KERN & Sohn GmbH
Ziegelei 1
D-72336 Balingen
E-Mail: info@kern-sohn.com
Service manual
Pallet truck scale
KERN VHT
Version 1.0
5/2009
GB
Tel: +49-[0]7433- 9933-0
Fax: +49-[0]7433-9933-149
Internet: www.kern-sohn.com
VHT-SH-e-0910
GB
KERN VHT
Version 1.0 5/2009
Service manual
Pallet truck scale
CONTENTS
1 HOW TO USE THIS SERVICE MANUAL............................................................ 4
2 THE PRINCIPLE OF THE PALLET TRUCK SCALE........................................... 5
2.1 MECHANICS................................................................................................ 5
2.2 LOAD CELLS ............................................................................................... 6
2.3 INDICATOR ................................................................................................. 7
2.4 BATTERY..................................................................................................... 7
3 POSSIBLE PROBLEMS...................................................................................... 8
4 DESCRIPTION OF PROBLEM AND WHERE TO LOOK FOR CAUSES............ 9
5 EXPLANATION OF POSSIBLE CAUSES AND HOW TO FIX THEM ............... 10
5.1 CHECK BATTERY ..................................................................................... 10
5.2 CHECK MECHANISM................................................................................ 10
5.3 CHECK LOAD CELLS................................................................................ 11
5.4 CHECK CABLING AND LOAD CELL BOARD ........................................... 12
5.5 CALIBRATE LOAD CELLS ........................................................................ 13
5.6 CHECK INDICATOR .................................................................................. 13
6 PARAMETER SETTINGS ................................................................................. 15
7 CALIBRATION INSTRUCTIONS....................................................................... 18
7.1 ZERO CALIBRATION ................................................................................ 18
7.2 SINGLE POINT CALIBRATION ................................................................. 19
7.3 MULTI-POINT CALIBRATION ................................................................... 20
8 HOW TO ADJUST THE LOWERING VALVE.................................................... 21
9 ERROR MESSAGES ........................................................................................ 22
10 DIMENSIONS OF PALLET TRUCK SCALE...................................................... 23
11 SPARE PARTS ................................................................................................. 24
2 VHT-SH-e-0910
Basic Information
Grundlegende Hinweise
The device must be repaired only by trained specialist staff or personnel with
professional formation (such as a repair-specialist accredited by law
concerning verification).
The service manual is obligatory for repair work.
After repair, original conditions of the device have to be restored.
Only original spare parts should be used.
Das Gerät darf nur von geschultem oder beruflich ausgebildetem
Fachpersonal (z. B. eichrechtlich anerkannter Instandsetzer) repariert werden.
Die Serviceanleitung ist bindend für Reparaturen.
Das Gerät muss nach erfolgter Reparatur wieder in den Originalzustand
zurückversetzt werden.
Es dürfen nur Originalersatzteile verwendet werden.
VHT-SH-e-0910 3
1 HOW TO USE THIS SERVICE MANUAL
This service manual helps you to solve technical problems with your mobile weighing
system.
In addition there is a calibration and parameter instruction.
Chapter 2 Explains the principle behind electronic weighing systems.
Chapter 3 Lists the most frequently occurring problems (A, B, C, D etc.). If your
problem is listed in this overview, remember the character and go to
Chapter 4.
Chapter 4 Connects the problem to possible causes (1, 2, 3, 4 etc.). The most
encountered cause is marked with a “Æ”. Remember the number(s) of
the cause you should check and go to Chapter 5.
Chapter 5 Explains the possible causes in more detail and describes possible
solutions.
Chapter 6 Explains the parameter settings.
Chapter 7 Explains the calibration procedure.
Chapter 8 Explains how to adjust the lowering valve.
!!! IMPORTANT !!!
Do not weld on the system with the load cells mounted. If the welding current passes
through the load cell, they will be destroyed.
Do not touch the contacts on the electronic boards. Static electricity will destroy
components.
4 VHT-SH-e-0910
2 THE PRINCIPLE OF THE PALLET TRUCK SCALE
The pallet truck scale consists of the following components:
1. Mechanics
2. Load cells
3. Indicator (module)
4. Battery
2.1 MECHANICS
The mechanical part is the pallet truck chassis with a special fork construction.
For the weighing system the pallet truck fork consists of two parts:
1. The basic chassis
2. The upper forks
1
Between the lower / basic fork construction and the upper fork, sensors / load cells
are mounted that will sense the force placed on the upper fork.
It is most important that all forces pass through the load cells and that no parts of the
basic fork, pushrod or load wheel holder of the pallet truck have mechanical contact
with the upper fork (weighing part).
2
VHT-SH-e-0910 5
2.2 LOAD CELLS
One of the two most important components of weighing pallet truck are the load cells.
A load cell is a rectangular steel component, built in the special pallet truck chassis,
in the lower part of the fork. The load cell has a deformation 0.07mm under a load of
1000 kg. This deformation depends on the weight of the load. In the load cell,
electrical resistor, called strain gauges, are glued to the load cell body.
The electrical resistance of the strain gauges in the load cells changes linearly with
the deformation of the load cell.
The load cell is connected with four wires to the indicator. Two wires, black and red,
supply an input voltage to the load cell. This voltage to the load cells is called
excitation. The output voltage of the load cell, called “signal”, green and white wires,
depends on the strain gauge resistance change.
With a maximum load on the load cells (example: 4 x 1000 kg), the signal voltage
(caused by the change in resistance) is approximately 0.01 Volt. The signal voltage
at 100 kg is only 0.0002 Volt. The signal change level with 1 kg weight change is only
0.000002 Volt. When working with such small electrical signals, the cabling has to be
100%. Therefore, the signal is transmitted from the load cells to the indicator via a
special cable. All connections have to be soldered and humidity or corrosion of
contacts will cause instability in the reading.
Strain gauge
6 VHT-SH-e-0910
2.3 INDICATOR
The indicator operates like an ohm/voltmeter. The change in resistance is measured,
translated and displayed as a weight. The indicator is a multitude more accurate then
a multimeter but in a very limited voltage range. It measures micro voltages at
extreme high accuracies, independent from temperature changes and distortion of
radio frequencies.
Because of the extremely small signal levels the board is very sensitive to humidity
and contact with chemical substances that will influence the solder contacts.
2.4 BATTERY
The power supply takes place via an 12V interchangeable battery module
(VHT-A01).
VHT-SH-e-0910 7
3 POSSIBLE PROBLEMS
The most frequently occurring causes of malfunctioning of the weighing
systems are:
• Supply: Worn out battery, fuse, or power supply
• Bad or broken contacts
• Jammed or worn out cabling
• Loose screws or bolts
• Mechanical problems: the upper part of the fork has contact with the chassis or
lifting mechanics of the pallet truck due to deformation, wear or accumulated dirt.
• Moisture in the electronics or load cells
These problems cause 99% of all possible failures and will result in the
following problem descriptions:
A. Nothing works. The display is dead, even when pressing the keys.
B. The indicator is unstable; the weight readout goes up and down.
C. Different weights are displayed for the same load when weighed several times.
D. The weighing system is accurate with lower weights but inaccurate with higher
weights.
E. The weighing system is inaccurate, however, the inaccuracy is linear, meaning
the error is always the same percentage of the weighed load.
F. Without a load, a positive or negative weight is displayed and it is not possible to
reset the display to 0kg. The scale reacts normally when a load is placed on the
scale.
G. An error message indicates over- or underload, with or without load on the scale.
H. The display does not react to loads being placed on or removed from the scale.
I. Keys do not work.
J. Segments fail on display.
For error messages displayed on the indicator, please refer to chapter 9.
8 VHT-SH-e-0910
4 DESCRIPTION OF PROBLEM AND WHERE TO LOOK
FOR CAUSES
A. Nothing works. The display is dead, even when pressing the keys.
1 Check battery and charger.
6 Check the indicator.
J Is the safety fuse still good, or is there a bad contact?
B. The indicator is unstable; the weight readout goes up and down.
2 Check the mechanism of the fork construction.
4 Check the load cell cables and the load cell calibration board.
6 Check the indicator for moisture or loose contacts. (5.6.2) up to (5.6.6)
3 Check the load cells.
J Are the screws tight?
C. The same load is lifted several times, but different weights are
displayed.
2 Check the mechanism of the fork construction.
3 Check the load cells.
J The weighing parts may not have contact with fixed, non weighing parts.
D. The weighing system is accurate with small weights, however, it is
inaccurate with heavy weights.
2 Check the mechanism of the fork construction.
J Because of the bending of the loading part of the system, the weighing part
has contact with the rigid part of the system.
E. The weighing system is inaccurate, however, the inaccuracy is linear.
This means that with a load of 100 kg the inaccuracy is 1 kg, with 500 kg it is
5 kg, and with a load of 1000 kg the inaccuracy is 10 kg.
J See calibration procedure.
F. Without a load on the forks a negative or positive weight is displayed. It
is not possible to reset the display to zero. The system works normally
once a weight is placed on the unit.
5 See calibration procedure.
J The zero setting has a restricted capacity. Calibrating the system will bring
the zero setting to within the restrictions.
H. The display does not react to loads being placed on the scale.
6 Check the indicator. Only 5.6.1 and 5.6.4.
4 Check the cabling.
3 Check the load cells.
I. Keys do not work.
6 Check the indicator.
J. Segments fail on display.
6 Check the indicator.
VHT-SH-e-0910 9
5 EXPLANATION OF POSSIBLE CAUSES AND HOW TO
FIX THEM
5.1 CHECK BATTERY
• Check the battery
Empty battery can be replaced with an 12V interchangeable battery module
(VHT-A01).
5.2 CHECK MECHANISM
5.2.1 Check whether weighing is obstructed mechanically.
Weigh yourself while standing on the extreme corners of the system. Your
weight must be identical on all corners. The difference between the weights
maybe up to one graduation.
If this is the case, it may be concluded that all load cells are working and the
mechanics are fine with small loads.
After finishing this test, load the weighing system with a normal or heavy load.
Using the tare key, the display is reset to zero. Now, with this weight on the
scale, load the corners of the weighing system by placing your own weight on
top or side of the weight that is on the scale. Each corner should give an
identical read-out plus or minus 1 or 2 kg. If the read-outs are not identical and
show a difference larger than 2 graduations, see 5.2.2.
5.2.2 Try to determine where there is interference between w eighing and non
weighing components.
It may be necessary to dismantle the system to see where the interference
occurs. Often there are traces on the paint that indicate the most likely place. If
there is doubt, assemble the weighing system with paper placed between the
weighing and non weighing parts. After loading the system to its full capacity
and maybe by moving (shacking) the load side ways, traces on the paper will
show where the friction might be.
Determine what can be done mechanically in order to end this friction. e.g.
align the load cells and the upper fork shoes, allow less moving space for the
lifting mechanics in the forks like the push rod and the load wheel holder. It
might be necessary to align the rods of the load wheels to prevent them from
touching the load cells. It can be that with an unloaded truck it is not possible
to see that friction does occur. Therefore see if the rods can touch the load
cells by pushing them towards the load cells. Clean the inside of the forks.
5.2.3 Are the bolts tightened correctly?
The load cells are mounted with bolts. These must be tightened correctly.
Check if all bolts are tightened firmly.
5.2.4 Are the fork shoes mounted freely? (Always check this!)
Underneath the pallet truck you can see whether the fork shoes are mounted
correctly and do not interfere with the frame (basis of the forks) at the sides.
Especially welding of the load wheel axel fixture can interfere. Sometimes
pieces of wood or stone can cause friction between weighing and nonweighing parts.
10 VHT-SH-e-0910
5.3 CHECK LOAD CELLS
5.3.1 When the weighing system is inaccurate, check whether all load cells
give the same weight
Using your own weight, this is very easy to check. Weigh yourself while
standing on the extreme corners of the system. Your weight must be identical
in all corners. It may vary one graduation. When the load cells get older, or
when one of them has been replaced, the difference may become somewhat
larger. When a large difference occurs, continue from 5.3.2.
5.3.2 Check whether the problem lies with the load cells or with the
mechanism
Dismantle the forks shoe (or the upper part of the fork). Place bolts in the
assembly holes of the load cells. Balance a test weight of approx. 1% of their
capacity on each load cell (on the bolts) and check whether each load cell
gives the same weight. The maximum difference may only be
1 graduation. When the difference is larger see 5.5. If there is no difference,
see 5.2.
5.3.3 If a high weight is shown, without a load, and it is not possible to
calibrate to 0kg, check if the load cells are working correctly.
Try to recalibrate the system (see 5). To check whether the problem is caused
by the indicator, it is most simple to replace the indicator and perform a simple
calibration. If this does not solve the problem see 5.3.4 and 5.3.5.
5.3.4 When the indicator shows an error message or is unstable
Turn off the indicator and measure with an ohm/voltmeter whether the
resistance between all load cell wires and the pallet truck chassis is infinite. No
resistance value at all is allowed between the black, white and green load cell
wires to the chassis.
The resistance between disconnected load cell excitation wires; black and red,
should be:
+/- 350 Ohm if one load cell is checked
+/- 87 Ohm if all 4 load cells are checked when connected parallel.
These values should also be measured between the load cell signal wires;
white and green.
With the indicator turned on, between the load cell excitation wires (black and
red) the following values should be measured:
• Standard system and without printer: 3.3 V DC.
• Legal for trade system (class III) and / or with a printer: 2.5V AC. Because
of a block voltage, depending on the voltmeter, a voltage between 2.2 or
2.5 will be measured.
If not, the indicator has a problem.
With the indicator turned on, with no load on the forks, between the load cell
signal wires, green and white, the following values should be measures:
• Standard system and without printer: 0.000 to 0.002 V DC. (V AC for
printer and /or approved systems)
VHT-SH-e-0910 11
If the signal level is higher or negative, there is a problem with the load cells.
If the signal is only slightly higher, it may be that it works anyway but may be
temporary.
If a problem is found, the last test can be repeated with the individual load
cells connected to see if one or more and which load cell(s) have the problem.
5.3.5 Check each individual load cell
The load cells are connected to the indicator with the load cell cables. The
cables are connected to each other by a coupling cover. By removing this, the
load cells can be tested individually.
1.Possibility:
Measure the power supply. The power between +power supply (mostly red)
and +signal (mostly green) and the power between –power supply (mostly
black) and –signal (mostly white) should be equal to 2Ω. The power between
the cables and the load cells should be infinite (∞).
2.Possibility:
To check whether the problem is caused by a single load cell: connect the
load cells to the indicator separately from each other (use the indicator as
voltmeter) and compare the data on the indicator per load cell. The values
should be almost identical. The weight shown is dependant on the calibration.
Is a value instable or varies considerably from the other values, then this load
cell should be replaced. Before replacing the load cell, the batteries should be
replaced.
5.3.6 If the display is unstable, check which load cell is defective
When the cables of the load cells are all disconnected, it is possible to test
each load cell separately. Connect each load cell separately to the indicator in
order to see if and which load cell is unstable. If the indicator reacts unstable
at each load cell, check again if the indicator is not the cause for this problem,
see 5.6.
5.4 CHECK CABLING AND LOAD CELL BOARD
5.4.1 Check for damaged cables
Touch the load cell cable or move it back and forth, especially where the cable
is connected. The indicator should not react to this. If the indicator reacts, then
the cable is damaged internally or there is moisture in the cable and the cable
needs to be replaced. The load cell board should also be checked. If the load
cell board of the connected cables is bent, without touching the contacts
points, and the indicator reacts, then there is a bad connection. If the load cell
board is oxidized then warming the solder points with a soldering unit can offer
a solution.
The cable can be replaced (temporarily) by another cable to see if this will
solve the problem.
12 VHT-SH-e-0910
5.5 CALIBRATE LOAD CELLS
Calibration of load cells
Standing on one of the two forks will load the load cells with your own weight.
Register the weight and then stand on the other fork. The difference should
not be more than 1 graduation (eg. 200 g). If there is a bigger difference, then
the load cells could be broken.
Position of the load cells in a pallet truck scale
5.6 CHECK INDICATOR
!!!!!!! Do not touch the contacts on the board. Static energy can destroy several
components !!!!!!!!
With mobile weighing systems, most problems are caused by shocks. Keep this in
mind when trying to locate a problem in the indicator housing or on the board. Don’t
be afraid to check and apply heavy shocks to the indicator. It is the only way to
discover problems that occur when the system is used. It will also show latent
problems.
5.6.1 Check the safety fuses
In the housing of the indicator, a safety fuse is mounted. Check this fuse with
an ohm/volt meter.
5.6.2 Check the separate components
When the indicator board has been taken out of the housing, it is possible to
see whether everything looks all right, whether other components are loose or
if bending the board changes the problem.
5.6.3 Check for broken or loose connections
None of the cables to the switch, safety fuse holder or plug should be loose.
VHT-SH-e-0910 13
5.6.4 If the display is unstable or does not react to weights, check whether the
indicator causes the problem
Disconnect the indicator from the load cells (also if the display will give an
error message). Connect each load cell individually. If the indicator remains
unstable or does not react to the different load cells, most likely the indicator
module is faulty.
5.6.5 If the display is unstable, check for moisture
Look for condensation or water drops on the plugs. Look closely at the circuit
board, when dismantling the upper plate and pulling out the plug from the
indicator module. Dry it with warm air. If the board is oxidised, it can help to
heat solder points carefully with a solder iron around the analogue circuit.
5.6.6 When can you be certain that the indicator board is faulty?
The display is faulty when:
- nothing changes when load cells are being disconnected
- nothing lights up with voltage (DC) at the right contacts, and functioning
keyboard
- the indicator remains unstable, even with only one load cell connected
- the display reacts when the indicator module is subjected to shocks
5.6.7 Check the touch panel.
Look at the flat cable. The silver conducting layer is very thin. Wear in a small
area can cause the touch panel to dysfunction.
The connector on the flat cable is very sensitive to humidity. Check for this. If
humid, heat this component for a longer period of time.
5.6.8 Check LCD display on the indicator
By bending the board slightly while functioning, in different directions and
diagonally, broken display contacts can be located.
14 VHT-SH-e-0910
6 PARAMETER SETTINGS
(SETUP MODE)
ATTENTION: before entering the setup mode make sure that the battery supply
is sufficient. A low battery may cause the micro-processor to block. If this
happens remove the empty battery and replace it with a fully charged battery.
You should be able to start the indicator in the normal way.
To enter the setup mode:
ON/
OFF
¾ Turn on the indicator and keep the
The indicator will go through all the normal routines (all segments on, software
version, calibration nr, and weight)
The display will show “P__01”.
The right digit is flashing.
At this stage you may proceed as follows:
¾ To enter parameter 01 press the [ ] key shortly.
The display will show the setting for this parameter at this moment.
¾ You may change the setting by using the [ ] or the [ ] key.
¾ You can accept the setting by pressing [ ].
¾ To move to the next parameter you press the [ ] key.
To leave the set-up mode you do the following:
¾ With P__XX in the display press the
The display will show “P__00”.
ON/
OFF
¾ Press the
If a change was made to the settings the display will show “SET__” briefly
UNIT
key again shortly.
and then return to the normal weighing mode. The calibration number will be
increased every time a change was made in the set-up and also after a new
calibration.
If no changes were made, the display will return directly into the normal
weighing mode.
In the following pages the different parameters are explained and the standard
settings are given.
Parameters which are not yet used will not be accessible or displayed with
underscores.
UNIT
key pressed for approx. 20 seconds.
ON/
OFF
UNIT
key shortly.
VHT-SH-e-0910 15
PARAMETERS
Parameter
01 Start-up unit (and print units) 1 = kg / 2 = lb 1
02 Smallest graduation step for
03 Largest graduation step for
04 Number of graduations for every
05 Weighing capacity system (full
06 Motion tolerance for stable 0-32
07 Filter size
08 Auto zero range 0=off 0.5 division
09 Zero range positive (+) 0-100 % (approved 2%) of span 10
10 Zero range negative (-) 0-100 % (approved 2%) of span 10
11 Test function
12-13 Not used
14 Start-up number to add in
15 Units switch mode active Yes / No Yes
16 Setpoint function 0-4
17 Application Basic (standard) or Peakhold (Phold) bASiC
18 Gravity value working area 9.750-9.850 9.810
19 Key function Remote – Local - Both Local
20 Baudrate comport 1 600-1200-2400-4800-9600-19200 9600
21 Databits comport 1 7-8 8
22 Parity comport 1 none/odd/even none
23 Stopbits comport 1 1-2 1
24 End character comport1 0=CR,1=CR+LF 0
25 Dataprotocol comport 1
26 Number of linefeeds comport 1 0-9 0
27-29 Not used
30 Baudrate comport 2 600-1200-2400-4800-9600-19200 9600
31 Databits comport 2 7-8 8
32 Parity comport 2 none/odd/even none
33 Stopbits comport 2 1-2 1
Function Settings Default
EU
0.1/0.2/0.5…………..10/20 0.2
multirange
0.1/0.2/0.5…………..10/20 1
multirange
0000-9900 divisions 1000
range
00000-99999 units 2200
scale)
1
sampling mode
off 0.5 grad./sec
1 grad./sec 2 grad./sec
4 grad./sec 8 grad./sec
16 grad./sec 32 grad./sec
0-12
0=off
1= light filtering, 12=heavy filtering
1 division 3 divisions
BASIC ADC Counts
10x Resolution
1-2-5-10-20-50-95 10
0=not used
1=overload gross (only 1 setpoint used)
2=overload net (only 1 setpoint used)
3=fill (2 setpoints used) no auto tare
4=fill (2 setpoints used) with auto tare
0-4
0= PC bi-directional command structure
1= not used
2= remote display continuously
3= printer (without date/time/switched supply)
4= not used
8
0.5
bASiC
0
0
16 VHT-SH-e-0910
Parameter
34 End character comport2 0=CR,1=CR+LF 0
35 Dataprotocol comport 2 0-4
36 Number of linefeeds comport 2 0-9 5
37 Printout form 0-1
38 Print format time/date European format dd/mm/yy hh:mm
39 Not used 0
40 Level switch 0 = not used 1 = N.C. 2 = N.O. 0
41 Delay trigger time level switch 0-10 sec. 3
42 Not used
43-49 Not used
50 Battery used 12VDC 6VDC 12v
51 Low Bat switch off time 0-99 minutes
52 Auto shut off time if not used 0-99 minutes
53 Not used
54 Peak hold time 0-7 4
55 Threshold value 9999 kg/lb 200
53-89 Not used
90 Reset to default parameter
91 Reset to default parameter
92-99 Not used
Function Settings Default
EU
3
0= PC bi-directional command structure
1= printer (without date/time/ no switched
supply)
2= remote display continuously
3= printer (with date/time/switched supply)
4= not used
0
0=standard 1=total
Euro
American format mm/dd/yy hh:mm
2
0= not switched off
30
0= always on
settings without altering calibration
parameters
settings including calibration
parameters
If parameter 01 was on 1 it will default to the
EU settings, if P01=2 the US settings will be
defaulted. New delivered boards will have the
EU settings.
If parameter 01 was on 1 it will default to the
EU settings, if P01=2 the US settings will be
defaulted. New delivered boards will have the
EU settings.
VHT-SH-e-0910 17
7 CALIBRATION INSTRUCTIONS
The calibration mode can only be reached from the standard weighing mode.
You cannot get into the calibration mode when you are in piece count mode.
There are two different ways to calibrate the system. In both cases a zero calibration
should be performed before the calibration takes place.
7.1 ZERO CALIBRATION
¾ Unload the system.
¾ Switch the system on.
¾ To enter the zero calibration mode press the key for 10 seconds.
After 3 seconds the display will show the last entered code.
After 7 seconds the display will go into the zero calibration mode and start
adjusting.
The display will show “Adj08” and run down until “Adj00”. The adjustment has
been completed.
The indicator shows the percentage of the total capacity that was adjusted.
For a normal weighing system this would be between 5 and 8 percent. A
larger percentage could mean one or more load cells are broken. A lower
percentage could mean the fork cover is not mounted.
The zero point has been defined, the system automatically returns to the
standard weighing mode.
18 VHT-SH-e-0910
7.2 SINGLE POINT CALIBRATION
The weighing system should be turned on and the zero calibration should already be
completed.
()
PRE-
¾ Press the
After 3 seconds the display will show the last entered pre-set tare value.
After 7 seconds the display will go into calibration mode.
The display will show the first calibration point with the pointer flashing.
¾ Using the [ ] and [ ] keys you can see the three earlier programmed values on
the display.
The pointer will move through to . is the first calibration
point, the second and the third.
When calibrating only one point the second and third values should be set to
zero.
¾ Use the [ ] and [ ] keys to move to the second calibration point.
The display will show the pointer flashing.
¾ Press the [ ] key.
The display will show the previously entered calibration value, with the last
segment flashing.
¾ Use the [ ],[ ] and [ ] keys to return all the segments to zero.
¾ Press the [ ] key.
¾ Use the [ ] and [ ] keys to move to the third calibration point.
¾ Repeat the above to set all the segments to zero.
¾ Press the [ ] key.
Calibrating the single point
¾ Use the [ ] and [ ] keys to return to the first point.
The indicator shows the value of the first calibration point.
The pointer is flashing.
¾ Load the weighing system with a known weight.
¾ Press the [ ] key to enter this weight onto the indicator.
The first segment starts flashing.
¾ Use the [ ] and [ ] keys to change all the segments until the proper weight has
been entered.
¾ Press the [ ] key to return to calibration mode.
The pointer will start flashing.
¾ Press the [ ] key for 3 seconds to confirm the entered weight.
This calibration number counts down from Adj 08 to Adj 00, the first calibration
point has now been set.
¾ Leave the calibration mode by pressing the [ ] or [ ] key until AP XX appears.
This number indicates the calibration sensitivity percentage, eg AP 07.
¾ Press the [ ] key.
The display now shows the value of the gravitation constant.
¾ Use the [ ],[ ] and [ ] keys to correct this for your position.
¾ Press the [ ] key to return to the standard weighing mode.
key for about 10 seconds.
VHT-SH-e-0910 19
7.3 MULTI-POINT CALIBRATION
The weighing system should be turned on and the zero calibration should already be
completed.
()
PRE-
¾ Push the
After 3 seconds the display will show the last entered pre-set tare value.
After 7 seconds the display will go into the calibration mode.
The display will show the first calibration point.
The pointer is flashing.
¾ Using the [ ] and [ ] keys you can see the three earlier programmed values on
the display.
The pointer will move through to . is the first calibration
point, the second and the third.
¾ Use the [ ] and [ ] keys to return to the first point.
The indicator shows the value of the first calibration point.
The pointer is flashing.
¾ Load the weighing system with a known weight.
¾ Press the [ ] key to enter this weight onto the indicator.
The first segment will start flashing.
¾ Use the [ ], [ ] and [ ] keys to change all segments until the proper weight has
been entered.
¾ Press the [ ] key to return to calibration mode.
The pointer will start flashing.
¾ Press the [ ] key for 3 to confirm the entered weight.
The calibration number counts down from Adj 08 to Adj 00, the first calibration
point has now been set.
¾ Move to the second calibration point.
The display will show the pointer flashing.
¾ Repeat the procedure for a second known weight. Be aware that the value of this
weight has to be higher than that of the first weight. If not, the display will show
ERR98 and return to the entry mode for the calibration point.
¾ Repeat the procedure for the third known weight.
¾ Leave calibration mode by pressing the [ ] or [ ] key until AP XX appears.
This number indicates the calibration sensitivity percentage, eg AP 07.
¾ Press the [ ] key.
The display now shows the value of the gravitation constant.
¾ Use the [ ], [ ] and [ ] keys to correct this for your position.
¾ Press the [ ] key to return to the standard weighing mode.
key for about 10 seconds.
20 VHT-SH-e-0910
8 HOW TO ADJUST THE LOWERING VALVE
If the lowering of the forks, after a longer period of time, no longer functions correctly,
please follow the below procedures:
1. Pump handle until forks lock into position (maximum height).
2. Bringing operating handle in neutral position for easy transportation of the goods.
3. Bring handle forward until it hits the stopper.
4. Loosen counter nut (open-end wrench 10mm). Slowly tighten pressure bolt
clockwise until the lowering process begins (Allen wrench 3mm).
As soon as the lowering process begins, tighten pressure bolt with 1.5 counter-
clockwise turns.
5. Tighten counter nut completely.
6. The lowering process on the unit should work correctly on each pump handle
position
pressure bolt
VHT-SH-e-0910 21
counter nut
9 ERROR MESSAGES ERROR MESSAGES
Error Possible cause
LO-BA
Err01
Err02
Err03
Err04
Err05
Err06
Err07
Err08
Err09
Err10
Err11
Err97
Err98
Err99
The battery status is too low; replace battery
Signal of the weighing cell unstable
Weighing system overloaded
Gross negative. This action is not allowed
Outside the zero range – Press any button
Exactness of piece calculation insufficient – Press any button
Load cell signal (A/D converter) too high
Load cell signal (A/D converter) too low
Calibration outside the range (negative)
Calibration outside the range (signal too low)
Calibration value of the 2nd (3rd) point lower than the value of the 1st (2nd)
point
Calibration from piece counting mode
Calibration blocked
The calibration value must be higher than the previous one
Actuation only allowed on the display device
22 VHT-SH-e-0910
10 DIMENSIONS OF PALLET TRUCK SCALE
Production tolerance ±2 mm
VHT-SH-e-0910 23
11 SPARE PARTS
EXPLODED DRAWING
24 VHT-SH-e-0910
KERN VHT 2T0.2T
No. Art. No. Description Quantity
SPARE PARTS LIST
LC-1000
1
MP-MP-6
2
FS-H-RAL9005
3
PT-H-RAL1028-RAL905
4
EP-LEVELSWITCH
5
EB-4-LC-21-41
6
HO-WHPT-CHINA-YELLOW
7a
HO-CP-WHPT-CHINA-YELLOW-
7b
APS
SA-CH-RAV (VHT-A02 EURO)
8
SA-BA-RAV (VHT-A01)
9
EP-FUSE-2A
10
BAP-FUSE-CAP
11
MP-SCREW-40-8
12
HOP-BAT-SPRING
13
HO-BAT-WF
14
SA-PR-INT-TH-KERN
15
PRP-PAP-TH-RAVAS-58-32-12
16
PRP-CA-APS-POWERSUPPLY
17
MP-BRACKET-WHPT-RAL9005-AP Mountig bracket APS
18
MP-BRACKET-ADA-21-PIN
19
MP-BRACKET-IN-21-41-HIGH Indicator mounting support
20
FR-21-KERN-VHT
21
IN-31
22
EB-31-OPT
23
EP-VOL-REGULATOR-7/40-5
24
PRP-CA-APS-RS232-500MM
25
Load cell (non approved version)
Mounting plate load cell 6 mm
Set fork shoes
Pallet truck chassis 540 x 1150 mm
Level switch 2° ( only approved version)
Load cell calibration board (option)
Steel housing indicator
Enclosure plate APS
Charger 230V - 12V
Battery module 12V - 1,2Ah with handle
Fuse 2A slow, 5x20mm
Fuse cover
Screw 4 x 8
Battery fixation clip
Battery housing
Plastic
printer
Single paper roll
Cable for thermal printer
Indicator adaptor bracket
Touch panel
Display board indicator 3100
Option board indicator 3100
Voltage regulator
Printer cable APS - RS232
1
1
1
1
1
1
1
1
housing
(overlay)
1
KERN VHT
4
4
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Serial number of system to be mentioned when ordering
VHT-SH-e-0910 25
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