented,
e.g. „2.01“.
The LED display  FUNCTION shows the baud rate of the serial interface, e.g. „9600“.
32
Subject to change without notice
• pushbuttons, the selected function will be indicated by the
proper LED.
If either the voltage or the current range or both too low or
high in order to achieve a meaningful result the FUNCTION
display will show 3 to 4 horizontal bars irrespective of the
function selected.
In PF mode such bars indicate that no meaningful power factor
can be calculated. There are several possible reasons:
1.
2.
3.
4.
No current or pure DC current.
No voltage or pure DC voltage.
Either the voltage or the current or both are too low.
Manually selected voltage or/and current ranges are too
low or too high.
Operating controls and displays
1
5
2
6
3
7
8
4
9
Warning signal in case of overrange
Overrange will be indicated by blinking horizontal bars in the
respective display(s) and an acoustical signal.
Warning signal setting
Switch off HM 8115-2 with switch Œ.
Switch HM8115-2 back on and push the righthand pushbutton
of the FUNCTION • pushbutton set.
Keep this button depressed until the LED “WATT“ will light up.
This function will remain stored unless changed.
‘ VOLT
Pushbuttons and a LED are provided for the manual or automatic selection of the voltage ranges. After turn-on the AUTO
LED will light up, the instrument will automatically select the
appropriate range. The selected range will be indicated by the
associated LED. If the voltage changes the range will automatically follow.
If any of the manual select pushbuttons is depressed the autorange mode will be left, the AUTO LED will extinguish. Then
any of the ranges can be manually selected. Pressing the AUTO
button will return the instrument to the autoranging function,
the AUTO LED will light.
The VOLT display  will show the voltage at the terminals. If an
inappropriate range was selected manually this will be shown
by blinking horizontal bars in the display(s) and an acoustical
warning.
“ AMPERE
Pushbuttons and LEDs are provided for the manual or automatic range selection.
After turn-on of the HM8115-2 the AUTO LED will light up, the
instrument will automatically select the optimum range. The
range selected will be indicated by the associated LED.
If the current changes the range will automatically follow. If any
of the manual select pushbuttons is depressed the AUTO function will be left, the AUTO LED will extinguish. Then the desired
range can be selected manually. Pressing the AUTO button will
return the instrument to the autoranging function.
11
10
12
14
13
The AMPERE display Ž will show the current through the
terminals. If an inappropriate range was selected manually
blinking horizontal bars will be displayed, and an acoustical
warning signal will sound off.
• FUNCTION
The following functions can
be selected by the FUNCT I O N p u s h b u t to n s a n d
shown on the associated
display:
Active power (Watt)
Reactive power (CAr)
Apparent power (VA)
Power factor PF
WATT (Active power)
After turn-on the instrument
will automatically select the
active power mode, the LED
will light up, the display 
will show the active power.
By using the FUNCTION
pushbuttons other functions
may be chosen.
10
11
Var (Reactive power)
In this mode the reactive power will be measured, the LED will
light up, the display  will show the reactive power.
The reactive power will be displayed as a positive value irrespective of any capacitive or inductive loads.
HINT
The reactive power display will also show correct
values if voltage or current are non-sinusoidal. The
apparent power (Urms x Irms) and the active power
(arithmetic mean of u(t) x i(t) ) are independent of
the waveform, the reactive power is calculated from
both.
Subject to change without notice
33
Operating controls and displays
Power factor (PF)
In this mode the power factor will be measured, the LED will
light up, the display  will show the power factor = active/ by
apparent power. The HM8115-2 allows the measurement of
the average of the instantaneous power irrespective of the
waveform as long as the specifications for crest factor and
frequency are observed.
STOP
Please note that a power factor can only be shown
for AC or AC + DC signals of sufficient minimum
amplitu-des. If the signal amplitude of either voltage or current or both is insufficient horizontal
bars will be displayed, this will also be the case if
DC is being measured.
HINT
cos ϕ is only defined for truly sinusoidal signals. As
soon as at least one of the signals is distorted a cos ϕ
derived from the phase shift between voltage and
current will not be identical to the true power factor.
Connectors
 MONITOR (BNC)
This is an analog output representing
the instantaneous active power e.g.
for display on a scope.
Examples:
50 V x 0,16 A
150 V x 16,0 A
500 V x 1,6 A
= 2408 W
= 2400 W
= 800 W
1 V (average)
1 V (average)
1 V (average)
If both voltage and current are equal to their full
scale values in the ranges selected and if both are
sinusoidal the monitor output signal will be 2 Vpp.
If the power is purely active the signal will oscillate
between 0 and 2 Vp, the average of this is 1 V.
HINT
For DC full scale values the monitor output will be
1 VDC.
Example 1:
A wirewound resistor of 1.47 K is connected to 70 Vrms. The
picture shows the voltage across the resistor and the monitor
output. The ranges selected are 150 V and 0.16 A which yields
a 24 W full scale 1 V average signal at this output. There is no
phase shift.
Voltage
at RL
RL: 1,47 kΩ
100 V
50 V
The instantaneous power
is the product of voltage
and current at time (t)
HINT
GND
Monitor
Signal
p(t) = i(t) · u(t)
in case of sine wave:
p(t) = û sin (ωt + ϕ) · î sin ωt
1
5
100 Vm
GND
The active power is the average of the instantaneous power integrated over the interval T = period divided by the period T:
P
1
= —
T
∫ î sin ωt
T
0
· û sin ( ωt + ϕ) dt
î · û · cosϕ
= ———————
2
= Ueff · Ieff · cos ϕ
The scope shows an undistorted instantaneous power signal.
The negative peak is equal to 0 V, the positive peak equals 0.27
V, thus the average equals 0.135 V.
The monitor output will always deliver the instantaneous power
no matter which function was selected. For positive instantaneous power the output will be positive, for negative instantaneous power it will be negative. If DC is being measured the
monitor output will hence deliver a DC signal.
The BNC terminal outer conductor is connected to the instrument
housing, however, the signal is isolated by a transformer.
The temperature dependent drift is automatically corrected
for by disconnecting the input/output terminals, during this
interval (100 ms) there will thus be no monitor signal. After
instrument turn-on the autozero will be activated every 3 seconds for the first minute, after warm-up the breaks will occur
every 2 minutes.
The average of the monitor output voltage will be
1 V if the input signals are such that the WATT display shows full scale. There is no indication of the
power range, the range has to be calculated and is
the product of the VOLT and AMPERE ranges.
STOP
34
Subject to change without notice
This average value multiplied by the full scale value 24 W equals
3.24 W which is the average power.
The HM8115-2 displays the following results:
Vrms = 70 V
Irms =0,048 A
P
=3,34 W
Q
S
PF
= 0,2 var
=3,32 VA
=1,00
Example 2:
A wirewound resistor of 311 ohms is connected to 50 Vrms/50
Hz. The picture shows the voltage across the resistor and the
monitor output.
The ranges are 50 V and 0.16 A, the full scale power is hence 8
W corresponding to 1 V average at the monitor output.
There is no phase shift with this purely resistive load. The scope shows an undistorted signal. The negative peak equals 0 V,
the positive peak 2 V, the average is thus 1 V.
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176
FAX 781.665.0780 - TestEquipmentDepot.com
Operating controls and displays
RL: V = 50 Vrms; I = 161 mArms; R = 311Ω
100 V
50 V
HINT
The frequency of the instantaneous power output
is twice the mains frequency of 50 Hz hence 100 Hz.
During one period of 50 Hz the maximum power reaches twice its maximum, twice it will be zero.
GND
Voltage
at RL
2V
Example 4:
A 311 ohm resistor is connected to a DC voltage of 50 V.
RL: V = 50 V; I = 161 mA; R = 311Ω
100 V
1V
50 V
GND
GND
Monitor
Signal
Voltage
at RL
2V
As the monitor output is 1 V and the full scale value is 8 W The
power equals 8 W. The HM 8115-2 displays:
Vrms = 50 V
Irms =0,161 A
P
=8,010 W
Q
S
PF
GND
=0,73 var
=8,038 VA
=1,00
Monitor
Signal
Example 3:
A resistor of 92 ohms and a capacitor of 10.6 uF are connected
in series to 50 Vrms /50 Hz.
Z =
R2 – Xc2
1
1
mit Xc = ———– = —–—
2πf · c
ω·c
The impedance of the series circuit Z = 314 ohms so that the levels are similar to those of the foregoing examples. The picture
shows the voltage across the load and the monitor output.
The ranges selected are 50 V and 0.16 A, the full scale power
range is again 8 W which is equivalent to 1 V average at the
monitor output.
RL: V = 50 Vrms; I = 161 mArms; R = 311Ω
100 V
50 V
GND
Voltage
at RL
2V
1V
GND
Monitor
Signal
TheHM8115-2 displays:
Vrms = 50 V
Irms =0,161 A
P
=2,416 W
Q
S
PF
1V
=7,67 var
=8,042 VA
=0,30
INPUT /
OUTPUT
(4 mm safety connectors)
The measuring circuit of
the HM8115-2 is sepa-rated from safety earth PE!
The two lefthand connectors are labelled INPUT
and are connected to the
power supply. The object
under test will be connected to the right-hand
connectors OUTPUT.
12
13
14
Please observe all relevant safety instructions if
voltages higher than the ones listed below are applied to the INPUT terminals.
Keep DC voltages disconnected from ground. Isolate AC voltages by inserting an isolation transformer.
Please note:
Voltages which exceed any of the following values
are considered dangerous:
1st
30 Vrms;
2nd
42.4 Vp;
3rd
60 VDC.
Voltages higher than those values may only be
applied by qualified personnel who know the applicable safety rules.
Disconnect the input voltage before unplugging the
safety connectors at the input terminals. Disregarding this can lead to accidents, in the worst case
there may be danger of life!
If objects specified for safety class I are connected
to the OUTPUT terminals without an isolation
transformer the safety earth must be separately
connected to the object under test, otherwise there
ist danger of life.
Subject to change without notice
35
Operating controls and displays
15
STOP
The safety plugs may become quite hot
at high currents.
STOP
The upper two terminals (red) are internally connected. Do not apply any voltage, this would be
short-circuited
The shunt is connected internally between the two
lower (black) terminals. Do not apply any voltage
either because this would practically short-circuit it.
The shunt is protected by a fuse which is accessible from the
front. Do not attempt to “repair“ a blown fuse or bridge it. Disconnect the input voltage before changing a fuse.
The current path is designed for a maximum of 16 Arms, hence
a FF 16 A is specified.
The maximum input voltage is 500 V. The maximum
peak voltage between any of the 4 terminals and
the instrument housing = protectve earth is 500 V.
Please note: Any voltage higher than those listed is
considered dangerous:
1st
30 Vrms;
2nd
42.4 Vp;
3rd
60 VDC.
Only qualified personnel well aware of the potential dangers is authorized to apply voltages higher
than those listed. The relevant safety rules must
be observed.
Fuses in the measuring circuit
The front panel fuse (FF 16 A)
protects the shunt. The circuit is designed for 16 Arms.
Type of fuse: FF 16 A 250 V,
size 6.3 x 32 mm, US standard: UL198G, CSA22-2 No.
590
12
13
14
Before exchanging a blown fuse the input voltage must be
disconnected. Do not attempt to „repair“ a blown fuse or to
bridge it.
Changing the measuring circuit fuse
The measuring circuit fuse
is accessible on the front panel.
Before exchanging the fuse remove all connections to the INPUT
and OUTPUT
terminals. Disconnect the HM8115-2
from the mains. Use a suitable screwdriver to turn the top of
the fuseholder counterclockwise while depressing it. The top
and the fuse can then be easily removed. Use only the specified type of fuse and do not attempt to „repair“ a blown fuse
or to bridge it. Any damage caused by using false fuses or by
bridging it will void the warranty.
36
Subject to change without notice
16
17
Serial interface
The RS-232 interface connector is located on the rear panel
(9-pin submin D). This bidirectional interface allows fetching of
data from the instrument and to remotely control it.
Mains voltage selector
The instrument can be powered by 115 or 230 V, 50 or 60 Hz.
The voltage selector switch is used to set the correct voltage.
Any change requires that the mains fuse be changed to the
appropriate value as indicated on the rear panel.
Mains voltage connector with integrated fuse holder
The mains connector is a standard type accepting cables with
plugs according to DIN 49457.
Operating controls and displays
Listing of software commands
These commands have to be transmitted as ASCII characters, they may be lower or upper key. Each command must use oDh
(Enter) at its end.
Command
PC > HM8115-2
Response
HM8115-2 > PC
Instrument status
*IDN?
HAMEG HM8115-2
VERSION?
version x.xx
STATUS?
function, range
General commands
VAL?
ranges and results
VAS?
ranges
function and
result
Bus commands
FAV0
none
. FAV1
none
Instrument settings
BEEP
none
BEEP0
none
BEEP1
none
Operating modes
WATT
none
VAR
none
VAMP
none
PFAC
none
AUTO:U
none
AUTO: I
none
MA1
value / function
MA0
SET:Ux
SET:U1
SET:U2
SET:U3
SET:Ix
SET:I1
SET:I2
SET:I3
none
none
none
Text
Instrument identification request
Request for the software version installed Response e.g.: version 1.01
Request for outputting all present instrument settings
functions:
WATT, VAR, VA, PF
voltage ranges:
U1 = 50 V, U2 = 150 V, U3 = 500 V
Current ranges:
I1 = 0,16 A, I2 = 1,6 A, I3 = 16 A
Request for outputting instrument settings and measurement results.
Example of VAr:
U3=225.6E+0 (225.6V in the 500 V range)
I2=0.243E+0 (0.243 A in the 1.6 A range)
VAR=23.3E+0 (Reactive power of 23.3 VAr)
“OF“ indicates range overflow. In case the command was sent during a
measurement cycle the response will come after its completion.
Selective request for the parameters and the result of FUNCTION.
Example if PF was selected: U3, I2, PF= 0.87E+0.
Disabling of all front panel controls VOLT, AMPERE, FUNCTION
Enabling of all front panel controls VOLT, AMPERE, FUNCTION
Generates a single acoustic signal
Acoustic signal disabled
Acoustic signal enabled
Active power
Reactive power
Apparent power
Power factor PF
AUTORANGE- function voltage enabled
AUTORANGE- function current enabled
Continuous transmission of parameters and results to the PC
Example of PF selected: U3,I2,cos=0.87E+0
“OF“ designates overflow. Transmission will be continued until ended by MA0.
Ends transmission started with MA1.
Disables autoranging resp. changes the voltage range to „x(Volt)“
Sets 50 V range
Sets 150 V range
Sets 500 V range
Disables autoranging resp. changes the current range to „x(Ampere)“
Sets 0.16 A range
Sets 1.6 A range
Sets 16 A range
Subject to change without notice
37
Serial interface
Serial Interface
Software
The HM8115-2 is well equipped for use in automated test systems. An optcoupler-isolated RS-232 interface is standard.
1. Installation
For the installation of the software HM8115-2 please start the
file setup.exe and follow the instructions of the installation
assistant.
Interface parameters
N, 8, 1, Xon-Xoff:
(No parity bit, 8 data bits, 1 stop bit, Xon-Xoff.
2. The program
A terminal program like HyperTerminal may be used for data transmission. After performing all settings in the terminal
program press the ENTER key once prior to sending the first
command to the HM8115-2
Baud rate
1200 or 9600 baud.
The software HM8115-2 was developed for the programmable
Hameg Instruments Power Meter HM8115-2. The power meter
can be connected with the PC by 3 different interfaces: Serial
interface (standard), USB interface (HO870) and GPIB interface
(HO880). If the USB interface is used, a virtual COM port has
to be installed. The COM port driver can be downloaded from
our website www.hameg.com
Changing interface parameters
Only the baud rate can be selected as either 1200 or 9600 baud.
In order to do this proceed as follows:
–
–
–
–
Turn off the HM8115-2.
Turn the instrument back on.
Press the lefthand FUNCTION pushbutton •
Press the lefthand pushbutton • and keep it depressed
until the LED “WATT“ lights up.
This new baud rate will be stored permanently unless
changed.
Serial interface
16
15
17
Picture 2.1: User interface
The RS-232 interface connector is located on the rear panel
(9pin submin D). The interface allows the transmission of data
from the instrument and its remote control.
F o r t h e c o n n e c t i o n b et w e e n t h e HM 8115 -2 a n d a
PC (COM port) any standard cable with 9pin submin D on both
sides may be used, provided it is shielded and < 3 m.
HINT
If a PC has a 25pin connector an adapter 25 to 9pin
has to be inserted, only 3 wires are used.
Connections:
POWER METER
PC COM Port (9poles)
Pin
name / function
Pin
2
Tx Data / output
2
Rx Data / input
3
Rx Data / input
3
Tx Data / output
5
Ground
5
Ground
38
Subject to change without notice
name / function
IMPORTANT WITH GPIB!
This software only supports National Instruments
GPIB cards and cards, that are fully compatible
with the National Instruments cards.
STOP
The program is devided into 4 parts (Settings, Control panel,
Measurement, Instruction), which are described in the following:
2.1 Settings
Six different parameters can be set:
Interface:
In this field the interface can be selected,
which is used for the connection to the PC.
Available settings: Com1-4, GPIB
GPIB address: Setting of the GPIB address the HM81152(only with GPIB)
Beep enable:
Activation/Deactivation of acoustic signals
Show data traffic: This option offers the possibility of letting the
data traffic in the editing fields ‘Command’
and ‘Answer’ indicate.
Device locked: With this option activated the instrument only can be operated by software. The control
elements are locked!
Glossary
Autotransfer:
With this button the automatic data transfer
between PC and HM8115-2 can be turned on
or off. If the autotransfer is off, the values in
the fields of the ‘Control Panel’ are not being
refreshed. This option should be only used, if
individual, manual instructions are sent with
the ‘Command’ field.
If the instrument is identified by the software, the ID of the isntrument is shown in the status field below. If the instrument
could not be identified the status field displays “NO DEVICE
DETECTET”. After program exit the software settings are stored (except the setting of “autotransfer”).
Please note that the identification can take 4-5 seconds!
2.2 Control Panel
In the field ‘Control Panel’ the current mesurement values are
displayed and are being refreshed every second. With the buttons below the data read-outs the measurement ranges can be
selected. The actual range is indicated by a green button. With
selection of the “Auto” function the HM8115-2 automatically
switches to the suitable voltage/current range.
2.3 Measurement
In the ‘Measurement’ field you can do automated measurements and store the values in a csv file (csv = Comma Separated Values).
With the ‘Start’ button the test series is started. The measurement value can be set in the field ‘Loop time’. After expiration
of the measurement intervall the software queries the values
from the power meter and displays the answer in the text field
on the left hand side. These values can be stored by opening
the menu ‘File – Save measurement’.
With the option ‘rotational measurement’ activated the measurement function are automatically alternated. For example
you can activate all options WATT, VAR, VA, PF. The functions
will be successively polled from the power meter and displayed
in the text field. With the ‘Stop’ button the current test series
is stopped. With the button ‘Clear List’” the content of the text
window is deleted and a new test series can be started.
2.4 Instructions
With these two fields and the ‘Send’ button you can send individual commands to the equipment. See the Operating Manual
of HM8115-2 for the command reference.
Please note, that the commands are sent to the instrument
without being checked by the software. If the HM8115-2 sends
an answer, it will be displayed in the ‘Answer’ field.
If you send the commands manually to the instrument, we
recommend to turn off the ‘autotransfer’ option. If the ‘Show
data traffic’ option is selected, all commands and answers are
shown in the fields ‘Command’ and ‘Answer’.
3. Deinstallation
For correct deinstallation of the software HM8115-2, please
open the option ‘Sofware’ of your ‘Windows Control Panel’. In
the ‘Software’ window select the entry HM8115-2 and press
‘remove’. The deinstallation assistant will automatically deinstall the software HM8115-2.
Glossary HM8115-2
Active power
AMPERE
Analog multiplier
Apparent power
Arithmetic mean value
Autoranging
Average power
Baud rate
Change of fuse
COM port
Crest factor
Form factor
Frequency
Front panel controls
FUNCTION
Fuse
Inductive
INPUT
Instantaneous value
Instrument status
Interface parameters
Isolated
Listing of commands
Mains voltage selection
Measuring circuit
MONITOR
Monitor output
Operating modes
OUTPUT
Overrange
Peak value
PF
PFAC
Phase angle
Phase shift
Power
POWER
Power factor
Protective earth
Range overflow
Range selection
Reactive current
Reactive power
Rectified mean value
Resistive load
Rms value
RMS, root-mean-square
RS-232 interface
Self test
Serial interface
Shunt
XON/XOFF protocol
30
28, 32, 33
32
31
29
25, 32, 33
34
32, 38
27
38
29
29
30, 34, 35
28
28, 32, 33, 34, 37
25, 27, 28, 32, 36
30, 31, 33
25, 28, 35
31
37
38
34, 38
37
36
32, 35, 36
28, 34
32, 34
37
25, 28, 35
25, 32, 33
29
31
37
29
30, 34
28, 32
32
31
25
37
25, 33
30
25, 30, 31, 32
29
35
29
29
38
32
25, 38
32, 36
37
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176
FAX 781.665.0780 - TestEquipmentDepot.com
Subject to change without notice
39
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