Chauvin Arnoux C.A 6550 User manual

Megohmmeters 10 kV and 15kV
GB - User’s manual
C.A 6550
C.A 6555

2
WARNING, risk of DANGER! The operator must refer to these instructions whenever this danger symbol appears.
Equipment protected by double insulation.
Caution! Risk of electric shock.
USB socket.
Earth.
The CE marking indicates conformity with European directives, in particular LVD and EMC.
Chauvin Arnoux has adopted an Eco-Design approach in order to design this appliance. Analysis of the complete
lifecycle has enabled us to control and optimize the effects of the product on the environment. In particular this
appliance exceeds regulation requirements with respect to recycling and reuse.
The rubbish bin with a line through it indicates that, in the European Union, the product must undergo selective
disposal in compliance with Directive WEEE 2002/96/EC. This equipment must not be treated as household waste.
Thank you for purchasing a megohmmeter C.A 6550 or C.A 6555.
For best results from your instrument:
read these operating instructions carefully,
comply with the precautions for use.
Definition of measurement categories:
Measurement category IV corresponds to measurements taken at the source of low-voltage installations.
Example: power feeders, counters and protection devices.
Measurement category III corresponds to measurements on building installations.
Example: distribution panel, circuit-breakers, machines or fixed industrial devices.
Measurement category II corresponds to measurements taken on circuits directly connected to low-voltage installations.
Example: power supply to electro-domestic devices and portable tools.
PRECAUTIONS FOR USE
This instrument and its accessories comply with safety standards IEC 61010-1, IEC 61010-031, and IEC 61010-2-30 for voltages
of 1000V in category IV.
Failure to observe the safety instructions may result in electric shock, fire, explosion, and destruction of the instrument and of
the installations.
The operator and/or the responsible authority must carefully read and clearly understand the various precautions to be taken
in use. Sound knowledge and a keen awareness of electrical hazards are essential when using this instrument.
If you use this instrument other than as specified, the protection it provides may be compromised, thereby endangering you.
Do not use the instrument on networks of which the voltage or category exceeds those mentioned.
Do not use the instrument if it seems to be damaged, incomplete, or poorly closed.
Before each use, check the condition of the insulation on the leads, housing, and accessories. Any item of which the insulation
is deteriorated (even partially) must be set aside for repair or scrapping.
Use only the leads and accessories supplied. Using leads (or accessories) of a lower voltage or category reduces the voltage
or category of the combined instrument + leads (or accessories) to that of the leads (or accessories).
Use personal protection equipment systematically.
Keep your hands away from the terminals of the instrument.
When handling the leads, test probes, and crocodile clips, keep your fingers behind the physical guard.
As a safety measure, and to avoid interference, do not move and do not handle the leads during measurements.

3
CONTENTS
1. FIRST USE................................................................................................................................................................................ 4
1.1. Delivery condition........................................................................................................................................................... 4
1.2. Accessories .................................................................................................................................................................... 4
1.3. Replacement parts ......................................................................................................................................................... 5
1.4. Specifications label ........................................................................................................................................................ 6
1.5. Charging the batteries.................................................................................................................................................... 6
1.6. Adjusting the brightness and contrast ........................................................................................................................... 7
1.7. Choice of language ........................................................................................................................................................ 8
1.8. Choice of measurement cable compensation................................................................................................................ 8
2. DESCRIPTION OF THE INSTRUMENT................................................................................................................................... 9
2.1. Functions...................................................................................................................................................................... 10
2.2. Display.......................................................................................................................................................................... 10
2.3. Keypad ......................................................................................................................................................................... 11
2.4. PC software.................................................................................................................................................................. 11
3. PROCEDURE ......................................................................................................................................................................... 12
3.1. Using the leads............................................................................................................................................................. 12
3.2. AC/DC voltage measurement....................................................................................................................................... 13
3.3. Insulation measurement ............................................................................................................................................... 13
3.4. Error indications ........................................................................................................................................................... 22
3.5. DAR (dielectric absorption ratio) and PI (polarization index)........................................................................................ 22
3.6. DD (dielectric discharge index)..................................................................................................................................... 24
3.7. Capacitance measurement .......................................................................................................................................... 26
3.8. Measurement of the residual current............................................................................................................................ 26
4. COMPLEMENTARY FUNCTIONS ......................................................................................................................................... 27
4.1. TEMP key ..................................................................................................................................................................... 27
4.2. ALARM key................................................................................................................................................................... 28
4.3. CONFIG key ................................................................................................................................................................. 28
4.4. DISPLAY key ............................................................................................................................................................... 33
4.5. GRAPH key................................................................................................................................................................... 33
4.6. FILTER key ................................................................................................................................................................... 34
4.7. HELP key...................................................................................................................................................................... 35
5. CONFIGURATION (SET-UP) .................................................................................................................................................. 36
5.1. Restoring the initial configuration................................................................................................................................. 36
5.2. General parameters...................................................................................................................................................... 37
5.3. Measurement parameters ............................................................................................................................................ 37
5.4. Adjustment of the test voltages.................................................................................................................................... 38
5.5. Adjustment of the alarm thresholds ............................................................................................................................. 39
6. MEMORY FUNCTION ............................................................................................................................................................ 40
6.1. Recording of the measurements .................................................................................................................................. 40
6.2. Reading recorded values.............................................................................................................................................. 42
6.3. Erasing the memory ..................................................................................................................................................... 44
6.4. List of coded errors ...................................................................................................................................................... 45
7. DATA TRANSFER SOFTWARE.............................................................................................................................................. 47
8. SPECIFICATIONS................................................................................................................................................................... 48
8.1. Reference conditions.................................................................................................................................................... 48
8.2. Characteristics per function ......................................................................................................................................... 48
8.3. Power supply................................................................................................................................................................ 54
8.4. Environmental conditions ............................................................................................................................................. 55
8.5. Construction specification............................................................................................................................................ 55
8.6. Compliance with international standards..................................................................................................................... 56
8.7. Variations in the domain of use .................................................................................................................................... 56
8.8. Intrinsic uncertainty and operating uncertainty ............................................................................................................ 56
9. MAINTENANCE...................................................................................................................................................................... 57
9.1. Maintenance................................................................................................................................................................. 57
9.2. Updating of the internal software ................................................................................................................................. 57
9.3. List of parameters ........................................................................................................................................................ 58
10. WARRANTY ......................................................................................................................................................................... 60

4
1. FIRST USE
1.1. DELIVERY CONDITION
1A C.A 6550 or a C.A 6555 with a screen protection film and a rechargeable battery.
2Three crocodile clips (red, black, and blue).
3Two test probes (red and black).
4One power cord 2 metres long for recharging the battery.
5One data transfer software program and one optical-USB cord.
6One safety lead (blue), 0.5m long, with two high-voltage plugs, one of them with a rear pick-up.
7Two safety leads (red and blue), 3 metres long, with high-voltage plugs at both ends.
8One shielded safety lead (black), 3m long, with two high-voltage plugs, one of them with a rear pick-up.
9One carrying bag for the accessories.
10 One user manual on CD-ROM (one file per language).
11 One multilingual safety data sheet.
12 Specifications labels (one per language).
1.2. ACCESSORIES
Set of 3 shielded safety leads (black, red, and blue), 3 metres long, with a high-voltage plug at one end (with rear pick-up on
the black lead) and a large crocodile clip at the other
➀➃
➁➂➇
➈
11
12
➅
➄
➆
10
English
Safetydatasheet Measuring Instrument in CATII or CAT III or CAT IV (en)
Foryour safety and to avoiddamage to property:
Readwhat follows carefully and observe theseprecautions
Readthe other documents provided carefully,including any documents onthe CD-ROM
Meaningsof the principal symbols that may be present on your product:
CAUTION!Riskof Danger!
Referto this safety datasheet and comply
withthe precautions for use.
CAUTION!Riskof electric shock!
Refer to this safety datasheet, to the user
manualandcomply with the prec autionsforuse.
Current clamp: Can be applied to or
removed from non-insulated or bare
conductorsatdangerous volt ages.
Currentclamp: Do not apply to or remove from
conductorsatdangerous volt ages.
The CE marking indicates compliance
withthe European "Low Voltage", "EMC",
"WEEE",and "RoHS" directives.
In the European Union, this product is
subjectto selective collection in accordance
withthe European WEEE directive. Do not
disposeof it as ordinary waste; contact the
manufacturer for information about
collectionpoints.
Earth
Doubleinsulation
Do not dispose of the batteries as ordinary
waste;takethem to acollectionpoint.
Conditionsof use
Temperature,Humidity: Comply with the valuesstated in the user manual.
Altitude: 2 000 m
Pollutiondegree : 2
Precautionsfor use
Thesesafety instructions must be respected to assure the personal safety and the environmentof use. If
youdo not comply with them, there isa risk ofelectricshock, explosion or re.
Ifyou use these instruments other than as specied or without observingthe elementary safety rules, the
protectionthey provide may be compromised, endangeringyou.
Thesafety of any system which may include these leads or accessories is the responsibility of the
assemblerof the system.
Each time before use, always check that the insulation ofthe leads or accessories is in good
condition.Any element whose insulation is damaged (even partially) mustbe removed from use and
scrapped.A change of colorof the insulating material is an indication of deterioration.
Thesteady-state voltages,currents, and measurement categories are marked on the instruments, on
thecords, and on the accessories. Complywith these values.
Use specic individual safety protections when hazardous live parts can be accessible in the
installationwhere the measure is performed
Beforeusing your instrument, check that it is in good working order (for example, by measuring a
knowndangerous voltage).
Ifthe manual states how to replace the fuse(s) of yourinstrument, use only the recommended fuses.
Beforereplacing the batteries(rechargeable or not), disconnect the leads of your instrument.
The use of ameasurement instrument, a lead or an accessory with a lower
categoryor voltage downgrades the use of the assembly (instrument + lead +
accessory)to the lowest categoryand/or operating voltage.
Using a measuring instrument in a category II or III or IV environment can be dangerous. Insuch
measurement environments, the operators mustbe trained and/or accredited and/or informed of the
safetymeasures to be taken.
Measurementcategories:
CATII: Measurement category II is for measurements performed on circuits directly connected to the
lowvoltage installation
Examples:measurements on household appliancesand portable tools.
CATIII:Measurement category III is for measurement performedin the building installation
Examples:distribution boards, circuit-breakers, machine or industrial equipment with permanent
connectionto the xed installation.
CATIV:MeasurementcategoryIVis formeasurementsperformedatthesourceofthelow-voltageinstallation.
Example: meters and measurements on primary overcurrent protection devices and ripple
controlunits.
Cleaning
Disconnectthe leads or thetest accessories
Usea soft cloth, dampened with soapy water. Rinse with a damp cloth and dry rapidly with a dry
clothor forced air. Do not use alcohol,solvents, or hydrocarbons.
Donot modify the leads or accessories. Any non-compliant repairs can cause risks of electric shock
orburns.

5
Shielded safety lead (black), 8 metres long, with a high-voltage plug with rear pick-up at one end and a large crocodile clip
at the other
Safety lead (red), 8 metres long, with a high-voltage plug at one end and a large crocodile clip at the other
Safety lead (blue), 8 metres long, with a high-voltage plug at one end and a large crocodile clip at the other
Shielded safety lead (black), 15 metres long, with a high-voltage plug with rear pick-up at one end and
a large crocodile clip at the other
Safety lead (red), 15 metres long, with a high-voltage plug at one end and a large crocodile clip at the other
Safety lead (blue), 15 metres long, with a high-voltage plug at one end and a large crocodile clip at the other
Thermocouple thermometer C.A. 861
Thermo-hygrometer C.A.846
1.3. REPLACEMENT PARTS
One carrying bag
Set of 3 HV leads, 3 metres long (red, blue, and black with rear pick-up)
Lead with rear pick-up (blue), 0.5 metre long
Set of 2 test probes (red and black)
Set of 3 crocodile clips
Optical-USB cord
European 2P mains cord
Screen protection film
For the accessories and spares, consult our web site:
www.chauvin-arnoux.com

6
1.5. CHARGING THE BATTERIES
When using the instrument for the first time, start by fully charging the batteries. Charging must be done at a temperature between
0 and 30°C.
> 90 Vac
< 260 Vac
50 / 60 Hz
Set the switch to OFF. Connect the mains cord.
MR
U-STEP
U-RAMP
U-VAR.
U-FIXED
OFF
SET-UP
OFF
Battery 1
Battery 2
2%
12.4 V
1953 mA
26.4°C
00:05:30
3%
11.7V
13 mA
26.7°C
00:05:20
Charging
During the charging, the instrument displays the
following information:
The percentage charge of each of the batteries, their voltages, their
charging currents, their temperatures, and the charging times.
To reduce the power to be supplied and make it possible to use the
instrument during the charging, the batteries are charged alternately
at 2A for 10 seconds. It is for this reason that the charging current
keeps varying.
The text on the side indicates:
Charging = battery being charged,
Full = battery fully charged,
Cold = battery too cold to be charged,
Hot = battery too hot to be charged,
Defect = battery faulty (must be replaced).
1.4. SPECIFICATIONS LABEL
Attach one of the 5 specifications labels, with your appropriate language, on the inside of the lid.

7

> 2s
HELP

HELP
Display Contrast
Backlight
CONTRAST & BACKLIGHT
Press the HELP key for more
than two seconds.
Press the keys to adjust the contrast.
Press the  keys to adjust the brightness.
Press the HELP key to validate.
These adjustments are stored even after the instrument is switched off.
Charging time:
between 6 and 10 hours, depending
on the initial charge condition.
Battery 1
Battery 2
Full
Full
100%
11.4 V
15 mA
55.1°C
02:34:41
100%
11.4 V
15 mA
55.1°C
02:34:24
Following prolonged storage, the batteries may be completely discharged. In this case, the first charge may take longer.
Charging when the instrument is in operation is also possible. In this case the symbol flashes.
The charging current then depends on the test voltage and on the resistance measured. If the power necessary for the measurement
approaches 10W, the batteries are no longer charging.
1.6. ADJUSTING THE BRIGHTNESS AND CONTRAST

8
1.7. CHOICE OF LANGUAGE
This choice is available only if the version of the electronic boards allows it.
To enter the language selection menu, press the CONFIG key and hold it down while turning the switch to SET-UP.
The language selection menu displays all of the languages available. Use the  keys to choose your language and press the
key to confirm or to cancel.
Installing the new language may take up to 30 seconds. The device then reboots.
1.8. CHOICE OF MEASUREMENT CABLE COMPENSATION
This choice is possible only if the internal software version allows it (see update § 9.2) and only with the red lead delivered with
the device (k22 marking at each end).
To enter the cable compensation selection menu, press the FILTER key and hold it down while turning the switch from OFF to
SET-UP.
Use the  keys to select the compensation and press the key to confirm or to exit.
After a few seconds, the device reboots.
+

CONFIG
MR
U-STEP
U-RAMP
U-VAR.
U-FIXED
OFF
SET-UP
SET-UP
English
Français
Deutsch
Italiano
Español
Svenska
+
MR
U-STEP
U-RAMP
U-VAR.
U-FIXED
OFF
SET-UP
SET-UP

FILTER
0 k Ω
44 k Ω

9
TEMP ALARM CONFIG DISPLAY
MEM
HELP
FILTER GRAPH
110-230V 50/60 Hz
80 VA max
MR
U-STEP
U-RAMP
U-VAR.
U-FIXED
OFF
SET-UP
1000V CAT III
600V CAT IV
( 2500V )
C.A 6555
15kV MEGOHMMETER
2. DESCRIPTION OF THE INSTRUMENT
Charging batteries.
Transfer of data to a PC.
Rotary switch to select a measurement function, SET-UP, or memory read.
To start and stop the measurements.
START/STOP

Arrow keys for browsing in the graphic screen.
ALARM MEM CONFIG DISPLAY
Activation/deactivation
of the alarms.
Recording of the
measurements.
Configuration of
the measurement
parameters.
Switches for next
screen.
TEMP HELP FILTER GRAPH
To refer the measured
resistance to the reference
temperature.
Help and backlight
key.
Smoothing of the
measurements.
Switch graph on/off
M
Connection terminals.
Graphic screen.

10
2.1. FUNCTIONS
C.A 6550 and C.A 6555 megohmmeters are high-end portable measuring instruments intended for the measurement of very high
electrical insulation and resistance values, mounted in a rugged site housing with a cover; they have graphic screens and can
operate on battery or mains power.
The C.A. 6550 makes insulation measurements at voltages up to 10,000V, the C.A. 6555 up to 15,000V.
Their main functions are:
detection and measurement of input voltage, frequency, and current;
quantitative and qualitative insulation measurement:
measurement at a fixed test voltage of 500, 1,000, 2,500, 5,000, 10,000 or 15,000V
dc
;
measurement at an adjustable test voltage between 40 and 15,000V
dc
;
measurement with a voltage ramp in the ranges from 40 to 1,100V or from 500 to 15,000V;
measurement with a voltage in steps from 40 to 15,000V;
non-destructive (Early break) test, test stopped at a preset current (Break at I-limit) or Burning;
calculation of the DAR, PI, and DD (dielectric discharge index) quality ratios;
calculation of the measured resistance referred to a reference temperature.
measurement of the capacitance of the circuit tested;
measurement of the residual current.
These megohmmeters contribute to the safety of electrical installations and equipment.
Their operation is managed by microprocessors that acquire, process, display, and store the measurements.
They have many advantages, such as:
digital filtering of insulation measurements;
measurement of the voltage;
the programming of thresholds to trigger audible alarms;
the timer for measurement duration checks;
the programming of a limitation of the measurement current;
the plotting of the resistance, voltage, and current vs. time curves and the current vs. voltage curve: R(t), U(t), I(t), and I(U);
protection of the device by fuse, with detection of defective fuse;
operator safety thanks to the automatic discharging of the test voltage on the tested device at the end of the measurement;
automatic power save mode of the device to save battery power;
indication of battery charge condition;
large graphic display with backlight capability;
a memory to store the measurements, a real-time clock, and a USB interface;
data export to a PC (using the software provided).
2.2. DISPLAY
The display unit is a graphic display with a resolution of 320x240 pixels.
It has built-in back-lighting, which can be controlled by a long press on the key (see §1.6).
2.2.1. EXAMPLE OF DISPLAY BEFORE THE MEASUREMENT
FIXED VOLTAGE
1000 V
Input voltage
Frequency
Input current
Date 2011.05.23
-0.1 V DC
0.2 Hz
112 pA
Time 10:31
BURN
500 V 2500 V
ALARM
Test Run Time 00:02:00
The blinking value can be
modified using the  keys.
Condition of the batteries.
Test with programmed duration. The alarm is enabled.
Programmed duration of the test.
Value of the external voltage
present on the terminals and its
frequency.
Current flowing between the
terminals. Date and time.
Value of the next lower available
test voltage.
Value of the next higher available
test voltage.
Type of measurement function.
No stop at current limit.

11
10 100 110 10 10
100 1100 1
kΩMΩGΩTΩ
303.3 MΩ
3.244 µA
Elapsed Time 00:00:48
DF 20s
984 V
ALARM
DH
I-LIM
The measurement smoothing
filtering is active, with a time
constant of 20 seconds.
Value of the insulation resistance.
True value of the test voltage.
Current flowing between the
terminals.
Elapsed time since the beginning
of the measurement.
Value of the insulation resistance
on the bargraph.
2.2.2. EXAMPLE OF DISPLAY DURING THE MEASUREMENT
2.2.3. EXAMPLE OF DISPLAY AFTER THE MEASUREMENT
995 MΩ
528 V 531 nA
Elapsed Time 00:01:12
DAR (30s/60s)
PI (1.0m/10m)
Capacitance
1.00
---
2 nF
RANGE E-BRKALARM
Value of the insulation resistance.
True value of the test voltage at
the end of the measurement.
The type of measurement is a
non-destructive test.
Current at the end of the
measurement.
Duration of the measurement.
Ancillary results.
The measurement of the
current range is fixed.
The voltage generated is >70V
dc
and therefore dangerous.
The symbol indicates blinking.
If values are undetermined, they are represented by - - - -.
Insulation resistance below the
alarm threshold.
Stop at current limit.
2.3. KEYPAD
If the audible signal has not been deactivated in SET-UP, the instrument confirms each key press by an audible beep. A higher-
pitched beep indicates that, pressing the key is prohibited or will have no effect.
A long press (press maintained for more than two seconds) is confirmed by a second audible beep.
2.4. PC SOFTWARE
This Pc software is used to:
transfer data stored in the instrument,
print customised test protocols in accordance with user needs,
create ExcelTM spreadsheets,
Set the instrument up and control it entirely via the USB link.
The recommended minimum configuration is a PC running XP, Vista, or Windows 7.

12
15 kV max
15 kV max
When measuring:
a voltage ≤1000V on mains,
insulation using a test voltage ≤5000V.
For an insulation measurement with a test voltage ≥5000V.
Measurements of voltages ≥1000V on mains must be made using the test probes only, with the user’s hands behind the guard
on the lead.
Remark: The leads with large clips (automobile battery charger type) proposed as accessories cannot be used for mains voltage
measurements because their jaws are not insulated.
3. PROCEDURE
When they leave the factory, the C.A. 6550 and C.A. 6555 are configured so that they can be used without modifying the parameters.
For most measurements, you simply choose the test voltage and press the START/STOP button.
If you want to modify parameters, most of them can be configured using the CONFIG key, and also in SET-UP.
The SET-UP function allows overall configuration of the instrument independently of which measurement functions are chosen.
The CONFIG key allows configuration of the chosen measurement function before and during a measurement.
A configuration modified in one of these two ways is updated for both (SET-UP or CONFIG key).
3.1. USING THE LEADS
Specific leads are supplied with the instrument. To use them, you must add test probes or crocodile clips (also supplied with the
instrument).
These accessories have guards. For safety reasons, the user’s hands must always be behind the guard.
The positions the hands must not go beyond are indicated below:

13
3.2. AC/DC VOLTAGE MEASUREMENT
Turning the switch to any insulation measurement position (U-FIXED, U-VAR, U-RAMP, or U-STEP) sets the instrument to AC/
DC voltage measurement. The voltage between the input terminals is measured at all times and indicated as RMS value on the
display unit: Input Voltage. Switching between AC and DC mode is automatic.
In the case of an AC signal, the instrument measures the frequency. It also measures the residual DC current between the terminals
of the instrument. This measurement is used to evaluate its impact on the insulation measurement about to be made.
The insulation measurements cannot be started if there is an excessively high external voltage (>0.4 UNwhere UNis the test
voltage, with a maximum of 1000 V
ac
) on the terminals.
FIXED VOLTAGE
500 V
Input voltage
Frequency
Input current
Date 2011.05.23
230 V AC
50.0 Hz
24.6 nA
Time 10:31
-- V 1000 V
BURN
When the external voltage exceeds 25V, the blinking ( ) symbol is displayed alongside it.
The only errors possible in a voltage measurement are:
The frequency is outside the measurement range (see §8.2.1)
The voltage is outside the measurement range (see §8.2.1).
3.3. INSULATION MEASUREMENT
%
The insulation measurement is made on an object that is not live.
This measurement varies greatly with the temperature and the relative humidity. It is therefore
essential to measure them using a separate device (see §1.2) and to record them with the
insulation value.
The ambient temperature and relative humidity can be entered in the instrument as parameters
and stored with the measurement result (see §4.1).
The value of the test voltage is generally twice the voltage at which the object to be tested is used, unless a standard stipulates
otherwise.
For example, for a motor that operates on 230V mains, the test will be performed at 500V.
3.3.1. DESCRIPTION OF THE MEASUREMENT PRINCIPLE
The instrument generates a DC test voltage equal to the chosen nominal voltage UNbetween the + and - terminals. More precisely,
the value of this voltage depends on the resistance to be measured (see the curves of §8.2.3). The instrument measures the
voltage and the current between the two terminals and from them deduces R=V/I.
The instrument measures the external voltage present on the terminals. It can make the measurement if the peak voltage is less
than 0.4 UNor 1000 V
ac
maximum. Above this value, it does not make the measurement.

DISPLAY
0250 500 750 1000
100
V
231V
50Hz 12,4pA
BURN

14
Set the switch to U-FIXED
FIXED VOLTAGE
500 V
Input voltage
Frequency
Input current
Date 2011.05.23
10 V AC
50.0 Hz
24 pA
Time 10:31
-- V 1000 V
BURN
The following screen appears.
Use the  keys to select the test voltage: 500, 1 000, 2 500, 5 000, 10 000, or 15 000V
dc
,
The device generates exactly the voltage selected if the resistance to be measured is indeed greater than RN= UN/ 1mA. If the
resistance measured is ≤ RN, the output voltage is less than UN. In this case, use the U-VAR function and adjust U so that the
voltage displayed during the test is at the desired value (see §4.3.2).
3.3.3. WITH A VARIABLE VOLTAGE
MR
U-STEP
U-RAMP
U-VAR.
U-FIXED
OFF
SET-UP
U-FIXED
3.3.2. WITH A FIXED VOLTAGE
Set the switch to U-VAR. The following screen appears.
There are already 3 preset voltages that can be modified in SET-UP (see §5). Use the  keys to select one of them:
Adjustable Voltage 1: 50V
Adjustable Voltage 2: 800V
Adjustable Voltage 3: 7,000V
Otherwise, use the keys to go to the voltage value, then use the  keys to adjust the value of the test voltage. The
adjustment is in 10V steps up to 1,000V, then in 100V steps. Keep the keys pressed to speed up the adjustment.
ADJUSTABLE VOLTAGE 1
50 V
Input voltage
Frequency
Input current
Date 2011.05.24
0.1 V AC
0.2 Hz
11 pA
Time 15:31
BURN
ADJUSTABLE VOLTAGE
750 V
Input voltage
Frequency
Input current
Date 2011.05.24
0.1 V AC
0.2 Hz
11 pA
Time 15:31
BURN
MR
U-STEP
U-RAMP
U-VAR.
U-FIXED
OFF
SET-UP
U-VAR.

15
3.3.4. WITH A VOLTAGE RAMP
This test is based on the principle that an ideal insulation produces the same resistance whatever the test voltage applied.
Any negative variation of the insulation resistance therefore means that the insulation is defective: the resistance of defective
insulation decreases as the test voltage increases. This phenomenon is barely observable with low test voltages. At least 2,500V
must therefore be applied.
Since the application of the voltage is gradual, it causes no premature ageing or deterioration of the device tested. Unlike the
increase in steps, the gradual increase of the current means that the capacitive current is constant. A variation of the current
therefore directly represents a variation of the insulation resistance.
Evaluating the result:
a negative slope of the resistance versus test voltage curve exceeding 500ppm/V generally indicates the presence of
mildew or other deterioration.
a larger negative slope, or a sudden drop, indicates the presence of localized physical damage (arcing, perforation of
the insulation, etc.).
The test with a voltage ramp is ideally suited for testing semiconductors (diodes, transistors, and thyristors). Take care in this case
to choose a non-destructive type of test: Break at I-limit (see § 4.3.1) and a maximum output current less than or equal to 1 mA.
Set the switch to U-RAMP. The following screen appears:
RAMP FUNCTION 1
Input voltage
Frequency
Input current
Date 2011.05.24
-0.1 V DC
0.2 Hz
55.7 nA
Time 15:31
Min. 50 V Max. 500 V
BURN
Test Run Time 00:03:00
MR
U-STEP
U-RAMP
U-VAR.
U-FIXED
OFF
SET-UP
U-RAMP
Use the  keys to select a preset test voltage ramp:
Ramp function 1: 50 to 500V
Ramp function 2: 500 to 5,000V
Ramp function 3: 1,000 to 10,000V
The voltages at the beginning and end of the ramp can be programmed with the CONFIG key (see §4.3). The duration of the test
is the sum of the three durations specified: the duration of the initial plateau, the duration of the ramp, and the duration of the
final plateau.
3.3.5. WITH A STEPPED VOLTAGE
The preset stepped voltage tests have ten plateaus. The duration of each of the voltage plateaus is identical. At the end of each
plateau, the capacitive current should be zero and only the measurement current remains.
Unlike the ramp test, the step test stresses the insulation and can cause a breakdown. A sudden increase of the current (or a sudden
decrease of the insulation resistance) means that a breakdown point is near. It is then possible to discontinue the measurement
by hand (by pressing the START/STOP button) or automatically (E-BRK or Break at I-Limit type of test; see §4.3.1).
A drop of 25% or more between the insulation resistance of one plateau and the next plateau is a sign of deterioration of the
insulation.

16
Set the switch to U-STEP. The following screen appears.
STEP FUNCTION 1
Input voltage
Frequency
Input current
Date 2011.05.24
1 V AC
50.0 Hz
24.6 nA
Time 15:31
BURN
Min. 50 V Max. 500 V
Test Run Time 00:05:00
Use the  keys to choose the preset step type of test:
Step function 1: 50 to 500V
Step function 2: 500 to 5.000V
Step function 3: 1.000 to 10.000V
The values of the voltages of each step, the number of steps, and the duration of each step can be programmed using the
CONFIG key (see §4.3).
3.3.6. CONNECTION
Depending on the measurements to be made, there are three ways of connecting the instrument.
In all cases, disconnect the device to be tested from mains.
Low insulation
Connect the red high-voltage lead between earth and the + terminal of the instrument. Connect the black high-voltage lead
between one phase of the motor and the - terminal of the instrument.
MR
U-STEP
U-RAMP
U-VAR.
U-FIXED
OFF
SET-UP
U-STEP
-
+
M

17
+
-G
G
+
-
M
High insulation
For very high insulation values, connect the small blue high-voltage lead between the rear pick-up of the black lead and the G
terminal of the instrument in order to avoid leakage current and capacitive current effects or to eliminate the influence of the
surface leakage current.
This reduces the influence of the operator’s hands and gives a more stable measurement.
Braid
Outer insulation
Insulation
Core
Using the guard eliminates the influence of the surface leakage current.
A conducting wire must be wrapped round the insulation.
Cable
Connect the red high-voltage lead between the braid and the + terminal of the instrument.
Connect the black high-voltage lead between the core and the - terminal of the instrument.
Connect the blue high-voltage lead between the insulation and the G terminal of the instrument.
Wire
surrounding
the insulation

18

CONFIG

ALARM
If the U-FIXED or U-VAR. test voltages have been selected, it is possible to select a measurement configuration by
pressing the CONFIG key (see §4.3):
Manual Stop
Manual Stop + DD
Timed Run
Timed Run + DD
DAR
PI
Then set the type of test, the maximum current, the current range, the filtering of the measurement, and the value
of the alarm threshold:
Test Type
Maximum Output Current
I-range
Disturbance Level
Alarm

DISPLAY
To enable the alarm, press the ALARM key. An audible beep will sound if the result of the measurement is below the
programmed threshold.
3.3.7. BEFORE THE MEASUREMENT
It is possible to configure the measurement using the CONFIG key
Press the START/STOP button to
start the measurement.
START/STOP

The instrument generates the high voltage. To indicate that the
measurement is in progress, the instrument emits an audible beep
every ten seconds (if the buzzer is switched on) and the START/
STOP button lights red.
START/STOP
3.3.8. DURING THE MEASUREMENT
At the end of a few seconds, the measurement is
displayed in digital form and in analog form on a
bargraph.
If the measurement is unstable, it is possible to apply a digital
filter in addition by pressing the FILTER key (see §4.6).

FILTER
If the test voltage generated is >5000V, the START/STOP button
blinks.
10 100 110 10 10
100 1100 1
kΩMΩGΩTΩ
995 MΩ
528 V 531 nA
Elapsed Time 00:00:23
Set: 500 V
E-BRK
Remark: the DISPLAY key is used to change between different screens of the same menu. While re-entering a menu, the last
used screen is shown.

19
It is possible to view the available numerical values by
pressing the DISPLAY key.

DISPLAY
995 MΩ
528 V 531 nA
Elapsed Time 00:01:12
DAR (30s/60s)
PI (1.0m/10m)
Capacitance
1.00
---
---
E-BRK
Set: 500 V
In the case of a step test voltage (10 steps at most) or ramp test voltage (3 steps), the progress of the steps is indicated.
Step 2 of 10.
Voltage of the second step.
Remaining measurement time.
5.03 GΩ
209.4 nA
Remaining Time 00:01:25
E-BRK
Step 2/10
10 100 110 10 10
100 1100 1
kΩMΩGΩTΩ
1030 V

GRAPH

CONFIG
MΩ
501 V 946 MΩ00:02:32
950
925
900
850
V
510
500
490
480
470
0 1:00 2:00 3:00 4:00
875
BURN
You can view the graphical representation of the measurement
results by pressing the GRAPH key. For more details, refer to § 4.5.
For U-VAR and U-FIXED it is also possible to change measurement parameters during the measurement by pressing the CONFIG
key. It is possible to fix the current measurement range, to add an analogue filter, or to change the test voltage if in the variable
test voltage mode U-VAR. For more details, refer to § 4.3.
In the case of a ramp measurement, the resistance displayed is always greater than the true resistance because of the permanent
capacitive current due to the permanent variation of the voltage. The value displayed will be exact only at the end of the test,
during the voltage plateau.

20
When the instrument is configured for a manual stop, once the measurement obtained is stable, press the START/
STOP button again to stop the measurement. In the other cases (programmed duration: Timed Run, Timed Run +
DD, DAR, PI, U-RAMP, or U-STEP), the measurement stops automatically at the end of the test.
START/STOP

At the end of the measurement, the instrument switches back to voltage measurement, but usually the result of the insulation
resistance measurement remains displayed. To display the voltage, press the DISPLAY key. In case of an external voltage>25V
is present, the instrument automatically switches to the screen with the test description screen and input voltage indication.
995 MΩ
528 V 531 nA
Elapsed Time 00:01:12
DAR (30s/60s)
PI (1.0m/10m)
Capacitance
1.00
---
---
E-BRKALARM
Value of the insulation resistance.
Value of the test voltage at the
end of the measurement.
Type of test.
The alarm is enabled and the
insulation resistance is below the
alarm threshold.
Duration of the measurement.
Ancillary results.
Current at the end of the
measurement.

DISPLAY
0250 500 750 1000
100
V
381V
DC
E-BRK
995 MΩ
502 V 503 nA
Elapsed Time 00:01:20
DAR (30s/60s)
PI (1.0m/10m)
Capacitance
1.00
---
<1 nF
E-BRK
3.3.9. AFTER THE MEASUREMENT
Once the measurement has been stopped, the instrument discharges the device being tested in a few seconds. For your safety,
therefore, wait a little before disconnecting the leads. Normally, this happens rapidly and the user is unaware of it. But if the
load is highly capacitive, the discharging time is longer. In this case, for as long as the voltage exceeds 25V, the instrument so
indicates on the display.
The DISPLAY key is used to look up all information available after the measurement. This information depends on
the type of measurement chosen (see §4.4).