HT HT2055 User manual

Copyright HT ITALIA 2020 Release EN 2.03 - 11/11/2020
ENGLISH
User manual

HT2055
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Instrument features ............................................................................................................................. 4
3PREPARATION FOR USE .......................................................................................................... 5
3.1Initial inspections .................................................................................................................................. 5
3.2Instrument power supply ...................................................................................................................... 5
3.3Storage................................................................................................................................................. 5
4DESCRIPTION OF PARTS.......................................................................................................... 6
4.1HT2055S station unit description ......................................................................................................... 6
4.1.1Modify of supply voltage for HT2055S unit........................................................................................ 6
4.2Description of test leads ....................................................................................................................... 7
4.2.1Front view.......................................................................................................................................... 7
4.2.2Top view ............................................................................................................................................ 7
4.2.3Backside view.................................................................................................................................... 8
5INITIAL OPERATIONS WITH HT2055M UNIT............................................................................ 9
5.1Settings................................................................................................................................................. 9
5.1.1Language selection ........................................................................................................................... 9
5.1.2Help screen ....................................................................................................................................... 9
5.1.3Synchronization............................................................................................................................... 10
5.1.4Default settings................................................................................................................................ 11
5.1.5Time/Date settings .......................................................................................................................... 11
5.2Messages at display........................................................................................................................... 11
6INITIAL OPERATIONS WITH HT2055S UNIT .......................................................................... 12
6.1Settings............................................................................................................................................... 12
6.1.1Default settings................................................................................................................................ 12
6.1.2Setting output power ....................................................................................................................... 13
6.1.3Setting alarm condition.................................................................................................................... 13
6.2Adjust contrast of display ................................................................................................................... 14
6.3Help screens ...................................................................................................................................... 14
6.4Messages at display........................................................................................................................... 14
7HOW TO PERFORM THE MEASUREMENTS.......................................................................... 15
7.1Theory of Step/Contact voltage measurements................................................................................. 15
7.2Step/Contact voltage measurement................................................................................................... 16
7.3Earth resistance measurement .......................................................................................................... 21
7.4Ground resistivity measurement ........................................................................................................ 23
8OPERATION WITH MEMORY................................................................................................... 25
8.1Saving results..................................................................................................................................... 26
8.2Recall result at display ....................................................................................................................... 26
8.3Delete saved results........................................................................................................................... 27
9CONNECTION OF THE INSTRUMENT TO PC ........................................................................ 28
9.1Installation of software and initial configurations (Win XP) ................................................................ 28
10MAINTENANCE......................................................................................................................... 30
10.1Replacement and charging batteries ................................................................................................. 30
10.2Replacement fuses of HT2055S unit ................................................................................................. 30
10.3Cleaning the instrument ..................................................................................................................... 30
10.4End of life............................................................................................................................................ 30
11TECHNICAL SPECIFICATIONS ............................................................................................... 31
11.1General characteristics....................................................................................................................... 32
11.2Environment ....................................................................................................................................... 33
11.3Standard accessories......................................................................................................................... 33
11.4Optional accessories .......................................................................................................................... 33
12SERVICE ................................................................................................................................... 34
12.1Warranty conditions............................................................................................................................ 34
12.2Service................................................................................................................................................ 34

HT2055
EN - 2
1 PRECAUTIONS AND SAFETY MEASURES
The instrument has been designed in compliance with standards IEC/EN61557-1 and
IEC/EN61010-1 regarding electronic measuring instruments.
CAUTION
For the operator’s safety and to prevent damaging the instrument, follow the
procedures described in this manual and carefully read all notes preceded by
the symbol .
Before and during measurements, carefully observe the following instructions:
Do not perform any measurement in humid environments, in the presence of gas or
explosive or inflammable material or in dusty areas
Even when no measurements are being performed, avoid any contact with the circuit
under test, with exposed metal parts, with unused measuring leads or circuits, etc.
Do not perform any measurement when anomalies are found in the instrument, such as
deformations, breaks, substance leaks, no display view, etc.
During instrument operation, the ventilation holes on casing of HT2055S unit should
always stay open to ensure enough air-flow for cooling
Disconnect all test leads, switch off the instrument and remove the mains cord before
changing the fuse on the HT2055S unit
Pay special attention when measuring voltages above 25V in special environments
(building yards, swimming pools, etc.) and 50V in ordinary environments, as there is
danger of electric shocks.
In this manual and on the instrument, the following symbols are used:
WARNING: Observe the instructions reported in the manual. An improper use
could damage the instrument and lead to dangerous situations for the operator.
AC voltage or current.
Instrument with double insulation.
1.1 PRELIMINARY INSTRUCTIONS
This instrument (HT2055M) has been designed for use in an environment with pollution
level 2
It may also be used to test industrial electrical systems up to CAT II 300V and CAT IV
50V to earth (HT2055S) and CAT IV 50V (HT2055M)
Follow the usual safety rules to protect the operator from dangerous currents and
protect the instrument against improper use
Never use the instrument standing on the floor, it must be placed on flat horizontal
surfaces
Only the accessories supplied with the instrument guarantee safety standards. They
must be in good conditions and replaced, if necessary, with identical models
Do not measure systems exceeding the current and voltage limit values specified
Do not perform measurements under environmental conditions out of the limit values
indicated in this manual
Before connecting the probes to the circuit under test, check that the correct function is
selected

HT2055
EN - 3
1.2 DURING USE
Carefully read the following recommendations and instructions:
CAUTION
Failure to observe the warnings and/or instructions may damage the
instrument and/or its components or generate a danger for the operator
Before selecting a new function, disconnect the measuring probes from the circuit
When the instrument is connected to the circuit under test, never touch any unused
lead
The auxiliary current probe can be subject to a higher voltage. Avoid the contact with
this probe during measurement
Avoid measuring resistance with external voltages. Even if the instrument is protected,
as an excess voltage may cause instrument malfunctions
1.3 AFTER USE
When measurements are completed, turn off the instrument by pressing the ON/OFF key.
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 is intended for
measurement category, commonly known as overvoltage category. In § 6.7.4: Measuring
circuits, it reads:
Circuits are divided into the following measurement categories:
Measurement category IV is for measurements performed at the source of a low-
voltage installation.
Examples are electric counters and measurements on primary devices protecting
against overcurrents and on ripple adjusting units.
Measurement category III is for measurements performed on installations inside
buildings.
Examples are measurements performed on distribution boards, circuit breakers, wiring
harnesses, including cables, bars, junction boxes, switches, sockets of fixed
installations and appliances designed for industrial use and other equipment, e.g.
stationary motors connected to fixed systems.
Measurement category II is for measurements performed on circuits directly
connected to the low-voltage installation.
Examples are measurements performed on household appliances, portable tools and
similar equipment.
Measurement category I is for measurements performed on circuits not directly
connected to the MAINS.
Examples are measurements performed on circuits not derived from the MAINS and on
circuits derived from the MAINS provided with a special (internal) protection. In this
latter case, the stress caused by the transients is variable; therefore, (OMISSIS) it is
necessary that the user knows the appliance’s resistance to transients.

HT2055
EN - 4
2 GENERAL DESCRIPTION
The instrument HT2055 you purchased grants accurate and reliable measurements as
well as the utmost safety provided it is used in compliance with the indications given in this
manual. Thanks to a new concept development it ensures double insulation and,
consequently, compliance with the requirements of overvoltage category IV.
The instrument is composed of the following two units:
HT2055S Station unit which can generate the test current in order to perform the
step/contact voltage and the earth/resistivity measurements
HT2055M Meter unit in order to perform the step/contact voltage measurements with
test current generated by the station unit.
2.1 INSTRUMENT FEATURES
Step/contact voltage measurement with test current of max 55A
Earth resistance measurement with 4 wire method
Ground resistivity measurement with Wenner method
Use of metal plates for step/contact voltage measurement
Initial synchronizing for autonomous use of the meter unit
DSP internal filtering for compensation of disturbance effect on the measurement
Internal memory for saving test
USB interface for data transfer to PC
Use of rechargeable batteries on meter unit
A dot matrix LCD offers easy-to-read results and all associated parameters. The operation
is straightforward and clear to enable the user to operate the instrument without the need
for special training (except reading and understanding this user manual).
Test results can be stored on the instrument. The new professional PC SW enables
straightforward transfer of test results and other parameters in both directions between the
test instrument and PC

HT2055
EN - 5
3 PREPARATION FOR USE
3.1 INITIAL INSPECTIONS
Before shipment, the instrument’s electronics and mechanics were inspected. All possible
precautions were taken to permit delivery of instrument free of damage. However, we
recommend generally inspecting the instrument in order to detect any damage suffered
during transport. Should you detect any anomalies, immediately contact the forwarding
agent or the dealer. Moreover, we recommend checking that the package contains all
parts listed in § 11.3. Should you find any discrepancy, please contact the dealer. Should it
be necessary to return the instrument, please follow the instructions reported in § 12.
3.2 INSTRUMENT POWER SUPPLY
The station unit HT2055S is power-supplied by 230V ± 10%, 50/60Hz mains while the
meter unit HT2055M is power-supplied through 6x1.2V IEC AA internal rechargeable
batteries which are recharged from the mains by means of a battery charger supplied as
standard accessory. The use of 6x1.5V type AA LR6 alkaline batteries is also possible for
this unit. The symbol “ “ indicates that the batteries are low and must be recharged.
To recharge or replace the batteries, follow the instructions given in § 10.1
CAUTION
Use NiMh rechargeable batteries IEC LR6 all of the same type for the
HT2055M unit
Do not charge alkaline battery cells

A
t the first use of HT2055M unit connect the instrument to the mains power
supply for at least 14 hours to fully charge batteries. When you charge the
batteries for the first time, it normally takes about 4 charge and discharge
cycles for the batteries to regain full capacity
3.3 STORAGE
In order to guarantee accurate measurements and protect the instrument from possible
failures, after a long storage period under extreme environmental conditions, wait for the
instrument to return to a normal condition (see the environmental specifications listed in §
11.2).

HT2055
EN - 6
4 DESCRIPTION OF PARTS
4.1 HT2055S STATION UNIT DESCRIPTION
Fig. 1: HT2055S unit description
CAPTION:
1 Protection fuse on mains (see § 11.1)
2 Switch for supply voltage selection (110/230V)
3 ON/OFF key to switch the instrument ON or OFF
4 Input connector for mains cord
5 RS-232 galvanic port for connection to HT2055M unit
6 C1/H terminal for connection of auxiliary earth probe
7 P1/S for connection of auxiliary voltage probe
8 P2/ES for connection of auxiliary current probe
9 C2/E for connection of auxiliary earth probe
10 HELP key
11 – 12 and keys for function selection and parameter settings
13 LCD display with backlit
14 Key for adjust contrast of display
15 MEM key for access to internal memory (see § 8)
16 ESC key to return at previous screen
17 , , , arrow keys and TEST key to activation measurements
4.1.1 Modify of supply voltage for HT2055S unit
1. Open the fuses compartment (see Fig. 1 – Part 1) with a screwdriver
2. Extract the red switch (see Fig. 1 – Part 2) from the fuses compartment
3. Rotate the switch in way to correctly read the “115V” or “230V” indication
correspondent to the desired supply voltage
4. Restore the switch in the fuses compartment and close it

HT2055
EN - 7
4.2 DESCRIPTION OF TEST LEADS
4.2.1 Front view
Fig. 2: HT2055M unit front view description
CAPTION:
1 ESC key to return at previous screen
2 MEM key for access to internal memory (see § 8)
3 , , , arrow keys and TEST key to activation measurements
4 Backlight key
5 LCD display
6 ON/OFF key to switch the instrument ON or OFF
7 - 8 and keys for function selection and parameter settings
4.2.2 Top view
Fig. 3: HT2055M unit top view description
CAPTION:
1
Test connector.
CAUTION: maximal allowed voltage between test terminals and ground is
50V. Maximal allowed voltage between test terminals is 100V
2 Power supply socket
3 PS/2 connector (for RS232 communication)
4 Protection cover
5 USB connection

HT2055
EN - 8
4.2.3 Backside view
Fig. 4: HT2055M unit backside view description
CAPTION:
1 Battery compartment cover
2 Safety information label
3 Fixing screws for battery compartment cover
Fig. 5: HT2055M battery compartment description
CAPTION:
4 Serial number label
5 Battery cells (6x1.2V NiMH type AA)
6 Battery compartment

HT2055
EN - 9
5 INITIAL OPERATIONS WITH HT2055M UNIT
Press the or function keys to display the below screens relative to the Step
Voltage, Contact Voltage and Settings (see Fig. 6)
Fig. 6: Screens of general menu
5.1 SETTINGS
The below operations are possible within Settings menu:
Language selection
Help screens on connections
Syncronizing with the station unit HT2055S
Restore of default conditions
Recall at display of saved results (see § 8.2) and clear memory (see § 8.3)
Setting of system time/date
5.1.1 Language selection
Fig. 7: Screen of language selection
1. Press or keys to enter Settings menu
2. Select the item “Select Language” with the or keys and press TEST key
3. Select the desired language with the or keys and confirm with TEST key
4. Press ESC key to exit and go back to the previous screen
5.1.2 Help screen
Fig. 8: Help screen
1. Press or keys to enter Settings menu
2. Select the item “Help” with the or keys and press TEST key
3. Select the desired help screen with the or keys
4. Press ESC key to exit and go back to the previous screen