Siemens SIWAREX WL270 CP-S SA User manual

Introduction 1
Notes on handling the
product
2
Description
3
Application planning
4
Installation
5
Service and maintenance
6
Technical data
7
Dimension drawings
8
Ordering data
9
Appendix
A
SIWAREX WL270
Mounting plates
CP-S SA
Operating Instructions
04/2009
A5E02522341B

Legal information
Warning notice system
This manual contains notices you have to observe in order to ensure your personal safety, as well as to prevent
damage to property. The notices referring to your personal safety are highlighted in the manual by a safety alert
symbol, notices referring only to property damage have no safety alert symbol. These notices shown below are
graded according to the degree of danger.
DANGER
indicates that death or severe personal injury will result if proper precautions are not taken.
WARNING
indicates that death or severe personal injury may result if proper precautions are not taken.
CAUTION
with a safety alert symbol, indicates that minor personal injury can result if proper precautions are not taken.
CAUTION
without a safety alert symbol, indicates that property damage can result if proper precautions are not taken.
NOTICE
indicates that an unintended result or situation can occur if the corresponding information is not taken into
account.
If more than one degree of danger is present, the warning notice representing the highest degree of danger will
be used. A notice warning of injury to persons with a safety alert symbol may also include a warning relating to
property damage.
Qualified Personnel
The device/system may only be set up and used in conjunction with this documentation. Commissioning and
operation of a device/system may only be performed by qualified personnel. Within the context of the safety notes
in this documentation qualified persons are defined as persons who are authorized to commission, ground and
label devices, systems and circuits in accordance with established safety practices and standards.
Proper use of Siemens products
Note the following:
WARNING
Siemens products may only be used for the applications described in the catalog and in the relevant technical
documentation. If products and components from other manufacturers are used, these must be recommended
or approved by Siemens. Proper transport, storage, installation, assembly, commissioning, operation and
maintenance are required to ensure that the products operate safely and without any problems. The permissible
ambient conditions must be adhered to. The information in the relevant documentation must be observed.
Trademarks
All names identified by ® are registered trademarks of the Siemens AG. The remaining trademarks in this
publication may be trademarks whose use by third parties for their own purposes could violate the rights of the
owner.
Disclaimer of Liability
We have reviewed the contents of this publication to ensure consistency with the hardware and software
described. Since variance cannot be precluded entirely, we cannot guarantee full consistency. However, the
information in this publication is reviewed regularly and any necessary corrections are included in subsequent
editions.
Siemens AG
Industry Sector
Postfach 48 48
90026 NÜRNBERG
GERMANY
A5E02522341B
Ⓟ 04/2009
Copyright © Siemens AG 2009.
Technical data subject to change

CP-S SA
Operating Instructions, 04/2009, A5E02522341B 3
Table of contents
1 Introduction................................................................................................................................................ 5
1.1 Purpose of this documentation ......................................................................................................5
1.2 History............................................................................................................................................5
1.3 Scope of delivery ...........................................................................................................................5
1.4 Environmental protection ...............................................................................................................5
2 Notes on handling the product................................................................................................................... 7
2.1 Notes on handling the product.......................................................................................................7
3 Description................................................................................................................................................. 9
3.1 Application......................................................................................................................................9
3.1.1 Use of the mounting plates ............................................................................................................9
3.1.2 Lifting protection...........................................................................................................................10
3.1.3 Overload protection......................................................................................................................10
3.1.4 Use of the grounding cable..........................................................................................................10
3.2 Layout and function......................................................................................................................11
3.2.1 Design and principle of operation of the mounting plates............................................................11
3.2.2 Design and function of the grounding cable ................................................................................12
4 Application planning................................................................................................................................. 13
4.1 Load cell dummies .......................................................................................................................13
4.2 Lifting protection...........................................................................................................................13
4.3 Load pick-up.................................................................................................................................14
4.4 Overload protection......................................................................................................................15
4.5 Guide elements............................................................................................................................16
4.6 Protection against explosion........................................................................................................17
5 Installation ............................................................................................................................................... 19
5.1 Safety information/instructions.....................................................................................................19
5.2 Installing mounting plates ............................................................................................................21
5.2.1 General installation information ...................................................................................................21
5.2.2 Overview ......................................................................................................................................21
5.2.3 Preparing the load cell and pressure piece set............................................................................22
5.2.4 Preparing the mounting plates.....................................................................................................23
5.2.5 Installing the load cell, pressure piece set and mounting plates .................................................23
5.2.6 Checking the installation ..............................................................................................................25
5.3 Installing the grounding cable ......................................................................................................26
5.4 Dismantling ..................................................................................................................................26
6 Service and maintenance ........................................................................................................................ 27
6.1 Servicing and maintenance..........................................................................................................27

Table of contents
CP-S SA
4 Operating Instructions, 04/2009, A5E02522341B
7 Technical data ......................................................................................................................................... 29
8 Dimension drawings ................................................................................................................................ 31
8.1 Dimensional drawing of the mounting plates .............................................................................. 31
8.2 Dimension drawing of the grounding cable................................................................................. 32
9 Ordering data........................................................................................................................................... 33
A Appendix.................................................................................................................................................. 35
A.1 Technical support........................................................................................................................ 35
Index........................................................................................................................................................ 37

CP-S SA
Operating Instructions, 04/2009, A5E02522341B 5
Introduction 1
1.1 Purpose of this documentation
These instructions contain all the information you need for commissioning and using the
device.
It is aimed at persons who install the device mechanically and commission it, as well as at
service and maintenance engineers.
1.2 History
The following versions of this documentation have been released to date. The changes apply
to the previous version:
Edition Comment / change
04/2009 Initial release
1.3 Scope of delivery
The scope of delivery is made up of the following components:
● Information sheet
● Mounting plate
The delivery unit comprises one mounting plate.
Note
Other scope of delivery information
You need two mounting plates for installing a load cell. Drawings of the mounting plates
can be found in Section Preparing the mounting plates (Page 23)
1.4 Environmental protection
Environmental protection
Devices described in this programming manual can be recycled owing to the low content of
noxious substances in their version. Please contact a certified waste disposal company for
eco-friendly recycling and to dispose of your old devices.

Introduction
1.4 Environmental protection
CP-S SA
6 Operating Instructions, 04/2009, A5E02522341B

CP-S SA
Operating Instructions, 04/2009, A5E02522341B 7
Notes on handling the product 2
2.1 Notes on handling the product
Proper use
Proper use means that this product must only be used within the limits of the technical
specifications and intended purposes of these operating instructions.
If this device is used properly in compliance with the safety notices, this device will not
present any danger.
This device can only function correctly and safely if it is transported, stored, set up and
mounted correctly.
Correct operation of the device must be ensured by complying with the technical
specifications.
Improper handling can result in death, personal injury or property damage.
Notes on liability for defects
We expressly point out that the product quality is exclusively and conclusively described in
the sales contract. The content of this product documentation is neither part of a previous or
existing agreement, promise or legal relationship, nor is it intended to modify these. All
obligations on the part of Siemens AG are contained in the respective sales contract, which
also contains the complete and solely applicable liability provisions. The provisions defined
in the sales contract for the responsibility for defects are neither extended nor limited by the
remarks in this document.
Delivery information
The current scope of delivery is listed on the shipping documents enclosed with the delivery
in accordance with the valid sales contract.
When opening the packaging, please observe the relevant information. Check the delivery
for completeness and undamaged condition. In particular, the order number on the rating
plate must be compared to the ordering data.
Before you start work, please read these operating instructions. They contain important
information and data whose observation ensures the general safety and functionality of this
device. The manual will help you to handle this product more easily and efficiently, allowing
you to achieve reliable results.

Notes on handling the product
2.1 Notes on handling the product
CP-S SA
8 Operating Instructions, 04/2009, A5E02522341B
Qualified personnel
In the context of this documentation, qualified personnel are people who are familiar with the
installation, mounting, commissioning, and operation of the product.
These people must have the following qualifications:
● They must be trained, instructed and authorized to operate and maintain devices and
systems in accordance with their place of work and in compliance with the safety
engineering standards for
– Electrical circuits
– High pressures
– Corrosive and hazardous media
● They must be trained, instructed and authorized to maintain and use appropriate safety
equipment according to the standards for safety engineering.
● In the case of devices with explosion protection, qualified persons must be trained,
instructed and authorized to perform work on electrical circuits in plants subject to
explosion hazards.
Protection against explosion
There is no potential risk of ignition from the mounting plates of the load cells. Therefore they
are not subject to the EC directive 94/9 EC (ATEX).
Trademarks
SIWAREX ® is a registered trademark of Siemens AG.
All other names appearing in these instructions may be trademarks; use of such names by
third parties for their own purposes may infringe upon owners rights.

CP-S SA
Operating Instructions, 04/2009, A5E02522341B 9
Description 3
3.1 Application
3.1.1 Use of the mounting plates
The mounting plates are used for positioning and securing the pressure piece set.
The mounting plates have the following characteristics:
● Simple installation of the pressure piece set and the load cell
Mounting plates for SIWAREX WL270 CP-S SA
The mounting plates for SIWAREX WL270 CP-S SA load cells are especially well suited for
installation in vehicle scales, platform weighing machines, and container weighers.
Figure 3-1 Mounting plates with pressure piece set and load cell
WARNING
Danger to life from collapse of the structure
Without any protective measures the structure can collapse if the load cell is not installed
correctly. This is why these mounting plates are necessary for installing the load cell with
the pressure piece set.
As an alternative installation units from the product range of Siemens can be used.

Description
3.1 Application
CP-S SA
10 Operating Instructions, 04/2009, A5E02522341B
3.1.2 Lifting protection
The lifting protection prevents the load bearing implements from being lifted off of the load
cells.
If there is a risk of the load bearing implement being lifted or toppled, then lifting protection is
required. This is required in the case of lightweight containers and tall, outdoor silos.
3.1.3 Overload protection
The overload protection protects load cells from a load that is too great.
There is overload protection against excessive loads in the measuring direction and overload
protection against excessive transverse forces.
Transverse forces are caused by, for example, wind, filling processes, acceleration, or
conveyor belt friction. If these forces exceed certain values, the load cells must be protected
from them.
3.1.4 Use of the grounding cable
The grounding cable is used to protect the load cells from undesired currents. The causes of
such currents are, for example:
● Equalizing currents with missing or faulty equipotential bonding conductors.
● A lightning strike nearby
● Welding work
● Static charge
Figure 3-2 Example usage of the grounding cable

Description
3.2 Layout and function
CP-S SA
Operating Instructions, 04/2009, A5E02522341B 11
3.2 Layout and function
3.2.1 Design and principle of operation of the mounting plates
Design
The mounting plates comprise the following components:
● Upper mounting plate ①
● Lower mounting plate ⑥
Together with the load cell and the pressure piece set the mounting plates represent a self-
centering bearing unit.






① Upper mounting plate
② Upper pressure piece, not included in the scope of delivery
③ Load cell, not included in the scope of delivery
④ Pin in lower pressure piece: Prevents the load cell from twisting
⑤ Lower twistproof pressure piece, not included in the scope of delivery
⑥ Lower mounting plate
Figure 3-3 Exploded view: Mounting plates with pressure piece set and installed load cell

Description
3.2 Layout and function
CP-S SA
12 Operating Instructions, 04/2009, A5E02522341B
Principle of operation
The mounting plates ensure that the pressure piece set is securely positioned with the load
cell.
Figure 3-4 Sectional view
3.2.2 Design and function of the grounding cable
Design
The grounding cable consists of a fine-gauge copper wire with a cross-section of 50 mm2
and two lugs, Ø 10 mm.
Principle of operation
The grounding cable represents an electrical bypass via the load cell and mounting plates.
High weld currents can destroy the load cell, pressure piece set, mounting plates or the
electronics. The electronics can be affected by voltage sparkovers of static discharges.

CP-S SA
Operating Instructions, 04/2009, A5E02522341B 13
Application planning 4
4.1 Load cell dummies
Principle of operation
Load cells are sensitive sensors. To protect the load cells from becoming damaged during
installation and transport, the load cells should only be installed at the last minute. During
installation and transport, the load cells should therefore be replaced by space holders, so-
called dummies or phantoms.
Dummies might be designed as follows:
● A copy of the installation unit by means of a welded construction for installation work
● Use of a SIWAREX WL270 compact installation unit
A copy of the installation unit by means of a welded construction
A piece of pipe or some other steel profile is welded between two plates with the hole pattern
for the fixing screws. Installation work can be carried out with the welded construction.
Use of a SIWAREX WL270 compact installation unit
The compact installation units are delivered pre-assembled. Compact installation units are
set to the installation height of the operational unit. With compact installation units, light
installation work can be carried out.
4.2 Lifting protection
The following figure shows a proposed solution for lifting protection. The X designates the
possible lifting path of the load bearing implement. The bore ØD must be larger than the
diameter of the bolt Ød. The movement of the load bearing implement must not be hindered.
'
G
;
Figure 4-1 Proposed solution for lifting protection

Application planning
4.3 Load pick-up
CP-S SA
14 Operating Instructions, 04/2009, A5E02522341B
4.3 Load pick-up
Mounting surfaces
For the mounting surfaces of the mounting plates, the following requirements apply:
● The positional and angular deviations of the mounting surfaces to each other should
correspond to the general tolerances for welded constructions in EN ISO 13920.
● Ensure that the foundations are absolutely firm and free of depressions. In concrete
foundations, flat steel plates should be poured in so that the mounting plates can be
installed on them.
● The mounting surfaces must be vertical to the measuring direction and preferably in one
plane.
● A plane of ≤ 0.2 mm is required for the mounting surfaces.
More than three support points
For more than three support points, the load bearing implement is usually statically
indeterminate. With firm foundations and load bearing implements, the load is not evenly
distributed to all load cells. The same applies to unstable mounts such as a steel
construction. Two diagonal load cells bear the main load. The other cells only support the
load bearing implement.
There are two ways to take this into consideration:
● Over-dimensioning of the load cells
● Height compensation of the support points
Over-dimensioning of the load cells
The rated load of the load cells is calculated such that with, for example, four support points
the entire weight can be borne by two load cells.
This also prevents an overload of the load cells if depressions in the foundation have to be
taken into consideration, e.g. for racks in the steel structure.
Height compensation of the support points
With this method, the output signals of all of the load cells are attuned to each other under a
load. To ensure that all of the load cells receive approximately the same load, spacer plates
are used to compensate the heights.
The output signals of the individual load cells correspond to the load distribution.
Proceed as follows to measure the output signals:
1. Disconnect the load cell wires SIG+ and SIG-.
2. Supply the load cells with power from the power supply.
3. Measure the output voltage between SIG+ and SIG- of each individual load cell.
4. Place spacing plates under the load cell bracket with the lowest value until the output
voltages are equal.

Application planning
4.4 Overload protection
CP-S SA
Operating Instructions, 04/2009, A5E02522341B 15
4.4 Overload protection
CAUTION
Irreparable faults and damage to the load cells
When using load cells with small rated loads, always provide overload protection in order to
protect the cells from becoming damaged. This applies both to the measuring direction and
the transverse direction.
If load cells are used beyond the maximum working load or the maximum transverse load,
this can cause irreparable faults and even fracturing of the load cell or the installation unit.
Overload protection in the measuring direction
Load cells can be protected against vertical overload by limiting the measuring path with
stops.
For load cells with high rated loads, the risk of an unintentional overload is not as great.
Possible additional loads can already be taken into consideration during the dimensioning of
the load cells.
Another method for protecting load cells from an overload is to over-dimension the load cells.
Overload protection in the transverse direction
For the CP-S SA load cells, the weight force is introduced into the load cells via bearing
surfaces. Up to a certain degree, these bearing surfaces allow lateral movement of the load
bearing implement or a change in its length as a result of expansion due to heat. They
generate a restoring force corresponding to the deflection, which re-centers the load bearing
implement. This freedom of movement is desired and necessary for accurate weighing.
If the transverse force is so great that it exceeds the restoring force of the load cell (and thus
the deflection limit), then corresponding protective measures are required. Pendulum limiters
or guide elements are suitable for this, for example.
Pendulum limiters must be constructed or set in such a way that the maximum deflection
cannot be exceeded in any direction. This is shown in two examples in the following figure.
6WRS
+ROH
%ROW
3ODWIRUP3ODWIRUP
s
s

s
s

Figure 4-2 Pendulum limitation with a maximum deflection of 4 mm as exemplified by two weighing
platforms

Application planning
4.5 Guide elements
CP-S SA
16 Operating Instructions, 04/2009, A5E02522341B
4.5 Guide elements
Use the guide elements in the following cases:
● A weight should be determined under the influence of transverse forces.
● Horizontal movement of the load bearing implement should be prevented.
A change in the distance between the support points, for example as a result of expansion of
the load bearing implement due to heat, must not lead to mutual tensioning of the guide
elements.
The following figure shows the ideal arrangement of guide elements.
Figure 4-3 Arrangement of guide elements
To ensure that no force components occur in the measuring direction, you must install guide
elements at precise right angles to the effective direction of the load cells.

Application planning
4.6 Protection against explosion
CP-S SA
Operating Instructions, 04/2009, A5E02522341B 17
Three guide elements are sufficient to statically fix a weighing platform or container.
NOTICE
Weighing errors
With four guide elements, there is a risk of the guide elements mutually tensioning, which in
turn induces weighing errors. If you nevertheless want to use four guide elements, the
guide elements must be installed with a sufficient amount of play.
Ensure that the guide elements to be used comply with the principles applicable to weighing
technology.
4.6 Protection against explosion
Protection against explosion
There is no potential risk of ignition from the mounting plates of the load cells. Therefore the
mounting plates are not subject to EC directive 94/9 EC (ATEX).

Application planning
4.6 Protection against explosion
CP-S SA
18 Operating Instructions, 04/2009, A5E02522341B

CP-S SA
Operating Instructions, 04/2009, A5E02522341B 19
Installation 5
5.1 Safety information/instructions
Load cells are precision components and must therefore be handled carefully. Particular
care must be taken during transport and installation.
WARNING
Danger to life from falling loads
•Load cells are not machine components which have been constructed with the normal
safety factors. For this reason, appropriate protection against falling and catastrophes
must be implemented in accordance with the potential risks.
•Use suitable hoisting equipment to lift the load carrier. Observe the appropriate safety
regulations.
CAUTION
Damage to load cells through incorrect handling
•SIWAREX load cells are only permitted to be mounted and connected by qualified
personnel.
•Mechanical shocks or falls can irreparably damage the load cell.
•When mounting the load cell, ensure that you do not damage or cut the cables of the
load cell. Load cells must not be carried by their connecting cables.
•Protect the load cells from shocks and welding currents. Replace the load cells with
dummies until the installation work on the scale structure is completed.
CAUTION
Damage to load cells through high currents
•If welding is undertaken after the load cells have been installed, ensure that the welding
current is not diverted through the load cells.
– You can do this by attaching the grounding clamp of the welding unit making reliable
contact close to the weld.
– Bridge the load cells with a ground cable, see Installing the grounding cable
(Page 26)
– Disconnect the individual load cells.
•Undesirable electrical currents can arise during lightning. To protect the load cell against
such currents, bridge the load cells using highly flexible grounding cables, see also
Installing the grounding cable (Page 26).

Installation
5.1 Safety information/instructions
CP-S SA
20 Operating Instructions, 04/2009, A5E02522341B
CAUTION
Damage to load cells through incorrect mounting
•Provide indented claws or crane eyebolts on the load carrier to ensure that hoisting gear
can be used safely.
•Load cells must never be overloaded. Put the load carrier down slowly for this reason.
With load cells of smaller rated loads in particular, there is a risk of stretching the load
cell bodies when attaching force transfer devices, e.g. when tightening locknuts.
•Adjust the existing overload protection to ensure that it can still reliably sense transfer of
the required load. The overload protection must permit a rise in weight unhindered until
the setpoint weight is reached.
•Protect the gap above the overload protection from deposits of dirt and ice.
•The load must be introduced in the measuring direction of the load cell. Torsional and
bending moments, eccentric loads and transverse loads are disturbance variables.
These disturbance variables cause errors in the measuring result and can damage the
load cells, pressure piece sets and mounting plates if the maximum limits are exceeded.
The mounting components normally allow so much room for movement that heat
expansion will not result in lateral loading.