Chauvin Arnoux C.A 6545 User manual

Megohmmeters
EN - User’s manual
C.A 6545
C.A 6547

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WARNING, risk of DANGER! The operator must refer to this user’s manual whenever this danger symbol appears.
Equipment protected by double insulation.
WARNING! Risk of electric shock. The voltage on the parts marked with this symbol may be dangerous.
For safety reasons, this symbol is displayed when such a voltage is generated.
Earth.
The CE marking indicates conformity with European directives, in particular LVD and EMC.
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 2012/19/EU. This equipment must not be treated as household waste.
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 device is compliant with safety standard IEC 61010-2-030 and the leads are compliant with IEC 61010-031, for voltages up
to 1000 V in category III or 600 V in category IV with respect to earth.
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 personal protection equipment systematically.
Use only the accessories delivered with the instrument.
Respect the value and type of the fuse (see § 8.1.2) to avoid damaging the instrument and cancelling the warranty.
Set the switch to OFF when the instrument is not in use.
The battery must be charged before metrological tests.
All troubleshooting and metrological checks must be performed by competent and accredited personnel.
Thank you for purchasing a C.A. 6545 or C.A. 6547 megohmmeter.
To obtain the best service from your instrument:
read this user manual carefully,
comply with the precautions for use.

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CONTENTS
1. PRESENTATION ....................................................................................................................................................................... 4
1.1. The megohmmeters ....................................................................................................................................................... 4
1.2. The accessories (for the C.A 6547 only)......................................................................................................................... 4
2. DESCRIPTION.......................................................................................................................................................................... 5
2.1. Casing ............................................................................................................................................................................ 5
2.2. Display............................................................................................................................................................................ 7
3. MEASUREMENT FUNCTIONS................................................................................................................................................ 8
3.1. AC/DC voltage................................................................................................................................................................ 8
3.2. Insulation measurements ............................................................................................................................................... 8
4. SPECIAL FUNCTIONS ........................................................................................................................................................... 10
4.1. 2nd key ........................................................................................................................................................................ 10
4.2. V-TIME/ key ............................................................................................................................................................. 10
4.3. R-DAR-PI-DD / R(t) key ............................................................................................................................................... 10
4.4. / ALARM key ......................................................................................................................................................... 13
4.5. u/ SMOOTH key......................................................................................................................................................... 13
4.6. pq key ........................................................................................................................................................................ 13
4.7. SET-UP Function (device configuration)....................................................................................................................... 13
5. USE ......................................................................................................................................................................................... 17
5.1. Measurement procedure .............................................................................................................................................. 17
5.2. Insulation measurement ............................................................................................................................................... 17
5.3. Capacitance measurement .......................................................................................................................................... 18
5.4. Residual and leakage current measurement ................................................................................................................ 18
6. MEMORY / RS 232 (C.A 6547) .............................................................................................................................................. 19
6.1. RS 232 Characteristics................................................................................................................................................. 19
6.2. Recording/PLAYBACK of stored values (MEM/MR key).............................................................................................. 20
6.3. Printing measured values (PRINT/PRINT MEM key) (C.A 6547) ................................................................................. 20
6.4. Printing with series-parallel adapter............................................................................................................................. 22
7. SPECIFICATIONS................................................................................................................................................................... 23
7.1. Reference conditions.................................................................................................................................................... 23
7.2. Characteristics per function ........................................................................................................................................ 23
7.3. Power Supply ............................................................................................................................................................... 26
7.4. Environmental parameters ........................................................................................................................................... 27
7.5. Construction specifications.......................................................................................................................................... 27
7.6. Compliance with international standards..................................................................................................................... 27
7.7. Variations in operating range........................................................................................................................................ 28
8. MAINTENANCE...................................................................................................................................................................... 29
8.1. Battery recharge ........................................................................................................................................................... 29
8.2. Replacing the fuse........................................................................................................................................................ 29
8.3. Cleaning ....................................................................................................................................................................... 29
8.4. Storing .......................................................................................................................................................................... 29
9. GUARANTEE .......................................................................................................................................................................... 30
10. DELIVERY CONDITION ....................................................................................................................................................... 31
10.1. Accessories ................................................................................................................................................................ 31
10.2. Spare parts................................................................................................................................................................. 31

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1. PRESENTATION
1.1. THE MEGOHMMETERS
The C.A 6545 and C.A 6547 megohmmeters are portable units, fitted into a rugged construction site casing with cover, operating
on battery or line power.
They are used to measure:
voltages,
insulation,
capacitance.
These megohmmeters help to ensure the safety of electrical installations and equipment.
Their operation is controlled by microprocessor for the acquisition, processing, measurement display, storage and printing of
results (C.A 6547).
They offer a wide range of advantages such as:
digital filtering of insulation measurements,
automatic voltage measurement,
automatic detection of the presence of AC or DC external voltage on terminals, before or during the measurements, which
inhibits or stops the measurements,
threshold programming, to trigger alarms using audible beeps,
the timer for measurement time checks,
protection of the device by fuse, with detection of defective fuses,
operator safety by means of automatic discharge of the residual high voltage on the equipment tested,
automatic power save mode of the device to save battery power,
indication of battery charge condition,
a large backlit LCD screen with a wide range of indicators making it very easy for the user to read.
The C.A 6547 integrates the following additional functions:
Memory (128 kb), real time clock and serial interface,
PC control of the device (using PC software, optional),
Printing in RS 232 or Centronics mode.
1.2. THE ACCESSORIES (FOR THE C.A 6547 ONLY)
1.2.1. PC SOFTWARE (OPTIONAL)
This PC software is used for:
recovering stored data, plotting the insulation resistance versus the test voltage application time, R(t),
printing customised test protocols in accordance with user needs,
creating text files to use spreadsheets (ExcelTM ...),
configuring and controlling the unit via the RS 232,
1.2.2. SERIAL PRINTER (OPTION)
This compact printer is used to print the measurement results directly in the field, whether stored or not.
1.2.3. SERIAL-PARALLEL ADAPTER (OPTION)
The optional RS232/Centronics adapter converts the serial interface (RS232) into a parallel printer interface (Centronics), enabling
direct printing of all measurements on A4-format office printers, without having to use a personal computer.

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2. DESCRIPTION
2.1. CASING
➇
➆
➅
➄
➃
➂
➁
➀
110-230V
50/60 Hz
20 VA max
C.A 6547
MEGOHMMETER
SMOOTH ALARM
V/TIME
FF 0.1A
380V-10kA
5x20mm
START/STOP
> 2500V
SET-UP
Var
50-5000V
5000V
10T Ω
2500V
10T Ω
1000V
4T Ω
500V
2T Ω
OFF
INTERFACE
MEM PRINT
MR PRINT MEM R(t)
2nd
( 2500V )
R-DAR-PI-DD
1000V CAT III
600V CAT IV

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➀3 safety terminals, Ø 4 mm, marked: "+", "G" and "-".
➁Access to terminal "G" protective fuse.
➂7-way rotary switch:
OFF: switches off unit power
500 V - 2 TΩ: insulation measurement at 500 V, up to 2 TΩ
1000 V - 4 TΩ: insulation measurement at 1000 V, up to 4 TΩ
2500 V - 10 TΩ: insulation measurement at 2500 V, up to 10 TΩ
5000 V - 10 TΩ: insulation measurement at 5000 V, up to 10 TΩ
Var. 50 - 5000 V: insulation measurement with variable test voltage
SET-UP: adjustment of unit configuration
➃1 yellow START / STOP push button: start / stop of measurement.
➄6 keys (C.A 6545) or 8 keys (C.A 6547) made of elastomer, each having a main function and a secondary function:
2nd Selection of the second function (in yellow Italics above each key).
R-DAR-PI-DD Primary function: before the insulation measurements, selection of required measurement type:
normal measurement, calculation of dielectric absorption ratio (DAR), calculation of polarisation
index (PI) or Dielectric Discharge test DD. After or during the measurements, display of R, DAR, PI,
DD and capacitance (µF).
R(t) Secondary function: display/no display of intermediate values of insulation resistance, test voltage
and time stamp, following a programmed time test (the V-TIME and pq keys may also be used).
V / TIME Primary function: In insulation, display of elapsed time from the beginning of measurement, then
of exact voltage generated. In MR (memory recall) mode, display of the date and time of the stored
measurement, of the exact test voltage and of the memory address OBJ:TEST.
Secondary function: activation/deactivation of “programmed time test” mode.
Primary function: ON/OFF of display backlight.
ALARM Secondary function: activation/deactivation of alarms programmed in SET-UP.
uPrimary function: Select a parameter for modification.
SMOOTH Secondary function: ON/OFF for display smoothing during insulation measurement.
pPrimary function: increments the displayed flashing parameter. Browse the list of intermediate
insulation results in the R(t) function.
qSecondary function: decrements the flashing parameter displayed. Browse the list of intermediate
insulation results in the R(t) function.
If the pand qkeys are pressed and held, the parameter changes faster.
On the C.A 6547 only
MEM Primary function: storage of measured values.
MR Secondary function: recall of stored data.
PRINT Primary function: immediate printing of measurement result.
PRINT MEM Secondary function: printing of memory content.
➅Backlit liquid crystal display.
➆Socket for connection to AC network (direct operation on AC network/battery recharge).
➇Male connector RS 232 serial interface connector (9-pin) for connection to a PC or printer (C.A 6547 only). On the C.A
6545, this connector is used for adjustments of the instrument only.

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2.2. DISPLAY
ALARM µFµA
0.1M
1M
10M
100M
1G
10G
100G
1T
REMOTE
OBJ.
min sec
SMOOTH
TEST
MEM MR
2
DARDD
PI
V
DC
AC
nA
nd
2.2.1. DIGITAL DISPLAY
The main digital display indicates the values for insulation measurement values: resistance, DAR PI, DD or capacitance).
The small digital display indicates the voltage measured or applied by the instrument.
During the insulation measurement, the elapsed time or the output voltage is displayed.
After the recording of a group of data (C.A 6547), the small display also indicates the date and time in MR (Memory recall) mode.
It is also used to indicate the memory address using the OBJ:TEST number. (see § 2.2.3).
2.2.2. BARGRAPH
The bargraph is active during insulation measurement (0.1 MΩto 1 TΩ). It is also used, to indicate the battery charge, and the
memory space.
2.2.3. SYMBOLS
MEM/MR indicates the storage (MEM) or memory reading (MR) operations (C.A 6547).
OBJ:TEST Memory address (C.A 6547): the number is displayed above, on the small digital display.
COM Indicates that the instrument is sending data to the printer via the interface (C.A 6547).
DAR/PI/DD indicates the mode chosen before the insulation measurement or the results of these measurements.
Voltage generated dangerous, U > 120 Vdc.
External voltage present.
Activation of the "Programmed-time test" mode or, on the SET-UP position of the switch, clock adjustment (C.A
6547). Flashes for each sample recorded.
2nd Indicates that the secondary function of a key will be used.
Indicates that the battery is low and must be recharged (see § 8).
The voltage is displayed on the small digital display for 2 seconds when the device is switched on. The main
display indicates “bat”.
The audio warning (buzzer) is activated.
Indicates that the automatic power save mode function is deactivated.
SMOOTH Smoothing of insulation measurement display.
REMOTE Remote control via interface (C.A 6547). In this mode, all keys and the rotary switch are inactive, except the
OFF position.
FUSE -G- Indicates that the fuse of input “G” is defective.

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3. MEASUREMENT FUNCTIONS
3.1. AC/DC VOLTAGE
Any rotation of the switch on an insulation position sets the unit to automatic AC / DC voltage measurement. The voltage is
measured continuously and indicated on the small display.
The start of the insulation measurements is inhibited if an excessively high external voltage is present on the terminals, before
pressing START. Also, if an excessively high parasitic voltage is detected during these measurements, they are automatically
stopped and the voltage is indicated (see § 3.2).
Switching between the AC and DC modes is done automatically, in AC mode the RMS value is indicated.
3.2. INSULATION MEASUREMENTS
When the switch is rotated to an insulation position, the main display shows “tESt” and the small display shows the selected
test voltage for a short time. If the test voltage is limited to a smaller value than selected, because of a test voltage limit set in
SET-UP (see § 4.7.6), “LIM” is shown (instead of “tESt”) together with the actual voltage value. After that the main display shows
“- - - - MΩ” and the small display shows the voltage present at the + and - terminals of the instrument.
If, when the START key is pressed, the external voltage present at the terminals of the unit is higher than the value defined by
the equation below, the insulation measurement is not triggered an audible warning signal sounds and the main display shows
the message “> diSt” for a short time, then the instrument returns to automatic voltage measurement.
Upeak > 0,4 x dISt x Un
with:
Upeak: peak or DC external voltage present on unit terminals
dISt: coefficient defined in the set-up menu (adjustable to 0.03 - 0.10 - 0.20 - default value: 0.03)
Un: test voltage chosen for insulation measurement
If the external voltage at the terminals of the unit is less than the value defined previously, the insulation measurement is authorised.
Pressing the START key immediately triggers the measurement. The value of the measurement is displayed on the main digital
display and on the bargraph. There is a beep every 10 seconds to indicate that a measurement is in progress.
If the voltage generated might be dangerous (> 120 V), the symbol is displayed.
If, during the insulation measurements, an external voltage higher than the value defined by the relation below is detected,
the measurement is aborted. The symbol flashes and the external voltage value is displayed on the small digital display.
U peak > (dISt + 1.1) Un
Note: Adjustment of the dISt factor optimises the measurement settling time. If there is no parasitic voltage present, the dISt
factor may be adjusted to the smallest value (0,03) to obtain the shortest possible settling time for the measurement.
If a significant parasitic voltage is present, the dISt factor may be increased so that the measurement is not interrupted or even
made possible in the first place. This means optimisation of the settling time in the presence of the parasitic voltage.
If the measurements are unstable, it is possible to use the SMOOTH function (see § 4.5).
Pressing on the V-TIME key during the measurement alternately displays the measurement time and the exact voltage generated
on the small display (see § 4.2).
The stopping of the measurement is caused by pressing the STOP key. After the measurement stops, the main result remains
displayed.
It is possible to scroll through all the other results available on the main display using the R-DAR-PI-DD key. This key may also
be used before the triggering of the measurement (see § 4.3).
If the "Programmed time test" mode was selected, the R(t) key is used to access all the intermediate results stored automatically
(see § 4.2 and 4.3).
If the ALARM function is activated, a buzzer will sound as soon as the measurement exceeds or falls below the programmed
threshold in the SET-UP configuration menu (see § 4.4).

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Display of values after a measurement
The indications below may be displayed:
R-DAR-PI-DD key V-TIME key
Main display Small display Small display
if the MR key is activated (C.A 6547)
Resistance
DAR
PI
DD 1
Current
Capacitance 2
R(t)
duration (min. sec)
duration (min. sec)
duration (min. sec)
duration (min. sec)
duration (min. sec)
duration (min. sec)
date, time, test voltage, OBJ:TEST
date, time, test voltage, OBJ:TEST
date, time, test voltage, OBJ:TEST
date, time, test voltage, OBJ:TEST
last test voltage
1: The value of DD is displayed only one minute after the measurement stops.
2: The capacitance measurement (µF) is displayed only after the measurement stops and the circuit has been discharged.

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4. SPECIAL FUNCTIONS
4.1. 2nd KEY
This key is used to select the secondary functions of the function keys. It is always related to the
2
nd symbol.
This symbol disappears as soon as the selected function key is pressed, unless the qkey is activated.
In this case, it disappears only if the 2nd key is pressed again or if other function keys are pressed. This is used to rapidly decrement
the parameters using the qkey without having to press the 2nd key each time.
4.2. V-TIME/ KEY
V-TIME primary function
This key is used to show all available secondary information on the small display, both during and after measurement.
In the insulation measurement function:
Time elapsed since the beginning of the measurement,
Measurement voltage,
In memory recall mode (MR) (C.A 6547): date, time, measurement voltage, measurement duration and OBJ:TEST number.
Secondary function (Programmed-time test)
The small display shows the measurement duration programmed in the SET-UP, the symbol is ON. Pressing the START
key starts the measurement.
By default, the measurement lasts 30 minutes, but this value can be changed in the SET-UP menu.
As soon as the measurement has started, the small display decrements the remaining time.
When this time reaches zero, measurement stops.
During the running of a programmed-time test, intermediate samples (resistance/voltage values as a function of time) are
automatically stored.
The time between samples is 30 s by default, but this value may be changed in the SET-UP menu.
The samples may be displayed using the R(t) function (see § 4.3) as long as a new measurement has not been launched. They
are erased at each new measurement.
They are automatically stored with the final value of the resistance when using the MEM function (storage) (C.A 6547).
If the position of the rotary switch is modified, or if the STOP key is pressed during the measurement, the measurement is
aborted.
4.3. R-DAR-PI-DD / R(t) KEY
R-DAR-PI-DD primary function
The R-DAR-PI-DD key is used to calculate automatically the Polarisation Index (PI) and the Dielectric Absorption Ratio (DAR) or
perform a Dielectric Discharge test (DD).
These PI and DAR values are particularly useful for monitoring the ageing of the insulation of rotating machines or very long
cables, for example.
On this type of component, the measurement is disturbed at the beginning by parasitic current flows (capacitive load current,
dielectric absorption current) which decrease with time. To measure exactly the representative leak current of the insulation, it
is therefore necessary to perform long duration measurements, to by-pass the parasitic currents present at the beginning of
measurements.
Then the PI or DAR ratios are calculated:
PI* = R 10 min / R 1 min (2 values to be noted during a 10-min. measurement)
DAR = R 1 min / R 30 s (2 values to be noted during a 1-min. measurement)

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The quality of the insulation is a function of the results.
DAR PI Condition of insulation
< 1,25 < 1 Insufficient or even
dangerous
< 2
< 1,6 < 4 Good
> 1,6 > 4 Excellent
For multilayer insulation, if one of the layers is defective but if all the others show strong resistance, the calculation of the PI and
PAR ratios is not sufficient to show up this type of problem. It is therefore necessary to supplement the PI and DAR indications
by a dielectric discharge test used to calculate the DD term.
This test measures the dielectric absorption of heterogeneous or multilayer insulation while ignoring the parallel-surface leak
currents. It consists of applying a test voltage for a period sufficient to electrically “charge” the insulation to be measured (a typical
value is the application of a 500 V voltage for 30 minutes).
An ordinary insulation measurement or a programmed-time test is done for the desired duration and at the desired test voltage.
When ending the insulation measurement the test object is discharged fast and the capacitance is measured. After one minute
the residual current through the test object is measured.
The term DD is then computed from the equation below:
current measured after 1 minute (mA)
DD = test voltage (V) x capacitance measured (F)
The indication of the insulation quality as a function of the resulting value is as follows:
DD value Insulation quality
7 < DD Very bad
4 < DD < 7 Bad
2 < DD < 4 Doubtful
DD < 2 Good insulation
Note: The dielectric discharge test is particularly suited for the insulation measurement of rotating machines and in general for
the insulation measurement of heterogeneous or multilayer insulation containing organic materials.
Utilisation of the R-DAR-PI-DD function
During or after a measurement, the R-DAR-PI-DD key is used to scroll through the values:
DAR (if measurement > 1 min)
PI 3 (if measurement > 10 min)
DD can only be calculated 1 mn after the end of the insulation measurement and circuit discharge, and only if it was
selected before beginning the measurement
Capacitance in µF (only after the stopping of the measurement and the discharging of the circuit)
Leakage current circulating in the installation in µA or nA
Insulation resistance in MΩor GΩor TΩ
Note: During the measurement, the DAR value is not available if DD was preselected before the measurement. During the
measurement the value PI is not available if DAR or DD was preselected before the measurement.
Automatic DAR or PI measurement:
If the R-DAR-PI-DD key is actuated during the voltage measurement before the start of a measurement, the display is as follows:
- - - - MΩ→DAR - - - - →PI - - - - →DD - - - -
↑
and the value of the input current (between terminals "+" and "-") is indicated.
Note: The input current may be a depolarisation current resulting from an earlier insulation measurement. It is recommended
to start a new DAR and PI measurement after the current has dropped to a negligible value (on the order of 100 pA) to
avoid variations on these measurements.
3: For the PI calculation, the 10 and 1 minute times can be modified in the SET-UP menu, so to adapt to any normative changes
or specific applications.

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Depending on the choice (DAR, PI or DD), here is the measurement procedure:
a) DAR: press START →the DAR symbol flashes and the display indicates “- - - -” as long as the calculation of the coefficient
is impossible (t < 1 min).
For example: DAR - - - -
After 1 min. the measurement stops, the DAR symbol becomes steady and the main display automatically shows the DAR
value if the calculation was possible.
The R-DAR-PI-DD key may be used during and after the measurement to see the insulation measurement performed, but it
does not provide the PI value, since the measurement did not last long enough.
b) PI: press START →the PI symbol flashes and the display indicates “- - - -” as long as the calculation of the coefficient is
impossible (t < 10 min).
For example: PI - - - -
After 10 min. the measurement stops, the PI symbol becomes steady and the main display automatically shows the PI value
if the calculation was possible.
During and after the measurement, the R-DAR-PI-DD key is used to display the DAR (after 1 min), the PI (after 10 min.) and
the insulation measurement.
c) DD: press START →the DD symbol flashes and the display indicates “- - - -” as long as the calculation of the coefficient is
impossible (insulation-measurement time + 1 min.).
For example: DD - - - -
1 min. after the measurement stops, the DD symbol becomes steady, the display automatically shows the value of DD if the
calculation was possible.
Therefore: if the measurement lasts 1 minutes →DAR
if the measurement lasts 10 minutes →PI
and 1 minute after the end of the measurement →DD
Note: If, during the measurement of DAR, PI, or DD, whether automatic or not, there is a strong external disturbance, or if the
insulation resistance exceeds the device’s measuring ranges, the measurement of DAR or PI is aborted and the following
is shown on the display:
In such case the measurement provides no result for DAR or PI.
A capacitance parallel to the insulation resistance extends the settling times of the measurements. This can affect or even
inhibit the measurement of DAR or PI (depending on the time set in SET-UP for recording the first resistance value). The
following table shows typical values for the capacitance parallel to the insulation resistance, at which a successful DAR or PI
measurement is still possible.
The display of the DD value is:
unknown (- - - -) if C < 1 nF or Idd < 100 pA
known and flashing if 1 nF ≤C < 10 nF and 100 pA ≤Idd < 1 nA
known and steady if C ≥10 nF and Idd ≥1 nA
(with C = measured capacitance and Idd = current measured after 1 minute)
Secondary function R(t)
The R(t) key is used to access the intermediate insulation resistance values measured as a function of time, after a measurement
in “Programmed-time test” mode (see § 4.2).
The time between each stored samples is programmed in the SET-UP configuration menu.
This function is also available on model C.A 6545 that has no RAM for the storage of measured data, or interface to recover this
data from the instrument on a PC.
After pressing the R(t) key, the instrument switches to display mode:
the small display indicates a time of 00:30 (if the sampling frequency is 30 s)
the main display indicates the corresponding value R.
DAR ou PI
or

13
The V-TIME key is used to alternate between time and voltage (on the small display), with the value R on the main display.
The pq key is used to scroll through all the samples stored during the measurement. This makes it possible to note the elements
for an R(t) and U(t) diagram.
It is therefore possible to perform, on-site, an R(t) analysis with no printer or PC.
A new press of the R(t) key, will exit the function.
4.4. / ALARM KEY
Primary function
This function is used to activate or deactivate the backlight.
Secondary function ALARM
Activation/deactivation of the ALARM function. The corresponding symbol is displayed when activated.
If this function is active and the limit programmed in the SET-UP menu is exceeded or fallen below during the measurement, the
ALARM symbol will flash and the buzzer (if activated) will sound continuously.
It is possible to program a different limit for each test voltage, the limits will be stored even if the instrument is switched off.
4.5. u/ SMOOTH KEY
Primary function u
Used to select a parameter for modification – the active parameter flashes.
It may be modified using the pq key (see § 4.6).
Secondary function SMOOTH
Used to activate a digital filter for insulation measurements. It affects only the display (which is smoothed) and not the measurements.
This function is useful in case of high instability of the displayed insulation values, caused by a strong capacitive component of
the part to be tested, for example. The time constant for this filter is approximately 20 seconds.
4.6. pq KEY
This function is used to modify the flashing parameters displayed, or to consult the R(t) values (see § 4.3).
In general, two figures (day, month, hour, min., sec., OBJ:TEST) flash.
The pand qfunctions have a "wraparound" mode: when the upper or lower modification limit is reached, the parameter to be
modified automatically jumps to the other limit. .
Primary function p:A brief press increments the displayed number by one unit.
A longer pressure on this key will cause fast incrementation.
Secondary function q:A brief press decrements the displayed number by one unit.
A long press, will cause rapid decrementation.
Contrary to all the secondary functions of the other keys, it is not necessary in this case to press the 2nd key each time to
access the function q. The
2
nd symbol remains displayed and therefore valid (for the function qonly) as long as the user
does not deactivate it by pressing the 2nd key again or another key.
4.7. SET-UP FUNCTION (DEVICE CONFIGURATION)
This function, located on the rotary switch, is used to change the configuration of the device by accessing directly the parameters
to be modified.
After turning the rotary switch to the SET-UP position:
all the segments of the display are activated for 1 second,
the number of the software version is displayed
the serial number of the device is displayed
PUSH then appears on the small display and btn on the main display, to prompt you to press a key.
The SET-UP function is then used to access directly the parameters to be modified, by pressing the corresponding key:
After pressing a key, the figures or symbols corresponding to the function selected appear on the screen.
The modifiable figures or symbols will flash. The normal modification procedure using the uand pq keys must be used.
All the parameters are recorded immediately and permanently.

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The following table defines the active keys in the SET-UP function and the corresponding display, with the possible adjustment
ranges.
Parameters
to be modified Control key Display
main small symbols values
Test duration, in “Programmed-
time test" mode tESt 30: 00 min. sec 01:00 - 59:59
1nd and 2nd time for PI calculation R-DAR-PI-DD
second
period
(10:00)
first period
(01:00) min: sec 00:30 - 59:59
Time between samples in
“Programmed-time test” mode R(t) 00: 30 min: sec 00:05 - 30:00
Limit for 500 V - 2 TΩALARM 500 kΩ500 V ALARM < 30 k-2 TΩand ><
Limit for 1000 V - 4 TΩALARM (2nd press) 1 MΩ1000 V ALARM < 100 k-4 TΩand ><
Limit for 2500 V - 10 TΩALARM (3rd press) 2.5 MΩ2500 V ALARM < 300 k-10 TΩand ><
Limit for 5000 V - 10 TΩALARM (4th press) 5 MΩ5000 V ALARM < 300 k-10 TΩand ><
Limit for Var-50/5000 V ALARM (5th press) 5 MΩSet ALARM < 10 k-10 TΩand ><
Time V-TIME 12:55 hour (00-23)
minute (00-59)
Date (Europe version) V-TIME (2nd press) 17.03 2000 dd.mm.yyyy
Version: USA, Europe V-TIME (3rd press) USA/Euro USA/Euro
Erase memory MEM then
MEM (2 s) cLr ALL MEM
Selective deletion of memory MEM then uand pq and
MEM (2 s) FrEE / OCC OBJ:TEST Number MEM 00 - 99
Baud PRINT 9600 bAUd 300 - 9600
or "parallel"
Buzzer On On / OFF
Auto cut-off (2nd press) On On / OFF
Configuration by default (3rd press)
then START DFLt SEt
Dielectric test voltage (4th press) SEt 100 V V 40 - 5100 V
Disturbance Limit voltage (5th press) 0.03 U dISt V 0.03 / 0.10 / 0.20
Automatic range (6th press) Auto rAnG Auto/1/2/3
Test voltage locking (7th press) oFF 1000 V On / OFF
40 - 5100 V
The values shown in this table, in the “main display” and “small display” columns, are default values programmed at the factory.
In case of mistaken modification, it is possible to restore them: see § 4.7.3.

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4.7.1. MEMORY DELETION
In SET-UP, press the MEM key:
The MEM symbol flashes,
ALL is shown flashing on the small display,
The main display indicates cLR.
To delete the entire memory, press again on the MEM key for 2 seconds:
The MEM symbol is displayed steady,
ALL is shown constant on the small display,
The main display indicates FrEE.
To delete the content of a specific OBJ:TEST:
Select the number using keys uand pq,
FrEE or OCC is shown on the main display,
Press again on the MEM key for 2 seconds to delete:
The OBJ:TEST is indicated on the small display,
The main display indicates FrEE.
4.7.2. OUTPUT IN BAUDS (RS 232)
In SET-UP, press the PRINT key:
The main display indicates the output in bauds, i.e. 300, 600, 1200, 2400, 4800, 9600 or Parallel.
On the small display, baud appears. The value may be modified using the keys pand q.
The “Parallel” display means that the parallel mode is selected, to print on parallel printers via the serial/parallel adapter (RS
232-Centronics).
4.7.3. DEFAULT CONFIGURATION OF THE DEVICE
In SET-UP, 3rd press on the key:
The small display shows SEt,
The main display shows DFLt (flashing).
Press on START to reconfigure the device using the default parameters (see previous table).
4.7.4. VOLTAGE DISTURBANCE LIMIT
In SET-UP, 5th press on the key:
The small display indicates dISt,
The main display shows 0.03U (flashing),
Modify this value if necessary using the pq key (choice between: 0.10 - 0.20 - 0.03).
Note: This adjustment provides the best compromise between the measurement settling time and the presence of external
parasitic voltages (§ 3.2).
If no parasitic voltage is present, this value will be chosen equal to 0.03 to obtain a rapid measurement settling time.
4.7.5. AUTOMATIC MEASURING RANGE
In the SET-UP, 6th press on the key:
The small display indicates rAnG,
The main display indicates Auto.
Use the pq key to choose a fixed (1, 2 or 3 on the main display) or automatic (Auto on the main display) measurement range
Note: The fixed measurement ranges correspond to the following measurement current ranges:
1: 50 pA to 200 nA
2: 150 nA to 50 µA
3: 30 µA to 3 mA
The choice of a fixed measurement range optimises the measurement settling time for a known insulation resistance.
Example: Choice of range 1 for a measurement greater than 500 GΩat 500 V.

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4.7.6. TEST VOLTAGE LIMIT
In the SET-UP, 7th press on the key:
The small display indicates 1000 V,
The main display indicates OFF,
Choose On or OFF using key pq and modify if necessary the value of the voltage using key uthen key pq.
Note: This function limits the test voltage for the insulation measurement to the maximum value which is set here, if this function
is enabled. This enables the device to be used by less experienced persons for specific applications (telephony, aerospace,
etc.).
This limit may be hidden by using the application software.
Example: By choosing On and a test voltage limit of 750 V, the measurement will be performed at 500 V for the corresponding
position on the rotary switch and at 750 V for all the other positions on the rotary switch (LIM appears for 3 seconds on
the main display).

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5. USE
5.1. MEASUREMENT PROCEDURE
Start up the instrument by setting the switch to the desired measurement position. All the segments of the LCD screen are
displayed, then the battery voltage.
Connect the + and - leads to the measurement points.
The input voltage is measured continuously and indicated on the small display.
If an external voltage higher than the authorised limit value (see § 3.2) is present, the measurement will be inhibited.
A press on START/STOP starts the measurement.
Another press on START/STOP stops the measurement. The last result remains displayed until the next measurement or the
rotation of the switch.
If a voltage higher than the authorised limit value (see § 3.2) appears during all the measurements, the device will indicate this
voltage on the small display using the flashing warning symbol and stop the measurement in progress.
Note: A certain number of special functions may be used (see § 4).
5.2. INSULATION MEASUREMENT
(See § 3.2)
With this function, the instrument can measure insulation between 10 kΩand 10 TΩ, according to the chosen test voltage (among
500 - 1000 - 2500 - 5000 V) or programmed voltage (between 40 V and 5100 V).
Position the switch on "500 V-2 TΩ", or "1000 V-4 TΩ", or "2500 V-10 TΩ", or "5000 V-10 TΩ" or "Var 50-5000 V"
Connect the device to the part to be tested.
If the voltage present is higher than the authorised limit value (see § 3.2) the measurement will be inhibited.
Start the measurement and note the results.
It is possible to scroll through all the results on the main display using the R-DAR-PI-DD key (see § 4.3) or on the small display
using the V-TIME key (see § 4.2).
R(t) is used to access the intermediate values measured and stored at a rate set in SET-UP, in "Programmed-time test" mode.
These samples are available until the start of another measurement or until the next rotation of the switch (see § 4.3)
To measure high insulation values (> 1 GΩ), you are advised to use the "G" guard terminal to remove the influence of surface
leakage currents. The guard terminal should be connected to a surface where surface leakage currents may flow via dust and
humidity: for example, the insulation surface of a cable or transformer, between two measurement points.
As soon as insulation measurements stop, the tested circuit is automatically discharged via an internal resistor of the device.
Connection diagram for measurement of low insulation values (example of a motor)
+
-
M

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Connection diagram for measurement of high insulation values
a) Example of a motor (reduction of capacitive effects)
+
G
-
M
b) Example of a cable (reduction of surface leakage effects)
G
-
+
5.3. CAPACITANCE MEASUREMENT
Capacitance measurement is performed automatically during the insulation measurement, and is displayed after the measurement
stops and the discharge of the circuit, using the R-DAR-PI-DD key.
5.4. RESIDUAL AND LEAKAGE CURRENT MEASUREMENT
The residual current circulating in the installation is measured automatically during an insulation measurement. It is displayed at
the end of the measurement with the R-DAR-PI-DD key.
External insulator
Braid
Insulator Guard
Cable
Core

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6. MEMORY / RS 232 (C.A 6547)
6.1. RS 232 CHARACTERISTICS
The speed in bauds may be adjusted to 300, 600, 1200, 2400, 4800, 9600, or “Parallel” (for printing on parallel printers via
the optional serial/parallel adapter).
This adjustment is performed in the SET-UP menu (see § 4.7.2).
Data format: 8 data bits, 1 stop bit, no parity, protocol Xon / Xoff.
Connection to serial printer.
22
33
55
Connection to a PC or a parallel printer.
Required links DB9 ➔B25 (➀→➁) ■Conversion DB25 ➔DB9 (➁→➂):
(standard null-modem cable):
1 ➔8 6 ➔20 2 ➔3
2 ➔2 7 ➔5 3 ➔2
3 ➔3 8 ➔4 7 ➔5
4 ➔6 9 ➔22
5 ➔7
➂
➁
➀
Front view Front view
9-pin female
connector to C.A 6547
9-pin male connector
to serial printer
9-pin connector
to C.A 6547 9-pin connector
to PC
25-pin connector 25-pin connector to PC or
serial-to-parallel adapter

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6.2. RECORDING/PLAYBACK OF STORED VALUES (MEM/MR KEY)
6.2.1. PRIMARY MEM FUNCTION (STORAGE)
This function is used to record results in the device’s RAM.
These results can be recorded at an address identified by an object number (OBJ) and a test number (TEST).
An object represents a “box” in which 99 tests can be stored. An object can thus represent a machine or an installation on which
a number of measurements will be performed.
1.When the key is activated, the MEM symbol flashes and the small display indicates the next free OBJ:TEST, for example, 02:01.
The main display indicates FrEE.
It is always possible to modify the OBJ:TEST using the uand the pq keys.
If the user selects an already occupied memory address, OCC appears on the main display.
If a new OBJ is selected, TEST is set to 01.
2.By pressing the MEM key again, the results of the present measurement will be recorded in the selected memory address
(whether occupied or not). The MEM symbol no longer flashes and remains displayed. The time and date of this recording are
stored with the data already available (R, U, t).
If the switch is turned before the second press of MEM, the record mode will be exited without the results being stored.
3. If a programmed-time test was performed, intermediate measurements (samples) are available (see § 4.3). They are automatically
recorded under the same OBJ number: TEST as the final measurement.
Memory space available
This function is automatically activated when recording a result.
Press once on MEM to obtain the next free OBJ:TEST; the indication of the bargraph is proportional to the free memory available.
If the entire memory is free, all the segments are activated.
If the entire memory is full, the left-hand bargraph arrow flashes.
When the recording is completed, the bargraph disappears.
6.2.2. SECONDARY MR FUNCTION
The MR function is used to recall data from the memory.
When the key is activated, the MR symbol is displayed (not flashing).
The small display indicates the last occupied OBJ:TEST, for example, 02:11.
“11” above the TEST symbol is flashing, the normal modification procedure with keys uand pq must be used to select the
desired OBJ:TEST.
If a new OBJ is selected, TEST is automatically set to the largest stored number.
The values at the address selected by OBJ:TEST are shown in the main display. Additional results can be viewed using the
R-DAR-PI-DD key.
The V-TIME key is active and gives access to date, time, voltage, duration and OBJ:TEST number of each stored measurement.
If the recording selected by the OBJ:TEST number corresponds to a programmed-time test , the R(t) values can be accessed
by pressing the R(t) key (see § 4.3).
To exit the R(t) mode and return to the normal memory recall condition (OBJ:TEST), press the R(t) key again.
To exit the MR function, press MR again or turn the switch.
6.3. PRINTING MEASURED VALUES (PRINT/PRINT MEM KEY) (C.A 6547)
If you use a serial printer, choose the appropriate communication speed in the SET-UP menu, between 300...9600 bauds, then
program the printer for the format used by the instrument (see § 6.1).
If you use a parallel printer, you must adjust the speed to “Parallel” in SET-UP and use the series/parallel adapter sold optionally
(connect in series the cable delivered + adapter + Centronics printer cable).
Two print modes are available:
Printing of the present measurement result (PRINT)
Printing of stored data (PRINT MEM)