HT Italia PQA819 User manual

Copyright HT ITALIA 2014 Version EN 2.01 - 26/05/2014
PQA819 – PQA820
User manual

PQA819 - PQA820
EN – 1
Table of contents
1.PRECAUTIONS AND SAFETY MEASURES...........................................................3
1.1.Preliminary instructions....................................................................................................3
1.2.During use........................................................................................................................4
1.3.After use...........................................................................................................................4
1.4.Definition of measurement (overvoltage) category..........................................................4
2.GENERAL DESCRIPTION .......................................................................................5
2.1.Foreword..........................................................................................................................5
2.2.Instrument functions.........................................................................................................5
3.PREPARATION FOR USE .......................................................................................6
3.1.Initial checks.....................................................................................................................6
3.2.Instrument power supply..................................................................................................6
3.3.Calibration........................................................................................................................6
3.4.Storage.............................................................................................................................6
4.NOMENCLATURE....................................................................................................7
4.1.Instrument description......................................................................................................7
4.2.Keyboard description .......................................................................................................7
4.3.Description of the LED.....................................................................................................7
5.INITIAL SETTINGS...................................................................................................8
5.1.Setting the electrical system ............................................................................................8
5.2.Setting type of clamp......................................................................................................11
5.3.Setting the clamp's full scale..........................................................................................11
5.4.Setting the value of transformation ratio of VTs.............................................................11
5.5.Setting limits for voltage anomalies ...............................................................................11
5.6.Setting the integration period.........................................................................................11
5.7.Setting a programmed start and stop.............................................................................12
5.8.Setting the instrument's date and time...........................................................................12
6.MEASURING PROCEDURES................................................................................13
6.1.Connection in a single-phase system............................................................................13
6.2.Connection in a three-phase 3-wire system...................................................................14
6.3.Connection in a three-phase 4-wire system...................................................................15
7.RECORDING OF ELECTRICAL PARAMETERS...................................................16
7.1.Starting recording...........................................................................................................16
7.2.While recording..............................................................................................................16
7.3.Stopping recording.........................................................................................................16
8.MEMORY MANAGEMENTS...................................................................................17
8.1.Clear data.......................................................................................................................17
9.TRANSFERRING DATA TO THE MANAGEMENT SOFTWARE ..........................18
9.1.Transferring data via USB port.......................................................................................18
9.2.Transferring data via WiFi..............................................................................................18
9.3.Connection to iOS/Android devices through WiFi..........................................................18
10.MAINTENANCE......................................................................................................19
10.1.General information................................................................................................19
10.2.Cleaning the instrument..........................................................................................19
10.3.End of life................................................................................................................19
11.TECHNICAL SPECIFICATIONS.............................................................................20
11.1.Technical characteristics........................................................................................20
11.2.Reference guidelines..............................................................................................21
11.3.General characteristics...........................................................................................21
11.4.Environment............................................................................................................21
11.4.1.Environmental conditions for use............................................................................... 21
11.5.Accessories ............................................................................................................21
12.APPENDIX – THEORETICAL OUTLINE................................................................22

PQA819 - PQA820
EN – 2
12.1.Voltage Anomalies..................................................................................................22
12.2.Voltage and current harmonics...............................................................................23
12.2.1.Limit values for harmonics ......................................................................................... 24
12.2.2.Causes of the presence of harmonics........................................................................ 24
12.2.3.Consequence of the presence of harmonics.............................................................. 25
12.3.Definitions of power and power factor....................................................................26
12.3.1.Conventions on powers and power factors................................................................ 27
12.4.Information on the measuring method....................................................................29
12.4.1.Integration period....................................................................................................... 29
12.4.2.Calculation of the power factor................................................................................... 29
13.SERVICE ................................................................................................................30
13.1.Warranty conditions................................................................................................30
13.2.Service....................................................................................................................30

PQA819 - PQA820
EN – 3
1. PRECAUTIONS AND SAFETY MEASURES
The instrument has been designed in compliance with directive IEC/EN61010-1 relevant to
electronic measuring instruments. For your safety and in order to prevent damaging the
instrument, please carefully follow the procedures described in this manual and read all
notes preceded by the symbol with the utmost attention.
Before and after carrying out the measurements, carefully observe the following
instructions:
Do not carry out any voltage or current measurement in humid environments.
Do not carry out any measurements in case gas, explosive materials or flammables are
present, or in dusty environments.
Avoid any contact with the circuit being measured if no measurements are being
carried out.
Avoid any contact with exposed metal parts, with unused measuring probes, circuits,
etc.
Do not carry out any measurement in case you find anomalies in the instrument such
as deformation, breaks, substance leaks, absence of display on the screen, etc.
In this manual, and on the instrument, the following symbols are used:
Warning: observe the instructions given in this manual; improper use could
damage the instrument or its components.
High voltage danger: electrical shock hazard.
Double-insulated meter
AC voltage or current
The voltage values indicated to the left of this symbol are referred to the ground
1.1. PRELIMINARY INSTRUCTIONS
This instrument has been designed for use in environments of pollution degree 2.
It can be used for voltage and current measurements on installations with overvoltage
category CAT IV 300V AC to earth and maximum rated voltage between inputs 415V
AC
Please take the standard safety precautions aimed at protecting you against dangerous
electrical currents and protecting the instrument against incorrect use
Only the accessories provided together with the instrument will guarantee safety
standards. They must be in good conditions and be replaced with identical models,
when necessary.
Do not test circuits exceeding the specified current and voltage limits.
Before connecting cables, alligator clips and clamps to the circuit being measured,
check that the desired configuration has been set.

PQA819 - PQA820
EN – 4
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.
When the instrument is connected to the circuit under test, do not touch any unused
terminal.
During current measurement, any other current near the clamp may affect
measurement precision.
When measuring current, always put the conductor as near as possible to the middle of
the clamp jaw, to obtain the most accurate reading.
1.3. AFTER USE
When measures are completed, switch off the instrument by pressing ON/OFF key.
If the instrument is not to be used for a long time, please follow the instructions for
storage described in § 3.4
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 what measurement
category, commonly called overvoltage category, is. § 6.7.4: Measured circuits, reads:
(OMISSIS)
Circuits are divided into the following measurement categories:
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 installation.
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

PQA819 - PQA820
EN – 5
2. GENERAL DESCRIPTION
2.1. FOREWORD
This manual refers to PQA819 and PQA820 models. In the whole manual, the word
“instrument” generically indicates PQA820 model, unless otherwise indicated. The
instrument allows for a totally new approach to electric measurements. Using computer-
aided instruments allows analyzing a huge amount of data with a simplicity and speed
impossible to obtain with any other system.
The differences between the models are listed in the following Table 1
Function description PQA819 PQA820
Recording of neutral current 
Recording of voltage anomalies (sags, swells) 
Recording of voltage unbalance 
Recording of voltage/current harmonics up to 49th order 
Recording of apparent power 
Recording of generated power/energy 
Recording of generated power factor / Cos
Number of selectable parameters 44 (fixed) 383 (fixed)
Recording autonomy (days) > 230
(@ IP=15min) > 30 (@ IP=10min)
Table 1: Differences between model PQA819 and PQA820
2.2. INSTRUMENT FUNCTIONS
The instrument allows performing the following functions:
A real-time display (with connection to PC and/or iOS/Android devices) of the values
of the electric quantities of a single-phase or three-phase system with or without neutral
and of the harmonic analysis of voltages and currents
Recording (through the appropriate setting) over time of the values of AC/DC voltages,
voltage unbalance (PQA820), voltage anomalies (sags, swells) with a resolution of
10ms (PQA820), AC/DC currents, neutral current (PQA820) of the values of the
relevant harmonics (PQA820), THD% value, of the values of active, reactive and
apparent powers (PQA820), of power factors and cos, of the values of active and
reactive energies, where recording is intended as saving in the instrument's memory
the values taken by the electrical quantities over time.
CAUTION
These terms will be used several times in this manual. We therefore invite
you to try and immediately focus the distinctions between the definitions
listed above.

PQA819 - PQA820
EN – 6
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 checking that the packaging contains
all components indicated in § 11.5. In case of discrepancy, please contact the Dealer. In
case the instrument should be replaced, please carefully follow the instructions given in §
13.
3.2. INSTRUMENT POWER SUPPLY
The instrument may be supplied in two ways:
External supply: red and yellow terminals (rated voltage field: 100 415V, 50/60Hz).
Internal supply: internal rechargeable batteries through red and yellow terminals.
CAUTION
When recording, we recommend ALWAYS using the external supply
If the external supply fails, the instrument automatically switches to the
internal supply provided by rechargeable batteries
3.3. CALIBRATION
The instrument has the technical specifications described in this manual. The instrument's
performance is guaranteed for one year starting from the date of purchase.
3.4. STORAGE
In order to guarantee precise measurement, after a long storage time under extreme
environmental conditions, wait for the instrument to come back to normal condition (see §
11.4.1).

PQA819 - PQA820
EN – 7
4. NOMENCLATURE
4.1. INSTRUMENT DESCRIPTION CAPTION:
1. Indication LEDs
2. Description of the indication LEDs
3. USB port
4. Voltage and Current inputs
5. Keyboard
Fig. 1: Instrument description
4.2. KEYBOARD DESCRIPTION
The keyboard includes the following keys:
ON/OFF: pressing this key to switches the instrument on. Press the key approx. 2s to
switches the instrument off. If the instrument do not switch off press and hold this key
for at least 5s
START/STOP: for manually starting and stopping recording (see § 7 and 7.3).
SYSTEM:It allows for the selection of the electrical system (Single phase, Three phase 3-
wire and 4-wire)
WiFi/RF: it allows for the selection of the communication mode, WiFi or RF (only for the
communication with other HT instruments).
4.3. DESCRIPTION OF THE LED
LED Description
POWER
It describes the status and supply mode of the instrument:
Off: instrument switched off
Flashing green: instrument switched on supplied by internal batteries
Flashing red: internal batteries almost flat
STATUS
It described the instrument status:
Off: No recording in progress
Flashing green: Recording in progress
Green: Instrument waiting to start recording. Recording will always start at
the beginning of the minute after the START button has been pressed
/ receipt of the start recording control
Flashing red: Memory full
Red: Internal error – use the management software to identify the type of
malfunction. Some of them may also prevent recording.
RF/WiFi It described what communication mode is currently set in the instrument: Off: WiFi mode
Flashing green: RF mode (only for connection with other HT instruments)
CONNECTION
It indicates if a WiFi or RF connection is active (according to the communication mode set)
SYSTEM
It indicates the electrical system currently set:
Off: Single-phase mode
Flashing green: Three-phase without neutral mode
Green: Three-phase with neutral mode
ERROR
It indicates possible connection errors:
Off: No error detected
Flashing red: Phase sequence incorrect
Red: One of the active powers measured by the instrument is negative.
Table 2: Description of LEDs

PQA819 - PQA820
EN – 8
5. INITIAL SETTINGS
CAUTION
The instrument may be configured only through the relevant management
software, except for the selection of the electrical system, which may also be
performed through the SYSTEM key in the instrument's keyboard
5.1. SETTING THE ELECTRICAL SYSTEM
This parameter allows selecting the type of electrical system to be analyzed. It is possible
to select the electrical system through the SYSTEM button in the instrument's keyboard.
Following configurations are available:
Single-phase system
Three-phase system without neutral (3-wires)
Three-phase system with neutral (4-wires)
Each electrical system is associated with a list of parameters automatically recorded by
the instrument (not modifiable).
SYMBOL DESCRIPTION
V1 RMS value of voltage of Phase 1 or DC
Freq. Mains frequency
I1 RMS value of Phase 1 current or DC
THDV1%, Harmonic distortion percentage factor of Phase 1 voltage
DCV1, Har1V1, ,Har49V1 Voltage harmonics of Phase 1 (PQA820)
THDI1% Harmonic distortion percentage factor of Phase 1 current
DCI1, Har1I1, ,Har49I1 Current harmonics of Phase 1 (PQA820)
P1+ Absorbed active power Phase 1
Ea1+ Absorbed active energy Phase 1
Q1i+ Absorbed inductive reactive power Phase 1
Er1i+ Absorbed inductive reactive energy Phase 1
Q1c+ Absorbed capacitive reactive power Phase 1
Er1c+ Absorbed capacitive reactive energy Phase 1
S1+ Absorbed apparent power Phase 1 (PQA820)
Es1+ Absorbed apparent energy Phase 1 (PQA820)
Pf1i+ Value of the absorbed inductive power factor of Phase 1
dPf1i+ + Value of the absorbed inductive cos

of Phase 1
Pf1c+ Value of the absorbed capacitive power factor of Phase 1
dPf1c+ Value of the absorbed capacitive cos

of Phase 1
P1- Generated active power Phase 1 (PQA820)
Ea1- Generated active energy Phase 1 (PQA820)
Q1i- Generated inductive reactive power Phase 1 (PQA820)
Er1i- Generated inductive reactive energy Phase 1 (PQA820)
Q1c- Generated capacitive reactive power Phase 1 (PQA820)
Er1c- Generated capacitive reactive energy Phase 1 (PQA820)
S1- Generated apparent power Phase 1 (PQA820)
Es1- Generated apparent energy Phase 1 (PQA820)
Pf1i- Value of the generated inductive power factor of Phase 1 (PQA820)
dPf1i- Value of the generated inductive cos

of Phase 1 (PQA820)
Pf1c- Value of the generated capacitive power factor of Phase 1 (PQA820)
dPf1c- Value of the generated capacitive cos

of Phase 1 (PQA820)
Table 3: List of the parameters automatically recorded for a single-phase system

PQA819 - PQA820
EN – 9
SYMBOL DESCRIPTION
V1PE, V2PE, V3PE RMS value of voltage of Phase 1, Phase 2, Phase 3 with respect to PE
V12, V23, V31 RMS value of delta voltages
Freq. Mains frequency
I1, I2, I3 RMS value of current of Phase 1, Phase 2, Phase 3 neutral
THDV1%, THDV2%, THDV3% Harmonic distortion percentagefactor of voltage of Phase 1, Phase 2, Phase 3
DCVx, Har1Vx, ,Har49Vx (x=1,2,3) - Voltage harmonics of Phase 1, Phase 2, Phase 3 (PQA820)
THDI1%, THDI2%, THDI3% Harmonic distortion percentage factor of current of Phase 1, Phase 2, Phase 3
DCIx, Har1Ix, ,Har49Ix (x=1,2,3) - Current harmonics of Phase 1, Phase 2, Phase 3 (PQA820)
u2, uo Unbalance of voltages - Percentage value of the negative sequence (PQA820)
uo Unbalance of voltages - Percentage value of the zero sequence (PQA820)
Pt+, P1+, P2+, P3+ Absorbed active power Total, Phase 1, Phase 2, Phase 3
Eat+, Ea1+, Ea2+, Ea3+ Absorbed active energy Total, Phase 1, Phase 2, Phase 3
Qti+, Q1i+, Q2i+, Q3i+ Absorbed inductive reactive power Total, Phase 1, Phase 2, Phase 3
Erti+, Er1i+, Er2i+, Er3i+ Absorbed inductive reactive energy Total, Phase 1, Phase 2, Phase 3
Qtc+, Q1c+, Q2c+, Q3c+ Absorbed capacitive reactive power Total, Phase 1, Phase 2, Phase 3
Ertc+, Er1c+, Er2c+, Er3c+ Absorbed capacitive reactive energy Total, Phase 1, Phase 2, Phase 3
St+, S1+, S2+, S3+ Absorbed apparent power Total, Phase 1, Phase 2, Phase 3 (PQA820)
Est+, Es1+, Es2+, Es3+ Absorbed apparent energy Total, Phase 1, Phase 2, Phase 3 (PQA820)
Pfti+, Pf1i+, Pf2i+, Pf3i+ Values of the absorbed inductive power factors Total, Phase 1, Phase 2, Phase 3
dPfti+, dPf1i+,d Pf2i+, dPf3i+ Values of the absorbed inductive cos

Total, Phase 1, Phase 2, Phase 3
Pftc+, Pf1c+, Pf2c+, Pf3c+ Values of the absorbed capacitive power factors Total, Phase 1, Phase 2, Phase 3
dPftc+, dPf1c+, dPf2c+, dPf3c+ Values of the absorbed capacitive cos

Total. Phase 1, Phase 2, Phase 3
Pt-, P1-, P2-, P3- Generated active power Total, Phase 1, Phase 2, Phase 3 (PQA820)
Eat-, Ea1-, Ea2-, Ea3- Generated active energy Total, Phase 1, Phase 2, Phase 3 (PQA820)
Qti-, Q1i-, Q2i-, Q3i- Generated inductive reactive power Total, Phase 1, Phase 2, Phase 3 (PQA820)
Erti-, Er1i-, Er2i-, Er3i- Generated inductive reactive energy Total, Phase 1, Phase 2, Phase 3 (PQA820)
Qtc-, Q1c-, Q2c-, Q3c- Generated capacitive reactive power Total, Phase 1, Phase 2, Phase 3 (PQA820)
Ertc-, Er1c-, Er2c-, Er3c- Generated capacitive reactive energy Total, Phase 1, Phase 2, Phase 3(PQA820)
St-, S1-, S2-, S3- Generated apparent power Total, Phase 1, Phase 2, Phase 3 (PQA820)
Est-, Es1-, Es2-, Es3- Generated apparent energy Total, Phase 1, Phase 2, Phase 3 (PQA820)
Pfti-, Pf1i-, Pf2i-, Pf3i- Generated inductive power factors Total, Phase 1, Phase 2, Phase 3 (PQA820)
dPfti-, dPf1i-,d Pf2i-, dPf3i- Generated inductive cos

Total, Phase 1, Phase 2, Phase 3 (PQA820)
Pftc-, Pf1c-, Pf2c-, Pf3c- Generated capacitive power factors Total, Phase 1, Phase 2, Phase 3 (PQA820)
dPftc-, dPf1c-, dPf2c-, dPf3c- Generated capacitive cos

Total, Phase 1, Phase 2, Phase 3 (PQA820)
Table 4: List of the parameters automatically recorded for a three-phase 3-wire system

PQA819 - PQA820
EN – 10
SYMBOL DESCRIPTION
V1, V2, V3 RMS value of voltage of Phase 1, Phase 2, Phase 3
V12, V23, V31 RMS value of delta voltages
Freq. Mains frequency
I1, I2, I3 RMS value of current of Phase 1, Phase 2, Phase 3
IN Neutral current (PQA820)
THDV1%, THDV2%, THDV3% Harmonic distortion percentage factor of Phase 1, Phase 2, Phase 3 voltage
DCVx, Har1Vx, ,Har49Vx (x=1,2,3) - Voltage harmonics of Phase 1, Phase 2, Phase 3 (PQA820)
THDI1%, THDI2%, THDI3% Harmonic distortion percentage factor of Phase 1, Phase 2, Phase 3 current
DCIx, Har1Ix, ,Har49Ix (x=1,2,3) - Current harmonics of Phase 1, Phase 2, Phase 3 (PQA820)
u2, uo Unbalance of voltages - Percentage value of the negative sequence (PQA820)
uo Unbalance of voltages - Percentage value of the zero sequence (PQA820)
Pt+, P1+, P2+, P3+ Absorbed active power Total, Phase 1, Phase 2, Phase 3
Eat+, Ea1+, Ea2+, Ea3+ Absorbed active energy Total, Phase 1, Phase 2, Phase 3
Qti+, Q1i+, Q2i+, Q3i+ Absorbed inductive reactive power Total, Phase 1, Phase 2, Phase 3
Erti+, Er1i+, Er2i+, Er3i+ Absorbed inductive reactive energy Total, Phase 1, Phase 2, Phase 3
Qtc+, Q1c+, Q2c+, Q3c+ Absorbed capacitive reactive power Total, Phase 1, Phase 2, Phase 3
Ertc+, Er1c+, Er2c+, Er3c+ Absorbed capacitive reactive energy Total, Phase 1, Phase 2, Phase 3
St+, S1+, S2+, S3+ Absorbed apparent power Total, Phase 1, Phase 2, Phase 3 (PQA820)
Est+, Es1+, Es2+, Es3+ Absorbed apparent energy Total, Phase 1, Phase 2, Phase 3 (PQA820)
Pfti+, Pf1i+, Pf2i+, Pf3i+ Values of the absorbed inductive power factors Total, Phase 1, Phase 2, Phase 3
dPfti+, dPf1i+,d Pf2i+, dPf3i+ Values of the absorbed inductive cos

Total, Phase 1, Phase 2, Phase 3
Pftc+, Pf1c+, Pf2c+, Pf3c+ Values of the absorbed capacitive power factors Total, Phase 1, Phase 2, Phase 3
dPftc+, dPf1c+, dPf2c+, dPf3c+ Values of the absorbed capacitive cos

Total. Phase 1, Phase 2, Phase 3
Pt-, P1-, P2-, P3- Generated active power Total, Phase 1, Phase 2, Phase 3 (PQA820)
Eat-, Ea1-, Ea2-, Ea3- Generated active energy Total, Phase 1, Phase 2, Phase 3 (PQA820)
Qti-, Q1i-, Q2i-, Q3i- Generated inductive reactive power Total, Phase 1, Phase 2, Phase 3 (PQA820)
Erti-, Er1i-, Er2i-, Er3i- Generated inductive reactive energy Total, Phase 1, Phase 2, Phase 3 (PQA820)
Qtc-, Q1c-, Q2c-, Q3c- Generated capacitive reactive power Total, Phase 1, Phase 2, Phase 3 (PQA820)
Ertc-, Er1c-, Er2c-, Er3c- Generated capacitive reactive energy Total, Phase 1, Phase 2, Phase 3 (PQA820)
St-, S1-, S2-, S3- Generated apparent power Total, Phase 1, Phase 2, Phase 3 (PQA820)
Est-, Es1-, Es2-, Es3- Generated apparent energy Total, Phase 1, Phase 2, Phase 3 (PQA820)
Pfti-, Pf1i-, Pf2i-, Pf3i- Generated inductive power factors Total, Phase 1, Phase 2, Phase 3 (PQA820)
dPfti-, dPf1i-,d Pf2i-, dPf3i- Generated inductive cos

Total, Phase 1, Phase 2, Phase 3 (PQA820)
Pftc-, Pf1c-, Pf2c-, Pf3c- Generated capacitive power factors Total, Phase 1, Phase 2, Phase 3 (PQA820)
dPftc-, dPf1c-, dPf2c-, dPf3c- Generated capacitive cos

Total, Phase 1, Phase 2, Phase 3 (PQA820)
Table 5: List of the parameters automatically recorded for a three-phase 4-wire system
CAUTION
The connections to the instrument's inputs must be consistent with the type of
system selected. For further information on the settings of this parameter,
please refer to the on-line guide of the management software

PQA819 - PQA820
EN – 11
5.2. SETTING TYPE OF CLAMP
The instrument is capable of managing two types of clamp meter:
STD: standard clamp with iron core
Flex: flexible clamp
It is also possible to differentiate the type of clamp used for phase and neutral current with
independent setting of used full scales.
The type of clamp selected must always be consistent with the type of clamp actually
used. For further information on the settings of this parameter, please refer to the on-line
guide of the management software
5.3. SETTING THE CLAMP'S FULL SCALE
This parameter allows selecting the full scale of the clamp used. It is possible to
differentiate the full scale of the clamp used for measuring phase and neutral current. For
the “Flex” clamp type it is possible to select 100A and 1000A values only. The selected
full scale must always be consistent with the full scale actually used. For further
information on the settings of this parameter, please refer to the on-line guide of the
management software.
5.4. SETTING THE VALUE OF TRANSFORMATION RATIO OF VTS
The instrument allows interfacing also with possible Voltage Transformers (VT) found in
the system to be measured and displays the value of the voltages found on the primary
transformers. To this aim it is necessary to set the value of the transformation ratio of the
voltage transformers installed. Selectable range is 1 3999
5.5. SETTING LIMITS FOR VOLTAGE ANOMALIES
The instrument allows the voltage anomalies (sags, swells) recording with preliminary
setting of a nominal voltage value (depending on the type of selected system) and the
minimum and maximum limit thresholds with percentage values selected between 1% and
30%. For further information on the settings of this parameter, please refer to the on-line
guide of the management software and § 12.1
5.6. SETTING THE INTEGRATION PERIOD
The value of this parameter determines every how many seconds the values of all
selected quantities will be archived in the instrument's memory (see § 12.4). Available
values: 5s, 10s, 30s, 1min, 2min, 5min, 10min, 15min, 60min
For further information on the settings of this parameter, please refer to the on-line guide
of the management software.

PQA819 - PQA820
EN – 12
5.7. SETTING A PROGRAMMED START AND STOP
Through these parameters it is possible to set the start/stop modes of a recording. In
detail:
START:MAN Recording of all selected quantities will be started at the beginning of
the first minute after the START/STOP key has been pressed by the
operator (see § 7).
STOP:MAN Recording of all selected quantities will be manually stopped by the
operator by pressing the START/STOP key (see § 7.3).
START:AUTO
STOP:AUTO
Recording of all selected quantities will be started/stopped at the set
date and time. To start recording, the operator will have to press
the START/STOP key to set the instrument to Stand-By waiting for
the set start date to be reached (see § 7).
For further information on the settings of this parameter, please refer to the on-line guide
of the management software.
5.8. SETTING THE INSTRUMENT'S DATE AND TIME
It is possible to set the instrument's date and time by sending to it the date and time of the
device on which the management software has been installed.
For further information on the settings of this parameter, please refer to the on-line guide
of the management software.

PQA819 - PQA820
EN – 13
6. MEASURING PROCEDURES
6.1. CONNECTION IN A SINGLE-PHASE SYSTEM
CAUTION
The maximum rated voltage between inputs is 415V AC, CAT IV 300V to
earth. Do not connect the instrument to voltages exceeding the limits given
in this manual
The rated supply voltage of the instrument (red-yellow terminals) must be
within the range: 100 415V, 50/60Hz
Fig. 2: Connection of the instrument to a single-phase system
CAUTION
If possible, cut out the power supply of the electrical system to be measured
before connecting the instrument.
1. Check and, if necessary, change the basic settings of the instrument (see § 5). In
particular set the Single-phase mode.
2. Connect the supply terminals (red and yellow) respecting the connections indicated in
Fig. 2
3. Connect the cables of the L1-N voltages, respecting the connections indicated in the Fig. 2
4. If you want to measure current and power, connect the clamp meter to the phase
conductor, respecting the direction indicated on the clamp and the connections
indicated in the Fig. 2
5. Connect the electrical system to be measured to voltage in case the system has been
momentarily put out of order to connect the instrument.
6. Check that the Error LED is off. In case it is on steady, check that the clamp meter is
connected respecting the direction indicated.
7. In case a USB or WiFi connection (see § 9) with a device is active on which a
management software is installed, the values of the available electrical quantities will
appear on the device's display. For further information, please refer to the on-line guide
of the management software.
8. If you want to record:
Check and, if necessary, change the values of the basic parameters (see § 5)
To start recording, press the START/STOP key (see § 7).

PQA819 - PQA820
EN – 14
6.2. CONNECTION IN A THREE-PHASE 3-WIRE SYSTEM
CAUTION
The maximum rated voltage between inputs is 415V AC, CAT IV 300V to
earth. Do not connect the instrument to voltages exceeding the limits given
in this manual
The rated supply voltage of the instrument (red-yellow terminals) must be
within the range: 100 415V, 50/60Hz
Fig. 3: Connection of the instrument to a three-phase 3-wire system
CAUTION
If possible, cut out the power supply of the electrical system to be measured
before connecting the instrument.
1. Check and, if necessary, change the basic settings of the instrument (see § 5). In
particular, it will be certainly necessary to set the Three-phase 3-wire mode.
2. Connect the supply terminals (red and yellow) respecting the connections indicated in
the Fig. 3
3. Connect the cables of the phase voltages L1, L2 e L3, respecting the connections
indicated in the Fig. 3. Connect the blue cable to the protective conductor.
4. If you want to measure currents and powers, connect the clamp meters to the phase
conductors, respecting the direction indicated on the clamps and the connections
indicated in the Fig. 3
5. Connect the electrical system to be measured to voltage in case the system has been
momentarily put out of order.
6. Check that the Error LED is off. In case it is:
On and flashing check that the voltages respect the correct phase sequence
On steady check that the clamp meter is connected respecting the direction
indicated
7. In case a USB or WiFi connection (see § 9) with a device is active on which a
management software is installed, the values of the available electrical quantities will
appear on the device's display. For further information, please refer to the on-line guide
of the management software
8. If you want to record:
Check and, if necessary, change the values of the basic parameters (see § 5)
To start recording, press the START/STOP key (see § 7)

PQA819 - PQA820
EN – 15
6.3. CONNECTION IN A THREE-PHASE 4-WIRE SYSTEM
CAUTION
The maximum rated voltage between inputs is 415V AC, CAT IV 300V to
earth. Do not connect the instrument to voltages exceeding the limits given
in this manual
The rated supply voltage of the instrument (red-yellow terminals) must be
within the range: 100 415V, 50/60Hz
Fig. 4: Connection of the instrument to a three-phase 4-wire system
CAUTION
If possible, cut out the power supply of the electrical system to be measured
before connecting the instrument.
1. Check and, if necessary, change the basic settings of the instrument (see § 5). In
particular, it will be certainly necessary to set the Three-phase 4-wire mode
2. Connect the supply terminals (red and yellow) respecting the connections indicated in
the Fig. 4
3. Connect the cables of the phase voltages L1, L2, L3, respecting the connections
indicated in the Fig. 4. Connect the blue cable to the system's neutral.
4. If you want to measure currents and powers, connect the clamp meters to the phase
conductors, respecting the direction indicated on the clamps and the connections
indicated in the Fig. 4
5. Connect the electrical system to be measured to voltage in case the system has been
momentarily put out of order.
6. Check that the Error LED is off. In case it is:
On and flashing , check that the voltages respect the correct phase sequence
On steady check that the clamp meter is connected respecting the direction
indicated
7. In case a USB or WiFi connection (see § 9) with a device is active on which a
management software is installed, the values of the available electrical quantities will
appear on the device's display. For further information, please refer to the on-line guide
of the management software.
8. If you want to record:
Check and, if necessary, change the values of the basic parameters (see § 5)
To start recording, press the START/STOP key (see § 7)

PQA819 - PQA820
EN – 16
7. RECORDING OF ELECTRICAL PARAMETERS
7.1. STARTING RECORDING
Recording can be started MANUALLY or AUTOMATICALLY. Once the setting phase has
been completed and after quitting the menu mode, the instrument will start recording by
following logic illustrated hereunder:
MANUAL: Recording will start at the beginning of the minute after the
START/STOP button has been pressed.
AUTO: If the operator has pressed the START/STOP key, the instrument will
wait until the date and time set for recording start have been reached and
then will start recording. If the operator does not press the
START/STOP key, instead, recording will NEVER start.
While the instrument is waiting to reach the starting date and time, the Status LED turns
on green steady.
CAUTION
When recording, we recommend ALWAYS using the external supply.
Before starting recording, the operator should make a real-time preliminary evaluation
of the system's situation, decide what to record and consistently set the instrument
To help the user in the setting phase, the instrument has been pre-set with a general
4-wire configuration for each selected electrical system, which should be suitable for
most of the cases in which the instrument is used
Pressing the START/STOP key starts recording the selected quantities according to
the specifications set in the menu (see § 5.7)
Since the default value of the integration periods is set to 15min, the instrument will
internally cumulate data in the temporary memory for that time. Once that time interval
has elapsed, the instrument will process the results saved in the temporary memory
and will save in the instrument's memory the first series of values relevant to recording
Therefore, assuming an integration period of 15min has been set, the duration of
recording will have to be at least of 15 minutes in order to produce a series of
recorded values which can therefore be transferred through the management software
In case recording is stopped before the selected integration period has completely
elapsed, the data cumulated in the temporary measurement will not be processed and
their relevant series of data will not be transferred to the instrument's memory.
7.2. WHILE RECORDING
While recording it is possible to display the following data using the management software:
Starting date and time of recording
Value of the integration period
Number of elapsed integration periods
Recording duration
Number of voltage anomalies detected
7.3. STOPPING RECORDING
Press the START/STOP key to stop recording.

PQA819 - PQA820
EN – 17
8. MEMORY MANAGEMENTS
The instrument has approximately 8MB for storing the values of the measured quantities.
Through the management software it is possible to receive information about the residual
recording duration compatible with the residual memory space and the settings made on
the instrument itself.
For further information on this issue, please refer to the on-line guide of the management
software.
CAUTION
All saved data can be seen only after transferring them onto a PC using
the management software
8.1. CLEAR DATA
It is possible to clear the whole instrument's memory by using the following procedure:
Switch off the instrument with ON/OFF key
Press and hold the SYSTEM key while switching on the instrument again by means of
the ON/OFF key.
The instrument will sound to confirm that the memory has been cleared.

PQA819 - PQA820
EN – 18
9. TRANSFERRING DATA TO THE MANAGEMENT SOFTWARE
The connection between the instrument and the management may occur through:
USB port by means connection with USB cable
WiFi connection
CAUTION
It is not possible to transfer data while recording
The selected port must NOT be engaged by other devices or
applications (e.g. a mouse, a modem, etc.)
Before making the connection, it is necessary to select WiFi
communication or the COM port used in the management software
To transfer data from the instrument onto a PC, please use the following procedure:
9.1. TRANSFERRING DATA VIA USB PORT
1. Switch on the instrument.
2. Connect the instrument's USB port with a port of the device on which the management
software has been installed.
3. Start the management software and select the downloaded data mode (for further
information on the settings of this parameter, please refer to the on-line guide of the
management software
9.2. TRANSFERRING DATA VIA WIFI
CAUTION
The transfer requires the use of a PC with an active and operative WiFi
connection (type integrated inside the PC or by installation of an USB-WiFi
adapter available in the market and can’t be supplied under any
circumstances by HT ITALIA)
1. Activate the WiFi connection on the target PC (ex: by using a WiFi key installed and
connected to a USB port, open the "Connect to a network" window by clicking the
network icon in the notification area (typically in the bottom right corner of the PC
screen), select the network "PQA820-xx", click "Connect" and wait for the confirmation
of the connection
2. Switch on the instrument.
3. Press the WiFi/RF key on the instrument in order to activate communication (RF/WiFi
LED off).
4. Start the management software and select the downloaded data mode with WiFi (for
further information on the settings of this parameter, please refer to the on-line guide of
the management software
9.3. CONNECTION TO IOS/ANDROID DEVICES THROUGH WIFI
The instrument can be connected remotely via WiFi connection to a Android/iOS
smartphones and/or tablets for the transfer of measurement data using the APP HT
Analysis. Proceed as follows:
1. Download and install the HT Analysis on the desired remote device (Android/iOS)
2. Put the instrument in data transfer mode to a PC (see § 9.2)
3. Take reference to the HT Analysis instruction for the management operation

PQA819 - PQA820
EN – 19
10. MAINTENANCE
10.1. GENERAL INFORMATION
While using and storing the instrument, carefully observe the recommendations listed in
this manual in order to prevent possible damage or danger during use:
Do not use the instrument in environments with high humidity levels or high
temperatures
Do not expose to direct sunlight
Always switch off the instrument after use.
10.2. CLEANING THE INSTRUMENT
Use a soft and dry cloth to clean the instrument. Never use wet cloths, solvents, water, etc.
10.3. END OF LIFE
CAUTION: the symbol on the instrument indicates that the appliance and its
accessories must be collected separately and correctly disposed of.