HT Instruments XL421 User manual

Copyright HT ITALIA 2021 Release EN 2.01 - 17/12/2021
ENGLISH
User manual

XL421 - XL422
EN - 1
TABLE OF CONTENTS
1.SAFETY PRECAUTIONS AND PROCEDURES .............................................................2
1.1Preliminary instructions ......................................................................................................... 2
1.2During use ............................................................................................................................. 3
1.3After use ................................................................................................................................ 3
1.4Measurement categories - definitions ................................................................................... 3
2GENERAL DESCRIPTION ..............................................................................................4
2.1Introduction............................................................................................................................ 4
2.2Functions............................................................................................................................... 4
3PREPARATION FOR USE ..............................................................................................5
3.1Preliminary checks ................................................................................................................ 5
3.2Power supply......................................................................................................................... 5
3.3Storage.................................................................................................................................. 5
4INSTRUMENT DESCRIPTION........................................................................................6
4.1Keyboard ............................................................................................................................... 6
5INITIAL SETTINGS .........................................................................................................6
5.1Date, Time and Measuring Interval ....................................................................................... 6
6OPERATIVE INSTRUCTIONS ........................................................................................7
6.1Using the instrument in a Single Phase system .................................................................... 7
6.2Using the instrument in a Three Phase system..................................................................... 9
7LED MESSAGES DESCRIPTION .................................................................................11
8CONNECTION OF INSTRUMENT TO PC ....................................................................11
9MAINTENANCE ............................................................................................................12
9.1General information............................................................................................................. 12
9.2Battery replacement ............................................................................................................ 12
9.3Cleaning .............................................................................................................................. 12
9.4End of life ............................................................................................................................ 12
10TECHNICAL SPECIFICATIONS ...................................................................................13
10.1Characteristics..................................................................................................................... 13
10.1.1Reference guidelines .................................................................................................................. 13
10.1.2General data ............................................................................................................................... 13
10.2Environmental conditions .................................................................................................... 13
10.2.1Climatic conditions ...................................................................................................................... 13
10.3Accessories ......................................................................................................................... 14
10.3.1Standard accessories.................................................................................................................. 14
10.3.2Optional accessories................................................................................................................... 14
11SERVICE.......................................................................................................................15
11.1Warranty conditions............................................................................................................. 15
11.2After-sale service................................................................................................................. 15

XL421 - XL422
EN - 2
1. SAFETY PRECAUTIONS AND PROCEDURES
This instrument has been designed in compliance with IEC/EN61010-1 directive. For your
own safety and to avoid damaging the instrument we suggest you follow the procedures
hereby prescribed and to read carefully all the notes preceded by the symbol .
CAUTION
Should you fail to keep to the prescribed instructions you could damage the
instrument and/or its components or endanger your safety.
Take extreme care of the following conditions while taking measurements:
Do not perform any measurement in humid or wet environments.
Do not use the instrument in presence of explosive gas (material), combustible gas
(material), steam or dust.
Do not touch the circuit under test if no measurement is being taken.
Do not use the instrument if it seems to be malfunctioning (i.e. if you notice
deformations, breaks, leakage of substances and so on).
The herewith symbols are used:
Caution: refer to the instruction manual; an improper use may damage the
instrument or its components
Danger high voltage: risk of electrical shocks
De-energize the plant under test before connecting the instrument
Double insulated instrument
AC voltage and current
1.1 PRELIMINARY INSTRUCTIONS
It can be used for CURRENT measurements up to 2500A on installations with
overvoltage category CAT III 1000Vto ground or CAT IV 600Vto ground.
Please use the standard safety precautions aimed at protection against dangerous
electric currents and protect the instrument against incorrect operations
Do not test circuits exceeding the current and voltage limits.
De-energize the plant under test before connecting the instrument. Take all the safety
precautions before taking actions on the plant.
Do not perform any test under environmental conditions exceeding the limits indicated
in this manual (see § 10.2).
Make sure that batteries are correctly installed.
Only the accessories supplied with the instrument guarantee compliance with the
safety standards. They must be in good conditions and must be replaced, if necessary,
with identical models.

XL421 - XL422
EN - 3
1.2 DURING USE
Carefully read the following recommendations and instructions:
CAUTION
Non compliance with warnings and/or instructions may cause damage to
the tester or its components or injure the operator.
During a current measurement keep the clamp as far as possible from cables not
involved in measurement.
During a current measurement keep the cable under test in the very middle of the jaws.
1.3 AFTER USE
If you expect not to use the instrument for a long period of time remove the batteries
and strictly follow the indications at § 9.2.
1.4 MEASUREMENT CATEGORIES - DEFINITIONS
The IEC/EN61010-1 guideline (Safety requirements for electrical equipment for
measurement, control and laboratory use, Part 1: General requirements) defines what a
measurement category (usually called “overvoltage category”) is. At § 6.7.4: Measuring
circuits it says:
(OMISSIS)
Circuits are divided into the following measurement categories:
Measurement category IV is for measurements performed at the source of low
voltage installations
Examples are electricity instruments and measurements on primary overcurrent protection
devices and ripple control units.
Measurement category III is for measurements performed in the building installation.
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 norm requires that the transient withstand capability of the equipment is made
known to the user.

XL421 - XL422
EN - 4
2 GENERAL DESCRIPTION
2.1 INTRODUCTION
The instrument was designed to grant the user the utmost safety conditions thanks to a
new concept assuring double insulation and overvoltage CAT III 1000Vto ground or CAT
IV 600Vto ground.
2.2 FUNCTIONS
This manual is referred to two models: XL421 and XL422. XL421 can recording a single
Current in single phase or three phase plant. XL422 can recording up to 3 Currents
simultaneously in single phase or three phase plant.
Where not expressly indicated the characteristics are common for both models.
The instrument can monitoring a plant for a long time thanks to a sophisticated memory-
managing algorithm. More exactly, the instrument uses the following sampling periods:
Measuring Interval XL421 – Autonomy (days) XL422 – Autonomy (days)
1s 5 1.5
6s 34 8
30s 170 42
1min 364 (*) 91
5min 1820 (*) 455 (*)
(*) Depending on batteries autonomy
The instrument starts each recording using the Measuring Interval set through PC
management software (see § 8). Just before the event of full memory, the instrument
applies the successive measuring Interval to all the memory, thus getting more free
memory locations. The instrument continues the data storing according to the new
Measuring Interval.

XL421 - XL422
EN - 5
3 PREPARATION FOR USE
3.1 PRELIMINARY CHECKS
This instrument has been checked mechanically and electrically before shipment. All
precautions have been taken to assure that the instrument reaches you in perfect
condition. However, it is advisable to carry out a rapid check in order to detect any
possible damage, which might have occurred in transit. Check the accessories contained
in the packaging to make sure they are the same as reported in § 11.
3.2 POWER SUPPLY
The instrument is powered by 2x1.5V type AA LR06 alkaline batteries. For battery fitting
operation procedure please see § 9.2.
CAUTION
The instrument, after fitted batteries, is always continuously ON also if
STATUS and ALARM LED are OFF. Pressing of START/STOP key activate
or disable recordings only.
During a recording the blinking ALARM LED every 3 seconds means a low
battery status.
3.3 STORAGE
In order to guarantee the accuracy of the measurements, after a period of storage in
extreme environmental conditions wait for the instrument to stabilize to within the listed
operating conditions (see § 10.2.1).

XL421 - XL422
EN - 6
4 INSTRUMENT DESCRIPTION
CAPTION:
1. Flexible head
2. “STATUS" LED
3. "ALARM" LED
4. RS232 port
5. "START/STOP" key
6. Press here to open
the head
Fig. 1: Instrument description
4.1 KEYBOARD
LED “STATUS” blinks every time the START/STOP key is pressed.
5 INITIAL SETTINGS
5.1 DATE, TIME AND MEASURING INTERVAL
It’s possible to set measuring interval as well as date and time by using the management
software. This program allows to:
Set the Measuring Interval.
Control data and time of the instrument’s internal clock.
Set instrument date and time.
Check battery status.
How to operate:
1. Connect the instrument to PC COM using included serial cable.
2. Run TopView software and open the “PC-Instrument Connection” section
3. Perform the detection of the instrument by using the “Find the instrument” or
“Autoset” keys
4. Select the “Configure the instrument” command and press the “Next” key in order to
set date/time in the instrument and the measurement interval in the “Integrated
Period” field selecting values 1s, 6s, 30s, 1min or 5min
5. Confirm with “Send” command
CAUTION
The instrument could keep the data stored even without batteries. The set date
and time don’t get lost provided that the battery replacement takes less than 2
minutes.

XL421 - XL422
EN - 7
6 OPERATIVE INSTRUCTIONS
6.1 USING THE INSTRUMENT IN A SINGLE PHASE SYSTEM
CAUTION
The measurement category is CAT III 1000Vto ground or CAT IV 600Vto
ground. Do not attempt to take any voltage measurements exceeding the
limits indicated in this manual. Exceeding the limits could cause electrical
shock or damage to the instrument.
Fig. 2: Instrument’s connection in Single Phase system
CAUTION
If possible de-energize the plant under test before connecting the instrument.
Take all the safety precautions before taking actions on the plant.
1. De-energize the plant under test before connecting the instrument.
2. Open the flexible head by pressing on expected points (see Fig. 1).
3. Clamp the cable under measurement with the head and close it.
4. To increase the reading accuracy the clamped cable must be in the middle of the head.
5. Re-energize the plant under test.
6. How to start a Recording:
If no recording was performed or if the recording data was already downloaded to a
PC, pressing and keeping the START/STOP key for 3 seconds. The STATUS LED
will be lighting for the same time, than will be stable lighting for 1 second and the
instrument will start the recording
If the recording data was not already downloaded to a PC but the operator wants
to overwrite these data, pressing and keeping the START/STOP key for 6
seconds. The STATUS LED will be quickly blinking during the key pressing for the
same time, than the LED will be stable lighting for 1 second and the instrument will
start the recording. The old recording will be deleted and overwritten by the new
one. The instrument will wait for the next minute beginning (second=00) and the
STATUS LED is double blinking. After that the recording starts and the STATUS
LED blinks every 3 seconds. The instrument is storing the data.

XL421 - XL422
EN - 8
7. During a Recording:
A STATUS LED 3 seconds blinking meaning that the recording is active and the
instrument is storing the data.
An ALARM LED 3 seconds blinking means that the batteries are low. During a
recording any RS232 communication is possible.
During Recording operations RS-232 serial communications to PC is not
possible.
8. Stop a Recording:
To stop a Recording pressing START/STOP key and keep it pressed for 3 seconds.
The STATUS LED will quickly blinks three times and the instrument will stop the
recording, then stop blinking.
For more details about the blinks of STATUS and ALARM LED meaning, please refer to
the § 7.

XL421 - XL422
EN - 9
6.2 USING THE INSTRUMENT IN A THREE PHASE SYSTEM
CAUTION
The measurement category is CAT III 1000Vto ground or CAT IV 600Vto
ground. Do not attempt to take any voltage measurements exceeding the
limits indicated in this manual. Exceeding the limits could cause electrical
shock or damage to the instrument.
Fig. 3: Instrument’s connection in Three Phase system
CAUTION
If possible de-energize the plant under test before connecting the instrument.
Take all the safety precautions before taking actions on the plant.
1. De-energize the plant under test before connecting the instrument.
2. Open the flexible heads by pressing on expected points (see Fig. 1).
3. Clamp the cables under measurement with the heads and close it.
4. To increase the reading accuracy the clamped cable must be in the middle of the head.
5. Re-energize the plant under test.
6. How to start a Recording:
If no recording was performed or if the recording data was already downloaded to a
PC, pressing and keeping the START/STOP key for 3 seconds. The STATUS LED
will be lighting for the same time, than will be stable lighting for 1 second and the
instrument will start the recording
If the recording data was not already downloaded to a PC but the operator wants
to overwrite these data, pressing and keeping the START/STOP key for 6
seconds. The STATUS LED will be quickly blinking during the key pressing for the
same time, than the LED will be stable lighting for 1 second and the instrument will
start the recording. The old recording will be deleted and overwritten by the new
one. The instrument will wait for the next minute beginning (second=00) and the
STATUS LED is double blinking. After that the recording starts and the STATUS
LED blinks every 3 seconds. The instrument is storing the data.