Chauvin Arnoux C.A 6456 User manual

1
Loop and earth Ohmmeter
C.A 6456
ENGLISH User's manual

2
Meaning of the symbol :
WARNING ! Consult the user manual before using the instrument.
Failure to follow or carry out the instructions in this user manual that are preceded by this symbol may
result in personal injury or damage to the instrument and the installations.
Consult the user manual before using the instrument!
Thank you for purchasing a C.A 6456 loop and earth ohmmeter.
To get the best service from this instrument :
■read carefully this user's manual,
■respect the safety precautions
PRECAUTIONS FOR USE
This instrument can be used on category III installations at voltages not exceeding 550V with respect
to earth. Category III meets the reliability and availability requirements of uses on fixed industrial installations
(cf. EN 61010-1 + A2).
■Never use the C.A 6456 tester on installations having a potential greater than 550V with respect
to earth.
■■
■■
■Check that none of the input terminals is connected and that the switch is set to OFF before
opening the instrument.
■Use connection accessories of which the overvoltage category and service voltage are greater than or
equal to those of the measuring instrument (600V, cat. III). Use only accessories that comply with safety
standards (EN 61010-031 and EN 61010-2-032).
■Do not immerse the C.A 6456 tester!
■Repairs and metrological verifications must be carried out by approved, qualified personnel.
WARRANTY
Unless otherwise stated, our warranty is valid for twelve months (12 months) following the date on which
the equipment is made available (extract from our General Conditions of Sale, available on request).

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SOMMAIRE
1PRESENTATION ...................................................................................................................... 4
1.1 Environmental conditions ........................................................................................................... 5
1.2 Compliance with standards ........................................................................................................ 5
1.3 Power supply ............................................................................................................................. 5
2DESCRIPTION ......................................................................................................................... 6
3GENERAL USE ........................................................................................................................ 9
3.1 Automatic checks ...................................................................................................................... 9
3.2 Instrument configuration (SET-UP) ......................................................................................... 10
3.3 Compensation of the leads ...................................................................................................... 11
3.4 Recording measurement results (MEM) .................................................................................. 13
3.5 Recalling recorded values (MR) ............................................................................................... 13
3.6 Erasing recorded values .......................................................................................................... 14
3.7 Printing measurement results (PRINT) .................................................................................... 15
3.8 Printing recorded values (PRINT MEM) .................................................................................. 15
4MEASUREMENTS ................................................................................................................. 16
4.1 Voltage measurement .............................................................................................................. 16
4.2 2P and 3P earth measurement ................................................................................................ 21
4.3 Earth measurement in live condition (REARTH) ...................................................................... 25
4.4 3-wire loop measurement (Z LOOP) ........................................................................................ 32
4.5 2-wire loop measurement (Z LINE) .......................................................................................... 35
4.6 Current measurement ( ) ............................................................................................... 37
5GLOSSARY............................................................................................................................ 39
6MAINTENANCE ..................................................................................................................... 40
6.1 Replacing the batteries ............................................................................................................ 40
6.2 Storage .................................................................................................................................... 40
6.3 Cleaning .................................................................................................................................. 40
6.4 Metrological verification ........................................................................................................... 40
6.5 Warranty ................................................................................................................................. 40
6.6 Customer service .................................................................................................................... 40
6.7 Repair ..................................................................................................................................... 40
7LIST OF CODED ERRORS .................................................................................................... 41
8TO ORDER ............................................................................................................................. 41

4
1. PRESENTATION
Portable instrument for testing and checking the safety of new and existing electrical installations (loop
ohmmeter).
Measurement functions :- Voltage,
- Frequency,
- Test of protective conductor, PE,
- Earth resistance with 2 auxiliary rods (3P method)
- Coupling resistance (2P method)
- Loop impedance, with display of the resistive part and of the inductive part,
- Calculation of short-circuit currents,
- Current, with clamp,
- Selective earth resistance (with clamp).
Execution : - 8-way central switch and 7-key keypad.
Display : - Backlit 160-segment LCD display unit with two simultaneous digital displays,
A1 and A2:
- 4 digits to display up to 4,000 measurement points,
- 3 decimal points for the different display ranges.

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1.1 ENVIRONMENTAL CONDITIONS
1.2 COMPLIANCE WITH STANDARDS
1.2.1 GENERAL
The instrument complies with the following standards:
EN 61010-1,
NF EN 61557 : parts 1, 3, 5 and part 10,
EN 60529.
1.2.2 SAFETY
The instrument complies with the requirements of standards EN 61010-1 and EN 61557, i.e. :
-service voltage: 550 V,
-measurement category: III with double insulation,
-level of pollution: 2.
1.2.3 ELECTROMAGNETIC COMPATIBILITY
The device is in conformity with standard IEC 61326-1:
Emissions : Requirements on class B equipment.
Immunity : Requirements on equipment used in discontinuous operation on industrial sites.
1.3 POWER SUPPLY
Power supply : 6 LR6 1.5V alkaline batteries; they can be replaced by rechargeable sealed
batteries having a capacity of at least 1,800 mAh.
Battery life : 30 hours or approximately :
- 10,000 loop measurements or under voltage earth measurements
- 1,000 earth measurements (2P/3P) during 30 seconds
- 30,000 voltage or current measurements during 5 seconds.
1 position of the phase conductor 12
"object" number for storage
2 auxiliary earth rod detected 13
main display unit A1
3 measurement smoothed for display 14
measurement without triggering of residual current differentials
(RCD) (low power signal)
4 audible buzzer activated 15
measurement with triggering of RCD (full power level)
5 communication in progress (serial link) 16
alarm function activated or display of an alarm threshold
6 battery charge level 17
secondary function activated
7 Auto standby function deactivated 18
type of quantity displayed
8 level of memory use 19
selective measurement
9 reading/recording in memory 20
"WARNING" indicator (if it appears, refer to the manual)
10
secondary display unit A2 21
compensation of measuring cables activated
11
"test" number for storage
Temperature : Service conditions: -10 to +55°C - storage and transport (without batteries): -40 to +70°C.
%RH (without cond.) : Service conditions: 85% max. - storage and transport (without batteries): 90% max.
Tightness : IP54 as per standard NF EN 60 529.

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2. DESCRIPTION
Preliminary remarks : Several types of action are possible on each key of the keypad, depending on whether
the user presses the key briefly (short press, < 2s, validated by a beep) or at length (long press, > 2s,
validated by a beep having a tone different from that of the beep emitted for a short press).
In what follows, these different actions are symbolized as follows:
for a short press on the key in question for a press > 2s on the key in question
3
1
2
6
5
4

7
18 WAY ROTARYSWITCH :
- OFF : instrument off
- 3P : earth measurement with 2 auxiliary rods
- 2P : AC or earth coupling resistance measurement
- REARTH / : earth measurement in a live condition, with one auxiliary rod (selective earth
if clamp connected)
- ZLOOP : loop impedance measurement with 3 wires (high or low current), between
phase (L) and earth (PE)
- ZLINE : loop impedance measurement with 2 wires (high current only), between two
phases or between phase and neutral
- : current measurement
- SET-UP : configuration of the instrument
Set the switch to OFF when the instrument is not in use
27-KEY KEYPAD :
The functions of the various keys are as follows for all the settings of the switch EXCEPT the SET-UP
position (see § 3.2).
Touche 2nd :
+ press on other key => access the secondary function of the key in question
(written in yellow italics below each key)
=> display the current time and date as long as the key is kept
pressed
Touche TEST / SMOOTH :
=> start/stop a measurement (except for voltage and
current measurements, which are made directly) and
exit from the error mode
=> compensation of the measuring cables.
=> smooth the measurement (SMOOTH mode)
Touche MORE / ALARM :
=> display the measurements and/or complementary
calculations of a function, possibly in association with
the key .
=> activate/deactivate the "alarm" function.
Touche :
=> display the measurements and/or complementary
calculations of a function, possibly in association with the
key .
2nd
TEST
TEST
2nd
+
SMOOTH
TEST
2nd
2nd +
ALARM
MORE
MORE
MORE

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=> select the memory block (OBJ) or line (TEST) for storage,
retrieval on screen, or printing
=> switch the backlighting of the display unit on/off
.
Key :
with the switch set to ZLOOP and/or ZLINE:
=> select the type of measurement ("tripping" or
"non-tripping" mode )
=> increment the value of the memory block (OBJ) or line (TEST)
=> decrement the value of the memory block (OBJ) or line
TEST)
Key MEM / MR :
=> store a measurement and all information linked to it.
=> display stored measurements.
Key PRINT (PRINT MEM) :
=> print the last measurement made
=> print the selected part of the memory (part or all)
+
PRINT MEM
or
+
MR
or
+
PRINT MEM
+
MEM
2nd MEM
PRINT
2nd
+
2nd
or
+
MR
or
+
PRINT MEM
2nd MEM
PRINT
+ +
+
2nd
MEM
+
MR
MEM
PRINT
2nd
2nd PRINT
+
MEM MEM
2nd

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3BACKLIT LCD DISPLAYUNIT
4OPTICAL SERIAL COMMUNICATION INTERFACE
5SAFETY INPUT TERMINALS , dia. 4mm, marked L, N, PE and P (terminal used for earth measurements
in a live condition).
maximum voltage with respect to earth = 550 V
6MARKED SOCKET FOR THE CONNECTION OF ACURRENT CLAMP
3. GENERAL USE
The measurements are made directly (voltage, frequency, and current if a clamp is connected) or by pressing
the TEST key.
Voltage and/or frequency measurements are accessible in all "active" settings of the switch.
3.1 AUTOMATIC CHECKS
3.1.1 POSITION OF PHASE (MAINS SOCKET) CHECK
Upon connection, the instrument measures the voltages between conductors "L" and "N" (ULN), between
conductors "L" and "PE"(ULPE), between conductors "N" and "PE" ‘(UNPE), and between the voltage probe - if
a rod is connected to the terminal P - and conductor "PE".
The conductor that has the highest potential is taken to be the phase, designated by the letter "L" and
identified by one of the following displays :
Or
The measuring cable supplied with the instrument bears a white mark making it possible to determine the
position of the phase on the mains socket.
The instrument also determines the frequency for any frequency ≥15.3Hz or DC
3.1.2 THE PROTECTIVE CONDUCTOR (PE) CHECK
In a loop measurement (ZLOOP) or an earth measurement in a live condition (REARTH), when the TEST
key is pressed, the instrument first measures the potential difference UCbetween the local earth (user's
potential, via the TEST key) and the "PE" terminal.
If UC> UL, where ULis the limit contact voltage (UL= 25 or 50 V : see § 3.2 : SET-UP), the instrument
indicates that it is impossible to make a measurement.
If a measurement is triggered, the instrument then monitors voltage UNPE : if it increases by more than 20 V,
the instrument stops the measurement and reports an error.
Pressing the TEST key again causes a return to voltage measurement mode.
In a loop measurement with 2 wires (ZLINE position), measurement of the potential between
the earth and the "PE" conductor is omitted

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3.1.3 MEASUREMENT CONDITIONS CHECK
or a measurement to be authorized, in addition to the above two checks (determination of the position of the
phase and of the voltage of the PE conductor), the following conditions must be satisfied:
- ULN, ULPE and UNPE < 550 V,
- voltage: f < 450Hz; current: 20Hz < f < 450Hz,
- loop or earth measurements in live condition: f = 15,3 to 65Hz,
- correct connection of the measuring cables (terminals connected and not interchanged).
Toute interdiction de mesure est accompagnée d'un message d'erreur (voir § 7), d'un bip d'erreur et
de l'affichage clignotant du symbole .
3.2 INSTRUMENT CONFIGURATION (SET-UP)
=> Set the rotary switch to the SET-UP position.
The parameter or value configured is validated upon return to the "PUSH btn" screen.
Warning: if the switch is turned before the return to the "PUSH btn" screen, the modified data are
lost.
The table below indicates the various parameters that can be configured and their programming sequence.
Remark: generally, changes from "ON" to "OFF" and/or changes of the values of the parameters are effected
using the key.
Parameter
Time / Date
Type of power supply
Activate/deactivate automatic
shutdown
Automatic shutdown time
Activate/deactivate the buzzer
Display the internal parameters of
the instrument
Number of measurements in
"SMOOTH" mode
Printing of configuration
Printer configuration
(data rate)
Default configuration
Presses Values
Euro (JJ/MM)
US (MM/JJ)
AAAA
HH:MM
bAtt
niMH
on
OFF
01 to 59 mm
on
OFF
serial no.
software version
date of calibration
LCD screen
2 to 5
300 to 9600 bauds
Default
values
User
adjustable
bAtt
on
5mn
on
3
9600
see §3.2.1
+successive
successive
+
+
2nd
+
2nd
2nd + 2x
+ 3x
2nd
+
2nd
TEST
+
2nd
2nd
PRINT
TEST
PRINT
TEST
MEM

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3.2.1 RESTORING THE DEFAULT CONFIGURATION
This can be used to restore the delivery configuration.
In SET- UP position:
for validation and programming
of the default configuration
3.3 COMPENSATION OF THE LEADS
The leads must be compensated for measurements of low loop and earth resistance values, in order to make
the measurements more accurate.
If a compensation already exists, the symbol is displayed. To view the compensation values, use the
MORE and44
44
4keys.
PUSH
btn
dFLt
PUSH
btn
TEST
TEST
Parameter
Erase memory (totally or partially)
Reference voltage for the
calculation of Ik
Value of the low current ITEST
in "non-tripping" measurement
Threshold voltag UL
Alarms :
Earth resistance threshold
Loop resistance or impedance
threshold
Measured current threshold
Presses Values
see § 4.3.2
6.9 or 12 mA
see § 4.2.2
25 or 50 V
Default
values
voltage
measured
12 mA
50 V
see §3.6
see § 4.2.2
see § 4.4.2
see § 4.6.2
x2
x3
x4
x3
+
MEM
MORE
MORE
MORE
2nd MORE x2
+
2nd MORE
+
2nd MORE

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3.3.1 APPLYING ACOMPENSATION
Set the switch to one the LOOP/RCD positions.
Connect one end of the three-conductor cord terminated by 3 leads to the device. Short-circuit the 3 leads.
In the case of a mains outlet, connect the two earth pins with the earth pins with leads.
Perform a long press on the TEST button.
During the measurement, the device displays "LEAd" and the symbol, and the dashes blink.
At the end of the measurement, the 44
44
4key is used to view the values of R∆∆
∆∆
∆L, R∆∆
∆∆
∆Nand R∆∆
∆∆
∆PE.
3.3.2 WITHDRAW ACOMPENSATION
Set the switch to one of the LOOP/RCD positions.
Connect nothing to the terminals, or leave the leads open.
Then perform a long press on the TEST button.
During the measurement, the device displays "LEAd" and the symbol and the dashes blink.
To exit from compensation of the leads, perform a second long press on the TEST key.
If the compensation of the leads is effective, the symbol is lit steadily.
If the compensation has not been performed, the symbol is not displayed and the compensation values are zero.
At the end of the measurement, the device reports that the result found is greater than 5 Ωand withdraws the
compensation of the leads.
For exit from compensation of the leads, perform a second long press on the TEST key.
3.3.3 POSSIBLE ERROR MESSAGES
Display - Indication Remark - Possible cause
The voltage on the terminals exceeds 2 V.
Check your connections.
The measured resistance of the leads is greater than 5 Ω.
If this is not intentional, to withdraw the compensation,
check your connections.
Hz
Uxy > 2V
> 5ΩΩ
ΩΩ
Ω

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3.4 RECORDING MEASUREMENT RESULTS (MEM)
IMPORTANT - Each measurement stored in the instrument is identified by 2 indices: an OBJ no. and a
TEST no.; a given object (OBJ) generally contains several TEST nos.
For example: an OBJ no. can be used to locate an installation, and the TEST nos. identify the various
measurements made on this installation.
At any time, the user can store the result of a measurement and all of the parameters associated with the
measurement: date, time, type of measurement, measurement parameters, etc.
The location proposed by default is the first free memory location.
selection of storage address using the following keys :
and
storage at the
selected address (2)
1) "FrEE": the selected memory location is free / "OCC": the selected memory location is occupied
(2) whether the location selected is occupied or not (previously recorded values are overwritten)
Note : Up to 100 measurements can be stored (e.g. 10 objects each having 10 tests, or any other combination).
3.5 RECALLING RECORDED VALUES (MR)
The group of measurements (OBJ) and the measurement (TEST) to be retrieved on the display unit are
selected using the and keys.
measurement
to be stored
03 06
OBJ TEST
FrEE (1)
mesure
mémorisée
MEM
+
MR
2nd MEM

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3.6 ERASING RECORDED VALUES
The memory of the instrument can be erased, totally or partially, in the SET-UP rotary switch position:
Complete Erasure of a memory block Erasure of a memory line
erasure of the (OBJ) (TEST)
memory
PUSH
btn
PUSH
btn
PUSH
btn
CLr
ALL
MEM
CLr
ALL
MEM
CLr
ALL
MEM
FrEE
ALL
MEM
PUSH
btn
02 07
OBJ TEST
OCC
MEM
02 07
OBJ TEST
FrEE
MEM
PUSH
btn
02 07
OBJ TEST
OCC
MEM
02 07
OBJ TEST
FrEE
MEM
PUSH
btn
Select the
memory
block (OBJ)
to erase
Select the
memory
line TEST
to erase
X 2
MEM
MEM
MEM
MEM MEM
MEM

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3.7 PRINTING MEASUREMENT RESULTS (PRINT)
: print the measurement made and all of the parameters attached to it.
Examples of printing tickets:
Remark : In the SET-UP position, pressing the PRINT key triggers printing of the configuration of the instrument.
3.8 PRINTING RECORDED VALUES (PRINT MEM)
Recorded values can be printed with the switch in any position except SET-UP or OFF.
to select the values to be printed
01 01 : 1st memory location used
06 05 : last memory location used
Printing of all measurements
between he 1st and last
memory location selected
PRINT MEM
2nd +PRINT
PRINT
PRINT

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4. MEASUREMENTS
4.1 VOLTAGE MEASUREMENT
4.1.1 DESCRIPTION OF THE FUNCTION
Voltage measurement is accessible with the switch in any position except SET-UP or OFF.
4.1.2 PREPARATION OF THE MEASUREMENT (CONNECTION)
=> Switch the instrument on
=> Connect the instrument to the installation using
the measuring cable terminated by a mains plug,
or
=> Use the separate cables to make the connection.
4.1.3 MEASUREMENT PROCEDURE
Once connected, the instrument indicates any voltage(s) present on its terminals.
Do not use the instrument on an electrical installation exceeding 550 V with respect to earth
4.1.4 MEASUREMENT RESULTS
The measured values and complementary results can be consulted directly using
the and Keys, whatever the setting of the switch.
Parameters accessible in the 3P:
Pressing the or key once more returns to the initial display.
Parameters accessible in the 2P:
Pressing the key once more causes a return to the initial display.
Initial display
Initial display
Hz
UHE
Hz
USE
(1st press)
RE ALARM
-------
RE ALARM
-------
(2nd press)
R∆∆
∆∆
∆E
UL
R∆∆
∆∆
∆E
UL
Initial display
Initial display
Hz
UHE
(1st press)
RE ALARM
-------
(2nd press)
R∆∆
∆∆
∆E
UL
MORE MORE
MORE MORE
MORE
MORE
MORE

17
Parameters accessible in the REarth setting:
Pressing the or key once more returns to the initial display.
Parameters accessible in the ZLoop setting:
Pressing the or key once more returns to the initial display.
Parameters accessible in the ZLine setting:
Pressing the or key once more returns to the initial display.
Initial display
(1st press)
(2nd press)
(3nd press)
Initial display
Hz
ULN
Hz
ULPE
Hz
UNPE
Hz
UP
(1st press)
RAALARM
----
RAALARM
----
RAALARM
----
RAALARM
----
(2nd press)
R∆∆
∆∆
∆L
UL
R∆∆
∆∆
∆PE
UL
R∆∆
∆∆
∆N
UL
----
UL
MORE MORE
MORE
Initial dispaly
(1st press)
(2 nd press)
Initial display
Hz
ULN
Hz
ULPE
Hz
UNPE
(1st press)
UREF
ZL ALARM
UREF
ZL ALARM
UREF
ZL ALARM
(2nd press)
R∆∆
∆∆
∆L
UL
R∆∆
∆∆
∆PE
UL
R∆∆
∆∆
∆N
UL
MORE MORE
Initial dispaly
(1st press)
(2 nd press)
Initial display
Hz
ULN
Hz
ULPE
Hz
UNPE
(1st press)
UREF
ZL ALARM
UREF
ZL ALARM
UREF
ZL ALARM
(2nd press)
R∆∆
∆∆
∆L
UL
R∆∆
∆∆
∆PE
UL
R∆∆
∆∆
∆N
UL
MORE MORE
MORE
MORE

18
Parameters accessible in the current measurement setting:
Pressing the or key once more returns to the initial display.
4.1.5 CHARACTERISTICS
4.1.5.1 Measurement ranges and accuracy
Frequency : the value displayed is guaranteed only for a voltage ≥≥
≥≥
≥ 10 VRMS (all settings of the switch
except ) or, in the , position, for a current ≥≥
≥≥
≥100 mARMS
Voltage
measurements
Measurements of
the potential of
the voltage probe
Contact
voltage
measurement
Frequency
measurement
Display range
Specified
measurement domain
Accuracy
Input impedance
Operating
frequency
Specified
measurement
domain
Accuracy
Input impedance
Operating
frequency
Display range
Specified
measurement domain
Resolution
Accuracy
400 V 4000 V
2.0 - 79.9 V 80.0 - 399.9 V 400 - 550 V (DC or RMS)
± 4% ± 5 pt ± 2% ± 1 pt ± 2% ± 1 pt
440 kΩ
DC and 15.3 à450 Hz
2.0 – 100.0 V
± 15% ± 2 pt (45Hz < freq. < 65Hz)
4.5 MΩin series with 4.7 nF
15.3 to 65 Hz
400 Hz 4000 Hz
15.3 – 399.9 Hz 400 – 450 Hz
0.1 Hz 1 Hz
± 0.1% ± 1pt
Initial dispaly
(1st press)
(2 nd press)
Initial display
Hz
I
Hz
I
Hz
I
(1st press)
Hz
ULN
Hz
ULPE
Hz
UNPE
(2nd press)
----
IALARM
----
IALARM
----
IALARM
MORE MORE
MORE

19
4.1.5.2 Influencing conditions
Influencing
quanstities
Temperature
Relative humidity
POwer supply voltage
Frequency
Series mode rejection in AC
50/60Hz series mode
rejection in DC
Common mode rejection in
50/60Hz AC
Limits of the domain
of use
-10 to + 55 °C
10 to 85 % HR at 45°C
6.8 to 10 V
15.3 to 450Hz
0 to 500 V DC
Variation of the measurement
Typical Maximum
1 %/10 °C ± 1pt 2 %/10 °C + 2pt
2 % 3 % + 2 pt
1 % / V + 1pt 2%/ V + 2pt
0.5% 1%
50dB 40dB

20
4.1.6 WARNINGS OR ERROR REPORTS
Preliminary remark: The complete list of coded errors is given in § 7.
Display - Indication Remark - Possible cause(s)
One of the voltages measured (ULN, ULPE, or UNPE)
is > 550V.
Frequency outside measurement domain
(depends on type of measurement)
N and PE reversed
N not connected
N not connected and L and PE reversed
In ZLINE position :
Permutation, PE-L-N instead of L-N-PE
L and PE reversed
Permutation, N-PE-L instead of L-N-PE
In ZLINE position :
L and PE reversed
Permutation, N-PE-L instead of L-N-PE
L not connected
L not connected and N and PE reversed
UNPE > UL(threshold voltage)
In 2P or 3P position:
One of the voltages is > maximum allowed spurious voltage.
In ZLOOP or REARTH position :
Potential difference between the local earth and PE too high
Press the TEST key to exit from the error conditions. .
Hz
> 550V
<15.3Hz (or) >65Hz
or 450Hz
ULN (or) UNPE (or) ULPE
Hz
ULN
HZ
UNPE > 25 (or) 50V
Er02
L
Er03
L
Er08
n PE
Hz
UNPE > 25 (or) 50V
Hz
UC> 25 (or) 50V
Hz
UHE (or) USE> 30V