HT Neptune User manual

Copyright HT ITALIA 2018 Release EN 1.00 - 31/10/2018
ENGLISH
User manual

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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 andTRMS 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.Storage.............................................................................................................................. 5
4.NOMENCLATURE........................................................................................................6
4.1.Description of the instrument............................................................................................. 6
4.1.1.Instrument’s initial screen ........................................................................................................... 6
4.2.Description of function keys .............................................................................................. 7
4.2.1.Key GO/HOLD............................................................................................................................ 7
4.2.2.Key H/H%/H ............................................................................................................................ 7
4.2.3.Key MODE/MXMNPK................................................................................................................. 8
4.2.4.Keys /e / ZERO .............................................................................................................. 8
4.2.5.Key VTEST/LIM.......................................................................................................................... 8
4.2.6.LoZ function................................................................................................................................ 9
4.2.7.AC+DC function.......................................................................................................................... 9
4.2.8.Inrush current function (INRUSH) .............................................................................................. 9
4.2.9.Disabling the Auto Power Off function........................................................................................ 9
4.2.10.Setting the full scale for flexible clamp transducer ................................................................... 10
5.OPERATING INSTRUCTIONS...................................................................................11
5.1.DC voltage measurement................................................................................................ 11
5.2.AC, AC+DC voltage measurement ................................................................................. 12
5.3.AC, DC, AC+DC voltage with low impedance (LoZ) ....................................................... 13
5.4.Resistance measurement and continuity test.................................................................. 14
5.5.Phase sequence and phase concordance with 1 terminal.............................................. 15
5.6.Measurement of insulation resistance............................................................................. 17
5.7.Continuity of protective conductors with 200mA ............................................................. 23
5.7.1.Function ZERO – Zeroing of test cable resistance................................................................... 27
5.8.Measurement of DC, AC, AC+DC, INRUSH current with clamp transducers ................. 29
6.MAINTENANCE .........................................................................................................33
6.1.Battery replacement ........................................................................................................ 33
6.2.Cleaning the instrument .................................................................................................. 33
6.3.End of life ........................................................................................................................ 33
7.TECHNICAL SPECIFICATIONS ................................................................................34
7.1.Technical characteristics ................................................................................................. 34
7.1.1.General characteristics............................................................................................................. 36
7.2.Environmental conditions for use .................................................................................... 36
7.3.Accessories..................................................................................................................... 36
8.ASSISTANCE.............................................................................................................37
8.1.Warranty conditions......................................................................................................... 37
8.2.Assistance....................................................................................................................... 37
9.THEORETICAL APPENDIXES...................................................................................38
9.1.Continuity of protective conductors ................................................................................. 38
9.2.Measurement of insulation resistance............................................................................. 39
9.2.1.Polarization Index (PI) .............................................................................................................. 42
9.2.2.Dielectric Absorption Ratio (DAR) ............................................................................................ 42
9.3.Voltage and current harmonics ....................................................................................... 43

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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 symbol with the utmost attention.
Before and after carrying out measurements, carefully observe the following instructions:
Do not carry out any 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 contact with exposed metal parts, with unused measuring probes, 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.
Pay special attention when measuring voltages higher than 50V, since a risk of
electrical shock exists.
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
DC voltage or current
Connection to earth
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 CAT
IV 600V, CAT III 1000V to earth and between inputs.
We recommend following the normal 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.
In case the lack of indication of the presence of voltage may represent a danger for the
operator, always carry out a continuity measurement before carrying out the
measurement on the live system, in order to confirm the correct connection and
condition of the leads.
Only the leads supplied with the instrument guarantee compliance with the safety
standards. They must be in good conditions. If necessary, only replace them with
original HT accessories.
Do not test circuits exceeding the specified voltage limits.
Do not perform any test under environmental conditions exceeding the limits indicated
in § 6.2.1
Check that the battery is correctly inserted.
Make sure that the LCD display and the rotary switch indicate the same function.

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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 rotary switch, disconnect the test leads from the circuit being
measured.
When the instrument is connected to the circuit being measured, do not touch any
unused terminal.
During current measurement, any other current near the clamps 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.
Do not measure resistance in case external voltages are present; even if the
instrument is protected, an excessive voltage may cause malfunction.
Before attempting any resistance measurement, cut off power supply from the circuit to
be measured and make sure that all capacitors are discharged, if present.
While measuring, if the value or the sign of the quantity being measured remain
unchanged, check if the HOLD function is enabled.
1.3. AFTER USE
When measurement is complete, set the rotary switch to OFF
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 what measurement
category, commonly called overvoltage category, is. § 6.7.4 reads: 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.

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2. GENERAL DESCRIPTION
The instrument carries out the following measurements:
DC / AC, AC+DC TRMS voltage
DC / AC / AC+DC TRMS voltage with low impedance (LoZ)
DC / AC / AC+DC TRMS current with standard clamp transducer
AC TRMS current with flexible clamp transducers
Automatic recognition of AC and DC quantities
Inrush current (Dynamic INRUSH - DIRC)
Current/voltage harmonics up to the 25th and THD% calculation
Resistance and Continuity test
Current and voltage frequency
Insulation resistance with test voltage 50,100,250,500,1000VDC
Measurement of Polarization Index (PI) and Dielectric Absorption Ratio (DAR)
Continuity of protective conductor with 200mA
Phase sequence with 1 terminal
Each of these functions can be selected by means of the appropriate switch. The
instrument is also equipped with function keys (see § 4.2), an analogue bargraph and
backlight. The instrument is also equipped with an Auto Power OFF function (which can be
disabled), which automatically switches off the instrument 15 minutes after the last time a
function key was pressed or the rotary switch was turned. To switch on the instrument
again, turn the rotary switch.
2.1. MEASURING AVERAGE VALUES ANDTRMS VALUES
Measuring instruments of alternating quantities are divided into two big families:
AVERAGE-VALUE meters: instruments measuring the value of the sole wave at
fundamental frequency (50 or 60 Hz).
TRMS (True Root Mean Square) VALUE meters: instruments measuring the TRMS
value of the quantity being tested.
With a perfectly sinusoidal wave, the two families of instruments provide identical results.
With distorted waves, instead, the readings shall differ. Average-value meters provide the
RMS value of the sole fundamental wave; TRMS meters, instead, provide the RMS value
of the whole wave, including harmonics (within the instruments bandwidth). Therefore, by
measuring the same quantity with instruments from both families, the values obtained are
identical only if the wave is perfectly sinusoidal. In case it is distorted, TRMS meters shall
provide higher values than the values read by average-value meters.
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 1A intensity, circulating on a
resistor, dissipates the same energy that, during the same time, would be dissipated by a
direct current with an intensity of 1A". 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.

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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 §
6.3.1. In case of discrepancy, please contact the Dealer.
In case the instrument should be returned, please follow the instructions given in § 7.
3.2. INSTRUMENT POWER SUPPLY
The instrument is supplied with 4x1.5V alkaline batteries type AAA IEC LR03, included in
the package. When batteries are flat, the symbol “” is shown on the display. To replace
the batteries, see § 6.1.
3.3. STORAGE
In order to guarantee precise measurement, after a long storage time, wait for the
instrument to come back to normal condition (see § 6.2.1).

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4. NOMENCLATURE
4.1. DESCRIPTION OF THE INSTRUMENT
CAPTION:
1. LCD display
2. Key / ZERO
3. Key/
4. Key MODE/MXMNPK
5. Key H/H%/H
6. Key VTEST/LIM
7. Key GO/HOLD
8. Rotary selector switch
9. Input terminal COM/
10.Input terminal V/+
Fig. 1: Description of the instrument
4.1.1. Instrument’s initial screen
1. Turn the rotary switch to any position to switch on the instrument. The following initial
screen is shown on the display for a few seconds to identify the internal Hardware and
Firmware version.
Fig. 2: Instrument’s initial screen
2. Turn the rotary switch to OFF to switch off the instrument.

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4.2. DESCRIPTION OF FUNCTION KEYS
4.2.1. Key GO/HOLD
Pressing the key GO/HOLD (for functions V, LoZV , and ) makes the instrument
hold the value of the quantity shown on the display. The message “HOLD” appears on the
display. Press the key again to exit the function. Pressing key GO/HOLD (for functions
M, Lo, , IRC) activates the corresponding measurement.
4.2.2. Key H/H%/H
Key H/H%/H (active in positions V, LoZV and ) allows the following operations:
Simple pressing of the key to display the amplitude of voltage and current harmonics
up to the 25th (Hdc, H01… H25) in absolute or percentage format in relationship with
the fundamentals of input signals (for voltage values VAC >0.5V and current values AC
> 0.5A and frequency in the range 42.5Hz ÷ 69Hz) and the percentage value of
parameter THD% (see § 9.3) as shown in Fig. 3. Use keys /ZERO and /to
increase/decrease the order of the harmonic.
Fig. 3: Display of amplitude of harmonic analysis
Long pressing of the key (at least 2s) in order to activate the H2O (Higher Harmonic
Ordering) ordering function of the amplitude of harmonics. In these conditions, function
“HOLD” is automatically activated and symbol “o” appears next to the displayed
harmonic order to indicate that the Ordering function is activated. The bargraph is
disabled and the instrument shows the value of amplitude of all the harmonics between
the DC value and the 25th, fundamental harmonic excluded, in a decreasing order
starting from the harmonic with the highest amplitude, as shown in Fig. 4
Fig. 4: Display of ordering of amplitude of harmonic analysis
In the example in Fig. 4, the harmonic with the highest value corresponds to the 7th.
Press key to observe the amplitude of the remaining harmonics and press key
H/H%/H again to switch between display in absolute and percentage values. Turn
the rotary switch to exit the function.

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4.2.3. Key MODE/MXMNPK
A simple pressing of key MODE/MXMNPK allows for the following operations:
Selection of measuring modes “AUTO”, “AC”, “DC”, “AC+DC” and “FREQ” in positions
V, LoZV
Selection of measuring modes “AUTO”, “AC”, “DC” and “AC+DC”, “FREQ” and “IRC”
(see § 4.2.8) in position
Selection of clamp transducer type in current measurement between options “”
(optional standard clamp) and “ ” (optional flexible clamp) in position
Selection of measurements “AUTO” “TMR” and “PI” in position M(see § 5.6).
Selection of measurements “AUTO” and “TMR” in position Lo(see § 5.7).
Selection of measurement of Resistance “” or Continuity test “” in position 
A long pressing (>2s) of key MODE/MXMNPK allows for the activation/deactivation of
continuous detection of maximum value (MAX), minimum value (MIN), positive peak (Pk+),
negative peak (Pk-) of the quantity (voltage or current) to be measured. The values are
constantly updated and are displayed cyclically every time the same key is pressed. This
function is not active in position . Press and hold key MODE/MXMNPK (>2s) or use the
selector to exit the function.
4.2.4. Keys /e / ZERO
A simple pressing of keys /and / ZERO allows for the following operations::
Setting of the full scale value of flexible clamp transducer (optional accessory - option
“” ) in position among values: 30A, 300A, 3000A for AC current measurement.
Setting of the full scale value of standard clamp transducer (option “” ) in position
among values: 1A, 10A, 30A, 40A, 100A, 200A, 300A, 400A, 1000A, 2000A, 3000A
for AC and DC current measurement.
Selection of harmonic order “DC ÷ 25°” in positions V, LoZV and
Selection of calculation time of RMS value in DIRC function (see § 4.2.8).
Setting of threshold values in positions Mand Lo.
Once insulation measurement is complete, the results appear on the display (M,
Vgen, PI, DAR).
Long pressing (>2s) of key /allows activating/deactivating display backlight. This
function is activated in any position of the rotary switch and is automatically deactivated
after approx. 2 minutes’ idling. Long pressing (>2s) of key / ZERO allows for the
following operations:
Zeroing of cable resistance in position Lo(see § 5.7)
Zeroing of cable resistance in position (see § 5.4)
4.2.5. Key VTEST/LIM
A simple pressing of key VTEST/LIM allows for the following operations:
Selecting test voltage in insulation measurement among the following options: 50V,
100V, 250V, 500V, 1000VDC in position M
Long pressing (>2s) of key VTEST/LIM allows for the following operations:
Setting the minimum threshold in insulation measurement among the following options:
no (no threshold), 0.10M, 0.230M, 0.50M, 1.00M, 100Min position M.
Setting the maximum threshold for continuity test in range: 0.05÷ 9.99in position
Lo.