KERN PBJ-N User manual

KERN & Sohn GmbH
Ziegelei 1
D-72336 Balingen
E-Mail: [email protected]
Tel: +49-[0]7433- 9933-0
Fax: +49-[0]7433-9933-149
Internet: www.kern-sohn.com
Service Manual
Precision balances
KERN PBJ-N
Version 1.0
02/2018
GB
PBJ_N-SH-e-1810

PBJ_N-SH-e-1810.docx 2
GB
KERN PBJ-N
Precision balances
Version 1.0 03/2018
Service manual
Content
1Basic Information ................................................................................................5
2Introdution............................................................................................................5
3Appliance overview .............................................................................................6
3.1 Keyboard overview..................................................................................................................... 7
3.2 In menu:....................................................................................................................................... 8
3.3 Numeric entry.............................................................................................................................. 8
3.4 Setting the decimal point when entering numerical values................................................... 9
3.5 Overview of display.................................................................................................................. 10
4Basic Information (General)..............................................................................11
4.1 Proper use................................................................................................................................. 11
4.2 Improper Use............................................................................................................................. 11
4.3 Warranty .................................................................................................................................... 11
4.4 Monitoring of Test Resources................................................................................................. 12
5Basic Safety Precautions..................................................................................12
5.1 Pay attention to the instructions in the Operation Manual ..................................................12
5.2 Personnel training ....................................................................................................................12
6Transport and storage.......................................................................................12
6.1 Testing upon acceptance......................................................................................................... 12
6.2 Packaging..................................................................................................................................12
7Unpacking, Setup and Commissioning ...........................................................13
7.1 Installation Site, Location of Use............................................................................................ 13
7.2 Unpacking / Scope of delivery ................................................................................................13
7.3 Placing....................................................................................................................................... 15
7.4 Mains connection .....................................................................................................................18
7.5 Switch power supply on........................................................................................................... 18
7.6 Connection of peripheral devices........................................................................................... 19
7.7 Initial Commissioning .............................................................................................................. 19
8Adjustment.........................................................................................................20
8.1 Manual adjustment by CAL button ......................................................................................... 20
8.2 Adjustment with internal weight .............................................................................................20
9Adjustment test..................................................................................................21
9.1 Adjustment test with external weight..................................................................................... 22
9.2 Adjustment test with internal weight......................................................................................23
9.3 Automatic adjustment by PSC (Perfect Self Calibration), only models PBJ...................... 24
9.4 Automatic adjustment by Clock-CAL..................................................................................... 24
10 Verification......................................................................................................26
11 The menu ........................................................................................................27
11.1 Navigation in the menu............................................................................................................ 27
12 Service, maintenance, disposal ....................................................................30
12.1 Clean.......................................................................................................................................... 30
12.2 Service, maintenance............................................................................................................... 30
12.3 Disposal..................................................................................................................................... 30

3 PBJ_N-SH-e-1810.docx
13 Instant help .....................................................................................................31
13.1 Error message: .........................................................................................................................32
14 Operating method for the adjustment service.............................................34
14.1 Gaining entry to the service menu.......................................................................................... 34
14.2 Service menu contents ............................................................................................................35
15 Balance assembly / dismantling precautions..............................................36
15.1 Dismantling / Assembly........................................................................................................... 36
15.2 Transporting Balance............................................................................................................... 36
15.3 DISMANTLING........................................................................................................................... 37
16 ASSEMBLY .....................................................................................................38
16.1 Replacement of Components..................................................................................................39
16.1.1 Replacing the Assy,Display (B4)......................................................................39
16.2 Replacing the Assy,Analog (B3) .............................................................................................39
16.3 DETACH THE ASSY,DISPLAY (B4) AND PLACE IT TO THE RIGHT OF THE BALANCE IN A
LOCATION FREE OF DIRT AND STATIC............................................................................................ 39
16.4 Replacing the Assy,I/F (B5) .....................................................................................................41
16.5 Replacing the Switch board assy (C3) ................................................................................... 41
16.6 Replacing the Assy,Detector (U8)........................................................................................... 42
16.7 Replacing the Weight loader assy (10) (UW series only) .....................................................42
16.8 Replacing the Unit assy (1)......................................................................................................43
16.9 Input of temperature coefficient data ..................................................................................... 43
16.10 Replacement of the level...................................................................................................... 43
17 Replacing the Force coil assy (L1)................................................................44
17.1 Dismantling ............................................................................................................................... 44
18 Assembly ........................................................................................................44
19 Dismantling/ Assembling the Weight loader assy (10) ...............................46
19.1 Dismantling ............................................................................................................................... 46
19.2 Assembly...................................................................................................................................48
19.3 Adjustment of the pin height of the calibration weight loading ..........................................48
20 Balance Adjustment.......................................................................................49
20.1 Adjustment of the Assy,Detector (U8) Height ....................................................................... 49
20.2 Adjustment of tilt errors...........................................................................................................50
20.3 Adjustment of Corner Load..................................................................................................... 51
21 Performance Inspection.................................................................................52
21.1 Repeatability ............................................................................................................................. 52
21.2 Corner load error ......................................................................................................................52
21.3 Built-in weight calibration........................................................................................................52
21.4 Linearity..................................................................................................................................... 53
21.5 Tilt error..................................................................................................................................... 53
22 Component Replacement Precautions.........................................................54
23 Drawing ...........................................................................................................55
24 11. Trouble shooting......................................................................................59
24.1 Information for Inferring the Cause of Board Failure ........................................................... 61
24.2 1Assy,Display (B4) ................................................................................................................... 61
24.3 Assy,Analog (B3)...................................................................................................................... 61
24.4 Voltages of each part (reference values) ...............................................................................62
24.5 Assy,I/F (B5)..............................................................................................................................62
24.6 Voltages of each part (reference values) ...............................................................................62
24.7 Writing in Simple Linear Coefficients (temporary, rough adjustment of linearity)............ 63
25 Adjustment of Linearity .................................................................................64
26 Editing EEPROM data ....................................................................................66
26.1 Using “Edit” .............................................................................................................................. 66

PBJ_N-SH-e-1810.docx 4

5 PBJ_N-SH-e-1810.docx
1 Basic Information
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.
Instructions about conformity-evaluated scales:
Repair must be carried only at 100% compliance with the type approval. A violation of this
specification will result in a loss of the type approval! After successful repair the balance will
have to be reverified before it can be used again in a statutorily regulated field.
Detailed instructions about conformity-evaluated scales:
Repair must be carried only at 100% compliance with the type approval. A violation of this
specification will result in a loss of the type approval!
After successful repair the balance will have to be reverified before it can be used again in a
statutorily regulated field.
2 Introdution
-
This service manual covers the PBJ_N series and is edited for the authorized servicing
personnel.
Note all rights are reserved. Copying any part of this manual is prohibited without our
permission.
In this lineup it is an eco product, Therefore, it is not intended to represent the repair manual
in detail, since the construction of the balance is very simple. It is therefore only referring to
the list of related to disposal spare parts.

PBJ_N-SH-e-1810.docx 6
3 Appliance overview
Models with readability d = 0.001 g:
Models with readability d ≥ 0.01 g:
Windshield
Weighing pan
Display
Keyboard
Levelling screw

7 PBJ_N-SH-e-1810.docx
3.1 Keyboard overview
In weighing mode:
Button
Description
Pressed once and released
Keep pressed for about 3
seconds
[ON/OFF]
Switches between the
operation and standby modes.
Exit menu / Return to weighing
mode
[CAL]
Invokes adjustment or menu
selection. (*1)
To display the menu
element recently set.
[TARE]
Taring / Setting to zero
No operation
[UNIT]
Switch over weighing unit (*3)
No operation
[PRINT]
Issue of weighing value to
external appliances (printer,
PC)
Issue of date and time to
external appliances.
*1 This key is used to set a value when percent (%), number of pieces (PCS), specific
weight
of solids (▼d) or specific weight of liquid (d) is displayed.
*3 Units different than „g” must be first set in the balance, before they can be used for
measurements. Only gram (g), percent (%) and number of pieces (PCS) are factory set.
ESC
ON/OFF
MENU
CAL
TARE/
UNIT
PRINT

PBJ_N-SH-e-1810.docx 8
3.2 In menu:
Button
Description
Pressed once and released
Keep pressed for about 3
seconds
[ON/OFF]
To return to a submenu or
weighing mode.
Return to weighing mode
[CAL]
Moves to the next menu item.
To display the menu
element recently set.
[TARE]
To select or set the menu
element recently displayed.
No operation
[UNIT]
Entering numeric values:
Increases the numeric value
of flashing digit by 1.
No operation
[PRINT]
Entering numeric values: To
go to the next position.
No operation
3.3 Numeric entry
Button
Description
Function
Navigation button 
Increase flashing digit
Navigation button 
Digit selection to the right
Navigation button
Confirm entry
ESC
Cancel input
With numerical input the indicator [#] appears.
„SET“ indicates that the value has been saved successfully.
„ERR“ means that the value could not be saved successfully; back to menu by
and repeat enter.
ESC
ON/OFF
MENU
CAL
TARE/
UNIT
PRINT

9 PBJ_N-SH-e-1810.docx
3.4 Setting the decimal point when entering numerical values
Entering a decimal point is necessary only for determining the specific gravity or if a multiplier
shall be defined for the user-defined unit.
Repeat actuating the button until the last digit flashes. Actuate the button again in
order to call up the decimal point setting mode. The reversed triangle symbol ▼or the current
decimal point flashes.
Actuate the button in order to move the decimal point to the required position by one
digit each.
Actuate the button to define the position of the decimal point. The message „SEt“
which appears for a short period of time indicates that setting has been completed.
PRINT
PRINT
UNIT
TARE/

PBJ_N-SH-e-1810.docx 10
3.5 Overview of display
Display
Designation
Description
Indicates that the weighed value is stable. (*1) It marks the
currently selected element during menu element selection.
Tare symbol
Informs about setting an initial tare value.
Weight symbol
It is displayed during adjusting the measuring range. It
indicates adjusting settings during menu selection. Flashes
prior to start of automatic adjustment.
Note:
If automatic adjusting of measuring range is not activated, a
user must perform it when this symbol flashes.
with built-in weight (PBJ models refer to chapter
9.31.1)
with external weight (PBS models refer to chapter
Fehler! Verweisquelle konnte nicht gefunden werden.).
[ ]
Brackets
The non-calibrated value is given in brackets in calibrated
scales.
Number symbol
Indicates numeric value entry.
Menu symbol
Appears during menu selection. Always shown when the
menu is locked.
Asterisk
Indicates that the displayed numeric value is not a mass
value.
Communication
symbol
Is lit up during communication with external appliances via
RS-232C cable. Shown when communication functions are
ON.
▼
Inverse triangle
symbol
Indicates the setting of specific weight measurement. It is
used as an alternative to the decimal point.
→0←
Zero indicator
Animal symbol
Shows the setting of animal weighing function.
Automatic storage
and zeroing symbol
Shows the setting of automatic saving and zeroing function.
M
Memory Symbol
Balance is in formula mode
Auto Print symbol
Displays set-up of the Auto Print function.
Standby mark
Appears when the balance power supply is in stand-by
mode. It is also displayed when operational function
changes into stand-by mode.
*1 Stabilisation symbol
When the stabilisation symbol is illuminated for a long time, the displayed value may
oscillate when a weight is slowly changed or stabilisation detection range is set to high
value.
Capacity display
Display of units
Stability display