HT HT9020 User manual

Copyright HT ITALIA 2016 Release 1.02 - 01/03/2016
HT9020
User manual

HT9020
EN - 1
Table of contents:
1.PRECAUTIONS AND SAFETY MEASURES ........................................................................... 2
1.1.Preliminary instructions .................................................................................................................... 2
1.2.During use ........................................................................................................................................ 3
1.3.After use ........................................................................................................................................... 3
1.4.Definition of measurement (overvoltage) category .......................................................................... 3
2.GENERAL DESCRIPTION ....................................................................................................... 4
2.1.Measuring average values and TRMS values ................................................................................. 4
2.2.Definition of true root mean square value and crest factor .............................................................. 4
3.PREPARATION FOR USE ....................................................................................................... 5
3.1.Initial checks..................................................................................................................................... 5
3.2.Instrument power supply .................................................................................................................. 5
3.3.Calibration ........................................................................................................................................ 5
3.4.Storage............................................................................................................................................. 5
4.OPERATING INSTRUCTIONS ................................................................................................. 6
4.1.Instrument description...................................................................................................................... 6
4.1.1.Description of the controls ................................................................................................................. 6
4.1.2.Alignment marks ................................................................................................................................ 6
4.1.3.Hand protection ................................................................................................................................. 7
4.1.4.Indication of the conventional direction of Current............................................................................. 7
4.2.Function keys description................................................................................................................. 8
4.2.1.F1, F2, F3, F4/OK keys ..................................................................................................................... 8
4.2.2.H/ESC/ key .................................................................................................................................... 8
4.3.Initial screen ..................................................................................................................................... 8
5.OPERATING INSTRUCTIONS ................................................................................................. 9
5.1.Instrument settings ........................................................................................................................... 9
5.2.AC Voltage detection........................................................................................................................ 9
5.3.DC Voltage measurement.............................................................................................................. 10
5.4.AC/AC + DC Voltage measurement............................................................................................... 12
5.4.1.Voltage Harmonics measurement ................................................................................................... 14
5.4.2.Phase Sequence and Phase Conformity ......................................................................................... 15
5.5.DC Current measurement .............................................................................................................. 19
5.6.AC/AC + DC Current measurement ............................................................................................... 21
5.6.1.Current Harmonics measurement.................................................................................................... 23
5.6.2.Dynamic Inrush current measurement............................................................................................. 24
5.7.DC Power and Energy measurement ............................................................................................ 26
5.8.AC/AC+DC Power and Energy measurement ............................................................................... 30
5.9.Resistance and Continuity test measurement ............................................................................... 36
6.MAINTENANCE ...................................................................................................................... 39
6.1.General information........................................................................................................................ 39
6.2.Battery replacement ....................................................................................................................... 39
6.3.Cleaning the instrument ................................................................................................................. 39
6.4.End of life ....................................................................................................................................... 39
7.TECHNICAL SPECIFICATIONS............................................................................................. 40
7.1.Technical characteristics................................................................................................................ 40
7.1.1.Reference guidelines ....................................................................................................................... 42
7.1.2.General characteristics .................................................................................................................... 42
7.2.ENVIRONMENT............................................................................................................................. 42
7.2.1.Environmental conditions for use..................................................................................................... 42
7.3.Accessories provided ..................................................................................................................... 42
8.SERVICE ................................................................................................................................ 43
8.1.Warranty conditions........................................................................................................................ 43
8.2.Service ........................................................................................................................................... 43
9.APPENDIX – THEORETICAL OUTLINE ................................................................................ 44
9.1.Calculation of powers in “AC 1P” mode ......................................................................................... 44
9.2.Calculation of powers in “AC 3P” mode ......................................................................................... 44
9.3.Calculation of powers in “DC” mode .............................................................................................. 44
9.4.voltage and current harmonics....................................................................................................... 45
9.5.Limit values for harmonics ............................................................................................................. 46
9.6.Causes FOR the presence of harmonics ....................................................................................... 46

HT9020
EN - 2
1. PRECAUTIONS AND SAFETY MEASURES
The instrument has been designed in compliance with directive IEC/EN61010-1 relative to
electronic measuring instruments. For your safety and in order to avoid damaging the
instrument, please carefully follow the procedures described in this manual and read all
notes preceded by the symbol paying the utmost attention.
Before and after carrying out measurements, carefully observe the following instructions:
Do not carry out any voltage or current measurement in humid environments
Do not carry out any measurement in case of gas, explosive and inflammable materials
or dusty environments
Avoid contact with the circuit under test if no measurement is carried out
Avoid contact with exposed metal parts, with unused measuring probes, circuits, etc.
Do not carry out any measurement in case of instrument’s anomalies such as
deformation, breaks, substance leaks, absence of displayed screen, etc.
Pay special attention when measuring voltages higher than 20V, since a risk of
electrical shock exists
The following symbols are used in this manual and on the instrument:
CAUTION: observe the instructions given in this manual; an improper use could
damage the instrument or its components.
High voltage danger: electrical shock hazard.
Double-insulated meter
AC voltage or current
DC voltage or current
Connection to earth
1.1. PRELIMINARY INSTRUCTIONS
This clamp has been designed for use in environments of pollution degree 2.
It can be used for CURRENT and VOLTAGE measurements on installations with
measurement category CAT IV 600V and CAT III 1000V. For a definition of
measurement categories, see § 1.4.
We recommend to follow the standard safety rules devised by the procedures for
carrying out operations on live systems and using the prescribed PPE to protect the
user against dangerous currents and the instrument against incorrect use.
Only the leads supplied with the instrument guarantee compliance with the safety
standards. They must be under good conditions and replaced with identical models,
when necessary.
Do not test circuits exceeding the specified current and voltage limits.
Check that the battery is correctly inserted.
Before connecting the test leads to the circuit under test, make sure that the switch is
correctly set.
Make sure that the LCD display and the switch indicate the same function.

HT9020
EN - 3
1.2. DURING USE
Please carefully read the following recommendations and instructions:
CAUTION
Failure to comply with the Caution notes and/or Instructions may damage
the instrument and/or its components or be a source of danger for the
operator.
Before activating the switch, remove the conductor from the clamp jaw or disconnect
the test leads from the circuit under test.
When the instrument is connected to the circuit, do not touch any unused terminal.
Keep your hands always under the hand protection. This protection is always located in
a suitable position to guarantee a correct safety distance from possible exposed or live
parts (see Fig. 3)
Avoid measuring resistance if external voltages are present. Even if the instrument is
protected, excessive voltage could cause a malfunction of the clamp.
During current measurement, any other current near the clamp may affect
measurement accuracy.
When measuring current, always put the conductor as close as possible to the middle
of the clamp jaw, to obtain the most accurate reading.
While measuring, if the value or the sign of the quantity under test remain unchanged,
check if the HOLD function is enabled.
1.3. AFTER USE
When measurement is complete, switch OFF the instrument.
If the instrument is not to be used for a long time, remove the batteries
1.4. DEFINITION OF MEASUREMENT (OVERVOLTAGE) CATEGORY
Standard IEC/EN61010-1: “Safety requirements for electrical equipment for measurement,
control and laboratory use, Part 1: General requirements” defines measurement category,
commonly called overvoltage category. In § 6.7.4: Measured circuits, circuits are divided
into the following measurement categories:
(OMISSIS)
Measurement category IV is for measurements performed at the source of the low-
voltage installation.
Examples are electricity meters and measurements on primary overcurrent protection devices
and ripple control units.
Measurement category III is for measurements performed on installations inside
buildings.
Examples are measurements on distribution boards, circuit breakers, wiring, including cables,
bus-bars, junction boxes, switches, socket-outlets in the fixed installation, and equipment for
industrial use and some other equipment, for example, stationary motors with permanent
connection to fixed installations.
Measurement category II is for measurements performed on circuits directly
connected to the low-voltage installation.
Examples are measurements on household appliances, portable tools and similar equipment.
Measurement category I is for measurements performed on circuits not directly
connected to MAINS.
Examples are measurements on circuits not derived from MAINS, and specially protected
(internal) MAINS-derived circuits. In the latter case, transient stresses are variable; for that
reason, the standard requires that the transient withstand capability of the equipment is made
known to the user.

HT9020
EN - 4
2. GENERAL DESCRIPTION
The HT9020 instrument carries out the following measurements:
DC and AC+DC TRMS voltage
DC and AC+CD TRMS current
Phase sequence and conformity test
AC powers and power factor on single-phase and/or balanced three phase systems
AC energies on single-phase and/or balanced three-phase systems
DC power
AC voltage harmonics up to 25° order and THD%
AC current harmonics up to 25° order and THD%
Frequency on voltage (with test leads) and current (with clamp jaw)
Resistance and continuity test
Electric motor starting currents (Dynamic Inrush)
Detection of AC voltage with and without contact with built-in sensor
Each of these functions can be selected using the 6-position selector switch, including
OFF position. Keys F1, F2, F3, F4/OK and H / ESC / are also provided. For their use,
please refer to § 4.2.
2.1. MEASURING AVERAGE VALUES AND TRMS VALUES
Measuring instruments of alternating quantities are divided into two big families:
AVERAGE-VALUE meters: instruments measuring the value of the single wave signals
TRMS (True Root Mean Square) VALUE meters: instruments measuring the TRMS
value of the quantity being tested
In the presence of a perfectly sinusoidal wave, both families of instruments provide
identical results. In the presence of distorted waves, on the other hand, the readings shall
differ. Average-value meters provide the RMS value of the sole fundamental wave, TRSM
meters, instead, provide the RMS value of the whole wave, including harmonics (within the
instrument’s bandwidth)
2.2. DEFINITION OF TRUE ROOT MEAN SQUARE VALUE AND CREST FACTOR
The root mean square value of current is defined as follows: "In a time equal to a period,
an alternating current with a root mean square value of the intensity of 1A, circulating on a
resistor, dissipates the same energy as that which would have been dissipated by a direct
current with the intensity of 1 A during the same time ". This definition results in the
numeric expression:
G= 
Tt
t
dttg
T
0
0
)(
12The root mean square value is indicated with the acronym RMS. The
Crest Factor is defined as the relationship between the Peak Value of a signal and its RMS
value: CF (G)=
RMS
p
G
GThis value changes with the signal waveform, for a purely sinusoidal
wave it is 2=1.41. In case of distortion, the Crest Factor takes higher values as wave
distortion increases.

HT9020
EN - 5
3. PREPARATION FOR USE
3.1. INITIAL CHECKS
Before shipping, the instrument has been checked from an electric as well as mechanical
point of view. All possible precautions have been taken so that the instrument is delivered
undamaged.
However, we recommend generally checking the instrument in order to detect possible
damage suffered during transport. In case anomalies are found, immediately contact the
forwarding agent.
We also recommend to check whether the package contains all components indicated in
§ 7.3. In case of discrepancy, please contact the Dealer.
In case the instrument should be replaced, please carefully follow the instructions given in
chapter 8.2.
3.2. INSTRUMENT POWER SUPPLY
The instrument is supplied by 2x1.5V LR03 AAA batteries. Replace them following the
instructions in § 5.2.
3.3. CALIBRATION
The instrument has the technical specifications described in this manual. The instrument’s
performance is guaranteed for one year.
3.4. STORAGE
In order to guarantee accurate measurements, after a long storage time under extreme
environmental conditions, wait for the instrument to come back to normal condition (see §
7.2.1)

HT9020
EN - 6
4. OPERATING INSTRUCTIONS
4.1. INSTRUMENT DESCRIPTION
4.1.1. Description of the controls
CAPTION:
1. Inductive clamp jaw
2. AC voltage indicator LED
3. Jaw trigger
4. Rotary selector switch
5. H/ESC/ key
6. F1,F2,F3,F4/OK function
keys
7. LCD display
8. Input terminal V
9. Input terminal COM
Fig. 1: Instrument description
4.1.2. Alignment marks
Put the conductor as close as possible to the middle of the jaws on the intersection of the
indicated marks (see Fig. 2) in order to meet the meter accuracy specifications.
CAPTION:
1. Alignment marks
2. Conductor
Fig. 2: Alignment marks

HT9020
EN - 7
4.1.3. Hand protection
CAPTION:
1. Hand protection
2. Safe area
Fig. 3: hand protection
Always keep your hands under the hand protection. This protection is always located in a
suitable position to guarantee a correct safety distance from possible exposed or live parts
(see Fig. 3)
4.1.4. Indication of the conventional direction of Current
The Fig. 4 shows an arrow which indicates the conventional direction of current
Fig. 4: Current direction arrow

HT9020
EN - 8
4.2. FUNCTION KEYS DESCRIPTION
4.2.1. F1, F2, F3, F4/OK keys
The F1, F2, F3, F4/OK keys perform different functions according to the measurement set
(for detailed information, see the single functions).
4.2.2. H/ESC/ key
A single press activates the Data HOLD function and the value of the measurement
quantity is frozen at display. The symbol "H" is displayed when this function is enabled.
This operating mode is disabled when “H” key is pressed again or the switch is operated.
To improve the readability of the values measured in dark places, the display has been
provided with a backlight function which is turned on and off by long-pressing “H” key. If
the feature is set in MAN mode (see § 5.1) the backlight deactivates after approximately
30 seconds after its activation, in order to save battery life.
The same key identify the ESC (Exit) functionality inside the different modes of the
instrument.
4.3. INITIAL SCREEN
When switching on the instrument, the initial screen appears for
a few seconds. It shows:
The instrument’s model
The instrument’s serial number
The instrument’s firmware version
HT9020
Sn 15120020
V. 2.00
CAUTION
Please note down this information, especially the firmware version, in case
it should be necessary to contact the service department.
After a few seconds, the instrument switches to the selected function.