HT Italia IMP57 User manual

Copyright HT ITALIA 2013 Version EN 3.00 - 04/01/2013
ENGLISH
User’s manual

IMP57
EN - 1
Contents:
1.SAFETY PRECAUTIONS AND PROCEDURES.................................................................................... 2
1.1.Preliminary Instruction ............................................................................................................................................................................................. 2
1.2.During use................................................................................................................................................................................................................. 3
1.3.After use..................................................................................................................................................................................................................... 3
1.4.Definition of measuring (overvoltage) category ................................................................................................................................................... 3
2.GENERAL DESCRIPTION ..................................................................................................................... 4
3.PREPARATION FOR USE ..................................................................................................................... 5
3.1.Initial Control.............................................................................................................................................................................................................. 5
3.2.Power Supply ........................................................................................................................................................................................................... 5
3.3.Calibration.................................................................................................................................................................................................................. 5
3.4.Storage ...................................................................................................................................................................................................................... 5
4.INSTRUMENT DESCRIPTION ............................................................................................................... 6
4.1.Instrument description ............................................................................................................................................................................................. 6
4.1.1.STATUS LED ...................................................................................................................................................................... 6
4.2.Instrument's commands ......................................................................................................................................................................................... 6
5.OPERATING INSTRUCTIONS ............................................................................................................... 8
5.1.Phase to Phase impedance measurement and Phase To Phase-Three-Phase Prospective Short Circuit Current Calculation......... 8
5.2.Phase to Neutral impedance measurement and Phase To Neutral Prospective Short Circuit Current Calculation............................... 9
5.3.Phase To Pe (Protection Conductor) impedance measurement and Phase to Pe Prospective Short Circuit Current Calculation ... 10
6.MASTER INSTRUMENT SETTINGS.................................................................................................... 11
6.1.Operating Instrument for “TYPE 1” Instrument ................................................................................................................................................. 11
6.1.1.Instrument Settings ........................................................................................................................................................... 11
6.1.2.Prospective Short Circuit Current Calculation ................................................................................................................... 12
6.1.3.Run the Test...................................................................................................................................................................... 12
6.1.4.Test results analysis.......................................................................................................................................................... 13
6.1.5.Anomalous results for "P-P", "P-N", "P-PE" Test .............................................................................................................. 14
6.2.Operating Instrument for “TYPE 2” Instrument ................................................................................................................................................. 17
6.2.1.Instrument Settings ........................................................................................................................................................... 17
6.2.2.Prospective Short Circuit Current Calculation ................................................................................................................... 17
6.2.3.Run the Test...................................................................................................................................................................... 18
6.2.4.Test result analysis............................................................................................................................................................ 18
6.2.5.Anomalous results for "P-P", "P-N", "P-PE" Test .............................................................................................................. 19
6.3.Operating Instrument for “TYPE 3” Instrument ................................................................................................................................................. 22
6.3.1.Instrument Settings ........................................................................................................................................................... 22
6.3.2.Prospective Short Circuit Current Calculation ................................................................................................................... 23
6.3.3.Run the Test...................................................................................................................................................................... 24
6.3.4.Test result analysis............................................................................................................................................................ 24
6.3.5.Anomalous results for "P-P", "P-N", "P-PE" Test .............................................................................................................. 25
6.4.Operating Instrument for “TYPE 4” Instrument ................................................................................................................................................. 28
6.4.1.Instrument Settings ........................................................................................................................................................... 28
6.4.2.Prospective Short Circuit Current Calculation ................................................................................................................... 29
6.4.3.Run the Test...................................................................................................................................................................... 29
6.4.4.Test result analysis............................................................................................................................................................ 29
6.4.5.Anomalous results............................................................................................................................................................. 29
6.5.Operating Instrument for “TYPE 5” Instrument ................................................................................................................................................. 32
6.5.1.Instrument Settings ........................................................................................................................................................... 32
6.5.2.Prospective Short Circuit Current Calculation ................................................................................................................... 32
6.5.3.Run the Test...................................................................................................................................................................... 32
6.5.4.Test result analysis............................................................................................................................................................ 32
6.5.5.Anomalous results............................................................................................................................................................. 33
7.TEST RESULTS DOWNLOAD............................................................................................................. 34
8.MAINTENANCE.................................................................................................................................... 34
8.1.General.................................................................................................................................................................................................................... 34
8.2.Instrument cleaning................................................................................................................................................................................................ 34
8.3.End of life ................................................................................................................................................................................................................. 34
9.TECHNICAL SPECIFICATIONS .......................................................................................................... 35
9.1.Technical Features ................................................................................................................................................................................................ 35
9.1.1.Safety Guidelines: ............................................................................................................................................................. 35
9.1.2.Safety standards ............................................................................................................................................................... 35
9.1.3.General Characteristics..................................................................................................................................................... 35
9.2.Environment............................................................................................................................................................................................................ 36
9.2.1.Environmental condition .................................................................................................................................................... 36
9.3.Accessories............................................................................................................................................................................................................. 36
10.SERVICE............................................................................................................................................... 37
10.1.Warranty .................................................................................................................................................................................................................. 37
10.2.Service ..................................................................................................................................................................................................................... 37

IMP57
EN - 2
1. SAFETY PRECAUTIONS AND PROCEDURES
This apparatus conforms with safety standards EN61557 and EN 61010 relating to
electronic measuring instruments.
For your own safety as well as that of the apparatus you are recommended to follow the
procedures described in this instruction manual and carefully read all the notes preceded
by the symbol .
WARNING
Should you fail to keep to the prescribed instructions you could damage the
instrument and/or its components or endanger your safety.
Strictly keep to the following instructions before and during measurements:
Do not take measurements in wet environments.
Do not effect measurements in environments with explosive gas, fuels or dust.
Keep you insulated from the object under test waiting for measuring.
Avoid any contact with exposed metal parts, ends of test leads not in use, circuits, etc.
Do not effect any measurement in case of unusual conditions of the instrument such as
deformation, breakage, leakage of substances, etc.
Pay careful attention when measuring voltages exceeding 20V because of the risk of
electric shock.
The following symbols are used in this manual:
Caution: refer to the instructions manual; improper use may damage the
apparatus or its components.
Double-insulated meter.
AC Voltage or Current.
1.1. PRELIMINARY INSTRUCTION
This instrument has been designed for use in environments with a degree of pollution
2.
It can be used for tests for Impedance measurements on electrical installations with
overvoltage category III up to 240V (Nominal Voltage to Earth) and up to 415V
(Nominal voltage Phase to Phase).
You are recommended to comply with the usual safety regulations aimed at:
Protecting you against dangerous currents.
Protecting the instrument against improper use.
Only the leads 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.
Do not effect any measurement in electrical system which doesn't comply with the
Voltage limits here indicated
Do not effect any measurement under environmental conditions beyond the limits
specified in paragraph 9.2.

IMP57
EN - 3
1.2. DURING USE
Carefully read the following recommendations and instructions:
WARNING
No compliance with the Warnings and/or Instructions may damage the
apparatus and/or its components or injure the operator.
When the instrument is connected to the tested circuit never touch any test lead which
is not being used.
The STATUS LED blinking in red indicates that the instrument is overheating. You will
have to wait until STATUS LED get back to GREEN status before executing new test.
Never execute more than 50 test in one hour.
The red colour (fixed) of STATUS LED indicates a dangerous situation. Disconnect
immediately Test Leads from the Circuit under Test.
1.3. AFTER USE
Always disconnect alligator clips from the circuit under Test before disconnecting Test
cables from Instrument's inputs.
1.4. DEFINITION OF MEASURING (OVERVOLTAGE) CATEGORY
The norm EN 61010: Safety requirements for electrical equipment for measurement,
control and laboratory use, Part 1: General requirements, defines what a measuring
category, usually called overvoltage category, is.
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 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.

IMP57
EN - 4
2. GENERAL DESCRIPTION
Dear Customer, we thank you for your patronage. The instrument you have just purchased
will grant you accurate and reliable measurements provided that it is used according to the
present manual’s instructions.
The instrument was designed to grant the user the utmost safety conditions thanks to a
new concept assuring double insulation and overvoltage category III 240V (to Earth).
The instrument can perform Phase to Phase, Phase to Neutral and Phase to Protection
Conductor (PE) Impedance measurement and Prospective Short Circuit current calculation
(according to EN 60909-0).
As the instrument execute a 4 wire measurement (Volt-ampermetric measurement mode),
the results aren't affected by Test Leads and alligator clips and it's not necessary to
execute any Test Cable calibration.
The instrument is provided of special cables with double-contact alligator clip: the back
and red part of the alligator clip are electrically separated and make two different test
points. So the red sides of the alligator clips represent the Current Circuit (C1 and C2)
while the black sides (P1 and P2) represent the Voltage measurement circuit.
The instrument is directly supplied by the Test Leads and the electrical network under test.
It's not provided of a keyboard because all commands and results are exchanged by
means the RS232 serial interface with the MASTER instrument. For further details see
paragraph.

IMP57
EN - 5
3. PREPARATION FOR USE
3.1. INITIAL CONTROL
This instrument has been checked mechanically and electrically prior to shipment.
Any care has been taken to ensure that the instrument reaches you under safe conditions.
You are recommended, however, to carry our a rapid check to detect any possible
damage which might have been caused during transport. Should this be the case,
immediately contact HT Italia.
Check also that the packaging contains all the parts listed under paragraph 9.3. In case of
discrepancies contact the dealer.
In case you have to send the instrument back please follow the instructions reported in
paragraph 10.
3.2. POWER SUPPLY
The instrument is directly supplied by the Test Leads and the electrical network under test.
the voltage mains must be in 220 – 415V range and the mains frequency must be in 50Hz
+/- 5% range.
3.3. CALIBRATION
The instrument fulfils the technical specifications listed in this manual. The performance of
the specifications are guaranteed for one year.
3.4. STORAGE
In order to grant the accuracy of the measurements, after a period of storage in extreme
environmental conditions, wait for the time necessary so that the apparatus is back to
normal measuring conditions (see environmental specifications listed in paragraph 9.2.

IMP57
EN - 6
4. INSTRUMENT DESCRIPTION
4.1. INSTRUMENT DESCRIPTION
P1 C1 C2 P2
CAT III
Input max:
415V~ between Inputs
240V~
P-P connecti on P-PE c onnect ionP-N conne ction
High resolution Line/Loop Imped ance teste r
Un: 220-415V~
Freq:
I : 200A
Z: 4.0m - 1999m
: 0. 1m - 1 999m
50Hz
testMax
Reading
~
Ik : 1A - 1999 kA
P.Supp ly : 2 20-415V~
Freq supply :
WW
WW
Reading
(P1-P2)
50Hz
Power: Max 10VA
±6 %
±6 %
P1 C1 C2 P 2 P1 C1 C2 P2P1 C1 C2 P 2
1
2
3
N
PE
1
2
3
N
PE
1
2
3
N
PE
1
2
3
LEGEND:
1 Terminals C1, P1, C2, P2 for impedance
tests.
2 STATUS LED
3 RS232 Serial interface.
Fig. 1: Instrument description
4.1.1. STATUS LED
The STATUS LED can assume the following colour
OFF: Instrument not supplied.
GREEN: Instrument ready for Test.
ORANGE: Test running.
RED (blinking): Instrument overheated. Please wait until LED status get back to
GREEN colour before executing new test.
RED (fixed): Disconnect immediately the instrument form the circuit under
test. Check the nominal voltage range (220 415V) and the
frequency range (47.5 52.5Hz). Also check anomalous
situation in paragraph 6.1.5, 6.2.5, 6.3.5, 6.4.5 and 6.5.5.
4.2. INSTRUMENT'S COMMANDS
1
2
LEGEND:
1 MASTER Instrument.
2 RS232 cable: C2001 or
C232NG1.
Fig. 2: Connecting IMP57 to MASTER instrument

IMP57
EN - 7
The instrument is fully controlled by means the RS232 serial interface. The IMP57 can be
connected to the following MASTER instruments:
MASTER Instrument Instrument Type Firmware Upgrading Proc.
GSC57, GSC53, GENIUS5080E,
GSC53N, SIRIUS 89 1 1.37 or successive User (*)
MACROTEST 5035, SIRIUS 87 2 1.16 or successive User (*)
COMBITEST 2019 1.33 or successive HT
COMBITEST420, COMBITEST419,
SPEEDTEST 418 3 1.02 or successive ----
FULLTEST4058 4 1.08 or successive HT
FULLTEST4050 5 A3.0 or successive HT
Table 1: Instruments Type
(*) If the Firmware release is older, please execute the Firmware upgrading procedure described in file
"Readme_Leggimi.pdf" included in package.
HT recommends to check the Firmware release of the MASTER instrument before attempt
to execute the test. This information is present in the "Switch-ON screen" of the MASTER
instrument.
Test results are sent by IMP57 to MASTER instrument through C2001 or C232NG1 cable.
All the stored test results can be reviewed on the MASTER instrument display and sent to
a personal computer.

IMP57
EN - 8
5. OPERATING INSTRUCTIONS
5.1. PHASE TO PHASE IMPEDANCE MEASUREMENT AND PHASE TO PHASE-
THREE-PHASE PROSPECTIVE SHORT CIRCUIT CURRENT CALCULATION
WARNING
Never use the instrument in electrical plants with Nominal phase to phase
voltage higher than 415V or a Nominal phase to neutral voltage or phase to
ground voltage higher than 240V.
The Phase to Phase impedance measurement entails the flowing of a current
up to 200A between the above said conductors. This can cause tripping of
magnetothermal switch having rated value lower than 200A. If necessary
execute the measurement upstream the switch.
If possible disconnect all the low impedance loads connected downstream the
point where the test is to be carried out as the impedance of the above said
loads results to be in parallel with the impedance under test.
Always make sure that the upper and lower metal plate of the alligator clips
make good contact with the conductors of the circuit under test.
Never disconnect the Alligator clips or Test leads during the Test.
P1 C1 C2 P2
1
2
3
N
PE
Fig. 3: Instrument connection for phase to phase impedance measurement
1. Connect the IMP57 RS232 to MASTER instrument through RS232 cable (see
paragraph 4.2).
2. Connect the alligator clip to the Electrical plant according to Fig. 3.
3. Insert the 4 safety connectors into corresponding instrument's inputs according to
sequence P1, P2, C2, C1 (see Fig. 3).
4. Check if the STATUS LED is light in Green.
5. Switch ON the MASTER instrument, select the "Phase to Phase Measurement mode"
and Start the Test (see chapter 6).
For further details and description about Test results and Save procedure see chapter 6.

IMP57
EN - 9
5.2. PHASE TO NEUTRAL IMPEDANCE MEASUREMENT AND PHASE TO
NEUTRAL PROSPECTIVE SHORT CIRCUIT CURRENT CALCULATION
WARNING
Never use the instrument in electrical plants with Nominal phase to phase
voltage higher than 415V or a Nominal phase to neutral voltage or phase to
ground voltage higher than 240V.
The Phase to neutral impedance measurement entails the flowing of a current
up to 116A between the above said conductors. This can cause tripping of
magnetothermal switch having rated value lower than 116A. If necessary
execute the measurement upstream the switch.
If possible disconnect all the low impedance loads connected downstream the
point where the test is to be carried out as the impedance of the above said
loads results to be in parallel with the impedance under test.
Always make sure that the upper and lower metal plate of the alligator clips
make good contact with the conductors of the circuit under test.
Never disconnect the Alligator clips or Test leads during the Test.
P1 C1 C2 P2
1
2
3
N
PE
Fig. 4: Instrument connection for phase to neutral impedance measurement
1. Connect the IMP57 RS232 to MASTER instrument through RS232 cable (see
paragraph 4.2).
2. Connect the alligator clip to the Electrical pant according to Fig. 4.
3. Insert the 4 safety connectors into corresponding instrument's inputs according to
sequence P1, P2, C2, C1 (see Fig. 4).
4. Check if the STATUS LED is light in Green.
5. Switch ON the MASTER instrument, select the "Phase to Neutral Measurement mode"
and Start the Test (see chapter 6).
For further details, description about Test results and Save procedure see paragraph 6.

IMP57
EN - 10
5.3. PHASE TO PE (PROTECTION CONDUCTOR) IMPEDANCE MEASUREMENT
AND PHASE TO PE PROSPECTIVE SHORT CIRCUIT CURRENT
CALCULATION
WARNING
Never use the instrument in electrical plants with Nominal phase to phase
voltage higher than 415V or a Nominal phase to neutral voltage or phase to
ground voltage higher than 240V.
The Phase to PE impedance measurement entails the flowing of a current up
to 116A between the above said conductors. This can cause tripping of
magnetothermal switch having rated value lower than 116A and will cause the
RCD tripping. If necessary execute the measurement upstream the switch or
RCD.
If possible disconnect all the low impedance loads connected downstream the
point where the test is to be carried out as the impedance of the above said
loads results to be in parallel with the impedance under test.
Always make sure that the upper and lower metal plate of the alligator clips
make good contact with the conductors of the circuit under test.
Never disconnect the Alligator clips or Test leads during the Test.
P1 C1 C2 P2
1
2
3
N
PE
Fig. 5:Instrument connection for phase to ground impedance measurement
1. Connect the IMP57 RS232 to MASTER instrument through RS232 cable (see
paragraph 4.2).
2. Connect the alligator clip to the Electrical pant according to Fig. 5.
3. Insert the 4 safety connectors into corresponding instrument's inputs according to
sequence P1, P2, C2, C1 (see Fig. 5).
4. Check if the STATUS LED is light in Green.
5. Switch ON the MASTER instrument, select the "Phase to PE Measurement mode" and
Start the Test (see chapter 6).
For further details, description about Test results and Save procedure see chapter 6.

IMP57
EN - 11
6. MASTER INSTRUMENT SETTINGS
Operating Instruction are given according to Table 1 - Instrument Type definition.
6.1. OPERATING INSTRUMENT FOR “TYPE 1” INSTRUMENT
6.1.1. Instrument Settings
Select LOOP rotary switch position.
Select one of the following connection by means F1 button.
"P-P", "P-N", "P-PE"
available among the functions "P-P", "P-N", "P-PE", " RA", " ".
Press F2 to Enable the "High Resolution Measurement Z2" working mode.
correspondently the Z2symbol will be displayed in the lower part of the
display.
When Z2working mode is enabled it's possible to select one of the
following measurement mode by means the F1 button.
“P-N"The instrument execute the High Resolution Phase-Neutral
impedance measurement and calculate the Prospective Short
circuit Current Calculation selected.
“P-P" The instrument execute the High Resolution Phase-Phase
impedance measurement and calculate the Prospective Short
circuit Current Calculation selected.
“P-PE"The instrument execute the High Resolution Phase-ground
impedance measurement and calculate the Prospective Short
circuit Current Calculation selected.
The F3 button allows the selection of Prospective Short Circuit current
calculation according to paragraph 6.1.2.
By pressing the F4 button the instrument will show the IMP57 Serial Number,
the Firmware release and the calibration date. Press ESC to quit this screen.
Press F2 button to quit High Resolution Measurement mode Z2.

IMP57
EN - 12
6.1.2. Prospective Short Circuit Current Calculation
Connection
Phase - Phase
(P-P) 2
3
3 HOT
PP
NOM
PP
MINphMIN Z
U
CI



Three Phase Minimum Prospective Short Circuit Current
2
3
3
PP
NOM
PP
MAXphMAX Z
U
CI



Three Phase Maximum Prospective Short Circuit Current
HOT
PP
NOM
PP
MINphMIN Z
U
CI



2
Two Phase Minimum Prospective Short Circuit Current
PP
NOM
PP
MAXphMAX Z
U
CI



2
Two Phase Maximum Prospective Short Circuit Current
Phase - Neutral
(P-N) HOT
NP
NOM
NP
MINNPMIN Z
U
CI



Single Phase Minimum Prospective Short Circuit Current
NP
NOM
NP
MAXNPMAX Z
U
CI



Single Phase Maximum Prospective Short Circuit Current
Phase-Protection conductor
(P-PE)
HOT
PEP
NOM
PEP
MINPEPMIN Z
U
CI



Fault to Ground Minimum Prospective Short Circuit
Current
PEP
NOM
PEP
MAXPEPMAX Z
U
CI



Fault to Ground Maximum Prospective Short Circuit
Current
Generic
MIS
NOM
STD Z
U
I 
Generic Prospective Short Circuit Current
where:
22
)5.1( XPXP
HOT
XP XRZ  
and
Voltage UNOM C
MIN C MAX
230V-10% < Vmeasured < 230V+ 10% 230V 0,95 1,05
230V+10% < Vmeasured < 400V- 10% Vmeasured 1,00 1,10
400V-10% < Vmeasured < 400V+ 10% 400V 0,95 1,05
6.1.3. Run the Test
When the IMP57 has been connected according to paragraph 5 and the MASTER
instrument has been set according to paragraph 6.1.1 and 6.1.2, you can run the Test by
means the START button.
During the test the STATUS LED will get Orange colour and when the Test is completed
the results will be shown on instrument display.

IMP57
EN - 13
6.1.4. Test results analysis
"P-P" Test result
After the Test the instrument will show a screen as indicated below:
LOOP 05.06.02 Phase – Phase Impedance(m)
Z= 35.3m
R=9.1mX=34.1m
IkMax3Ph=14kA
V1-2=394V FRQ=50.0HZ
P-P Z2
Phase – Phase Resistance(m)
Measured Voltage
Phase – Phase Reactance(m)
Frequency
Prospective Short Circuit
Current
FUNC ZSTD ICAL RMT
The Prospective Short Circuit Current is calculated according to one of the relationship
indicates in paragraph 6.1.2 for Phase-Phase connection.
You can save these results by pressing the SAVE button twice.
"P-N" Test result
After the Test the instrument will show a screen as indicated below:
LOOP 05.06.02 Phase – Phase Impedance(m)
Z= 27.0m
R=5.3mX=26.4m
IkMaxP-N=8.9kA
V1-2=226V FRQ=50.0HZ
P-N Z2
Phase – Phase Resistance(m)
Voltage measured
Phase – Phase Reactance(m)
Frequency
Prospective Short Circuit
Current
FUNC ZSTD ICAL RMT
The Prospective Short Circuit Current is calculated according to one of the relationship
indicates in paragraph 6.1.2 for Phase-Neutral connection.
You can save these results by pressing the SAVE button twice.

IMP57
EN - 14
"P-PE" Test result
After the Test the instrument will show a screen as indicated below:
LOOP 05.06.02 Phase – Phase Impedance(m)
Z= 27.0m
R=5.3mX=26.4m
IkMaxP-N=8.5kA
V1-2=226V FRQ=50.0HZ
P-PE Z2
Phase – Phase Resistance(m)
Voltage Measured
Phase – Phase Reactance(m)
Frequency
Prospective Short Circuit
Current
FUNC ZSTD ICAL RMT
The Prospective Short Circuit Current is calculated according to one of the relationship
indicates in paragraph 6.1.2 for Phase-Neutral connection.
You can save these results by pressing the SAVE button twice.
6.1.5. Anomalous results for "P-P", "P-N", "P-PE" Test
LOOP 05.06.02
Z= - - - - - 
R=-----X=-----
IkSTD=----A
V1-2=231V FRQ=50.0HZ
NO IMP57
P-N Z2
FUNC ZSTD ICAL RMT
The message " NO IMP57" indicate that IMP57 doesn't reply to RS232 commands of the
MASTER instrument. Please check if:
1. The MASTER instrument is connected to IMP57 through C2001 optical cable.
2. The STATUS LED is green.

A
fter pressing START
button, the message on
side indicates that the
MASTER instrument is
supplied by using the
External power supply
adapter. Disconnect the
External power supply
adapter.
LOOP 05.06.02
Z= - - - - - 
R=-----X=-----
IkSTD=----A
V1-2=231V FRQ=50.0HZ
REMOVE POWER
P-N Z2
For operator safety it is
allowed to execute
measurement only when
the MASTER instrument is
supplied by Batteries
FUNC ZSTD ICAL RMT

IMP57
EN - 15

A
fter pressing START
button, the message on
side indicate that the
mains voltage is too low
(<190V).
LOOP 05.06.02
Z= - - - - - 
R=-----X=-----
IkSTD=----A
V1-2=181V FRQ=50.0HZ
LOW VOLTAGE
P-N Z2
Low Voltage Indication
FUNC ZSTD ICAL RMT

A
fter pressing START
button, the message on
side indicate that the
mains voltage is >460V
(415V + 10%).
LOOP 05.06.02
Z= - - - - - 
R=-----X=-----
IkSTD=----A
V1-2=461V FRQ=50.0HZ
HIGH VOLTAGE
P-P Z2
High Voltage Indication
FUNC ZSTD ICAL RMT

A
fter pressing START
button, the message on
side indicate that test
current is too low
(>10A). Please check
that alligator clip are in
contact with mains
conductors.
LOOP 05.06.02
Z= - - - - - 
R=-----X=-----
IkSTD=----A
V1-2=461V FRQ=50.0HZ
CURRENT NOT OK
P-P Z2
FUNC ZSTD ICAL RMT

IMP57
EN - 16
If the instrument is
overheated the display
will show the message
on side.
Please wait until the
LED STATUS on IMP57
get back to Green light.
LOOP 05.06.02
Z= - - - - - 
R=-----X=-----
IkSTD=----A
V1-2=461V FRQ=50.0HZ
HIGH TEMP
P-P Z2
FUNC ZSTD ICAL RMT Instrument overheated
If You get the message
on side after pressing
START button, please
contact HT Service.
LOOP 05.06.02
Z= - - - - - 
R=-----X=-----
IkSTD=----A
V1-2=461V FRQ=50.0HZ
Error 5
P-P Z2
FUNC ZSTD ICAL RMT
PREVIOUS RESULT CAN'T BE STORED INTO INSTRUMENT MEMORY.
If the instrument
measure an impedance
higher than 1999mwill
show the message on
side. Disable the Z2
High Resolution
measurement mode and
execute standard LOOP
measurement.
LOOP 05.06.02 The ">" symbol indicate
that the measure is higher
than 1999m
Z> 1999m
R>1999mX>1999m
IkSTD=----A
V1-2=461V FRQ=50.0HZ
P-P Z2
FUNC ZSTD ICAL RMT
You can save these results by pressing the SAVE button twice.

IMP57
EN - 17
6.2. OPERATING INSTRUMENT FOR “TYPE 2” INSTRUMENT
Operating Instruction are given according to Table 1 - Instrument Type definition.
6.2.1. Instrument Settings
Select LOOP rotary switch position.
Select one of the following connection by means FUNC button.
"P-P", "P-N", "P-PE"
available among the functions "P-P", "P-N", "P-PE", " RA", " ".
Press Un/IΔnto enable the "High Resolution Measurement Z2" working
mode. correspondently the LOWand LOOP symbols will be displayed in
the lower part of the display.
When Z2working mode is enabled it's possible to select one of the
following measurement mode by means the FUNC button.
“P-N"The instrument execute the High Resolution Phase-Neutral
impedance measurement and calculate the Prospective Short
circuit Current.
“P-P" (The instrument execute the High Resolution Phase-Phasel
impedance measurement and calculate the Prospective Short
circuit Current.
“P-PE"The instrument execute the High Resolution Phase-ground
impedance measurement and calculate the Prospective Short
circuit Current.
Press Un/IΔnbutton to quit High Resolution Measurement mode Z2.
6.2.2. Prospective Short Circuit Current Calculation
Independently by the connection selected, the instrument calculated the Prospective short
circuit current as:
MIS
NOM
STD Z
U
I 
Standard Prospective Short Circuit current
where
Voltage UNOM
230V-10% < Vmeasured < 230V+ 10% 230V
230V+10% < Vmeasured < 400V- 10% Vmeasured
400V-10% < Vmeasured < 400V+ 10% 400V

IMP57
EN - 18
6.2.3. Run the Test
When the IMP57 has been connected according to paragraph 5 and the MASTER
instrument has been set according to paragraph 6.2.1and 6.2.2, you can run the Test by
means the START button.
During the test the STATUS LED will get Orange colour and when the Test is completed
the results will be shown on instrument display.
6.2.4. Test result analysis
"P-P" Test Results
After the Test the instrument will show a screen as indicated below:
LOW

LOOP
100.0m
P-P
392V 4.0 kA
Phase-Phase Impedance [m]
Measured Voltage
Prospective short circuit Current
You can save these results by pressing the SAVE button twice.
"P-N" Test Results
After the Test the instrument will show a screen as indicated below:
LOW

LOOP
100.0m
P-N
232V 2.3 kA
Phase-Neutral Impedance [m]
Measured Voltage
Prospective short circuit Current
You can save these results by pressing the SAVE button twice.