Salter Brecknell CS-250 User Manual

CS-250 Series

CHAIR SCALE

SERVICE MANUAL (v1.06D)

CS-250 Series Chair Scales Service Manual

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CONTENTS

1. PRECAUTIONS……………………………………………………………..2

2. INTRODUCTION……………………………………………………………3

3. SPECIFICATIONS……………………………………………………….....4

3.1Specifications………………………………………………………………...4

3.2 Load Cell Specification...............................................................…...5

4. INSTALLATION……….…………………………………………………….6

5. DESCRIPTION……….....................................................................8

6. OPERATION………………………………………………………………..10

1. Power ON/OFF…………………………………………………………10

2. Zero……………………………………………………………………...10

3. Tare……………………………………………………………………...10

4. Hold function…………………………………………………………....10

5. BMI function…………………………………………………………….11

6. Unit change…………………………………………………………….11

7. PARAMETER……………………………………………………………….12

8. CALIBRATION……………………………………………………………..1 4

9. BATTERY OPERATION…………………………………………………..15

10. RS-232 OUTPUT………………………………………………………………17

11. MAINTENANCE……………………………………………………………18

11.1 General………………………………………………………………..18

11.2 Error codes……………………………………………………………19

11.3 Determine the Problem……………………………………………...19

11.4 Testing Load Cell………………………………………………………19

11.5 Check PCB Voltages………………………………………………...21

11.6 Trouble Shooting……………………………………………………..21

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WARNING

DISCONNECT ALL POWER TO THIS UNIT
BEFORE INSTALLING, CLEANING, OR
SERVICING. FAILURE TO DO SO COULD
RESULT IN BODILY HARM OR DAMAGE THE
UNIT.

CAUTION

 Permit only qualified persons to service the instrument
 Before connecting or disconnecting any components, remove the

power.

 Failure to observe these precautions bodily harm or damage to or

destruction of the equipment.

1. PRECAUTIONS

 The chair scale is a precision electronic instrument, handle it

carefully.

 Do not install the scale in direct sunlight.
 Verify the local voltage and receptacle type are correct for

the scale.

 Only use original adaptor, other could cause damage to the

scale.

 Pluggable equipment must be installed near an easily

accessible socket outlet.

 Avoid unstable power sources. Do not use near large users

of electricity such as welding equipment or large motors.

 Avoid sudden temperature changes, vibration, wind and

water.

 Avoid heavy RF noise.
 Keep the scale clean

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2. INTRODUCTION

 The CS-250 series chair scales, that amplifies signals from a load cell,

converts it to digital data and displays it as a mass value.

 It is accurate, fast and versatile series of general purpose balances with %

weighing functions and accumulation.

 Ergonomically optimized seat, comfortable, safe and reliable.
 Grasp the handrails in two ways: gross grip area, vertical grip area.
 Handrails with rubber material, comfortable and safe.
 Adjustable angle of instruments to meet the user reading.
 4 transportation wheels with brake.
 Footrest foldable, when folded out with low distance to the floor.
 Each single armrest foldable.
 Bag for power supply fixed on the chair, when power supply not in use.
 Optional RS-232 interface, can connect computer and printer.

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Model

CS-250

Maximum Capacity

250kg

Readability

100g

Resolution

1/2,500

Tare range

-249.9kg

Minimum Capacity

2000g

Linearity ±

200g

Common Specifications

Interface

RS-232 Output Optional

Stabilisation Time

2 Seconds typical

Operating Temperature

0°C - 40°C / 32°F - 104°F

Power supply (external)

12V/500mA AC power adapter

Calibration

Automatic External

ADC

Σ-Δ

Display

25 mm high 6 digits LCD with auto backlight and

loading bar graph

Housing

Aluminium platform, ABS plastic indicator

Gross weight

19kg

3. SPECIFICATION

3.1 Specifications

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Model No

L6D

Rated Capacity (kg)

2.5/3/5/6/8/10/15/20/30/35/40/50

Sensitivity

2.0±0.2 mv/v

Excitation Voltage

5~12V

Material

Aluminum

Cable

0.3~3m Φ 4mm

Input Resistance

409Ω ±6Ω/1065Ω ±15Ω

Out put Resistance

350Ω ±3Ω/1000Ω ±10Ω

Temperature Range

-35°C ~ +65°C

Safe overload

150%F.S

Ultimate overload

300%F.S

Error

±0.0233%F.S

Creep (20min)

±0.020%F.S

Zero Balance

0±5%mV/V

Max. Platform Size

250x350mm

3.2 Load Cell Specifications

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4. INSTALLATION

Unpacking

Carefully take the balance out of its package, make it sure its not damaged and
all accessories are included.

 Remove the weighing scale from the carton.
 Remove the protective covering. Store the packaging and to use if you

need to transport the scale later.

 Inspect the scale and terminal for damage.
 Make sure all components are included

Accessories,

1. Balance

2. Adaptor

3. Product manual

Level Adjusting

Place the scale on a table.
Check the water mark. If, bubble is not centre

adjust the leveling feet until reach centre. Check
the level when you change the location.

Charging Battery

 To charge the battery insert the adaptor pin to jack, jack is locating rear side

of the scale. Adaptor simply plug into the mains power. The scale no
needs to be turned on.

 The battery should be charged for 12 hours for full capacity.
 In the display there is an indicator show the status of battery charging.

When the scale is plugged into the mains power the internal battery will be
recharged. If the indicator off, the battery has a full charge. If it is on, the
battery is nearly discharged and if yellow, the battery is being charged.

 Do not use any other type of power adaptor than the one supplied with the

scale.

 Verify that the AC power socket outlet is properly protected.

Note: Please charge the battery before using the scale for the first time

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Installation

RS-232 Connecter

USB Connecter
Load cell Connecter

Adaptor Jack

 Place the scale on a table.
 Connect the adaptor pin in to the scale adaptor jack. Adaptor jack is

locating, rear side of the scale.

 Adaptor connects into your AC power socket.

Pluggable equipment must be installed near
an easily accessible socket outlet with a
protective ground/ earth contact.

 Turn on the On/Off key. If you want to turn off,

press the key again.

 Display will be show the version number and will be starting self checking.
 After self checking, display will be come to normal weighing mode.
 Warm-up time of 15 minutes stabilizes the measured values after

switching on.

 Calibrate with exact calibration weights, minimum 1/3 of the scale capacity

want to use for calibration. For calibration see details in parameter.

Then you can start your operation

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Turns the scale power On / Off

Set to hold mode

Set to BMI mode

Enter into the menu

Sets display to Zero

Subtracts weight of container

Set weight unit

5. DESCRIPTION

Key Board

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Display

DISPLAY

FUNCTION

STABLE

Indicator for Display stability

ZERO

Indicator for Zero display

TARE

Indicator for Tare display

NET

Indicator for Net weight

GROSS

Indicator for Gross weight

BMI

Indicator for BMI operations

Indicator for BMI graph

Cm/inch

Indicator for measuring units

Lb/kg

Indicator for weight units

Indicator for Charging status of battery
Voltage has dropped

Low Voltage
Fully Charged

CS-250 Series Chair Scales Service Manual

CS-250 Series Chair Scales Service Manual

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6. OPERATION

Initial Start-up

Warm-up time of 15 minutes stabilizes the measured values after switching on.

6.1 Power ON/OFF

Switch on the scale by pressing . The display is switched on and the
self test is started.
If you want to switch off press the key again.

6.2 Zero

Environmental conditions can lead to the balance exactly zero in spite
of the pan not taking any strain. However, you can set the display of

your balance to zero any time by pressing key and therefore
ensure that the weighing starts at zero.

6.3 Tare

The weight of any container can be tared by pressing key so that with

subsequent weighing the net weight of the object being weighed is always
displayed.

 Load weight on the pan.
 Press key. Zero is displayed, and tare is subtracted.

 Remove weight from the platform. Tared weight is displayed. It can

set only one tare value. It can display with a minus value.

 Press key. Zero is displayed, tare weight is cleared.

6.4 Hold function

The weight(>20d) of any container can be hold by pressing key, the weight
value will be hold on the display, press key again will turn back to normal

weighing mode.

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6.5 BMI function

Press key on the weighing mode, display will show the last setting of the
height value “xxxxxx”, and “BMI” indicator will turned on

Press key to select the height to cm / inch
If necessary, use and keys to setting new height value, then press

key confirm.
Display will be show the BMI graphics bar and weighing value.

Press key will turn back to weighing mode, BMI” indicator will be turned off.

6.6 Unit change

Press key to select the weight unit (kg/lb).
When in BMI settings, it can select to cm/ inch.

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Menu

Sub
Menu

Description

F1 off

Off 0

To set to turn off scale automatically, as per
selecting time, when scale not in use.

Off 3

Off 5

off15

Off 30

P cont

Send data continuous

SEirE

Set the remote display

ask

ASK mode
Command R: read data
Command T: Tare
Command Z: Zero

F1 off

7. PARAMETERS

Enter the Menu

 In the normal weighing mode, press key
 Display will be show

Choose the Menu / Sub Menu

 Press , it can choose menu block or options one by one.

Enter the Selected Menu

 Press , it can confirm which will be shown displayed.

Enter in to TECH

 When display showed Pi n , press and keys to enter the

function

Escape from the Menu

 Press key, it can escape from the menu to weighing mode.

Parameter Block

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F2 COM

P cnt2

Another mode, to send data continuous,

P STAB

Send data when the display stable

F3 bk

Bl on

Set the backlight always on.

Bl off

Set the backlight always off.

Bl au

Set the backlight automatic on.

F4 str

Str on

Multi tare operation turn on

Str of

Multi tare operation turn off

tch

pin

Press password to enter into the technical
parameter

P1 spd

Spd 7.5

To select display AD speed,

Spd 15

Spd 30

Spd 60

P2 cal

Cur ut

kg

Select to current weighing unit “kg”
Cur ut lb

Select to current weighing unit “lb”

Cal ut
kg

Select to calibration unit “kg”
Cal ut lb

Select to calibration unit “lb”

desc

To select scale decimal points;
Options: C 0, C 0.0, C 0.00, C0.000

C0.0000

Inc

To select scale division/increment;
Options: Div 1, Div 2, Div 5, Div 10,

Div 20, Div 50

Cap

Select to set scale capacity

Cal

Scale Calibration; details check the calibration
section

tri

To modify the calibration.
This display will be show XXXXX. For trimming
the load cells, showing primary weight.
You can calculate new rate by this formula:

N2=N1+N1×[(K2-K1)÷K2]
N1: primary rate, N2: new rate, K1: calibrate
weight, K2: display weight

count

To show the scale internal count

reset

Reset the scale

setgra

Set the local gravity value

Note: When Jumper K2 is connected on the PCB, then only can access

“tch” parameters.

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unload

0100..00lb

load

pass

F1 off

tch

pin

P1 spd

P2 cal

Cur utlb

Cal utlb

desc

8. CALIBRATION

Simple Calibration;

 Turn on the scale.
 Press key during normal weighing, display will be show
 Press key to confirm display will be show last calibrated test weight

value.

 If necessary, use and keys to change new test weight value,

then press key confirm

 Display will be show
 Place the test weight on the chair.

 After stable, press key confirm
 Display will be show
 Then will start self-test and will come to normal display.

Calibration Settings in the Parameter;

 Turn on the scale. And when in the normal display
 Press key, display will be show
 Press key until to display
 Press key to confirm display will be show
 Press and keys, display will be show
 Press key to show display
 Press key to enter calibration. Display will show
 Press key to choose the weighing unit(kg/lb) for to select unit of

current operation, press key to confirm.

 Display will show
 Press key to choose the calibration unit(kg/lb) for to select unit of

calibration, press key to confirm

 Display will show

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Cal

0100..00lb

load

pass

 Press key until display show
 display will be show

 Press key to confirm display will be show last calibrated test weight

value.

 If necessary, use and keys to change new test weight value,

then press key confirm

 Display will be show
 Place the test weight on the chair.

 After stable, press key confirm
 Display will be show
 Then will start self-test and will come to normal display

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9. BATTERY OPERATION

The Medical Scales can be operated from the battery if desired. The battery life
is approximately 40 hours.

When the battery needs charging a symbol on the weight display will turn on. The
battery should be charged when the symbol is on. The scale will still operate for
about several minutes after which it will automatically switch off to protect the
battery.

To charge the battery simply plug into the mains power. The scale does not need
to be turned on.

The battery should be charged for 12 hours for full capacity.
Just under the quantity display is an LED to indicate the status of battery

charging. When the scale is plugged into the mains power the internal battery
will be charged. If the LED is green the battery has a full charge. If the LED is
green the battery has a full charge. If it is blue indicates the battery is being
charged.

As the battery is used it may fail to hold a full charge. If the battery life becomes
unacceptable then contact your distributor.

Note: Useless battery should be want to use for recycle.

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Pin ２

RXD

Input

Receiving data

Pin ３

TXD

Output

Transmission data

Pin ５

GND ― Signal ground

10. RS-232 OUTPUT

The CS-250 Series of scales can be ordered with an optional RS-232 output.

Specifications:

RS-232 output of weighing data
ASCII code
600~9600 Baud

No Parity

RS-232 (9pin D type connector)

9pin D Connecter:
Scale Computer/Printer
Pin 2: Pin 3

Pin 3: Pin 2
Pin 5: Pin 5

Note: If data is not getting in PC/Printer, want to inter-change one of the Pin 2
and Pin3 connections

CS-250 Series Chair Scales Service Manual

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WARNING

DISCONNECT ALL POWER TO THIS UNIT
BEFORE INSTALLING, CLEANING, OR
SERVICING. FAILURE TO DO SO COULD
RESULT IN BODILY HARM OR DAMAGE THE
UNIT.

CAUTION

 Permit only qualified persons to service the instrument
 Before connecting or disconnecting any components, remove the

power.

 Failure to observe these precautions bodily harm or damage to or

destruction of the equipment.

11. MAINTENENCE

11.1. General

If the scale does not operate properly, find out the problem as possible.
Determine whether the problem is constant or alternate. Be aware that problems
can be caused by mechanical or electrical influences.

Check the following.

 Water
 Corrosive materials
 Vibrations or temperature or wind
 Physical damage

Check the scale cables for damage, and check all connections and connecters

for any loose contact or incorrect connection

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Error Code

Description

POSSIBLE CAUSES

Err 4

Zero range exceeded, due
to turning on or by pressing

 Goods on the platform
 Overload, when

zeroing the scale.

 Improper calibration
 Load cell problem
 PCB problem

Err 6

A/D Count out of the range

 Platform not installed
 Load cell problem
 PCB problem

Err 19

Auto zero out of limit

 Remove the goods

from the chair and turn
on again.

Cleaning

 Disconnect the power before cleaning.
 Use a cloth with mild suds and light cleaning agents.
 Make sure that fluid not able to get into the device.
 Use a clean and soft cloth for rub off.

11.2. Error Codes

11.3. Determine the Problem

Determine whether the problem is in the PCB or the Load Cell

 Remove power from the system, and disconnect the load cell connection

from the PCB

 Connect the PCB to a load cell simulator
 Reapply power and test the PCB
 If problem goes away, its source is probably in the Load cell. Check the

wiring, connecter, load cell and mechanical components of the load cell.
If problem persists, its source is probably in the PCB. Check the PCB voltages,
connecters, cables and function programs

11.4. Testing Load cell

For testing load cell, remove power from the system, and disconnect the PCB
from the Load cell

Physical Test:

 Check the moisture, or foreign material inside.
 Check load cell surface badly rusted or corroded

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Measuring Points

Resistance

Red (+ Exc) to Black ( –Exc)

409 ±6Ω

Green (+Sig) to White ( –Sig)

350Ω ±3Ω

 Check the strain gauge areas become compressed
 Check any physical damage (body bent or twisted) to the load cell
 Check load cell cable, all leads are connected, any cut, splits or tears.
 Check load cell for proper input and output resistances

Electrical Test:

Use an accurate multimeter to check the ohms
Load Cell Connections

Signal + Green
Supply + Red

Signal - White

Supply - Black
Shield

Resistance

Leakage Resistance

 Check each of the load cell wires to the load cell cable screen.
 Check each of the load cell wires to the load cell body.

These readings should be greater than 1000mΩ or OL.
If this reading is less than 1000 mΩ, then this load cell has leakage between
the internal circuit and the load cell body or cable screen

Zero Balance

 Connect the load cell to a stable DC source of between 5 to 10V
 Connect multimeter to mV and connect to the load cell signal wires
 The meter should read 0.00mV ± approximately 1 % of full load.

If the output reads greater than ±10% of full scale capacity, then the load cell
will require replacement.

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Problems

Possible cause

Common Solutions

Display is blank.
No self test

Mains power is turned
off. Power supply faulty
or not plugged. Internal
battery is not charged.
On/Off switch problem

Check power is getting inside the
scale and on/off switch is working.
Verify the voltages, which is on the
power labels.

Blank display
after self test

Pan not installed.
Unstable weight, load
cell damaged

Check the pans are installed
correctly. Try to turning on again.

11.5. Check PCB Voltages

If the problem is in the PCB, use a multimeter to check the following voltages

11.5.1 AC Power

Check the AC power socket out put voltage.

 Voltage must be a -20% and +10% of the normal AC voltage.

11.5.2 Adaptor Voltage

Check the adaptor output cable connecter voltage

 Voltage must be minimum 9VDC and maximum 15VDC

11.5.3 PCB Input Voltage

Check the PCB input power connecter voltage

 Voltage must be minimum 9VDC in to the pin AD+

11.5.4 Check Battery Voltage and Charging Voltage

1. Check the Battery Voltage,

 Voltage must be minimum 6VDC. If below the 6VDC connect the adaptor

for charging

 The battery voltage below the 5.5VDC, replace the battery and install new

6V/3.4Ah battery.

2. Check the Battery Charging Voltage;

 Remove the battery connection terminals (Red and Black) from the battery.
 Connect the power and turn on the scale
 Voltage into the terminal minimum 6.5VDC

11.6 Trouble Shooting

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OL or -------

Maximum capacity
exceeded. Load cell or
mechanics damaged.
Power supply faulty

Check the platform is installed
correctly. Try to turn on the scale
again. Do the calibration again

------- or NULL
displayed

Weight is on the
platform is below
permissible limit. Pan
not installed correctly.
Power supply faulty.
Load cell or
mechanism faulty

Check the platform is installed
correctly. Try to turn on the scale
again.
Do the calibration again

Display is
unstable

Goods touching
somewhere. Air
variation or any
vibrations.
Temperature
changed . Load cell or
connections faulty.
Power supply faulty

Check the scale is in acceptable
location.
Check the connecters and load cell.
Check the power supply and battery

Weight value
incorrect

Calibration error.
Platform of load cell
touching somewhere.
Wrong weighing unit

Use accurate weight for to do the
calibration
Check the pan and load cell is
installed proper and touching.
Check the parameter settings.
Check the load cell and connecters

Can not use full
capacity

Over load protection
stoppers or transport
locks are not removed.
Parameters are set
incorrectly.
AD problem.
Load cell or
mechanism damaged

Check the stoppers and locks under
the platform.
Check the weighing unit and
parameter settings.
Check the load cell.

Platform Corner
Weight different

Over load protection
stoppers or transport
locks are not removed.
Load cell or
mechanism damaged

Check the stoppers and locks under
the platform.
Use accurate weight for to do the
calibration
Check the load cell.

Battery not
charging

Mains voltage problem
Charging circuit
problem
Battery Problem

Check the mains and adaptor.
Check the battery.
Check the charging circuit

Brecknell Weighing Products

1000 Armstrong Dr.

Fairmont, MN 56031

Toll free: 800-637-0529

Tel: [phone] Fax: [phone]

e-mail: [e-mail]

www.brecknellscales.com