KERN RFC 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
Price calculating balance
KERN RFC
Version 1.0
02/2018
GB
RFC-SH-e-1810

2 RFC-SH-e-1810
GB
KERN RFC
Price calculating balance
Version 1.0 03/2018
Service manual
Content
1Basic Information .........................................................................................4
2Introdution.....................................................................................................4
3Appliance overview......................................................................................5
3.1 Overview of display............................................................................................................6
3.2 Display weight.....................................................................................................................7
3.3 Display basic price .............................................................................................................7
3.4 Display sale price ...............................................................................................................7
3.5 Battery loading status display ..........................................................................................7
1.1 Keyboard overview.............................................................................................................8
4Basic Information (General).........................................................................9
4.1 Proper use...........................................................................................................................9
4.2 Improper Use.......................................................................................................................9
4.3 Warranty ..............................................................................................................................9
4.4 Monitoring of Test Resources...........................................................................................9
5Basic Safety Precautions...........................................................................10
5.1Pay attention to the instructions in the Operation Manual ..........................................10
5.2 Personnel training ............................................................................................................10
6Transport and storage................................................................................10
1.2 Testing upon acceptance ................................................................................................10
6.1 Packaging / return transport ...........................................................................................10
7Unpacking, Setup and Commissioning....................................................11
7.1 Installation Site, Location of Use....................................................................................11
7.2 Unpacking .........................................................................................................................11
8Placing.........................................................................................................12
8.1 Scope of delivery / serial accessories: ..........................................................................12
8.2 Mains connection .............................................................................................................12
8.3 Storage battery operation (optional) ..............................................................................12
9Adjustment..................................................................................................13
10 Verification...............................................................................................15
10.1 Adjustment switch and seals ..........................................................................................16
10.2 Checking the balance verification settings ...................................................................16
11 The menu .................................................................................................17
11.1 Access to menu ................................................................................................................17
11.2 Navigation in the menu:...................................................................................................17
11.3 Menu overview..................................................................................................................18
12 Instant help..............................................................................................20
13 Error messages.......................................................................................21

RFC-SH-e-1810 3
14 Drawing....................................................................................................23
14.1 without pole.......................................................................................................................23
14.2 with pole ............................................................................................................................24
15 Circuit diagram........................................................................................25
15.1 MCU....................................................................................................................................25
15.2 Power.................................................................................................................................26
15.3 Display board....................................................................................................................26
16 Trouble shooting.....................................................................................27
17 Maintanace...............................................................................................29
17.1 General ..............................................................................................................................29
17.2 Cleaning.............................................................................................................................29
17.3 Determine the Problem....................................................................................................29
17.4 Check the Load ce ll ..........................................................................................................29
17.5 Load Cell Connections.....................................................................................................30
17.6 Check PCB Voltages........................................................................................................30
17.7 AC Power...........................................................................................................................30
17.8 Adaptor Voltage................................................................................................................30
17.9 PCB Input Voltage............................................................................................................30
17.10 Check Battery Voltage and Charging Voltage ..........................................................31
17.11 Replace Main Board .....................................................................................................31
17.12 Replace Load Cell.........................................................................................................31
17.13 Replace Battery.............................................................................................................32

4 RFC-SH-e-1810
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 RFC 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.

RFC-SH-e-1810 5
3 Appliance overview
Models without vertical display:
Models with post-mounted display:
1. Weighing pan
2. Bubble level
3. Post-mounted display
4. Footscrews
5. Mains adapter connection
6. ON/OFF switch
7. RS 232 interface
8. Battery compartment
9. Adjustment switch

6 RFC-SH-e-1810
3.1 Overview of display
Operator and secondary display (standard on the backside of models without
post-mounted display):
Additional post-mounted display for models with tripod:

RFC-SH-e-1810 7
3.2 Display weight
Here, the weight of your goods is displayed.
Indicator next to symbol displays:
Rechargeable battery very low
NET
Net weight
Stability display
a
Zeroing display
3.3 Display basic price
Basic price, can be switched over from € / kg or € / 100 g.
Indicator next to symbol displays:
€/kg
Basic price in €/kg
€/100 g
Basic price in €/100 g
AUTO CLEAR
Set basic price is deleted automatically when balance
is unloaded
3.4 Display sale price
Here the sales price is displayed in Euro [€].
Indicator next to symbol displays:
BAR
Calculating the change (see chap. 10.3)
3.5 Battery loading status display
red
Charging storage battery
green
Rechargeable battery completely reloaded

8 RFC-SH-e-1810
3.6 Keyboard overview
Selection
Function
~
Numerical keys, PLU-keys
In menu: Invoke parameter
Delete
Save basic price (press key for a long time),
see chap. 10.2
Call-up basic price (press and hold key for a short time), see
chap. 10.2
Switch-over unit € / kg € / 100g
Issue to external device
In menu:Parameter selection
Calculating the change, see chap. 10.3
Taring, see chap. 9.3
In menu: Storing settings
For activated function, the set basic price is automatically
deleted when the balance is unloaded.
Enter basic price per piece (without weighing)
Zeroing
In menu: Back to weighing mode
Decimal point

RFC-SH-e-1810 9
4 Basic Information (General)
4.1 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 pan. As soon as a
stable weighing value is reached the weighing value can be read.
4.2 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“! (Example: Slowly draining fluids from a container on the
balance.)
Do not leave permanent load on the weighing pan. This may damage the measuring
system.
Impacts and overloading exceeding the stated maximum load (max) of the balance,
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.
4.3 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
4.4 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 RFC-SH-e-1810
5 Basic Safety Precautions
5.1 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.
5.2 Personnel training
The appliance may only be operated and maintained by trained personnel.
6 Transport and storage
1.1 Testing upon acceptance
When receiving the appliance, please check packaging immediately, and the appliance
itself when unpacking for possible visible damage.
6.1 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 the glass wind screen, the weighing platform,
power unit etc. against shifting and damage.