Readability (d) 1 g / 2 g 2 g / 5 g 2 g / 5 g
Weighing range (max) 3 kg / 6 kg 6 kg / 15 kg 6 kg / 15 kg
Minimum load (Min) 20 g 40 g 40 g
Verification value (e) 1 g / 2 g 2 g / 5 g 2 g / 5 g
Verification class III III III
Reproducibility 1 g / 2 g 2 g / 5 g 2 g / 5 g
Linearity ± 1 g / 2 g ± 2 g / 5 g ± 2 g / 5 g
Recommended
adjustment weight, not
added (class)
Warm-up time 10 minutes
Stabilization time (typical) 2 sec.
Weighing unit kg
Auto Off Available options 5, 15 min.
Ambient temperature -10°C – 40°C
Moist environment 0 % - 80 % (non-condensing)
Electric Supply
Dimensions display unit
(B x D x H) mm
Weighing surface mm 300 x 240 x 80 300 x 240 x 80 400 x 300 x 80
6 kg
(M1)
Input voltage 220 V – 240 V, 50 Hz
Power pack secondary voltage 9V, 800mA
250 x 160 x 58
15 kg
(M1)
15 kg
(M1)
Weight kg (net) 6.5 6.5 11
Interface RS 232
4
IFB-BA-e-1012
KERN IFB 30K5DM IFB 60K10DM IFB 60K10DLM
Readability (d) 5 g / 10 g 10 g / 20 g 10 g / 20 g
Weighing range (max) 15 kg / 30 kg 30 kg / 60 kg 30 kg / 60 kg
Minimum load (Min) 100 g 200 g 200 g
Verification value (e) 5 g / 10 g 10 g / 20 g 10 g / 20 g
Verification class III III III
Reproducibility 5 g / 10 g 10 g / 20 g 10 g / 20 g
Linearity ± 5 g / 10 g ± 10 g / 20 g ± 10 g / 20 g
Recommended
adjustment weight, not
added (class)
Warm-up time 10 minutes
Stabilization time (typical) 2 s
Weighing unit kg
Auto Off Available options 5, 15 min.
Ambient temperature -10°C – 40°C
Moist environment 0 % - 80 % (non-condensing)
Electric Supply
Dimensions display unit
(B x D x H) mm
Weighing surface mm 400 x 300 x 80 400 x 300 x 80 500 x 400 x 80
30 kg
(M1)
Input voltage 220 V – 240 V, 50 Hz
Power pack secondary voltage 9V, 800mA
250 x 160 x 58
60 kg
(M1)
60 kg
(M1)
Weight kg (net) 11 11 18
Interface optional RS232
IFB-BA-e-1012
5
KERN IFB 150K20DM IFB 150K20DLMIFB 300K50DM
Readability (d) 20 g / 50 g 20 g / 50 g 50 g / 100 g
Weighing range (max) 60 kg / 150 kg 60 kg / 150 kg 150 kg / 300 kg
Minimum load (Min) 400 g 400 g 1000 g
Verification value (e) 20 g / 50 g 20 g / 50 g 50 g / 100 g
Verification class III III III
Reproducibility 20 g / 50 g 20 g / 50 g 50 g / 100 g
Linearity ± 20 g / 50 g ± 20 g / 50 g ± 50 g / 100 g
Recommended
adjustment weight, not
added (class)
Warm-up time 10 minutes
Stabilization time (typical) 2 s
Weighing unit kg
Auto Off Available options 5, 15 min.
Ambient temperature -10°C – 40°C
Moist environment 0 % - 80 % (non-condensing)
Electric Supply
Dimensions display unit
(B x D x H) mm
Weighing surface mm 500 x 400 x 80 650 x 500 x 80 650 x 500 x 80
150 kg
(M1)
Input voltage 220 V – 240 V, 50 Hz
Power pack secondary voltage 9V, 800mA
150 kg
(M1)
250 x 160 x 58
300 kg
(M1)
Weight kg (net) 18 24 24
Interface optional RS232
6
IFB-BA-e-1012
2 Appliance overview
1. Battery status display
2. Keyboard
3. Weight display
4. Tolerance tag, see chpt. 7.6
5. Weighing unit
6. Levelling screw
7. Spirit level (underneath weighing platform)
IFB-BA-e-1012
7
2.1 Keyboard overview
Button Function
Turn on/off
• Zeroing
Navigation key
Navigation key
Navigation key
Navigation key
• Confirm entry
Taring
At numeric input increase flashing digit
Scroll forward in menu
• Display sum total
• Digit selection to the right
• Add weighing value in summation memory
• Digit selection to the left
• Calculate weighing data via interface
8
C
ESC
• Delete
• Switch-over gross weight net weight
• Back to menu/weighing mode
• Activate animal weighing function
• Activate weighing with tolerance limits
• Delete total added memory
IFB-BA-e-1012
2.1.1 Numeric input via navigation keys
Press current setting appears. The first digit is flashing and can be
changed.
If the first digit is not to be changed, press and the second digit will start
flashing. Each time you press , the display unit jumps to the subsequent
digit, returning to the first digit after the last digit has been pressed.
To change the selected (flashing) digit, press
value appears. Then select by using additional digits and change these by using
Finish entry with .
2.2 Overview of displays
Display Significance
Rechargeable battery very low
STABLE Stability display
ZERO Zero display
repeatedly until the desired
GROSS Gross weight
NET Net weight
AUTO Automatic add-up enabled
Kg Weighing unit
M+ Adding
LED
Indicators for weighing with tolerance limits
+ / / -
IFB-BA-e-1012
9
3 Basic Information (General)
3.1 Proper use
The balance you purchased is intended to determine the weighing value of material
to be weighed. It is intended to be used as a “non-automatic balance”, i.e. the
material to be weighed is manually and carefully placed in the centre of the weighing
plate. As soon as a stable weighing value is reached the weighing value can be read.
3.2 Improper Use
Do not use balance for dynamic weighing. In the event that small quantities are
removed or added to the material to be weighed, incorrect weighing results can be
displayed due to the “stability compensation“ in the balance. (Example: Slowly
draining fluids from a container on the balance.)
Do not leave permanent load on the weighing plate. This may damage the measuring
system.
Impacts and overloading exceeding the stated maximum load (max) of the weighing
plate, minus a possibly existing tare load, must be strictly avoided. Balance may be
damage by this.
Never operate balance in explosive environment. The serial version is not explosion
protected.
The structure of the balance may not be modified. This may lead to incorrect
weighing results, safety-related faults and destruction of the balance.
The balance may only be used according to the described conditions. Other areas of
use must be released by KERN in writing.
3.3 Warranty
Warranty claims shall be voided in case
• Our conditions in the operation manual are ignored
• The appliance is used outside the described uses
• The appliance is modified or opened
• Mechanical damage or damage by media, liquids, natural wear and tear
• The appliance is improperly set up or incorrectly electrically connected
• The measuring system is overloaded
3.4 Monitoring of Test Resources
In the framework of quality assurance the measuring-related properties of the
balance and, if applicable, the testing weight, must be checked regularly. The
responsible user must define a suitable interval as well as type and scope of this test.
Information is available on KERN’s home page (www.kern-sohn.com with regard to
the monitoring of balance test substances and the test weights required for this. In
KERN’s accredited DKD calibration laboratory test weights and balances may be
calibrated (return to the national standard) fast and at moderate cost.
10
IFB-BA-e-1012
4 Basic Safety Precautions
4.1 Pay attention to the instructions in the Operation Manual
Carefully read this operation manual before setup and commissioning, even if you
are already familiar with KERN balances.
4.2 Personnel training
The appliance may only be operated and maintained by trained personnel.
5 Transportation & Storage
5.1 Testing upon acceptance
When receiving the appliance, please check packaging immediately, and the
appliance itself when unpacking for possible visible damage.
5.2 Packaging / return transport
Keep all parts of the original packaging for a possibly
required return.
Only use original packaging for returning.
Prior to dispatch disconnect all cables and remove
loose/mobile parts.
Reattach possibly supplied transport securing devices.
Secure all parts such as glass wind screen, weighing
platform, power unit etc. against shifting and damage.
IFB-BA-e-1012
11
6 Unpacking and implantation
6.1 Installation Site, Location of Use
The balances are designed in a way that reliable weighing results are achieved in
common conditions of use.
You will work accurately and fast, if you select the right location for your balance.
On the installation site observe the following:
• Place the balance on a firm, level surface;
• Avoid extreme heat as well as temperature fluctuation caused by installing
next to a radiator or in the direct sunlight;
• Protect the balance against direct draughts due to open windows and doors;
• Avoid jarring during weighing;
• Protect the balance against high humidity, vapors and dust;
• Do not expose the balance to strong humidity for extended periods. Non-
permitted condensation (condensation of air humidity on the appliance) may
occur if a cold appliance is taken to a considerably warmer environment. In
this case, acclimatize the disconnected appliance for ca. 2 hours at room
temperature.
• Avoid static charge of goods to be weighed or weighing container.
• Being of protection type IP 67 as per DIN EN 60529, the weighing scale is
suitable for short-term use in wet conditions.
Major display deviations (incorrect weighing results) may be experienced should
electromagnetic fields (e.g. due to mobile phones or radio equipment), static
electricity accumulations or instable power supply occur. Change location or remove
source of interference.
6.2 Unpacking/implantation
Take the balance carefully out of the package, remove the plastic cover and
place it in the designated work area.
Scope of delivery / serial accessories:
• Balance, see chpt. 2
• Mains power supply
• Operating instructions
12
IFB-BA-e-1012
Accurate weighing results require a weighing bridge with perfect horizontal alignment.
During initial installation and after each change of work area it is necessary to level
the weighing bridge.
As the spirit level is underneath the weighing platform it has to be removed.
Level balance with foot screws until the air bubble of the water balance is in the
prescribed circle.
6.3 Mains connection
Power is supplied via the external mains adapter. The stated voltage value must be
the same as the local voltage. Only use original KERN mains adapters. Using other
makes requires consent by KERN.
6.4 Adjustment
As the acceleration value due to gravity is not the same at every location on earth,
the balance must be coordinated in compliance with the underlying physical weighing
principle to the existing acceleration due to gravity at its place of location (only if the
balance has not already been adjusted to the location in the factory). This adjustment
process must be carried out for the first commissioning, after each change of location
as well as in case of fluctuating environment temperature. To receive accurate
measuring values it is also recommended to adjust the balance periodically in
weighing operation.
•Access to menu block “P2 CAL” is locked in verified scales.
Access to menu requires breaking of seal and activation of verification
switch (See chpt 6.5 ).
The instrument will have to be reverified by a bureau of standards and a
new seal attached if a seal was broken before applications subject to
verification can be recommenced.
Please follow verification instructions (See chpt. 6.5).
•The weight to be used depends on the capacity of the scale. Carry out
adjustment as near as possible to the scale’s maximum weight. Info
about test weights can be found on the Internet at: http://www.kernsohn.com
•Observe stable environmental conditions. Warm-up time required for
stabilisation.
IFB-BA-e-1012
13
Switch on instrument and press during self-test.
Press , , in turn and the first menu block “PO
CHK“ will appear.
Press repeatedly until “P2 CAL“ appears.
Press and the first menu item “COUNT“ will appear
At verified scales, press first the adjustment switch.
Press repeatedly until “CAL“ appears.
Press .
Wait for stability display, then press . Ensure that there
are no objects on the weighing plate.
The currently set adjustment weight will be displayed.
Change by pressing the navigation keys (See chpt 2.1.1);
select desired setting; currently enabled digit will be flashing.
Acknowledge by .
Carefully place adjusting weight in the centre of the weighing
plate. Wait for stability display, then press .
After successful adjustment the appliance automatically
returns to weighing mode.
•An adjusting error or incorrect adjusting weight will be indicated by the error
message, repeat adjustment procedure.
14
IFB-BA-e-1012
6.5 Verification
General introduction:
According to EU directive 90/384/EEC balances must be verified if they are used as
follows (legally controlled area):
a) For commercial transactions if the price of goods is determined by weighing.
b) For the production of medicines in pharmacies as well as for analyses in the
medical and pharmaceutical laboratory.
c) For official purposes.
d) For manufacturing final packages.
In cases of doubt, please contact your local trade in standard.
Verification notes:
An EU Qualification Approval is in existence for verified weighing systems. If a
balance is used where obligation to verify exists as described above, it must officially
verified and re-verified in regular intervals.
Reverification is carried out according to relevant national statutory regulations. The
validity for verification of balances in Germany is e.g. 2 years.
The legal regulation of the country where the balance is used must be observed!
• Verification of the weighing system is invalid without the "seal".
Notes on verified weighing systems
Position for seals and verification switches
1. Self-destructing seal
2. Verification switch
3. Cover verification switch
4. Self-destructing seal
IFB-BA-e-1012
15
7 Operation
7.1 Start-up
Press , and the instrument will carry out a self-test . The instrument is
ready for weighing when a weight display appears.
7.2 Switching Off
Press until the display disappears.
7.3 Zeroing
Resetting to zero corrects the influence of light soiling on the weighing plate.
Resetting range ± 2 % max.
The instrument comprises an automatic zero setting function, however, the
instrument can be reset to zero whenever needed as described below.
Remove load from weighing system
Press , and the zero display as well as the ZEROindicator will appear.
7.4 Simple weighing
Place goods to be weighed on balance.
Wait for stability display STABLE.
Read weighing result.
Overload warning
Overloading exceeding the stated maximum load (max) of the device, minus a
possibly existing tare load, must be strictly avoided. The instrument may be
damaged by overloading.
Exceeding of maximum load is indicated by “----“ as well as a signal sound.
Remove load from weighing system or reduce preload.
16
IFB-BA-e-1012
7.5 Weighing with tare
Deposit weighing vessel. After successful stop check press the button.
The zero display and the indicator NET appear.
The weight of the container is now internally saved.
Weigh the material, the net weight will be indicated.
The weight of the weighing container will be displayed as a minus number after
removing the weighing container.
The tare procedure can be repeated as many times as necessary, for example
with initial weighing of several components for a mix (add-on weighing). The limit
is reached when the total weighing range capacity is full.
Switch between gross weight and net weight by pressing the key.
To delete the tare value, remove load from weighing plate and press .
7.6 Weighing with tolerance range
You may determine an upper and lower limit for weighing with tolerance limits in
order to ensure that the weighed load remains exactly within the fixed tolerance
limits.
During tolerance checks such as dispensing, portioning and sorting, the instrument
will indicate any lower deviation or exceeding of limits with the help of a visual signal
or audio sound.
Acoustic signal:
The audio sound depends on the setting of the menu block “BEEP“.
Options:
• no
• ok
• ng
Acoustic signal turned off
Acoustic signal sounds when load is within tolerance
limits
Acoustic signal sounds when load is beyond tolerance
limits
IFB-BA-e-1012
17
Optical signal:
Three colour pilot lamps indicate whether load is within the two tolerance limits.
The signal lamps provide the following information:
+
Settings for tolerance weighing may be set either by calling up menu block “P0 CHK“
(See chpt. 8) or by applying the faster option of pressing the key combination
Settings
Press and at the same time in weighing mode.
Goods to be weighed above tolerance limit
Goods to be weighed within tolerance range
Goods to be weighed below tolerance limit
-
Red signal lamp
glowing
Green signal lamp
glowing
Red signal lamp
glowing
Press ; the display used for entering the lower limit SET L
appears.
Press ; current setting appears.
Use the navigation keys (See chpt. 2.1.1) for entering the
lower limit, e. g. 1000 kg; the currently active digit will be
flashing.
Confirm input by .
Select SET H using
18
IFB-BA-e-1012
Press , the current setting for the upper limit will be
shown.
Use the navigation keys (See chpt. 2.1.1) to set the upper
limit, e. g. 1100 kg; the currently active digit will be flashing.
Confirm input by .
Select BEEP by.
Press , the current setting for the audio sound will be
shown.
Use (no, ok, ng) to select the desired setting.
Confirm input by .
Press and the weighing system will go into tolerance
weighing mode. From here evaluation takes place whether
the goods to be weighed are within the two tolerance limits.
Weighing with tolerance range
Tare, if using a weighing container.
Put on goods to be weighed, tolerance control is started
• The tolerance control is not active when the weight is under 20d.
• To delete limits enter a value of “00.000 kg“.
IFB-BA-e-1012
19
7.7 Manual totalizing
With this function the individual weighing values are added into the summation
memory by pressing and edited, when an optional printer is connected.
• Menu settings:
Add up:
Place goods to be weighed A.
Wait until the stability display STABLE appears, then press . The weight value
will be saved and a printout received if an optional printer is connected.
Remove the weighed good. More weighed goods can only be added when the
display = zero.
„P1 COM“ „MODE“ „PR2““, see chap. 8
• The totalisation function is not active when the weight is under 20d.
Place goods to be weighed B.
Wait until the stability display appears, then press . The weight value will be
added to the summation memory and possibly printed. The number of weighing
processes followed by the total weight will be shown for 2 sec.
Add more weighed goods as described before.
Please note that the weighing system must be unloaded between the individual
weighing procedures.
This process can be repeated until the capacity of the weighing system is
exhausted.
Display of the saved weighing data:
Press
and the number of weighings followed by the total weight will be
shown for 2 sec. To receive a printout, press during this display.
20
IFB-BA-e-1012
Delete weighing data:
Press and at the same time. The data in the summation memory are
deleted.
Printout example:
***************
NO. 1
1.000kg
***************
NO. 2
0.500kg
***************
NO. 3
0.700kg
***************
total
NO. 3
1
2
3
4
2.200kg
1 First weighing
2 Second weighing
3 Third weighing
4 Number of weighings / total
+
IFB-BA-e-1012
21
7.8 Automatic adding-up
With this function the individual weighing values are automatically added into the
summation memory when the balance is unloaded without pressing and edited,
when an optional printer is connected.
• Menu settings:
„P1 COM“ „MODE“ „AUTO““, see chpt. 8
Indicator AUTO is displayed.
Add up:
Place goods to be weighed A.
After the standstill control sounds a signal tone. The weighing value is added to
the summation memory, followed by printing.
Remove the weighed good. More weighed goods can only be added when the
display = zero.
Place goods to be weighed B.
After the standstill control sounds a signal tone. The weighing value is added to
the summation memory, followed by printing. The number of weighings, followed
by the total weight, will be shown for 2 sec.
Add more weighed goods as described before.
Please note that the weighing system must be unloaded between the individual
weighing procedures.
This process can be repeated until the capacity of the weighing system is
exhausted.
Display and delete the weighing data, as well as printout examples
see chpt. 7.7.
22
IFB-BA-e-1012
7.9 Animal weighing
The animal weighing function is ideal for unstable loads.
The weighing system calculates and displays a stable mean average from several
weighing values.
The animal weighing program may either be enabled by calling up menu block “P3 OTH“ „ANM“ „ON“ (See chpt. 8) or by using the faster option of a key
combination.
Place the load onto the weighing system and wait until it is fairly stable.
Press and at the same time, a signal sounds, meaning that the animal
weighing function is enabled.
During the calculation of a mean average you can add or remove loads as the
mean average will be continuously updated.
To disable the animal weighing function press and at the same time.
7.10 Lock keyboard
Go to menu item “P3 OTH“ „LOCK“, see chpt. 8, and enable/disable the keyboard
interlock. The enabled function will be locked after 10 minutes of inactivity. “K-LCK“
will be displayed as soon as a key is pressed.
To cancel locking, keep pressed
, and at the same time (2s) until “U
LCK“ appears.
7.11 Display background illumination
Keep pressed (3s) until “setbl“ appears.
Press again and the current setting will be displayed.
IFB-BA-e-1012
23
Use to select desired setting.
bl on
bl off
bl Auto
Background lighting is on continuously
Background illumination off
Automatic background illumination on when weighing plate is
loaded
Save entry by or cancel using .
7.12 Automatic switch-off function “AUTO OFF“
The instrument will switch off automatically after a set time when the display unit or
weighing bridge has been idle.
Keep pressed (3s) until “setbl“ appears.
Call up AUTO OFF function using
Press
- current setting appears.
Use to select desired setting.
of on
of 5
of 15
AUTO OFF function disabled
Weighing system will switch off after 5 min
Weighing system will switch off after 15 min
Save entry by or cancel using .
24
IFB-BA-e-1012
8 Menu
Navigation in the menu:
Call up menu
Select menu block
Switch on instrument and press during self-test.
Press in turn , , and the first menu block
“PO CHK“ will appear.
With help of , the individual menu items can be
selected one after the other.
Select setting
Change settings
Acknowledge setting /
exit the menu
Return to weighing
mode
Confirm selected menu item with . The current
setting will be displayed.
Use the navigation keys, see chpt. 2.1 to switch between
the available settings.
Save entry by
To exit menu, press
or cancel using .
repeatedly.
IFB-BA-e-1012
25
Overview:
Menu block
Main menu
PO CHK
Menu item
Sub-menu
Available settings / definition
SET H Upper limit, for entry see chpt. 7.6
Weighing with
Tolerance limits,
see chpt. 7.6
P1 COM
Interface
parameters
SET LO Lower limit, for entry see chpt. 7.6
BEEP
MODE
no
ok
ng
CONT
ST1
STC
Acoustic signal turned off for weighing with
tolerance limits
Acoustic signal sounds if load is within tolerance
limits
Acoustic signal sounds if load is beyond
tolerance limits
Continuous data output
One output for stable weighing value
Continuous data output of stable
Weighing values
PR1
Output after pressing
PR2
AUTO
Manual add-up, see chpt. 7.7
After pressing
added to summation memory and issued.
Automatic add-up, see chpt. 7.8
This function is used to automatically add and
send individual weighing values to the
summation memory whilst weighing instrument
is being unloaded.
, weighing value will be
P2 CAL
P3 OTH
s. Kap. 7.9 / 7.10
ASK
Remote control instructions:
R, “read“
T, “tare“
Z, “zeroing“
BAUD Available baud rate 600, 1200, 2400, 4800, 9600
Pr
7E1 7 bits, even parity
7o1 7 bits, odd parity
8n1 8 bits, no parity
PTYPE
tPUP Standard printer setting
LP50 Not documented
COUNT Display internal resolution
DECI Position of the decimal dot
DUAL Weighing scale type, capacity and readability (non-
verified) or verification value (verified).
CAL Adjustment, see chpt. 6.5
GrA Not documented
LOCK
ANM
on Keyboard interlock enabled
off Keyboard interlock disabled
on Animal weighing enabled
off Animal weighing disabled
26
IFB-BA-e-1012
9 Service, maintenance, disposal
9.1 Cleaning
• Before cleaning, disconnect the appliance from the operating voltage.
• Do not apply aggressive detergents (solvents etc.).
9.2 Service, maintenance
The appliance may only be opened by trained service technicians who are authorized
by KERN.
Before opening, disconnect from power supply.
9.3 Disposal
Disposal of packaging and appliance must be carried out by operator according to
valid national or regional law of the location where the appliance is used.
9.4 Error messages
Error message Description Possible causes
- - - - -
Should other error messages occur, switch balance off and then on again. If the error
message remains inform manufacturer.
Maximum load exceeded
Zeroing range exceeded
due to switching-on balance
or pressing (normally
4% max)
Value outside the A/D
changer range
• Remove load from scale
or reduce preload.
• Object on the weighing
plate
• Overload when zeroing
• Improper adjustment
• Damaged weighing cell
• Damaged electronics
• Weighing plate not
installed
• Damaged weighing cell
• Damaged electronics
IFB-BA-e-1012
27
10 Data output RS 232C
Weighing data can be issued according to menu settings either via the RS 232C
interface or by pressing via the interface.
This data exchange is asynchronous using ASCII - Code.
The following conditions must be met to provide successful communication between
the weighing balance and the printer.
• Use a suitable cable to connect the weighing balance to the interface of the
printer. Faultless operation requires an adequate KERN interface cable.
• Communication parameters (baud rate, bits and parity) of balance and printer
must match. For detailed description of interface parameters see chpt. 8,
menu block „P1 COM“
10.1 Technical Data
Connector 25 pin d-subminiature bushing
Pin 2 input
Pin 3 output
Pin 5 signal earth
Baud rate 600/1200/2400/4800/9600
Parity 8 bits, no parity / 7 bits, even parity / 7 bits, odd parity
28
IFB-BA-e-1012
10.2 Printer mode
• Standard printout “weighing data“
ST Stable value
US Instable value
GS Gross weight
NT Net weight
<lf> Space line
<lf> Space line
• Printout “summation memory“
**************
<lf> Space line
TOTAL NO: 3 Number weighing processes
TOTAL wgt.: 0.447KG Total of all individual weighings
In case of an error in the program process, briefly turn off the balance and disconnect
from power supply. The weighing process must then be restarted from the beginning.
Help:
Fault Possible cause
The displayed weight does
not glow.
The displayed weight is
permanently changing
The weighing result is
obviously incorrect
Should other error messages occur, switch balance off and then on again. If the error
message remains inform manufacturer.
• The balance is not switched on.
• Mains power failure (mains cable defective).
• Power supply interrupted.
• (Rechargeable) batteries are inserted incorrectly or