2 METTLER TOLEDO Service Manual PBA426 / PBA426x 09/09Order number 72230074
Congratulations on choosing the quality and precision
of METTLER TOLEDO. Proper use according to these
instructions and regular calibration and maintenance by
our factory-trained service team ensure dependable and
accurate operation, protecting your investment. Contact
us about a ServiceXXL agreement tailored to your needs
and budget.
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and important notifications concerning your METTLER
TOLEDO product.
Service XXL
General Information ..................................................4
Information for Operation in Ex area .........................5
Spare Parts ..............................................................7
PBA426(x)-A.../QA ....................................................7
PBA426(x)-BB.../B.../QB ............................................9
Repair ....................................................................11
Safety precautions ....................................................11
Replacing the load cell .............................................11
Replacing absorber rubber ........................................13
Settings .................................................................14
Setting corner load and overload limits .......................14
Technical Data and Tolerances .................................16
Technical data .......................................................16
Calibration error tables .............................................17
Information about capacity and preload ......................18
Contents
1
2
3
3.1
3.2
4
4.1
4.2
4.3
5
5.1
6
6.1
6.2
6.3
3
METTLER TOLEDO Service Manual PBA426 / PBA426x09/09 Order number 72230074
4 METTLER TOLEDO Service Manual PBA426 / PBA426x 09/09Order number 72230074
General Information
1 General Information
This service manual contains instructions for the repair and
maintenance work of the PBA426(x) weighing platform.
All repair and maintenance work is to be performed by autho-
rized Mettler-Toledo Service Technicians.
It is assumed that the reader is familiar with the operation of
the device and can refer to the relevant operating instructions
when necessary.
The service concept has been designed so that defective parts
can be replaced using a few standard tools and simple aids.
Working with the service manual
The exploded view drawings are provided as a guide for assem-
bling and disassembling work and for identifying the order
numbers for spare parts.
When ordering spare parts, please use the information given
in the spare parts lists. The item numbers in the first column
“Item” correspond to those on the corresponding exploded view
drawing.
PBA426(x)-... analog weighing platforms
PBA426(x)-... analog weighing platforms can be connected to
analog METTLER TOLEDO weighing terminals.
Analog-digital-signal conversion takes place within the termi-
nal. All scale and country specific parameters are stored in the
terminal.
5
METTLER TOLEDO Service Manual PBA426 / PBA426x09/09 Order number 72230074
2 Information for Operation in Ex area
The explosion-protected PBA426x... weighing platforms
are approved for operation in ATEX Zone 1/21 and FM I.S.
Class I, II, III Div. 1 areas.
There is an increased risk of injury and damage when
the explosion protected weighing platforms are used in a
potentially explosive atmosphere.
Special care must be taken when working in such hazard-
ous areas.
Ex approval
▲
▲
▲
▲
▲
No modifications may be made to the terminal and no
repair work may be performed on the modules. Any
weighing platform or system modules that are used
must comply with the specifications contained in the
installation instructions. Non-compliant equipment
jeopardises the intrinisc safety of the system, cancels
the Ex approval and renders any warranty or product
liability claims null and void.
Peripheral devices (operational terminals) not Ex
approved may only be used in a safe area and may
not exceed the maximum supply voltage or the maxi-
mum voltage of the weighing cells.
The safety of the weighing system is only guaranteed
when the system is operated, installed and maintained
in accordance with the respective instructions.
Also comply with the following:
- the instructions for the system modules
- the regulations and standards in the respective country
- the applicable statutory requierments for electrical
equipment installed in hazardous atmospheres in
the respective country
- all instructions related to safety iissued by the owner
Before start-up and following service work, check the
explosion protected weighing system for the proper
condition of all safety-related parts.
6 METTLER TOLEDO Service Manual PBA426 / PBA426x 09/09Order number 72230074
General Information
Operation
▲
▲
▲
Installation / Maintenance
▲
▲
▲
▲
▲
Service
▲
▲
▲
Competence
Prevent the build-up of static electricity. Always wear suitable working
clothes when operating or performing service work in an hazardous
area.
Do not use protective hoods.
Avoid causing damage to the weighing platforms.
Installation and maintenance work may be carried out on the weighing
platform in the hazardous zone, providing the following conditions
are fulfilled:
- the owner issued a permit (“spark permit” or “fire permits”)
- the area has been rendered safe and the owner’s safety coordinator
has confirmed that there is no danger
- the necessary tools and any requiered protective clothing are pro-
vided (danger of the build-up of static electricity)
The certification papers (certificates, manufacturer’s declaration) must
be present.
Lay cables in such a way that they are protected from damage.
Only route cables into the housing of the system modules via the
earthing cable gland or METTLER TOLEDO plug and ensure proper
seating of the seals.
Always disconnect the system from the power supply before commenc-
ing maintenance work. Where certain inspections, tests or adjustments
require the system to remain connected to the power supply, this work
must be performed with particular care.
Service technicians must have attended a product-specific course of
training for hazardous-duty equipment.
Service work should be performed outside hazardous zones whereever
possible. Service work includes dismanteling an Ex unit inside the
hazardous zone and moving it into the safe zone.
Only use parts or modules s pecified in the spare parts list as replace-
ment. Do not separate connectors until the weighing system has been
deenergised.
The weighing platform may only be installed, maintained and repaired
by authorised METTLER TOLEDO service personnel.
8 METTLER TOLEDO Service Manual PBA426 / PBA426x 09/09Order number 72230074
Spare Parts
Item Designation Order number
1 Load plate
•240x300mm/9.5”x11.8”forPBA426(x)-A... 72211576
•228x228mm/9”x9”forPBA426(x)-QA... 72211581
2 Absorbing rubber assembly 72 211 265
3 Load cell
•20kgforPBA426(x)-A3/A6/QA3/QA6 72228077
•50kgforPBA426(x)-A15 72228078
4 Level indicator, complete 71 209 286
5 Levelling foot, complete, 1 piece 72 185 977*
*For an ICS scale and/or a PBA426 platform with suffix “H” order 72 211 176
(Hygienic Feet)
10 METTLER TOLEDO Service Manual PBA426 / PBA426x 09/09Order number 72230074
Spare Parts
Item Designation Order number
1 Load plate
• 300x400mm/11.8”x15.7”forPBA426(x)-BB.. 72211577
• 305x305mm/12”x12”forPBA426(x)-QB... 72211582
• 400x500mm/15.7”x19.7”forPBA426(x)-B.. 72211579
2 Absorbing rubber assembly 72 211 265
3 Load cell
• 50kgforPBA426(x)-QB15/BB30/QB30/B30 72228078
• 100kgforPBA426(x)-BB60/B60 72228079
4 Levelling foot, complete, 1 piece 72 185 977**
5 Level indicator, complete 71 209 286
6 Absorbing rubber, 1 piece 72 211 267
7 Load cell spacer kit (incl. screws)* 72 243 211
*only needed for B-Size
**For an ICS scale and/or a PBA426 platform with suffix “H” order 72 211 176
(Hygienic Feet)
11
METTLER TOLEDO Service Manual PBA426 / PBA426x09/09 Order number 72230074
4 Repair
Safety Precautions
DANGER
Electric Shock Hazard!
▲
▲
CAUTION
Precision electronic components may be damaged due
to static electric discharge!
▲
Replacing the Load Cell
Removing the Load Cell
1.
2.
3.
4.
5.
Note: Only the original Mettler-Toledo Ex approved load cell
to be used for replacement.
Always unplug power cord before performing any work
on the weighing platform.
Allow only qualified personnel to service the weighing
platform.
Always wear an grounding wrist strap during all work
on the weighing cell in order to divert static electricity
discharges.
Disconnect the load cell at the weighing terminal.
Remove the load plate.
Loosen the fastening screws of the load cell at the
housing top section and lift off the top section of the
housing.
Loosen the fastening screws of the load cell at the
housing bottom section.
If appropriate, loose the cable clamp and remove the
load cell.
4.1
4.2
4.2.1
12 METTLER TOLEDO Service Manual PBA426 / PBA426x 09/09Order number 72230074
Repair
Installing the Load Cell
1.
2.
3.
4.
5.
6.
Note
•
•
4.2.2
Insert the new load cell in the housing bottom section.
Align the load cell parallel and tighten it with the fasten-
ing screws to the housing bottom section. For tightening
torque values refer to the table below.
Put on the housing top section together with the cell
support.
Align the housing top section parallel to the housing bot-
tom section and screw it to the load cell. For tightening
torque values refer to the table below.
If appropriate fix the cable with the cable clamp.
Put on the load plate.
The load cells are calibrated at the factory in such a way
that adjustment of the corner load is not necessary.
After the load cell has been replaced, the corner load and
overload limits have to be reset, see page 14, Chapter
5, Settings.
Type Load plate Cell Cell Load cell Tool 2) Tightening
[mm] [inch] support support screws1) torque
bottom top
PBA426(x)-A...
240 x 300 9.5 x 11.8 None None M6 x 16 Size 10 10 Nm
PBA426(x)-BB.
300 x 400 11.8 x 15.7 None None M6 x 20 Size 10 10 Nm
PBA426(x)-B…
400 x 500 15.7 x 19.7 *16.5 mm / *16.5 mm / M8 x 20 Size 13 20 Nm
0.65” 0.65”
PBA426(x)-QA..
229 x 229 9 x 9 None None M6 x 16 Size 10 10 Nm
PBA426(x)-QB..
305 x 305 12 x 12 None None M6 x 20 Size 10 10 Nm
1)Hexagon head screws *To fix the cell support use M6 x 20 hexagon
2)Hexagon spanner socket head screws, Spanner size 5, 10 Nm
13
METTLER TOLEDO Service Manual PBA426 / PBA426x09/09 Order number 72230074
4.2.3
4.3
Connecting the Load Cell to the Weighing Terminal
➜
SLP535 load cell
Terminal Color
EXC+ blue
EXC– black
SIG+ white
SIG– red
SEN+ green
SEN– grey
Shield yellow
Replacing Absorber Rubber
1.
2.
3.
4.
5.
Connect the load cell to the weighing terminal in accor-
dance with the color coding below.
Remove the load plate.
Remove the absorbing rubber that has to be replaced by
loosening the screw.
Place the new absorbing rubber on the corresponding
position.
Screw in the absorbing rubber on the four corners; press
the absorbing rubber (center) onto the stainless steel
supporting bar.
Put on the load plate.
14 METTLER TOLEDO Service Manual PBA426 / PBA426x 09/09Order number 72230074
Settings
5 Settings
Setting Corner Load and Overload Limits
1.
2.
3.
4.
5.
6.
5.1
Remove the load plate and put on a weight that corre-
spondsapproximately that of the load plate.
Switch on the weighing terminal.
Loosen the lock nut of the first adjusting screw for the
corner load (1).
Turn the adjusting screw in until the display value begins
to change. If necessary, repeat this process until the exact
point is determined.
Starting from this position turn the adjusting screw back
by the amount listed in table 5.1.x and secure the adjusting
screw in this position using the lock nut.
Repeat steps 3 to 5 for the corner load screws (2) to (4)
and the overload screws (5) and (6).
15
METTLER TOLEDO Service Manual PBA426 / PBA426x09/09 Order number 72230074
Values in Millimeter and Kilogram
Values in Inch and Pound
5.1.1
5.1.2
Corner load limit Overload limit
PBA426(x)- Dimensions Max. load Corner load Adjusting Overload Adjusting
[mm] [kg] value [kg] screws 1 – 4 value [kg] screws 5, 6
3 2.5...3.5 0.90 mm 5...8 0.38 mm
A... 240 x 300 6 5...6 1.90 mm 10...15 0.70 mm
15 11...12 3.30 mm 20...23 0.90 mm
BB... 300 x 400 30 25...30 1.00 mm 45...50 0.38 mm
60 42...50 1.50 mm 80...100 0.40 mm
30 25...30 1.40 mm 45...50 0.25 mm
B... 400 x 500 60 45...55 2.20 mm 80...100 0.30 mm
QA... 229 x 229 3 2.5...3.5 0.60 mm 5...8 0.33 mm
6 5...6 1.30 mm 10...15 0.60 mm
15 11...12 0.40 mm 20...23 0.15 mm
QB... 305 x 305 30 25...30 0.80 mm 45...50 0.25 mm
60 42...50 1.20 mm 80...100 0.45 mm
Corner load limit Overload limit
PBA426(x)- Dimensions Max. load Corner load Adjusting Overload Adjusting
[inch] [lb] value [lb] screws 1 – 4 value [lb] screws 5, 6
5 5.5...7.7 0.035” 11...17.6 0.0146”
A... 9.5 x 11.8 10 11...13.2 0.073” 22...33 0.027“
25 24.2...26.4 0.130“ 44... 50.6 0.035”
BB... 11.8 x 15.7 50 55...66 0.038” 99...110 0.015”
100 92.4...110 0.058” 176...220 0.015“
50 55...66 0.054” 99...110 0.0096”
B... 15.7 x 19.7 100 99...121 0.085” 22...33 0.0115“
QA... 9 x 9 5 5.5…7.7 0.023” 11...17.6 0.0127”
10 11…13.2 0.050” 22...33 0.023“
25 24.2...26.4 0.015” 44...50.6 0.0058”
QB... 12 x 12 50 55...66 0.031” 99…110 0.0096”
100 92.4...110 0.046” 176...220 0.017”
16 METTLER TOLEDO Service Manual PBA426 / PBA426x 09/09Order number 72230074
Technical Data and Tolerances
6 Technical Data and Tolerances
Technical Data
According OIML 3000e
According NTEP 5000d
Note on Linearity
3-point linearization should be used for verified or verifiable
weighing platforms. The tolerances at the test points set dur-
ing manufacturing (0%, 50 %, 100 % of the nominal load)
are listed in the Calibration error table.
Notes on Calibration
•
•
6.1
6.1.1
6.1.2
Maximum load 3 kg 6 kg 15 kg 30 kg 60 kg
Resolution (standard) 3000e 3000e 3000e 3000e 3000e
Calibration class III III III III III
Readability 1 g 2 g 5 g 10 g 20 g
Repeatability (typ.) 1.05 g 2.1 g 5.25 g 10.5 g 21 g
Linearity (typ.) 1.05 g 2.1 g 5.25 g 10.5 g 21 g
Corner load test weight 1 kg 2 kg 5 kg 10 kg 20 kg
Corner load tolerance (max.) 1 g 2 g 5 g 10 g 20 g
Temperature stability (max.) 20 ppm/°C
Maximum load 5 lb 10 lb 25 lb 50 lb 100 lb
Resolution (standard) 5000d 5000d 5000d 5000d 5000d
Calibration class III III III III III
Readability 0.001 lb 0.002 lb 0.005 lb 0.01 lb 0.02 lb
Repeatability (typ.)
0.00105 lb 0.0021 lb 0.00525 lb 0.0105 lb 0.021 lb
Linearity (typ.) 0.00105 lb 0.0021 lb 0.00525 lb 0.0105 lb 0.021 lb
Corner load test weight 2 lb 4 lb 10 lb 20 lb 40 lb
Corner load tolerance (max.) 0.001 lb 0.002 lb 0.005 lb 0.01 lb 0.02 lb
Temperature stability (max.) 20 ppm/°C
With verified scales, calibration must be performed exter-
nally with test weights in accordance with the configured
maximum load.
With non-verified scales, test weights of at least 1/2 maxi-
mum weight are required.
17
METTLER TOLEDO Service Manual PBA426 / PBA426x09/09 Order number 72230074
Calibration Error Tables
Calibration Error Table for 1 x 3000e
Calibration Error Table for 1 x 5000d
6.2
6.2.1
6.2.2
Maximum Calibration error limit: Calibration error limit: Calibration error limit:
load 0.5e 1e 1.5e
3 kg 0...0.5 kg 0.5 g 0.5...2 kg 1 g 2...3.5 kg 1.5 g
6 kg 0...1 kg 1 g 1...4 kg 2 g 4...6 kg 3 g
15 kg 0...2.5 kg 2.5 g 2.5...10 kg 5 g 10...15 kg 7.5 g
30 kg 0...5 kg 5 g 5...20 kg 10 g 20...30 kg 15 g
60 kg 0...10 kg 10 g 10...40 kg 20 g 40...60 kg 30 g
Maximum Calibration error limit: Calibration error limit: Calibration error limit: Calibration error limit:
load 0.5d 1d 1.5d 2.5d
5 lb 0...0.5 lb 0.0005 lb 0.5...2 lb 0.001 lb 2...4 lb 0.0015 lb 4...5 lb 0.0025 lb
10 lb 0...1 lb 0.001 lb 1...4 lb 0.002 lb 4...8 lb 0.003 lb 8...10 lb 0.005 lb
25 lb 0...2.5 lb 0.0025 lb 2.5...10 lb 0.005 lb 10...20 lb 0.0075 lb 20...25 lb 0.0125 lb
50 lb 0...5 lb 0.005 lb 5...20 lb 0.01 lb 20...40 lb 0.015 lb 40...50 lb 0.025 lb
100 lb 0...10 lb 0.01 lb 10...40 lb 0.02 lb 40...80 lb 0.03 lb 80...100 lb 0.05 lb
18 METTLER TOLEDO Service Manual PBA426 / PBA426x 09/09Order number 72230074
Technical Data and Tolerances
Information about Capacity and Preload
1
2
3
4 5
6
7
8
9
1
2
3
4
5
6
7
8
9
5.3
Maximum load range of the load cell (E
max
)
Maximum preload
= Maximum load range 1 – Maximum load 3
Maximum load
= Maximum load range 1 – Maximum preload 2
Preload top section
Preload weighing pan
Preload ex works
= Preload top section 4 + Preload weighing pan 5
Mechanical prelaod reserve
= Maximum preload 2 – Preload ex works 6
The zero-set range (switching on) can be set
The zero-set range must lie within the maximum preload.
The zero-set range may amount to a max. of 18 % of the
maximum load.
Zero-set range ± 2 % of the maximum load
5.3.1
5.3.2
Preload Table in Kilogram
Preload Table in Pound
19
METTLER TOLEDO Service Manual PBA426 / PBA426x09/09 Order number 72230074
Type Dimensions Max. Preload Preload Preload Mech. Zeroset Max.
[mm] load top weighing ex works preload range load
(3) section pan (6) reserve (8) range
(4) (5) (7) (1)
PBA426(x)-A3 240 x 300 3 1.45 1.2 2.65 14.35 0.54 20
PBA426(x)-A6 240 x 300 6 1.45 1.2 2.65 11.35 1.08 20
PBA426(x)-A15 240 x 300 15 1.45 1.2 2.65 32.35 2.7 50
PBA426(x)-BB30 300 x 400 30 2.14 1.82 3.96 16.04 5.4 50
PBA426(x)-BB60 300 x 400 60 2.14 1.82 3.96 36.04 10.8 100
PBA426(x)-B30 400 x 500 30 3.5 3.17 6.67 13.33 5.4 50
PBA426(x)-B60 400 x 500 60 3.5 3.17 6.67 33.33 10.8 100
PBA426(x)-QA3 228 x 228 3 1 0.93 1.93 15.07 0.54 20
PBA426(x)-QA6 228 x 228 6 1 0.93 1.93 12.07 1.08 20
PBA426(x)-QB15 305 x 305 15 1.68 1.47 3.15 31.85 2.7 50
PBA426(x)-QB30 305 x 305 30 1.68 1.47 3.15 16.85 5.4 50
PBA426(x)-QB60 305 x 305 60 1.68 1.47 3.15 36.85 10.8 100
Type Dimensions Max. Preload Preload Preload Mech. Zeroset Max.
[inch] load top weighing ex works preload range load
(3) section pan (6) reserve (8) range
(4) (5) (7) (1)
PBA426(x)-A3 9.5 x 11.8 5 3.2 2.6 5.8 33.2 0.9 44
PBA426(x)-A6 9.5 x 11.8 10 3.2 2.6 5.8 28.2 1.8 44
PBA426(x)-A15 9.5 x 11.8 25 3.2 2.6 5.8 79.2 4.5 110
PBA426(x)-BB30 11.8 x 15.7 50 4.7 4 8.7 51.3 9 110
PBA426(x)-BB60 11.8 x 15.7 100 4.7 4 8.7 111.3 18 220
PBA426(x)-B30 15.7 x 19.7 50 7.7 7 14.7 45.3 9 110
PBA426(x)-B60 15.7 x 19.7 100 7.7 7 14.7 105.3 18 220
PBA426(x)-QA3 9 x 9 5 2.2 2.1 4.3 34.7 0.9 44
PBA426(x)-QA6 9 x 9 10 2.2 2.1 4.3 29.7 1.8 44
PBA426(x)-QB15 12 x 12 25 3.7 3.3 7 78 4.5 110
PBA426(x)-QB30 12 x 12 50 3.7 3.3 7 53 9 110
PBA426(x)-QB60 12 x 12 100 3.7 3.3 7 113 18 220
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