s
SIWAREX R
Mounting units for BB series
Instruction Manual Revision 11/2012
Document-No.: A5E00295975A Page 2
s
SIWAREX R
Mounting elements for load cells in the BB series
Instruction Manual
Chapter Overview
Warning and Safety Terms ............................................................................... 4
General 5
1. General Conditions for Installation and Assembly ........................... 7
1.1 Lift lock ................................................................................................ 7
1.2 Overload Protection ............................................................................. 7
1.3 Guide Elements .................................................................................... 8
1.4 Load Cell Dummies ............................................................................ 10
1.5 Load Cell Handling ............................................................................. 10
1.6 Welding and Installation Work............................................................ 11
1.7 Mounting ........................................................................................... 11
1.8 Installation Surfaces ........................................................................... 12
1.10 Dismantling ........................................................................................ 13
1.11 Explosion Protection .......................................................................... 13
2 Elastomer Bearing ............................................................................ 14
2.1 Technical Description ......................................................................... 14
2.1.1 Application Range ........................................................................................ 14
2.1.2 Construction ................................................................................................. 14
2.1.2.1 Elastomer Bearing Construction BB 10 - 200 kg ...................................... 14
2.1.2.2 Construction Elastomer Bearing BB 350 / 500 kg .................................... 15
2.2 Assembly ............................................................................................ 16
2.2.1 Assembly Elastomer Bearing BB 10 - 200 kg ....................................... 16
2.2.2 Assembly Elastomer Bearing BB 350 / 500 kg ..................................... 19
2.3 Technical Data.................................................................................... 21
2.3.1 Function Data ............................................................................................... 21
2.3.2 Dimensions ................................................................................................... 22
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2.4 Care and Maintenance ....................................................................... 24
2.5 Ordering Data ............................................................................................... 25
3 Combi-Mounting Unit ...................................................................... 26
3.1 Technical Description ......................................................................... 26
3.1.1 Application Range ........................................................................................ 26
3.1.2 Construction ................................................................................................. 26
3.1.2.1 Construction Combi-Mounting Unit BB 10 - 200 kg ................................ 26
3.1.2.2 Combi-Mounting Unit BB 350 / 500 kg ..................................................... 27
3.2 Assembly ............................................................................................ 28
3.2.1 Assembly Combi-Mounting Unit BB10 - 200 kg .................................. 28
3.2.2 Combi-Mounting Unit BB 350 / 500 kg ............................................... 32
3.3 Technical Data.................................................................................... 35
3.3.1 Function Data ............................................................................................... 35
3.3.2 Dimensions ................................................................................................... 36
3.4 Care and Maintenance ....................................................................... 38
3.5 Ordering Data .................................................................................... 38
4 Ground cable .................................................................................... 39
4.1 Technical Description ......................................................................... 39
4.1.1. Application Range ........................................................................................ 39
4.1.2 Construction ................................................................................................. 39
4.2 Assembly ............................................................................................ 39
4.3 Dimensions ........................................................................................ 40
4.4 Care and Maintenance ....................................................................... 40
4.5 Ordering Data .................................................................................... 40
Document-No.: A5E00295975A Page 4
Warning and Safety Terms
DANGER
means, that death, severe injury to persons or damage to equipment can be
caused, if the respective safety measures have not been taken.
WARNING
means, that death or severe injury can be caused, if the respective safety
measures are not taken.
CAUTION
with a warning triangle means that failure to take the necessary precautions may
lead to minor injury.
CAUTION
without a warning triangle means that failure to take the necessary precautions
may lead to property damage.
IMPORTANT
means that failure to observe the appropriate instructions may lead to an
undesirable result or condition.
NOTE
means a notice concerning possible advantages of conforming with the
recommendation.
Copyright © Siemens AG 2012 All rights reserved
Circulation or duplication of this document, utilization and
disclosure of its contents are not permitted as long as not explicitly
approved. Offenders will be liable for damages. All rights, including
rights created by patent grant or registration of a utility model or
design, are reserved.
Siemens AG
Automation and Drives
Process Instrumentation and Analytics
D-76181 Karlsruhe
Disclaimer
We have tested the contents of this document for compatibility
with the described hardware and software. This does not exclude
the possibility of discrepancies in which case, we do not guarantee
the complete compatibility of this document. The information in
this document is assessed regularly and any necessary corrections
are included in the following revision. We are grateful for any
suggestions of improvement.
© Siemens AG 2012
Subject to technical changes.
Document-No.: A5E00295975A Page 5
General
Please read this manual before starting work! It contains important notes and data
for ensuring the general safety and functionality of this device. This information will
simplify the utilization of this product and will lead to more precise and secure
measurement results.
Intended Utilization
Intended utilization means that this product is only to be utilized within the
limitations defined in the technical specifications and purposes of use in this
operating manual.
There are no dangers associated with this device when conforming with the safety
notes and the intended utilization.
The fail-safe and secure operation of this device depends on proper transportation,
storage, installation and assembly as well as on careful operation and
commissioning.
Proper operation of this device can only be ensured if the specifications provided in
technical data are observed.
Improper handling can cause death, bodily harm and damage to equipment.
Notes on Product Liability
We expressly point out that the nature of the product is described exclusively and
conclusively in the sales contract. The contents of this product documentation are
not part of an earlier or existing agreement, acceptance or legal relationship nor do
they affect these in any way. All obligations of Siemens result from the sales
contract, which also contains the full and solely valid liability agreement. The
provisions concerning product liability specified in the sales contract are not
extended or limited by the information provided in this document.
Delivery Notes
The respective scope of delivery is listed on the enclosed shipping documents
according to the valid contract of sale.
Please observe the instructions printed on the packaging when opening. Check that
the delivered goods are complete and undamaged. In particular, compare the order
number on the type plate with the order data.
Qualified Personnel
Qualified personnel, in regards to the safety-related information in this manual and
the product itself, are persons who are familiar with the installation, assembly,
commissioning and operation of this product. They must be authorized and
qualified to install, put into operation and maintain devices, systems and circuits in
accordance with national safety rules and regulations.
Document-No.: A5E00295975A Page 6
Brand names / Trademarks
SIWAREX ® is a registered trademark of Siemens AG.
The other designations in this manual may be trade marks, which if used by third
parties, may infringe upon the rights of the proprietor.
Document-No.: A5E00295975A Page 7
1. General Conditions for Installation and Assembly
1.1 Lift lock
Lift locks prevent the head plate being lifted from the load cells or permanently
mounted load cells from being overloaded by force against the measuring direction.
Lift locks are necessary if there is a danger of the load platform being lifted or
tipped. This is possible with light high containers or with silos that are not affixed
for example.
Lift locks are integrated in the combi-
mounting units of the BB series. When
using the mounting units, the lift locks
should be planned constructively. A
suggestion for an effective solution is
shown in Fig. 1-1. The measurement X
indicates the possible lift-path of the
load platform. The drill hole ØD must
be larger than the bolt diameter Ød.
The movement of the load platform
may not be hindered.
1.2 Overload Protection
Overload protection means protecting load cells from loads in the direction of
measurement that are too great. Forces that exceed the load limits for the load cells
can also come from the side.
Overload protection in the direction of measurement
Load cells are normally protected against vertical overloading by placing a stop-bolt
under the transmission of force. The path of measurement for the load cell is
limited in this manner. On load cells with high nominal loads, the danger of
accidental overloading is not so great. Any possible excessive loading can be taken
into account while dimensioning the load cells.
Another way of protecting load cells from overloading is in over-dimensioning the
load cells.
Overload protection from the side
Cross-forces exist because of wind, filling procedures, acceleration or conveyor belt
friction for example. If these forces exceed certain values, the load cells must be
protected.
The force of the weight is transferred to the load cells via elastomer bearings or
oscillation bolts. These elements allow a certain amount of sideways movement of
the load platform or a change in length due to thermal expansion. They generate a
responsive force which centers the load platform position again corresponding with
the occurring movement. This freedom of movement is expressly desired and is also
required for precise weighing. If transverse forces are so high that the responsive
force of the oscillation bolts or the elastomer bearings achieves the permitted
limits, then safety measures are to be taken. These could be oscillation limits or
guide elements (see chapter 1.3). Oscillation limits must be constructed or set so
that the permitted movement, on all sides, cannot be exceeded. In Fig. 1-2, this is
displayed in two examples.
Fig 1-1 Suggested lift
lock solution
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Load cells of the BB series have oscillation limits integrated in them with the combi-
mounting units.
CAUTION
When using load cells with low nominal loads, overload protection are to be used,
cross-directional as well, in order to protect the cells from damage.
The use of load cells above the maximum working load or the maximum cross-load
can lead to irreparable faults or damage to the load cells or the mounting unit.
1.3 Guide Elements
Guide elements compensate for cross-forces immediately. They allow no sideways
movement of the load platform. At the same time, they cannot change shape when
distances change in the support points (e.g. thermal expansion). Guide element
positioning is shown in Fig. 1-3. They are used if the weight must be determined
under the influence of a transverse force.
Guide elements must be constructed perpendicular to the effective direction of the
load cells so that there are no force components in the direction of measurement.
Stretching the guide elements is best avoided when they are positioned with the
same direction of rotation. To fasten a loading platform or a container in a static
position, three guide elements will suffice. With four guide elements, there is a
danger of these putting force on each other and that this could cause weighing
errors. If four guide elements are used anyway, they should be installed with
enough play to compensate.
The guide elements should correspond with the principles used in the weighing
technology. Ball-pin guides for up to 1000 kN transverse force are also available
upon request.
±2.8
±4
2.8
±4
±4
4
Limit stop
Drill hole
Bolt
PlatformPlatform
±2.8
±4
2.8
±2.8
±4
2.8
±4
±4
4
Limit stop
Drill hole
Bolt
PlatformPlatform
Oscillation limiters at a permitted oscillation of 4 mm in a dual weighing
platform example.
Fig. 1-2 Oscillation limit example
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Fig. 1-3 Guide Positioning
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1.4 Load Cell Dummies
Load cells are sensitive sensors. To protect them from damage, they should only be
handled as late as possible for installation and transport. During installation and
transport, these should be replaced by dummies or phantoms. Dummies can be
constructed as follows for example:
1. A replica of the mounting element using a welded construction.
A pipe or any other steel profile can be welded between two plates with the
respective hole format for the fastening bolts. The overall height
corresponds with the installation height of the mounting element. This is
the most stable and secure version. Rough assembly work can be
performed.
2. Using a SIWAREX R Combi-mounting unit.
The Combi-mounting units are supplied as completely assembled units. The
units are set at the approximate installation height for an operational unit.
Slight adjustments can be made during the installation.
1.5 Load Cell Handling
DANGER
Load cells and mounting units are not machine elements that are constructed
using standard safety factors. It is therefore absolutely necessary to prepare for the
potential danger with respective supports or other means of protection.
CAUTION
To protect against undesirable electrical current, such as static discharge that can
occur during welding or which can be caused by lighting for example, the load
cells should be bridged with highly flexible grounding cable (e.g. SIWAREX R
ground cable 7MH3 701-1AA1).
SIWAREX R load cells may only be installed and connected by qualified personnel.
Load cells are precision components and are to be handled carefully. Pay special
attention during transport and assembly.
CAUTION
Mechanical jolts or dropping could irreparably damage the load cells.
Load cells are not to be carried by their connecting cables.
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Loads must be introduced precisely in the direction of measurement of the load
cells. Torsion and bending moments, off-center loading and transverse loads are
disturbance forces that lead to incorrect measurements and can cause damage if
exceeding the permitted limitations of the load cells and mounting elements.
The mounting components allow enough play in movement that thermal expansion
does not lead to transverse loading.
1.6 Welding and Installation Work
As long as installation work is not complete on the scale, the load cells should be
replaced with dummies to protect them from jolts or welding current.
CAUTION
If welding is required after installing the load cells, make absolutely sure that the
welding current is not routed through the load cells. The ground clamp of the
welder is to be securely connected in the direct vicinity of the point to be welded.
The load cells must be bridged with a ground cable. The individual load cells are to
be disconnected. The free cable ends should be insulated.
1.7 Mounting
Load cells are never to be overloaded. Slowly put the load platform on. Especially
with load cells having lower nominal loads, there is a danger that external forces
during installation, e.g. tightening counter nuts, will bend the load cell bodies.
WARNING
Proper tools are to be used for lifting the load platform. Ensure that the respective
safety regulations are followed.
NOTE
Molded brackets or eyebolts should exist on the loading platform for the proper
utilization of lifting instruments.
If overload security mechanisms are available, set them up so that the desire load
can be taken on safely. They must permit an unrestricted increase in weight up to
the set weight.
The gap between the load cell and the overload protection is to be guarded from
contamination and icing.
Overload protection is to be checked regularly during maintenance work for easy
adjustment.
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DANGER
Contaminated, icy or incorrectly set overload protection will create blockages
which cause incorrect measurements or can cause injury or damage to the
machinery by overloading the scale.
CAUTION
Proper assembly and installation of load cells and mounting elements is to be
ensured by checking the assembly dimensions and freedom of movement for
example. Incorrect assembly can cause damage to load cells and mounting
elements.
Ensure that the cable is not damaged, disconnected or separated.
Wrap and hang the cable in a loop hanging down on vertical cable mounts to
divert any moisture away from connections.
1.8 Installation Surfaces
The following conditions are to be met for mounting element installation surfaces:
The position and slope deviation of the installation surfaces to one-another
should correspond with the general tolerances for welded constructions,
EN ISO 13920.
The foundation must be absolutely solid and unable to sink. Level steel
plates should be cast in cement foundations upon which the mounting
elements are mounted.
The anchorage points must be perpendicular to the direction of
measurement and should preferably all be at the same level.
If there are more than three mounting points, then the suspension is normally
statically indeterminate. It is inevitable that the load will not be evenly distributed
over all load cells on a stiff foundation with stiff loading platforms. Two diagonally
positioned load cells support the main load. The other cells only support the load
platform. There are two ways to handle this problem:
1. By over-dimensioning the load cells
The nominal load of the load cells is calculated so that the overall weight can be
supported on two load cells using four mounting points for example.
This will also prevent load cell overloading if there is a possibility of the foundation
sinking.
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2. Mounting point height adjustment
The output signals of all load cells are determined one after the other when they
are loaded. In order to achieve similar loading on all of them, spacer plates are
used to adjust the height. The spacer plates are pushed in between the brackets
and the head plate of the mounting element for the best results.
The output signals of the individual load cells correspond with load distribution. The
output signals are measured as follows:
Disconnect load cell lines SIG+ and SIG-.
Supply the load cells with the supply voltage (e.g. 10.2V).
Measure the output voltage between SIG+ and SIG- on each individual load
cell.
Now put spacer plates under the brackets for the load cell with the lowest
value until the output voltages match.
The load cell seat must be horizontal, level over the full-coverage and like the load
cell underside, absolutely clean.
The contact surface that introduces the force is to be coated with high-performance
grease.
1.10 Dismantling
When dismantling the load cells, the same safety and security measures are to be
followed as for the installation and assembly.
All power supply lines are to be switched off.
Secure the load platform from falling.
User appropriate lifting mechanisms and tools.
Take all load off of the load cells and carefully remove them without any
excessive force (no jolting movements).
Do not cut the cable if the load cells are to be used again or if being sent in
for repair.
To not step on or pull on the cable for moving the load cells.
1.11 Explosion Protection
There is no danger of explosion caused by the mounting elements of the load cells
and therefore they are not subject to the EC Directive 94/9 EG (ATEX).
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2 Elastomer Bearing
2.1 Technical Description
2.1.1 Application Range
The elastomer bearing is used for protecting the load cells if there is the possibility of
having to deal with jolts or oscillation.
This has a self-centering effect on the load platform. In combination with the base plate,
this is a simple solution for load cell assembly. The BB 10 - 200 kg elastomer bearing is
rigidly attached to the load cell and the loading platform. It also provides limited lifting
security.
2.1.2 Construction
2.1.2.1 Elastomer Bearing Construction BB 10 - 200 kg
A complete elastomer bearing unit BB 10 - 200 kg consists of basic order-components
base plate with overload protection, load cell and elastomer bearing.
The base plate (1) is bolted to the foundation with four bolts. The load cell (3) is fastened
to the base plate (1) with two hexagon bolts (5) and the spacer bar (2). The elastomer
bearing (10) is affixed to the load cell (3) with a hexagon bolt (8). The elastomer bearing
(10) is bolted to the load platform. The load platform is centered with the elastomer
bearing (10) this way. Transverse movement of the load platform is permitted to a certain
degree.
The measurement path of the load cell (3) is limited by the adjustable overload security
mechanism (7). This protects from accidental damage caused by overloading.
The elastomer bearing (10) is a rubber-metal combination made of neoprene and stainless
steel.
No. Designation No. Designation
1 Base plate 6 Nut
2 Spacer bar 7 Overload protection
3 Load cell 8 Hexagon head screw
4 Washer 9 Washer
5 Hexagon head screw 10 Elastomer bearing
Fig. 2-1 Construction Elastomer Bearing BB 10 - 200 kg
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2.1.2.2 Construction Elastomer Bearing BB 350 / 500 kg
A complete elastomer bearing unit consists of basic order-components base plate with
overload protection, load cell, oscillation housing and elastomer bearing.
The base plate (1) is bolted to the foundation with four bolts. The load cell (3) is fastened
to the base plate with two Allen Screws (5) and the spacer bar (2). The oscillation housing
(9) is put in the load cell (3) and is secured with a retaining ring (8). The elastomer
bearing (12) is seated with the oscillation bolts as force transmission mechanism (11) in
the oscillation housing (9) and is bolted to the load platform. The elastomer bearing (12),
and therefore the load platform as well, is centered with the force transmission
mechanism (11). Transverse movement of the load platform is permitted to a certain
degree. A flat seal (10) between the elastomer bearing (12) and the oscillation housing
(9) protect the force transmission mechanism from any contamination.
The measurement path of the load cell (3) is limited by the adjustable overload security
mechanism (7). This protects from accidental damage caused by overloading.
The elastomer bearing is a rubber-metal combination made of neoprene and stainless
steel.
No. Designation No. Designation
1 Base plate 7 Overload protection
2 Spacer bar 8 Retaining ring
3 Load cell 9 Oscillation housing
4 Washer 10 Flat seal
5 Cylinder head screw 11 Force transmission
6 Nut 12 Elastomer bearing
Fig. 2-2 Construction Elastomer Bearing BB 350 / 500 kg
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2.2 Assembly
The conditions for installation are very different. The load platform can be very low or
relatively high. It could be a container, a platform or a conveyor for example. The
following assembly instructions can only be taken as general guidelines.
WARNING
Proper tools are to be used for lifting the load platform. Ensure that the respective
safety regulations are followed.
The load platform should always be built on dummies to begin with, so that the load cells
are protected from damages during assembly. The load platform must then only be lifted
a few millimeters from bracket to bracket to position the elastomer bearing. The following
description of assembly procedures is based on this situation.
2.2.1 Assembly Elastomer Bearing BB 10 - 200 kg
Assembly procedures: (Numbering see Fig 2-3)
1. Load cell preparation:
A data sheet is supplied with every load cell with the calibration values for that
load cell. This is found in a supply pocket which is stuck on the packaging. Take
the data sheet and store it in a safe place.
Unpack the load cell.
2. Base plate preparation:
Unpack the base plate.
3. Elastomer bearing preparation:
Unpack the elastomer bearing (10).
4. Assemble the elastomer bearing unit:
NOTE
Please follow the guidelines from chapter 1.5 Load Cell Handling when working
with load cells.
CAUTION
An incorrect or incomplete assembly can result in damaging load cells, mounting
components and the loading platform.
DANGER
A falling loading platform can result in death, severe injury or damage to
equipment depending on exposure.
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Bolt the elastomer bearing (10) to the load cell (3) with the hexagon bolt (8) and
the washer (9). Hold the elastomer bearing (10) down when tightening the
hexagon bolt (8) to prevent damage being done to the load cell. The arrow on the
front of the load cell indicates the direction of measurement.
Lie the spacer bar (2) on the base plate (1) so that both holes are aligned with the
threaded holes in the base plate (1) and so that it is even. The spacer bar (2) is
asymmetrical.
Put the load cell (3) on the spacer bar (2) using 2x hexagon bolts (5) and 2x
washers (4).
Tighten the 2x hexagon bolts (5) to 23 Nm torque. Do not use the load cell as
leverage when tightening the bolts as this can cause damage to the load cell.
5. Install the elastomer bearing unit:
Loosen the bolts on the dummies
Lift the loading platform from the first bracket and remove the dummy.
Install the elastomer bearing unit and screw the bolts in loosely.
Slowly lower the loading platform.
Install the remaining elastomer bearing units as described.
Ensure that the elastomer bearings are not under tension.
Tighten the fastening bolts.
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6. Setting the overload protection:
Load the loading platform with the
maximum applicable load.
Set the overload protection
mechanism (7) in connection with the
nut (6) to 0.05 - 0.1 mm, see
dimension X in Fig. 2-4.
Dimension X must exist after
tightening the nut (6) as well.
Fig. 2-3 Assembly Elastomer Bearing BB 10 - 200 kg
Fig. 2-4 Setting up the overload
protection
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DANGER
Contaminated, icy or incorrectly set overload protection will create blockages
which cause incorrect measurements or can cause injury or damage to the
machinery by overloading the scale.
2.2.2 Assembly Elastomer Bearing BB 350 / 500 kg
Assembly procedures: (Numbering see Fig. 2-5)
1. Load cell preparation:
A data sheet is supplied with every load cell with the calibration values for that
load cell. This is found in a supply pocket which is stuck on the packaging. Take
the data sheet and store it in a safe place.
Unpack the load cell.
2. Base plate preparation:
Unpack the base plate.
3. Elastomer bearing preparation:
Unpack the elastomer bearing (12).
Check that the flat seal is properly seated on the elastomer bearing.
4. Oscillation housing preparations:
Unpack the oscillation housing (9).
Remove the retaining ring (8) from the oscillation housing.
5. Assemble the elastomer bearing unit:
NOTE
Please follow the guidelines from chapter 1.5 Load Cell Handling when working
with load cells.
CAUTION
An incorrect or incomplete assembly can result in damaging load cells, mounting
components and the loading platform.
DANGER
A falling loading platform can result in death, severe injury or damage to
equipment depending on exposure.
Insert the oscillation housing (9) into the load cell (3). The arrow on the front of
the load cell indicates the direction of measurement.
Install the retaining ring (8) in the groove in the oscillation housing (9).
Lie the spacer bar (2) on the base plate (1) so that both holes are aligned with the
threaded holes in the base plate (1).
Put the load cell (3) on the spacer bar (2) using 2x Allen screws (5) and 2x
washers (4).
Tighten the 2x Allen screws (5) to 70 Nm torque. Do not use the load cell as
leverage when tightening the bolts as this can cause damage to the load cell.
Smear the round surface of the force transmission for the elastomer bearing (12)
with bearing grease and install it in the oscillation housing (9).
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6. Install the elastomer bearing unit:
Loosen the bolts on the dummies
Lift the loading platform from the first bracket and remove the dummy.
Install the elastomer bearing unit and screw the bolts in loosely.
Slowly lower the loading platform.
Install the remaining elastomer bearing units as described.
Ensure that the elastomer bearings are not under tension.
Tighten the fastening bolts.
Fig. 2-5 Assembly Elastomer Bearing BB 350 / 500 kg
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7. Setting the overload protection:
Load the loading platform with the
maximum applicable load.
Set the overload protection
mechanism (7) in connection with the
nut (6) to 0.05 - 0.1 mm, see
dimension X, Fig. 2-6, is.
Dimension X must also exist after
tightening the nut (6).
DANGER
Contaminated, icy or incorrectly set overload protection will create blockages
which cause incorrect measurements or can cause injury or damage to the
machinery by overloading the scale.
2.3 Technical Data
2.3.1 Function Data
Nominal load 10 kg - 200 kg 350 / 500 kg
Permitted transverse movement ± 4 mm ± 4 mm
Fig. 2-6 Setting the Overload
Protection
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2.3.2 Dimensions
Fig. 2-7 Dimensions BB 10 - 200 kg
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Fig. 2-8 Dimensions BB 350 / 500 kg
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2.4 Care and Maintenance
General
The physical properties of most rubber goods will change in adverse conditions or if
improperly handled. Rubber components can become unusable when it becomes too soft
or too hard, gets deformed or cracks, peels or has any other surface damage. The changes
can be caused by the effects of e.g. ozone, heat, light, humidity, solvent or long periods of
tension.
If properly handled and stored, rubber products will retain the effective properties over a
long period of time (several years).
Service life and Inspections
The service life of elastomer components depends on the type and the load.
Rubber undergoes a natural aging process.
With loads that are within the permitted range, a service life of over 6 years can be
expected.
The rubber-metal components are maintenance-free during operation. The round surface
of the oscillation bolt is to be greased if necessary.
A visual inspection of the components should be performed 6 months after installation
and once per year thereafter. Checking the bond between the rubber and metal can be
done using a manual mechanical bond test. This is done by pressing the rubber back with
a blunt "test-iron" (pressure ridge with arc).
If portions of the rubber surface are coming apart in the bonding zone between the
elastomer and the metal or if surface cracks appear in the individual elastomer layers,
observe those areas (in intervals).
Replacement
A replacement is necessary if:
if 70% of the initial rubber thickness is achieved through setting and loading,
if the weather has caused visible cracking over cm2 rubber surface,
the item is excessively swollen due to undue oil seepage,
the rubber-metal bond is breaking down,
mechanical damage resulting from the sensitivity of the rubber leading to further
damage to the product is present.
Cleaning
Cleaning solutions with a neutral pH value are recommended and covalent cleaning
solvents such as gasoline for example are not to be used under any circumstances.
Components should be rinsed with water after cleaning in certain cases. Otherwise the
rubber-metal bond is to be protected from cleaning solvents using constructive means.
The use of sharp or jagged objects, wire brushes or abrasive paper products is not
permitted. The flat seal may not be subjected to direct streams of water. The round
surface of the oscillation bolt is to be re-greased when necessary.
The overload protection mechanism is to be checked for any contamination.
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2.5 Ordering Data
Elastomer bearing
for load cells with a
nominal load of
Order number
Elastomer bearing
Order number
Base plate
Order number
Oscillation
housing
10 - 50 kg 7MH4 133-2KE11 7MH4 133-3DG11 -
100 - 200 kg 7MH4 133-3DE11 7MH4 133-3DG11 -
350 / 500 kg 7MH4 130-4AE11 7MH4 133-3KG11 7MH4 133-3KP11
In the order numbers above, the load cells are not included.
Document-No.: A5E00295975A Page 26
3 Combi-Mounting Unit
3.1 Technical Description
3.1.1 Application Range
Combi-mounting units are for direct force transmission to the load cells.
These are self-centering on the load platform.
The combi-mounting units have the following features:
Integrated oscillation limitation.
Integrated lift protection with the BB 10 - 200 kg.
Can be used as dummy for light assembly work.
Slow, controlled lowering of the head plate.
Can be used as transit security by affixing the head plate to protect the load cells.
3.1.2 Construction
3.1.2.1 Construction Combi-Mounting Unit BB 10 - 200 kg
The combi-mounting unit consists of the base and head plates and two countersinking
bolts as oscillation limiters and lift protection. Combined with the load cell, it is a
multifunctional storage unit.
The base plate (1) is bolted to the foundation with four bolts. The load cell (3) is fastened
to the base plate (1) with two hexagon bolts (5) and a spacer bar (2). An oscillation
housing (12) is inserted in the head of the load cell (3). The oscillation bolt (16)
positioned in it. The oscillation bolt is supported by to pressure pieces (13) and (15). Both
pressure pieces (13) and (15) are bonded in the oscillation housing (12) and the head
plate (17). The head plate (17) is supported on the oscillation bolt (16). The head plate
(17) is bolted to the loading platform. The loading platform is centered with the oscillation
bolt (16). Transverse movement of the load platform causes a response that puts the load
platform back in the rest position.
The counter-sunk bolts (8) limit the possible movement of the head plate (17). Their
second function is to prevent the head plate from being lifted.
A flat seal (14) between the oscillation housing (12) and the head plate (17) protects the
force transmission mechanism from contamination.
The base plate is equipped with an adjustable overload protection mechanism (10). This
limits the measurement path of the load cell (3) and protects the equipment from any
damages that might be caused by accidental overloading.
(Numbering see Fig. 3-1)
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3.1.2.2 Combi-Mounting Unit BB 350 / 500 kg
The combi-mounting unit consists of the base and head plates and two countersinking
bolts as oscillation limiters and lift protection. Combined with the load cell, it is a
multifunctional storage unit.
The base plate (1) is bolted to the foundation with four bolts. The load cell (3) is fastened
onto the base plate (1) with two Allen screws (5) and a spacer bar (2). A pressure piece (9)
is inserted into the head of the load cell (3). The ball (10) is inserted into this. The ball is
supported against a second pressure piece (11) which is bonded in the head plate (12).
The head plate (12) is bolted to the loading platform. The loading platform is centered
with the ball (10). Transverse movement of the load platform causes a response that puts
the load platform back into the rest position.
The counter-sunk bolts (15) limit the possible movement of the head plate (12). Their
second function is to prevent the head plate from being lifted.
(Numbering see Fig. 3-2)
No. Designation No. Designation
1 Base plate 10 Overload protection
2 Spacer bar 11 Retaining ring
3 Load cell 12 Oscillation housing
4 Washer 13 Pressure piece
5 Hexagon head screw 14 Flat seal
6 Nut 15 Pressure piece
7 Half-nut 16 Oscillation bolt
8 Countersunk screw 17 Head plate
9 Nut
Fig. 3-1 Construction Combi-Mounting Unit BB 10 - 200 kg
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3.2 Assembly
3.2.1 Assembly Combi-Mounting Unit BB10 - 200 kg
The conditions for installation are very different. The load platform can be very low or
relatively high. It could be a container, a platform or a conveyor for example. The
following assembly instructions can only be taken as general guidelines.
WARNING
Proper tools are to be used for lifting the load platform. Ensure that the respective
safety regulations are followed.
The load platform should always be built on dummies to begin with, so that the load cells
are protected from damages during assembly. The load platform must then only be lifted
a few millimeters from bracket to bracket to position the combi-mounting unit. The
following description of assembly is based on this situation.
No. Designation No. Designation
1 Base plate 9 Pressure piece load cell
2 Spacer bar 10 Ball
3 Load cell 11 Pressure piece head plate
4 Washer 12 Head plate
5 Cylinder head screw 13 Nut
6 Ground cable 14 Washer
7 Hexagon head screw 15 Countersunk screw
8 Washer
Fig. 3-2 Construction Combi-Mounting Unit BB 350 / 500 kg
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Assembly procedures: (Numbering see Fig. 3-3)
1. Load cell preparation:
A data sheet is supplied with every load cell with the calibration values for that
load cell. This is found in a supply pocket which is stuck on the packaging. Take
the data sheet and store it in a safe place.
Unpack the load cell.
2. Combi-Mounting Unit preparation:
NOTE
The lifting path of the head plate (17) must be set from approximately 2 mm with
the counter-sunk bolts (8), see dimension X in Fig. 3-5. Setting this lifting path is
easier if performed before installing the load cell. The combi-mounting unit must
be disassembled in order to install the load cell.
The combi-mounting units are pre-assembled before delivery. Adjust the head
plate (17) using the two counter-sunk bolts (8) and the two nuts (7) to:
functional installation height 80 mm
+ lifting path 2 mm
= installation height 82 mm
These preparations and following the handling procedures as described in the
following prevent any extra work in adjusting later.
When using the combi-mounting units as dummies, this 2 mm must also be taken
into account or it can be adjusted later.
Unpack the combi-mounting unit.
Scope of delivery:
- Combi-Mounting Unit, assembled
- Oscillation bolt (16)
- Oscillation housing (12) with flat seal (14)
Set the lifting path for the head plate (17) as described above.
Install the top nuts (7) onto the lower nuts (6) and tighten.
Loosen the lower nuts and unscrew the counter-sunk bolt (8) from the base plate
(1). Leave the counter-sunk bolt (8) in the head plate (17), do not loosen the nuts
(6) and (7) put the head plate (17) to the side.
Check the flat seal (14) for proper seating.
Smear the ball surface of the oscillation bolt (16) with bearing grease.
3. Assemble the Combi-Mounting Unit:
NOTE
Please follow the guidelines from chapter 1.5 Load Cell Handling when working
with load cells.
CAUTION
An incorrect or incomplete assembly can result in damaging load cells, mounting
components and the loading platform.
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DANGER
A falling loading platform can result in death, severe injury or damage to
equipment depending on exposure.
Insert the oscillation housing (12) into the load cell (3). The arrow on the front of
the load cell indicates the direction of measurement.
Install the retaining ring (11) in the groove of the oscillation housing (12).
Lie the spacer bar (2) on the base plate (1) so that both holes are aligned with the
threaded holes in the base plate (1) and so that it is even. The spacer bar (2) is
asymmetrical.
Put the load cell (3) on the spacer bar (2) using 2x hexagon bolts (5) and 2x
washers (4).
Tighten the 2x hexagon bolts (5) to 23 Nm torque. Do not use the load cell as
leverage when tightening the bolts as this can cause damage to the load cell.
Smear the ball surface of the oscillation bolt (16) with bearing grease and insert it
into the oscillation housing (12).
Set the head plate (17) on the oscillation bolt (16).
Screw the counter-sunk bolt (8) into the base plate (1) and tighten the lower nut
(6).
Loosen nut (7) from nut (6), turn it upwards on the threads and tighten against
the head plate (17). This optimally centers the head plate over the base plate,
pressure is relieved on the load cell and it is protected against overloading during
the installation.
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4. Installing the Combi-Mounting Unit:
Loosen the bolts on the dummies.
Lift the loading platform from the first bracket and remove the dummy.
Set the combi-mounting unit in place and loosely install the fastening bolts.
Slowly lower the loading platform.
Install the remaining combi-mounting units as described.
Tighten the fastening bolts.
Loosen the nuts (7) and slowly lower the head plate (17).
Turn nut (7) to nut (6) and tighten.
Fig. 3-3 Assembly Combi-Mounting Unit BB 10 - 200 kg
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5. Setting the overload protection:
Load the loading platform with the
maximum applicable load.
Set the overload protection
mechanism (10) in connection with
the nut (9) to 0.05 - 0.1 mm, see
dimension X in Fig. 3-4.
Dimension X must also exist after
tightening the nut (9).
DANGER
Contaminated, icy or incorrectly set overload protection will create blockages
which cause incorrect measurements or can cause injury or damage to the
machinery by overloading the scale.
5. Assembly Inspection:
The loading platform must be
able to swing freely.
The counter-sunk bolts (8) should
be as close as possible to the
center in the holes of the head
plate (17). The head plate
therefore has optimal freedom of
movement on all sides and no
secondary forces can be
generated.
The counter-sunk bolts (8) must
not protrude past the head plate (17).
DANGER
Incorrectly adjusted counter-sunk bolts cause blockages which in turn result in
incorrect measurements or can lead to overloading the scale and damage to
equipment or injury to persons.
3.2.2 Combi-Mounting Unit BB 350 / 500 kg
Assembly procedures: (Numbering see Fig. 3-7)
1. Load cell preparation:
A data sheet is supplied with every load cell with the calibration values for that
load cell. This is found in a supply pocket which is stuck on the packaging. Take
the data sheet and store it in a safe place.
Unpack the load cell.
Fig. 3-4 Setting the overload
protection
Fig. 3-5 Overload Protection and
Oscillation Limitation
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2. Combi-Mounting Unit preparation:
NOTE
The lifting distance of the head plate (12) must be set to approximately 3 mm,
see dimension X in Fig. 3.8. Setting this lifting distance is easier if performed
before installing the load cell. The combi-mounting unit must be disassembled in
order to install the load cell.
The combi-mounting units are pre-assembled before delivery. Adjust the head
plate (12) using the two counter-sunk bolts (15) and the two upper nuts (13) to:
functional installation height 73 mm
+ lifting distance 3 mm
= installation height 76 mm
These preparations and following the handling procedures as described in the
following prevent any extra work in adjusting later.
When using the combi-mounting units as dummies, this 3 mm of extra height is
to be taken into account or it can be adjusted later.
Unpack the combi-mounting unit.
Scope of delivery:
- Combi-Mounting Unit, assembled
- Pressure pieces (9)
- Ball (11)
Set the lifting distance of the head plate (12) as described above.
Turn the upper nut (13) to the lower nut (13) and tighten.
Loosen the lower nut (13) and remove the counter-sunk bolt (15) from the base
plate (1). Leave the counter-sunk bolt (15) in the head plate (12), do not loosen
the nuts (13) and put the head plate (12) to the side.
3. Assemble the Combi-Mounting Unit:
NOTE
Please follow the guidelines on handling load cells in chapter 1.5 Load Cell
Handling.
CAUTION
Incorrect or incomplete assemblies can lead to damages to the load cells,
mounting units and the loading platform.
DANGER
A falling loading platform can result in death, severe injury or damage to
equipment depending on exposure.
Lie the spacer bar (2) on the base plate (1) so that both holes are aligned with the
threaded holes in the base plate (1) and so that it is even. The spacer bar (2) is
asymmetrical.
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Put the load cell (3) on the spacer bar
(2) using 2x Allen screws (5) and 2x
washers (4). The arrow on the front
of the load cell indicates the direction
of measurement, see Fig. 3-6.
Tighten the 2x Allen screws (5) to 70
Nm torque. Do not use the load cell
as leverage when tightening the
bolts since this could damage the
load cell.
Insert the pressure piece (9) in the
load cell.
Smear the ball (10) with bearing
grease and insert it into the pressure
piece (9).
Set the head plate (12) on the ball (10).
Screw the counter-sunk bolt (15) into the base plate (1) and tighten the lower
nuts (13).
Loosen the upper nut (13) from the lower nut (13), turn it upward and tighten
against the head plate (12). This optimally centers the head plate over the base
plate, pressure is relieved on the load cell and it is protected against overloading
during the installation.
Fig 3-7 Assembly Combi-Mounting Unit BB 350 / 500 kg
Fig. 3-6 Installation Position
Load Cell
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Fig. 3-8 Overload Protection and
Oscillation Limitation
4. Installing the Combi-Mounting Unit:
Loosen the bolts on the dummies.
Lift the loading platform from the first bracket and remove the dummy.
Set the combi-mounting unit in place and loosely install the fastening bolts.
Slowly lower the loading platform.
Install the remaining combi-mounting units as described.
Tighten the fastening bolts.
Loosen the upper nuts (13) and slowly lower the head plate (12).
Turn the upper nuts (13) to the lower nuts (13) and tighten.
5. Assembly Inspection:
The loading platform must be
able to swing freely.
The counter-sunk bolts (15)
should be positioned as close to
the middle of the holes in the
head plate (12) as possible. The
head plate therefore has optimal
freedom of movement on all
sides and no secondary forces can
be generated.
The counter-sunk bolts (15) are
not permitted to protrude past the
head plate (12).
DANGER
Incorrectly adjusted counter-sunk bolts cause blockages which in turn result in
incorrect measurements or can lead to overloading the scale and damage to
equipment or injury to persons.
3.3 Technical Data
3.3.1 Function Data
Nominal load 10 - 200 kg 350 / 500 kg
Permitted Transverse Movement: ± 2 mm ± 2.5 mm
Lifting distance of the head plate 2 - 2.5 mm 3.5 - 3 mm
Max. Transverse Force 1,7 kN 2,5 kN
Max. lifting force 2,5 kN 2,5 kN
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3.3.2 Dimensions
Fig. 3-9 Dimensions Combi-Mounting Unit BB 10 - 200 kg
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Fig. 3-10 Dimensions Combi-Mounting Unit BB 350 / 500 kg
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3.4 Care and Maintenance
Combi-mounting units are to be inspected depending on the environmental conditions. If
there is a high degree of dust, contamination, humidity etc., the maintenance intervals
are to be chosen respectively. These are to be kept free of course contamination. The flat
seal may not be subjected to direct streams of water. The round surfaces of the oscillation
bolts are to be greased when necessary. The overload protection mechanism should be
inspected for contamination.
3.5 Ordering Data
Combi-mounting units for
load cells with a nominal
load of
Order number
10 - 200 kg 7MH4 133-3DC11
350 / 500 kg 7MH4 133-3KC11
In the order numbers above, the load cells are not included.
Document-No.: A5E00295975A Page 39
4 Ground cable
4.1 Technical Description
4.1.1. Application Range
The ground cable is used for protecting the load cells from unwanted currents. These
currents could be cause by e.g.:
as equalization currents for missing or faulty, voltage equalization lines,
a lightning bolt in the vicinity,
welding or
static discharge.
The ground cable is an electrical shunt for the load cell and mounting unit. High welding
currents can damage load cells, mounting units or the electronics. Voltage spikes from
static discharge can damage the electronics.
4.1.2 Construction
The ground cable consists of a fine-strand copper wire with a cross-section of 50 mm2 and
two eyelets, Ø 10mm.
4.2 Assembly
A permanent screw-contact is to be made for fastening the ground cable, e.g. M10, on the
loading platform and the foundation.
Fig. 4-1 Application example Ground Cable
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4.3 Dimensions
4.4 Care and Maintenance
The connections of the cable are to be inspected regularly for corrosion and conductivity.
4.5 Ordering Data
Designation Order number
Ground cable 7MH3 701-1AA1
Fig. 4-2 Dimensions Ground Cable
