LEM LH1050 User manual

LH1050
AC/DC Clamp On Power Meter
Operating Instructions

1
CONTENTS PAGE
1 INTRODUCTION .................................... 2
1.1 Instrument Features ........................... 3
2 SPECIFICATION ..................................... 4
2.1 Electrical Data...................................... 4
2.2 General Data ........................................ 6
3 OPERATING INSTRUCTIONS ................ 7
3.1 Current Measurement ......................... 8
3.2 Voltage Measurement ......................... 9
3.3 Power 1Ø Measurement .................... 10
3.4 Power 3Ø Measurement .................... 11
3.5 Frequency Measurement .................... 12
3.6 Logging................................................. 12
4 SAFETY .................................................... 13
5 BATTERY REPLACEMENT ..................... 14
6 WARRANTY ............................................. 15
7 OTHER PRODUCTS ................................ 16
Issue 2 02/97

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1. INTRODUCTION
The advanced design of the LH series instruments
ensures reliable and accurate measurements under a
wide range of operating conditions. Power meter
features include:
•AC/DC voltage and current measurement
•Watts, VA, VAR and PF
•Built in 3 phase power capability
•Frequency
•Bargraph for dual parameter display
•REC mode giving MIN, MAX, AVG readings
•Hold function to save a complete data set for
power measurements
•Autoranging and Autozeroing facility
•Digital output for data logging*
The LH series of instruments conform to the latest
international directives and standards concerning
safety and electromagnetic compatibility.
•European Low Voltage Directives 73/23/EEC and
93/68/EEC
•European EMC Directives 89/336/EEC and
93/68/EEC
•Submitted for approval to UL 3111-1
Safety Standards
IEC 1010-1: 1992-09 Safety requirements for
electrical equipment for measurement, control and
laboratory use.
Part 2-032: 1994-12 Particular requirements for hand
held current clamps for electrical measurement and
test.
Part 2-031: 1993-02 Particular requirements for hand
held probe assemblies for electrical measurement and
test.
600V Cat III Pollution degree 2
EMC Standards
RF Susceptibility
EN 50082-1: 1992 3V/m Residential, Commercial and
Light Industry
RF Emissions
EN 50081-1: 1992 Residential, Commercial
and Light Industry
FCC Part 15 Class B
* Requires optional accessory
1.1 Instrument Features

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The main operating features of the instrument are as
follows. See Fig. 1.
(1) Clamp-on jaws for current measurement
(2) Jaw opening lever
(3) Rotary switch for function selection
(4) Push button switch for VA, VAR and PF
measurements in Watts mode. Press and hold for
2 seconds for REC mode (Min, Max, Av.)
(5) Push button switch for HOLD, saves complete
data set when in single phase Watts mode. Press
and hold for 2 seconds for Amps ZERO.
(6) Digital output for logging to a PC.
(7) and (8) - Test lead input terminals
Fig. 1
Instrument Features
2. SPECIFICATION
1
2
4
7
8
3
5
6

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2.1 Electrical data
(All accuracies stated at 23°C ± 1°C)
2.1.1 Current measurement
(RMS and DC)
Measuring range ............... 0 -1000A DC or ACpk
Autorange facility ............... 400A / 1000A
Resolution ......................... 100mA in 400A range
1A in 1000A range
Accuracy
I > 20A ............ ± 1.5% rdg ± 5 digits
I ≤20A ............ ± 1A
All measurements
DC and 30Hz to 1kHz
Maximum overload 10,000A or
RMS x frequency < 400,000
Amps RMS is a true RMS measurement
2.1.2 Voltage measurement
(RMS and DC)
Measuring range................ 0 - 600V DC or AC
Autorange facility ............... 400V / 600V
Resolution.......................... 100mV in 400V range
1V in 600V range
Accuracy V > 40V........... ± 1% rdg ± 5 dgts
V ≤40V........... ± 1V
Maximum overload 1000V RMS
All measurements DC and 30Hz to 1kHz
2.1.3 Watts measurement (Single and 3 Phase)
(RMS and DC)
Measuring range................ 0 - 600kW DC or 425kW
in AC
Autoranging facility............. 40kW, 400kW
600kW
Resolution.......................... 10W in 40kW
100W in 400kW
1kW in 600kW
Accuracy W > 2kW ............ 2.5% rdg ± 5 dgts
W < 2kW ............ ± 0.08kW
Frequency range DC and 30Hz to 1kHz
Current Range ................... 30A to 1000A Pk
Voltage Range................... 40V to 600V RMS

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Maximum input 600VRMS / 1000A Pk
Maximum overload 1000V RMS / 10,000A
2.1.4 VA measurement (Single and 3 Phase)
(RMS and DC)
Measuring range................ 0-600kVA DC or 425kVA
in AC
Autorange Facility 40kVA, 400kVA,
600kVA
Resolution.......................... 10VA in 40kVA
100VA in 400kVA
1kVA in 600kVA
Accuracy VA > 2kVA ...... ±2.5% rdg ±5 dgts
VA < 2kVA ...... ±0.08kVA
Frequency Range............... DC and 30Hz to 1kHz
Current Range ................... 30A to 1000A Pk
Voltage Range................... 40V to 600V RMS
Maximum input 600V RMS / 1000A Pk
Maximum Overload 1000V RMS / 10,000A
2.1.5 VAR measurement (Single and 3 Phase)
(RMS)
Measuring range................ 0-425kVAR
Autorange Facility 40kVAR, 400kVAR,
600kVAR
Resolution.......................... 10VAR in 40kVAR
100VAR in 400kVAR
1kVAR in 600kVAR
Accuracy VAR > 2kVAR . ±2.5% rdg ±5 dgts
VAR < 2kVAR . ±0.08kVAR
Frequency Range............... 30Hz to 1kHz
Current Range ................... 30A to 1000A Pk
Voltage Range................... 40V to 600V RMS
Maximum input 600V RMS / 1000A Pk
Maximum Overload 1000V RMS / 10,000A
2.1.6 Power Factor (Single and 3 Phase)
Measuring range 0.3 cap 1.0 ..0.3 ind
(72.5øcap ..... 1.0 .... 72.5° ind)
Resolution.......................... 0.01
Accuracy............................ ± 3°
Frequency range................ 30Hz to 1kHz
Voltage range..................... 40V to 600V RMS
Current range..................... 30A Pk to 1000A Pk
Measurement overload ...... 1000V / 10,000A

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2.1.7 Frequency measurement
(From Current or Voltage sources)
Measuring range ............... 30Hz to 1kHz
Resolution.......................... 0.1Hz
Accuracy 40 - 70Hz............ ± 0.5% rdg
30 - 1000Hz ....... ± 1% rdg
Current Range ................... 30A to 1000A Pk
Voltage Range................... 40V to 600V RMS
2.1.8 Digital output
A digital interface for connection to a PC is available
as an optional accessory for data logging. The
instrument outputs the displayed value. Additional
data is sent when in Watts and Hz settings:
Function Output
Watts.................................Watts, VA, VAR, PF
Hz......................................Hertz, Volts or Amps
Output rate.........................2400 baud
2.2 General Data
2.2.1 Display
Display 4000 count 10mm high characters.
MIN
MAX
AVG
AC+DC Identifies AC, DC or AC + DC
IIIIIIIIIIIII Bargraph display
H
2.2.2 Power Supply
Battery Type 9V Alkaline PP3 ,NEDA1604 or IEC
6LR61
REC Mode minimum,
maximum or average
readings
Low batter
y
indicato
r
Hold
WARNING (See Manual)

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Battery life typically 10 hours continuous operation.
2.2.3 Environmental
FOR INDOOR USE ONLY
Reference conditions. All accuracies stated at
23°C ± 1°C
Temperature coeff. of current ±0.1% of rdg per °C
Temperature coeff. of voltage ±0.1% of rdg per °C
Operating Temperature 0°C to 50°C (32°F to 122°F)
Maximum Relative Humidity 80% for temperatures up
to 31°C (87°F) decreasing linearly to 50% Relative
Humidity at 40°C (104°F)
Storage Temperature -20°C to +60°C (-4°F to 140°F)
Maximum operating altitude 2000m.
2.2.4 Mechanical
Dimensions............ Length 251mm / 9.88”
Width 98mm / 3.86”
Depth 52mm / 2.05”
Weight ................... 500g / 1.1 lbs.
Case Material......... Bayblend T85MN
Jaw Opening.......... 55mm / 2.2”
Accessories ........... Voltage probes
Digital Interface lead *
Carrying case
Operators manual
Cleaning................. The unit can be cleaned
with an Isopropanol
impregnated cloth.
Do not use abrasives or other
solvents.
* Optional accessory
3. OPERATING INSTRUCTIONS
International Symbols
The instrument function is selected by a rotary switch
with the following positions :-
OFF Instrument off
VVolts TRMS
AAmps TRMS
Important Information
(See Manual)
AC + DC
Double Insulation

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WWatts TRMS
W3∅
∅∅
∅3 Phase Watts
Hz Frequency
On power up the instrument enters a calibration mode
in which CAL is displayed. During this period the
instrument must not be clamped on any current
carrying conductors.
3.1 Current Measurement
•Remove any Voltage test leads from the
instrument.
•Move the rotary switch to the Amps position
•Press the trigger to open the jaws and clamp them
around the current carrying conductor as shown in
Fig. 2
•Read the display
•Press the HOLD / ZERO button to freeze the
display. Press and hold (2 seconds) to zero the
display.
•Press and hold the REC button (2 seconds) to
activate the REC mode.
•Press the REC button again to cycle through Min,
Max, Average readings. Press and hold the REC
button (2 seconds) to exit the REC mode.
Fig. 2
Current Measurement
3.2 Voltage Measurement

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•Move the rotary switch to the Volts position.
•Insert the test leads into the sockets on the front of
the instrument, the red lead to the VΩterminal and
the black lead to the COM terminal, as shown in
Fig. 3.
•Apply the test leads across the component whose
voltage is to be measured. Read the displayed
value.
•Press the HOLD / ZERO button to freeze the
display.
•Press and hold the REC button (2 seconds) to
activate the REC mode.
•Press the REC button again to cycle through Min,
Max, Average readings. Press and hold the REC
button (2 seconds) to exit REC mode.
Fig. 3
Voltage Measurement
3.3 Power Measurement (Single phase)
SAFETY WARNING
To avoid possible electric shock and
damage to the instrument, do not attempt to
measure any voltage that might exceed the
maximum range of the instrument - 600Vrms
and 1kHz

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•Move the rotary switch to the W position
•Insert the test leads into the sockets on the front of
the instrument. Connect the red lead to the V
terminal, and the black lead to the COM terminal
•Press the trigger to open the jaws, and clamp
them on the current carrying conductor, as shown
in Fig. 4
•Apply the test leads to the circuit under test. Read
the displayed value.
•Use the VAR VA PF/REC button to cycle though
the W, VA, VAR, PF measurements. In PF mode
the bargraph displays the corresponding Watts
value. Press and hold for more than 2 seconds to
enter or exit from the REC mode. Single pushes
will then allow movement through the MIN, MAX,
AVG and present readings.
•Press the HOLD / ZERO button to freeze the
display. When in Watts single phase mode the
Hold function saves all parameters which can then
be viewed by pressing the VA, VAR, PF button or
moving the rotary switch to the required setting.
Fig. 4
Power Measurement
3.4 Power Measurement (3Ø, 3 phase)

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•Move the rotary switch to the W3Ø position
•Insert the test leads into the sockets on the front of
the instrument. Connect the red lead to the V
terminal, and the black lead to the COM terminal
•Press the trigger to open the jaws, and clamp
them on the phase L1 current carrying conductor
as shown Fig. 5
•Apply the test leads to the circuit under test
•The positive lead to L2 and the negative lead to L3
•Read the displayed value. Use the VAR VA
PF/REC button to cycle though the W, VA, VAR,
PF measurements. In PF mode the bargraph
displays the corresponding Watts value. Press
and hold for more than 2 seconds to enter or exit
from the REC mode. Single pushes will then allow
movement through the MIN, MAX, AVG and
present readings
•Press the HOLD / ZERO button to freeze the
display. When in Watts 3 phase mode the Hold
function saves all other power parameters which
can then be cycled through using the VA VAR PF
button
Fig. 5
3Ø Power Measurement
3.5 Frequency Measurement

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•Move the rotary switch to the Hz position
•Insert the test leads into the sockets on the front of
the instrument. Connect the red lead to the V
terminal, and the black lead to the COM terminal
•To measure the frequency of the voltage supply
apply the test leads to the circuit as shown in Fig.
3 and read the display
•To measure the frequency of the current press the
trigger to open the jaws, and clamp them on the
current carrying conductor, as shown in Fig. 2 and
read the display
•When configured to measure power (Fig. 4) with
voltage leads connected and the current clamped
around the conductor, the instrument displays the
frequency of the current source (providing ARMS >
5.0). If ARMS < 5.0A, a volts frequency
measurement will be made (providing VRMS >
5.0V), otherwise ---.- will be displayed
•Press the HOLD / ZERO button to freeze the
display.
•The bargraph displays the corresponding current
or voltage value
•Press and hold the VAR VA PF REC button for
more than 2 seconds to enter or exit from the
REC mode. Single pushes will then allow
movement through the MIN, MAX, AVG and
present readings
3.6 Logging
A slider switch located in the battery compartment
enables the data output. When the data output is
enabled the autopower off is disabled to allow
continuous data logging. In this mode battery lifetime
is reduced.
Slide switch
Position Autopower off Data output
OFF Enabled Disabled
ON Disabled Enabled
An interface cable for connecting the instrument to the
serial port of a PC together with Windows runnable
software is available as an optional accessory.

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Fig. 6
Current Measurement / Logging
4. SAFETY
The instrument has been designed to comply with
IEC1010-2-032 Installation Category (Overvoltage
Category) III 600V Pollution degree 2 and
UL 3111-1. The product range conforms with the EEC
Low Voltage Directive 73/23/EEC and 93/68/EEC.
IEC 1010 is a safety standard which has the following
features:
•Installation categories I to IV relate the maximum
working voltage to overvoltage transients that can
be expected in the measuring environment. For
the LH range of instruments, 600V CATIII, the
maximum expected transients must not exceed
6kV peak.
•In a pollution degree 2 environment the internal
design of the instrument can cope with transient
conductivities due to condensation.
Safe operation of the instrument is the
responsibility of the operator who must be suitably
qualified and/or authorised.
Users of this equipment and or their employees
are reminded that Health and Safety Legislation
require them to carry out valid risk assessments of
all electrical work so as to identify potential
sources of electrical danger and risk of electrical
injury such as from inadvertent short circuits.

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Where the assessments show that the risk is
significant then the use of fused test leads
constructed in accordance with the HSE guidance
note GS38 ‘Electrical Test Equipment for use by
Electricians’ is advised.
Maximum Safe Voltage
Current :- 600V MAXIMUM AC RMS or DC between
uninsulated conductor and ground and maximum
frequency of 1kHz. This limitation applies to bare
conductors only.
Voltage:- 600V MAXIMUM AC RMS or DC between
live conductor and ground. 600V MAXIMUM AC RMS
or DC between VΩand COM terminals and a
maximum frequency of 1kHz.
Important Information
•The instrument is intended for indoor use only.
•Do not attempt to take any measurement of
current or voltage higher than the maximum range
of the instrument.
•The unit is not hermetically sealed and should
NOT be brought into contact with surface water.
•Frequently inspect the test leads and the
instrument for damage. If the instrument is
physically damaged or does not function properly,
it should not be used.
USE ONLY SUITABLY RATED VOLTAGE TEST
LEADS TO IEC 1010-2-031. (600V CAT III Pollution
Degree 2).
5. BATTERY REPLACEMENT
Replacement with other than the specified battery will
invalidate the warranty.
Fit only Battery Type 9V Alkaline MN1604, IEC 6LR61
or equivalent.
will appear on the top row of the LCD display to
indicate that the minimum operating battery voltage
has been reached.
To change the battery, see Fig. 7
•Switch off the instrument
•Undo the retaining screw on the battery cover and
lift the cover clear of the unit.
•
SAFETY WARNING
Before removing the battery cover, make sure
that all external voltages are disconnected
from the instrument. For certainty remove all
leads.

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•Replace the used battery.
•Ensure the battery cover is replaced and the
locking screw tightened, before further use.
Fig. 7
Battery Replacement
6. WARRANTY
Your LEM HEME clamp on power meter is
guaranteed for one year from the date of purchase
against defective material or workmanship. If the
meter fails during the warranty period, we shall at our
discretion, repair or replace it with a new or
reconditioned unit provided we are satisfied that the
failure is due to defective material or workmanship. To
make a claim under warranty, the meter should be
returned to us, postage prepaid, with a description of
the defect. The use of a battery, other than that
specified invalidates this warranty.
Goods alleged by the buyer to be defective shall not
form the subject of any claim for injury, loss, damage,
or any expense howsoever incurred whether arising
directly or indirectly from such alleged defects other
than death or personal injury resulting from the seller‘s
negligence.
No condition is made or to be implied nor is any
warranty given or to be implied as to the life or wear of
goods supplied or that they will be suitable for any
particular purpose or for use under specific conditions,
notwithstanding that such purpose or conditions may
be made known to the seller.
7. OTHER PRODUCTS

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The LEM group offers a wide range of non-invasive
transducers, probes and instrumentation for the
measurement and analysis of current, voltage and
power.
Since the introduction of the world’s first digital
AC/DC clamp-on ammeter in 1982, LEM HEME has
continued to provide innovative test and
measurement solutions encompassing current
measurement from 5mA to 2000A.
LEM HEME policy is one of continuous product
improvement and the company reserves the right
to revise the above specifications without notice.
Changes to this version include:
index sheet: 1∅Power Measurement
Page 6, I less than 20A +- 1A
V less than 40V +-1V, 30Hz to 1kHz
Power and Frequecy measurements
V range >40V rms I range >30A Pk
p6 Battery life 10 hours
Inst/rms = on/off
These changes need to be applied to other languages
AH 01/05/97