PI P-844 User manual

P844M0001EN ‒ 11/13/2018
User Manual
P-844 PRELOADED PIEZO ACTUATORS
MOTION | POSITIONING

Contents
1 Legal Information.........................................................................................................4
2 About this Document..................................................................................................5
2.1 Objective and Target Group..............................................................................5
2.2 Explanation of Symbols....................................................................................5
2.2.1 Typographic Conventions................................................................. 5
2.2.2 Symbols Used.................................................................................... 5
2.3 Figures................................................................................................................6
2.4 Downloading Manuals...................................................................................... 6
3 Safety............................................................................................................................7
3.1 Intended Use......................................................................................................7
3.2 General Safety Instructions.............................................................................. 7
3.3 Organizational Measures.................................................................................. 7
3.3.1 User Manual....................................................................................... 8
3.3.2 General Personnel Qualification.......................................................8
4 Product Description..................................................................................................... 9
4.1 Model Overview.................................................................................................9
4.2 Product Labeling................................................................................................9
4.2.1 Type Plate........................................................................................... 9
4.3 Scope of Delivery...............................................................................................9
4.4 Overview.......................................................................................................... 10
4.5 Suitable Electronics......................................................................................... 10
5 Unpacking...................................................................................................................11
6 Installation................................................................................................................. 12
6.1 Avoiding Mounting Errors.............................................................................. 12
6.2 Mounting the P-844 and Connecting to a Protective Earth Conductor........13
6.3 Fixing the Load................................................................................................ 14
6.4 Connecting the P-844.......................................................................................15
7 Startup / Operation................................................................................................... 16
7.1 Determining the Operating Parameters.........................................................16
7.1.1 Calculating the Effective Mass........................................................16
7.1.2 Calculating the Maximum Operating Frequency of the Loaded
Piezo Actuator.................................................................................. 17
7.1.3 Calculating the Forces that Occur During Dynamic Operation.... 17
7.1.4 Calculating the Power Requirement for Sinusoidal Operation.... 17
7.2 Starting and Operating the P-844................................................................... 18
7.3 Discharging the P-844...................................................................................... 20
8 Maintenance...............................................................................................................22
8.1 Cleaning............................................................................................................22
CONTENTS P844M0001EN ‒ 11/13/2018
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9 Troubleshooting......................................................................................................... 23
10 Transportation............................................................................................................24
11 Customer Service Department.................................................................................25
12 Technical Data............................................................................................................ 26
12.1 Specifications...................................................................................................26
12.2 Maximum Ratings........................................................................................... 26
12.3 Ambient Conditions and Classifications........................................................27
12.4 Dimensions...................................................................................................... 29
13 Old Equipment Disposal........................................................................................... 30
14 Appendix.................................................................................................................... 31
14.1 Pin Assignment................................................................................................31
14.1.1 Voltage Connector........................................................................... 31
15 EU Declaration of Conformity...................................................................................32
CONTENTS P844M0001EN ‒ 11/13/2018
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1 Legal Information
The following company names and brands are registered trademarks of Physik Instrumente
(PI) GmbH & Co. KG:
PI®, PIC®, NanoCube®, PICMA®, PIFOC, PILine®, NEXLINE®, PiezoWalk®, PicoCube®,
PiezoMove®, PIMikroMove, NEXACT®, Picoactuator®, PInano®, NEXSHIFT®, PITOUCH®,
PIMag®, PIHera, Q-Motion®
The patents held by PI can be found in our list at http://www.physikinstrumente.com/en/
about-pi/patents.
© 2018 Physik Instrumente (PI) GmbH & Co. KG, Karlsruhe, Germany. The text, photographs,
and drawings in this manual are protected by copyright. With regard thereto, Physik
Instrumente (PI) GmbH & Co. KG reserves all rights. The use of any text, images and
drawings is permitted only in part and only when indicating the source.
Original instructions
First print: 11/13/2018
Document number: P844M0001en, CBo
Subject to change. This manual is superseded by any new release. The latest versions of the
user manuals are available for download (p. 6) at www.pi.ws.
Publisher:
Physik Instrumente (PI) GmbH & Co. KG
Auf der Roemerstrasse 1
76228 Karlsruhe
Germany
[email protected]
www.pi.de
Customer service department:
Physik Instrumente (PI) GmbH & Co. KG
Auf der Roemerstrasse 1
76228 Karlsruhe
Germany
[email protected]
www.pi.de
1 LEGAL INFORMATION P844M0001EN ‒ 11/13/2018
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2 About this Document
2.1 Objective and Target Group
This user manual contains the information needed for the intended use of the P-844.
Basic knowledge of closed-loop systems, motion control concepts, and applicable safety
measures is assumed.
2.2 Explanation of Symbols
This chapter explains the symbols and markings used by PI in their user manuals.
2.2.1 Typographic Conventions
Symbol / Label Meaning
1.
2.
Action consisting of several steps whose sequential order must be ob-
served
■ List items
p. 5 Cross-reference to page 5
RS-232 Labeling of an operating element on the product (example: socket of
the RS-232 interface)
Start > Settings Menu path in the PC software (example: to open the menu, the Start
and Settings menus must be clicked successively)
POS? Command line or a command from PI's General Command Set (GCS)
(example: command to get the axis position)
Device S/N Parameter name (example: parameter where the serial number is stor-
ed)
5Value that must be entered or selected via the PC software
2.2.2 Symbols Used
Symbol / Label Meaning
General hazard symbol
DANGER
Dangerous situation
Failure to observe can lead to death or serious injury.
►Measures for avoiding the risk.
WARNING
Dangerous situation
Failure to observe can lead to serious injury.
►Action to take to avoid the risk.
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CAUTION
Dangerous situation
Failure to observe can lead to minor injury.
►Actions to take to avoid the risk.
NOTICE
Dangerous situation
Failure to observe can lead to material damage.
►Action to take to avoid the risk.
Information
Additional information on the P-844 that can affect your application.
2.3 Figures
For better understandability, the colors, proportions and degree of detail in illustrations can
deviate from the actual circumstances. Photographic illustrations may also differ and must
not be seen as guaranteed properties.
2.4 Downloading Manuals
The latest versions of the user manuals can be downloaded (p. 6) at www.pi.ws.
For products that are supplied with software (data storage device in the scope of delivery),
access to the manuals is protected by a password. Protected content is only displayed on the
website after entering the access data. You need the data storage device for the product to
get the access data.
If a manual is missing or problems occur with downloading, contact our customer service
department (p. 25).
Downloading Manuals
1. Open the website www.pi.ws.
2. If the product was shipped with a data storage device: Log into the website:
a) Click Login.
b) Enter the login data.
The login data is in the [...]_Releasenews_[...].pdf in the Manuals directory on the
data storage device.
If necessary: Follow the link and register yourself to get the login data.
c) Click Login or press the Enter key.
3. Search for the product:
a) Click Search.
b) Enter the product number up to the period (e.g., P-844) into the search field.
c) Click Start search or press the Enter key.
d) If necessary: Click Load more results at the bottom of the list.
4. Click on the corresponding product in the list of search results.
5. Click the Downloads tab.
➔The manuals are shown under
Documentation .
6. Click on the desired manual and save it.
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3 Safety
3.1 Intended Use
The P-844 is a laboratory device as defined by DIN EN 61010-1. It is intended for indoor use
and use in an environment that is free of dirt, oil, and lubricants.
In accordance with its design, the P-844 is intended for the following applications:
■Positioning of loads; see "Specifications" (p. 26)
■Dynamic positioning
■Vibration absorption
■Force generation
Motion is along one axis.
The P-844 is not intended for applications in areas where failure would result in considerable
risks for human beings or the environment.
The intended use of the P-844 is only possible when completely mounted and connected.
The P-844 must be operated with suitable electronics (p. 10) from PI. The electronics are not
in the scope of delivery of the P-844.
The P-844 may not be used for purposes other than those stated in this user manual. The
P-844 may only be used in compliance with the technical specifications and instructions in
this user manual.
3.2 General Safety Instructions
The P-844 is built according to state-of-the-art technology and recognized safety standards.
Improper use of the P-844 may result in personal injury and/or damage to the P-844.
►Use the P-844 only for its intended purpose and if it is in perfect condition.
►Read the user manual.
►Eliminate any faults and malfunctions that are likely to affect safety immediately.
The operator is responsible for correct installation and operation of the P-844.
Temperature changes and compressive stress can induce charges in the P-844 piezo actuator.
After disconnection from the electronics, the piezo actuator can remain charged for several
hours. Touching live parts of the P-844 can result in minor injury from electric shock.
►Do not open the P-844.
If the protective earth conductor is missing or not properly connected, risk of dangerous
touch voltages on the P-844 in the event of malfunction or failure of the system. If touch
voltages exist, touching the P-844 can lead to minor injury from electric shock.
►Connect the P-844 to a protective earth conductor before startup.
►Do not remove the protective earth conductor during operation.
►If the protective earth conductor has to be temporarily removed (e.g., for modifications),
reconnect the P-844 to the protective earth conductor before restarting.
Mechanical forces can destroy the P-844.
►Avoid knocks that affect the P-844.
►Do not drop the P-844.
►Avoid torques, bending forces, and lateral forces on the tip of the P-844.
►Do not exceed the maximum permissible loads (p. 26).
3.3 Organizational Measures
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3.3.1 User Manual
►Always keep this user manual available with the P-844. The latest versions of the user
manuals can be downloaded (p. 6) at www.pi.ws.
►Add all information from the manufacturer such as supplements or technical notes to the
user manual.
►If you give the P-844 to a third party, also include this user manual as well as other
relevant information provided by the manufacturer.
►Only use the device on the basis of the complete user manual. Missing information due to
an incomplete user manual can result in minor injury and damage to equipment.
►Only install and operate the P-844 after you have read and understood this user manual.
3.3.2 General Personnel Qualification
The P-844 may only be installed, started up, operated, maintained, and cleaned by authorized
and appropriately qualified personnel.
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4 Product Description
4.1 Model Overview
Actuators without sensor
Product number Description
P-844.10 Preloaded piezo actuator, 15 µm travel range, 3000 N / 700 N
P-844.20 Preloaded piezo actuator, 30 µm travel range, 3000 N / 700 N
P-844.30 Preloaded piezo actuator, 45 µm travel range, 3000 N / 700 N
P-844.40 Preloaded piezo actuator, 60 µm travel range, 3000 N / 700 N
P-844.60 Preloaded piezo actuator, 90 µm travel range, 3000 N / 700 N
4.2 Product Labeling
4.2.1 Type Plate
Figure 1: Type plate of the P-844
1. Data matrix code (example; contains the serial number)
2. Product number (example)
3. Serial number (example), individual for each P-844
Meaning of the position (counting from the left):
1 = internal information,
2 and 3 = year of manufacture,
4 to 9 = consecutive numbers
4. Warning and conformity symbols (old equipment disposal (p. 30), CE mark (p. 32))
4.3 Scope of Delivery
Product number Description
P-844 Actuator model according to order (p. 9)
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4.4 Overview
Figure 2: Example product view
1. Tip with M8 thread
2. AF10 wrench flat for open-end wrench
3. Housing, consisting of housing tube [3a] and base [3b]
4. Cable exit (sensor connector): For P-845 models only.
5. Cable exit (voltage connector)
6. AF17 wrench flat for open-end wrench
Arrow: Positive direction of motion of the tip
4.5 Suitable Electronics
The P-844 must be connected to suitable electronics that supply the necessary voltage for
operating the P-844. The following electronics are suitable for operating the P-844:
Product number Description
E-503 Piezo amplifier module, 3 channels, -30 to 130 V
E-505 Piezo amplifier module, 1 channel, -30 to 130 V
E-610 Piezo amplifier / servo controller, 1 channel, -30 to 130 V
E-617 High-power piezo amplifier, 1 channel, -30 to 130 V
E-621 Piezo amplifier / servo controller module, 1 channel, -30 to 130 V
E-625 Piezo amplifier / servo controller, 1 channel, -30 to 130 V
E-663 Piezo amplifier, 3 channels, -20 to 120 V
E-709 Digital piezo controller, 1 channel, -30 to 130 V
E-831 Piezo amplifier module, 1 channel, -30 to 130 V
To order, contact our customer service department (p. 25).
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5 Unpacking
NOTICE
Destruction of the P-844 due to mechanical overload!
Mechanical forces can destroy the P-844.
►Avoid knocks that affect the P-844.
►Do not drop the P-844.
Unpacking the P-844
1. Unpack the P-844 with care.
2. Compare the contents with the scope of delivery according to the contract and the
delivery note.
3. Inspect the contents for signs of damage. If any parts are damaged or missing, contact
our customer service department (p. 25) immediately.
4. Keep all packaging materials in case the product needs to be returned.
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6 Installation
6.1 Avoiding Mounting Errors
Piezo actuators may only be loaded axially. The following figures intend to help you to avoid
mounting errors.
Figure 3: Not tightly screwed at both ends and no angles
A: Wrong: Angular error at the tip
B: Right: Axial loading of the actuator
C: Wrong: The actuator is screwed tight at both ends
Figure 4: Ball tips or flexures for decoupling lateral forces and bending forces
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Figure 5: No lateral forces or torques
A: Wrong: Shearing force due to lateral force
B: Right: Axial loading of the actuator
C: Wrong: Torsion due to torque
6.2 Mounting the P-844 and Connecting to a Protective Earth
Conductor
The protective earth connection of the P-844 is established as follows:
■Mounting hole in the base of the P-844
■Suitable, conductive screw
■The underlying surface that is connected to the protective earth conductor
Pay attention to the applicable standards for connecting the protective earth conductor.
Tools and Accessories
■Suitable protective earth conductor: Cable cross section ≥ 0.75 mm2
■Electrically conductive screw of suitable size and length (see "Dimensions" (p. 29))
■Open-end wrench for holding the base (p. 10) of the P-844 (see "Dimensions" (p. 29) for
across flats size)
■Suitable screwdriver
Requirements
✓You have read and understood the general safety instructions (p. 7).
✓You have read and understood the section "Avoiding Mounting Errors" (p. 12).
✓The P-844 is not connected to the electronics.
✓The P-844 is discharged (p. 20).
✓You have provided a suitable surface for mounting the P-844:
■The underlying surface has suitable mounting holes (p. 29).
■The underlying surface is connected to a protective earth conductor.
■The underlying surface is sufficiently conductive to ensure proper function of the
protective earth conductor.
✓You have accounted for the space required to route cables without bending and
according to regulations.
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CAUTION
Risk of electric shock if the protective earth conductor is not connected!
If the protective earth conductor is missing or not properly connected, risk of dangerous
touch voltages on the P-844 in the event of malfunction or failure of the system. If touch
voltages exist, touching the P-844 can lead to minor injury from electric shock.
►Connect the P-844 to a protective earth conductor before startup.
►Do not remove the protective earth conductor during operation.
►If the protective earth conductor has to be temporarily removed (e.g., for modifications),
reconnect the P-844 to the protective earth conductor before restarting.
Information
The P-844 can heat up during operation. The heat produced during operation can affect your
application.
Mounting the P-844
1. Use an open-end wrench to hold the base of the P-844 in position.
2. Screw the P-844 onto a suitable underlying surface. For this purpose, screw into the
mounting hole in the bottom of the base (p. 29).
3. Remove the open-end wrench from the base.
6.3 Fixing the Load
Tools and Accessories
■Nut of suitable size and length (see "Dimensions" (p. 29))
■Open-end wrench for holding the tip (p. 10) of the P-844 (see "Dimensions" (p. 29) for
across flats size)
■Suitable tool for tightening the nuts
Requirements
✓You have read and understood the general safety instructions (p. 7).
✓You have read and understood the section "Avoiding Mounting Errors" (p. 12).
✓The P-844 is not connected to the electronics.
✓The P-844 is discharged (p. 20).
NOTICE
Destruction of the piezo actuator due to mechanical overload!
Torques, bending and lateral forces, tensile stress, and excessive loads can destroy the piezo
actuator.
►Do not exceed the maximum permissible loads according to the specifications (p. 26).
►Avoid torques, bending forces and lateral forces on the tip of the piezo actuator.
►Avoid torques on the base when the tip is tightly clamped.
►Make sure that the center of load of the moving system is on the motion axis of the piezo
actuator.
►Use suitable structures or guide elements (e.g., ball tips or flexure guides) to avoid
uneven load distribution.
►Pay attention to the information on parallelism in the "Dimensions" section (p. 29).
►Do not screw the piezo actuator tight at both ends.
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Fixing the Load
1. Use an open-end wrench to hold the tip of the P-844 in place.
2. Tighten the nut to secure the load on the tip.
3. Remove the open-end wrench from the tip.
6.4 Connecting the P-844
Tools and Accessories
■If necessary: Suitable cable set
■If necessary: Suitable screwdriver for the locking screws of the connectors.
Requirements
✓You have read and understood the general safety instructions (p. 7).
✓You have read and understood the user manual for the electronics used.
✓You have installed the electronics properly.
✓The electronics are switched off.
NOTICE
Damage due to incorrect connection of the P-844!
Connecting unsuitable electronics or a wrong cable can damage the P-844 or the electronics.
►Connect the P-844 only to suitable electronics from PI (p. 10).
►Use cables from PI only to connect the P-844 to the electronics.
Connecting the P-844
1. Connect the P-844's voltage plug to the voltage socket on the electronics.
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7 Startup / Operation
7.1 Determining the Operating Parameters
Limiting factors for the operation of the piezo actuator:
■Resonant frequency:
The operating frequency may not exceed one third of the resonant frequency of the
loaded piezo actuator. See "Calculating the Maximum Operating Frequency of the Loaded
Piezo Actuator" (p. 17).
■Maximum push/pull force capacity (p. 26):
The mass of the load to be moved and the operating frequency of the piezo actuator must
be selected so that any dynamic forces generated during operation do not exceed the
maximum push/pull force capacity of the piezo actuator. See "Calculating the Forces that
Occur During Dynamic Operation" (p. 17).
■Maximum permissible operating temperature of the piezo actuator (p. 26):
The greater the operating frequency, the operating voltage (peak-to-peak), and the
capacitance of the piezo actuator, the greater the thermal power generated in the piezo
actuator. The operating frequency, operating voltage and operating time must be selected
so that the maximum permissible operating temperature of the piezo actuator is not
exceeded. For the maximum permissible operating frequency without cooling, see
column B of the table in "Maximum Ratings" (p. 26).
Peak and average output current of the electronics:
The electronics used (p. 10) for operating the P-844 must meet the following requirements:
■The electronics can provide the required current. See "Calculating the Power Requirement
for Sinusoidal Operation" (p. 17).
■The output current of the electronics does not exceed the maximum power consumption
of the piezo actuator. See "Maximum Ratings" (p. 26).
7.1.1 Calculating the Effective Mass
Figure 6: Calculation of the effective mass of a unilaterally clamped piezo stack actuator
without load (left) and with additional load (right).
1. Find the mass m of your piezo actuator in the data table (p. 26).
2. Determine the additional load M.
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3. Calculate the effective mass meff of the unloaded piezo actuator and meff' of the loaded
piezo actuator using the formulas in the figure above.
7.1.2 Calculating the Maximum Operating Frequency of the Loaded Piezo
Actuator
Information
In the following calculation, the maximum permissible operating temperature of the piezo
actuator is not taken into account. During operation without cooling, the maximum
operating temperature may already be exceeded when the operating frequency is still below
the limit value calculated in the following.
►For the maximum permissible operating frequency without cooling, see column B of the
table in "Maximum Ratings" (p. 26).
1. Calculate the resonant frequency of the loaded piezo actuator with the following formula:
Variables:
f0' = Resonant frequency of the loaded piezo actuator [Hz]
f0 = Resonant frequency of the unloaded piezo actuator [Hz]; see "Data Table" (p. 26).
meff = Effective mass; approx. 1/3 of the mass of the piezo actuator [kg]
meff' = Effective mass meff + additional load M [kg]
See also "Calculating the Effective Mass" (p. 16).
2. Calculate the maximum operating frequency of the loaded piezo actuator with the
following formula:
fmax = f0'/3
Variables:
fmax = Maximum operating frequency of the loaded piezo actuator [Hz]
f0' = Resonant frequency of the loaded piezo actuator [Hz]
7.1.3 Calculating the Forces that Occur During Dynamic Operation
1. Use the following formula to calculate the dynamic forces acting on the piezo actuator
during sinusoidal operation with the frequency f:
Variables:
Fdyn = Dynamic force [N]
meff' = Effective mass meff (approx. 1/3 of the mass of the piezo actuator) + additional load
M [kg], see also "Calculating the Effective Mass" (p. 16)
ΔL = Displacement in the application (peak-to-peak) [m]
f = Frequency [Hz]
Example: The dynamic forces are approximately ±40 N at 1000 Hz, 2 µm displacement
(peak-peak) and 1 kg effective mass.
7.1.4 Calculating the Power Requirement for Sinusoidal Operation
1. Calculate the average current requirement for sinusoidal operation using the following
formula:
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2. Calculate the peak current requirement for sinusoidal operation using the following
formula:
Variable Description Notes
IaRequired average current of the ampli-
fier (source / sink) [A]
It is essential that the power adapter
can supply enough current.
Imax Required peak current of the amplifier
(source / sink) [A]
The provided peak current depends on
the internal storage capacity of the am-
plifier.
f Operating frequency [Hz] Details on the operating frequency see
"Overview of Limiting Factors" (p. 16).
C Capacitance of the piezo actuator [F (=
As/V)]
See "Data Table" (p. 26) for the small-
signal capacitance of the piezo actua-
tor.
For large-signal conditions, a safety
factor of 70 % should be added to the
small-signal capacitance.
Up-p Operating voltage (peak-to-peak) [V] Voltage difference between positive
and negative peak voltage
7.2 Starting and Operating the P-844
Tools and Accessories
■Electronics from PI (p. 10)
Requirements
✓You have read and understood the general safety instructions (p. 7).
✓For startup with a load or in a multi-axis system: You have installed the P-844
properly (p. 12).
✓You have read and understood the user manual for the electronics used.
✓If a digital controller is used: You have read and understood the manual for the PC
software used.
✓The electronics and if required, the PC software, have been installed (see the user manual
for the electronics).
CAUTION
Risk of electric shock if the protective earth conductor is not connected!
If the protective earth conductor is missing or not properly connected, risk of dangerous
touch voltages on the P-844 in the event of malfunction or failure of the system. If touch
voltages exist, touching the P-844 can lead to minor injury from electric shock.
►Connect the P-844 to a protective earth conductor before startup.
►Do not remove the protective earth conductor during operation.
►If the protective earth conductor has to be temporarily removed (e.g., for modifications),
reconnect the P-844 to the protective earth conductor before restarting.
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CAUTION
Burning due to hot surface!
The surface of the P-844 and the surroundings can heat up during operation. Touching the
P-844 and surrounding parts can result in minor injuries from burning.
►Make sure that the hot P-844 and the surrounding parts cannot be touched.
NOTICE
Destruction of the piezo actuator due to electric flashovers
Using the P-844 in environments that increase the electrical conductivity can lead to the
destruction of the piezo actuator by electric flashovers. Electric flashovers can be caused by
moisture, high humidity, liquids, and conductive materials (e.g., metal dust). In addition,
electric flashovers can also occur in certain air pressure ranges due to the increased
conductivity of the air.
►Avoid operating the P-844 in environments that can increase the electrical conductivity.
►Operate the P-844 only within the permissible ambient condition and
classifications (p. 27).
NOTICE
Destruction of the piezo actuator due to dynamic forces!
Dynamic forces can be generated during dynamic operation that cancel out the preload of
the piezo actuator. Operating without a preload can destroy the actuator.
►Do not exceed the maximum push/pull capacity according to the specifications (p. 26).
►Pay attention to the notes in "Determining the Operating Parameters" (p. 16).
NOTICE
Destruction of the piezo actuator due to excessive operating frequencies!
Excessive operating frequencies can destroy the piezo actuator.
►Select the operating frequency so that the following conditions are met:
■The maximum operating frequency may not exceed one third of the resonant frequency
(see "Data Table" (p. 26) for the resonant frequency of the unloaded piezo actuator and
see "Calculating the Maximum Operating Frequency of the Loaded Piezo Actuator" (p. 17)
for the resonant frequency of the loaded piezo actuator).
■Any dynamic forces generated during operation do not exceed the maximum push/pull
force of the piezo actuator (see "Calculating the Forces that Occur During Dynamic
Operation" (p. 17) and "Specifications" (p. 26)).
NOTICE
Reduced lifetime of the piezo actuator due to permanently high voltage!
The permanent application of a high voltage to piezo actuators leads to a considerable
reduction in the lifetime of the piezo ceramic.
►When the P-844 is not being used (e.g., to ensure temperature stability of the electronics),
discharge (p. 20) it.
►If possible, limit the maximum operating voltage during continuous operation.
NOTICE
Operating voltage excessively high or incorrectly connected!
Operating voltages that are too high or incorrectly connected can cause damage to the P-844.
►Pay attention to the operating voltage range (p. 26), which is specified for the P-844.
►Pay attention to correct pin assignment (p. 31).
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NOTICE
Damage after reconnecting due to a charged P-844!
The P-844 can remain charged when the connecting cable is pulled out of the electronics
during operation. Reconnecting a charged P-844 to electronics during operation can cause a
mechanical impulse that will damage the P-844.
►Do not pull the connecting cable of the P-844 out of the electronics during operation.
►If the connecting cable of the P-844 is accidentally pulled out of the electronics during
operation: Switch off the electronics before you reconnect the P-844.
NOTICE
Destruction of the piezo actuator due to overheating!
Overheating can destroy the piezo actuator.
►Adjust the operating voltage, operating frequency and/or operating time so that the
maximum operating temperature (p. 26) of the piezo actuator is not exceeded; see
"Maximum Ratings" (p. 26) and "Determining the Operating Parameters" (p. 16).
NOTICE
Uncontrolled oscillation!
Oscillation can cause irreparable damage to the P-844. Oscillation is indicated by a humming
noise and can be caused by the following:
■A change in the load and/or dynamics requires the operating parameters to be adjusted.
■The P-844 is operated near to its resonant frequency.
►If you notice oscillation, stop the P-844 immediately.
Starting and Operating the P-844
1. Start up the electronics (see the user manual for the electronics).
2. Configure the electronics for the P-844 during startup. If you are using a digital controller
from PI, run the PC software and select the entry in the positioner database that matches
the P-844 exactly.
3. Start a few motion cycles for testing purposes (see the user manual for the electronics).
7.3 Discharging the P-844
The P-844 must be discharged in the following cases:
■When the P-844 is not in use but the electronics remain switched on to ensure
temperature stability
■If the P-844 is accidentally disconnected from the electronics during operation
■Before disassembling (e.g., before cleaning and transporting the P-844) as well as for
modifications
Requirements
✓You have read and understood the general safety instructions (p. 7).
Tools and Accessories
■Electronics from PI (p. 10)
Discharging a P-844 Connected to the Electronics
1. Set the piezo voltage to 0 V on the electronics.
7 STARTUP / OPERATION P844M0001EN ‒ 11/13/2018
20 MOTION | POSITIONING