Delta Tau Geo Direct PWM Amplifier User manual

^1 USER MANUAL
^3U03U042 Geo 3U Direct PWM Drive
(New Version)
^3 Geo 3U Direct PWM Drive, 3U042
^4 5xx-603729-xUx2
^5 July 26, 2006
Single Source Machine Control
Power // Flexibility // Ease of Use
21314 Lassen Street Chatsworth, CA 91311 // Tel. (818) 998-2095 Fax. (818) 998-7807 // www.deltatau.com
Copyright Information
© 2006 Delta Tau Data Systems, Inc. All rights reserved.
This document is furnished for the customers of Delta Tau Data Systems, Inc. Other uses are
unauthorized without written permission of Delta Tau Data Systems, Inc. Information contained in this
manual may be updated from time-to-time due to product improvements, etc., and may not conform in
every respect to former issues.
To report errors or inconsistencies, call or email:
Delta Tau Data Systems, Inc. Technical Support
Phone: (818) 717-5656
Fax: (818) 998-7807
Email: support@deltatau.com
Website: http://www.deltatau.com
Operating Conditions
All Delta Tau Data Systems, Inc. motion controller products, accessories, and amplifiers contain static
sensitive components that can be damaged by incorrect handling. When installing or handling Delta Tau
Data Systems, Inc. products, avoid contact with highly insulated materials. Only qualified personnel
should be allowed to handle this equipment.
In the case of industrial applications, we expect our products to be protected from hazardous or
conductive materials and/or environments that could cause harm to the controller by damaging
components or causing electrical shorts. When our products are used in an industrial environment, install
them into an industrial electrical cabinet or industrial PC to protect them from excessive or corrosive
moisture, abnormal ambient temperatures, and conductive materials. If Delta Tau Data Systems, Inc.
products are directly exposed to hazardous or conductive materials and/or environments, we cannot
guarantee their operation.
Safety Instructions
Qualified personnel must transport, assemble, install, and maintain this equipment. Properly qualified
personnel are persons who are familiar with the transport, assembly, installation, and operation of
equipment. The qualified personnel must know and observe the following standards and regulations:
IEC 364 resp. CENELEC HD 384 or DIN VDE 0100
IEC report 664 or DIN VDE 0110
National regulations for safety and accident prevention or VBG 4
Incorrect handling of products can result in injury and damage to persons and machinery. Strictly adhere
to the installation instructions. Electrical safety is provided through a low-resistance earth connection. It is
vital to ensure that all system components are connected to earth ground.
This product contains components that are sensitive to static electricity and can be damaged by incorrect
handling. Avoid contact with high insulating materials (artificial fabrics, plastic film, etc.). Place the
product on a conductive surface. Discharge any possible static electricity build-up by touching an
unpainted, metal, grounded surface before touching the equipment.
Keep all covers and cabinet doors shut during operation. Be aware that during operation, the product has
electrically charged components and hot surfaces. Control and power cables can carry a high voltage,
even when the motor is not rotating. Never disconnect or connect the product while the power source is
energized to avoid electric arcing.
After removing the power source from the equipment, wait at least 10 minutes before touching or
disconnecting sections of the equipment that normally carry electrical charges (e.g., capacitors, contacts,
screw connections). To be safe, measure the electrical contact points with a meter before touching the
equipment.
The following text formats are used in this manual to indicate a potential for personal injury or equipment
damage. Read the safety notices in this manual before attempting installation, operation, or maintenance
to avoid serious bodily injury, damage to the equipment, or operational difficulty.
WARNING
A Warning identifies hazards that could result in personal injury or death. It
precedes the discussion of interest.
Caution
A Caution identifies hazards that could result in equipment damage. It precedes the
discussion of interest.
Note
A Note identifies information critical to the user’s understanding or use of the
equipment. It follows the discussion of interest.
REVISION HISTORY
REV.
1
DESCRIPTION
REPLACED COVER PRODUCT PHOTO
DATE
CHG
APPVD
07/25/06
CP
D.DIMITRI
3U Servo Amplifier
Table of Contents
Copyright Information................................................................................................................................................i
Operating Conditions .................................................................................................................................................i
Safety Instructions.................................................................................................................................................... ii
INTRODUCTION .......................................................................................................................................................1
Compatible Motors....................................................................................................................................................2
Maximum Speed....................................................................................................................................................2
Torque...................................................................................................................................................................2
Motor Poles ..........................................................................................................................................................3
Motor Inductance..................................................................................................................................................3
Motor Resistance ..................................................................................................................................................3
Motor Back EMF ..................................................................................................................................................3
Motor Torque Constant ........................................................................................................................................4
Motor Inertia ........................................................................................................................................................4
Motor Cabling ......................................................................................................................................................4
RECEIVING AND UNPACKING .............................................................................................................................5
Use of Equipment......................................................................................................................................................5
Environmental Specifications....................................................................................................................................5
Electrical Specifications ............................................................................................................................................6
Recommended Fusing and Wire Gauge ....................................................................................................................6
Wire Sizes .............................................................................................................................................................6
Physical Specifications..............................................................................................................................................7
MOUNTING ................................................................................................................................................................8
SYSTEM WIRING......................................................................................................................................................9
Fuse and Circuit Breaker Selection......................................................................................................................9
Use of GFI Breakers.............................................................................................................................................9
Transformer and Filter Sizing ..............................................................................................................................9
Noise Problems...................................................................................................................................................10
Operating Temperature ......................................................................................................................................10
Amplifier Cooling Considerations ......................................................................................................................11
Single Phase Operation ......................................................................................................................................11
Power Supply Considerations .................................................................................................................................11
Wiring AC Input......................................................................................................................................................11
Wiring Earth-Ground ..............................................................................................................................................12
Earth Grounding Paths.......................................................................................................................................12
Wiring 24 V Logic Control .....................................................................................................................................13
Regen (Shunt) Resistor Wiring ...............................................................................................................................13
Shunt Regulation.................................................................................................................................................14
Minimum Resistance Value.................................................................................................................................14
Maximum Resistance Value ................................................................................................................................14
Energy Transfer Equations.................................................................................................................................14
Bonding ...................................................................................................................................................................18
Filtering ...................................................................................................................................................................18
CE Filtering........................................................................................................................................................18
Input Power Filtering .........................................................................................................................................18
Motor Line Filtering ...........................................................................................................................................18
3U DRIVE CONNECTIONS....................................................................................................................................21
PWM Input Connector ............................................................................................................................................21
Axis #1 PWM input connector ............................................................................................................................21
P1 (36-pin Mini-D Connector) ...........................................................................................................................21
Axis #2 PWM Input connector ............................................................................................................................22
P2 (36-pin Mini-D Connector) ...........................................................................................................................22
Motor Output Connector .........................................................................................................................................23
Table of Contents
ii
3U Servo Amplifier
Wiring the Motor Thermostats ................................................................................................................................24
Motor Temperature Switch .................................................................................................................................24
GEO 3U PWM BACKPLANE CONNECTIONS...................................................................................................25
3UBP8A, 300-603730-10x......................................................................................................................................25
J1: 3U Geo Drive backplane slot........................................................................................................................25
J2: 24V Input Molex Connector..........................................................................................................................26
J3: FAN output Molex Connector.......................................................................................................................26
TB1: AC input Power and Regen Resistor Connector ........................................................................................26
TB2: Regen Resistor Connector .........................................................................................................................26
DIRECT PWM COMMUTATION CONTROLLER SETUP ..............................................................................28
Key Servo IC Variables...........................................................................................................................................28
Key Motor Variables ...............................................................................................................................................28
DC BRUSH MOTOR DRIVE SETUP WITH NON-TURBO PMAC ..................................................................29
Hardware Connection ........................................................................................................................................29
I-Variable Setup..................................................................................................................................................29
DC BRUSH MOTOR DRIVE SETUP WITH TURBO PMAC ............................................................................31
Commutation Phase Angle: Ixx72...........................................................................................................................31
Special Instructions for Direct-PWM Control of Brush Motors..............................................................................31
Testing PWM and Current Feedback Operation .....................................................................................................32
Purpose...............................................................................................................................................................33
Preparation.........................................................................................................................................................33
Position Feedback and Polarity Test..................................................................................................................34
PWM Output and ADC Input Connection ..............................................................................................................34
PWM/ADC Phase Match ....................................................................................................................................35
Synchronous Motor Stepper Action ....................................................................................................................35
Current Loop Polarity Check .............................................................................................................................35
Troubleshooting..................................................................................................................................................35
SETTING I2T PROTECTION .................................................................................................................................36
CALCULATING MINIMUM PWM FREQUENCY.............................................................................................37
PWM DRIVE COMMAND STRUCTURE.............................................................................................................38
Default Mode...........................................................................................................................................................38
Enhanced Mode.......................................................................................................................................................38
TROUBLESHOOTING............................................................................................................................................39
Error Codes .............................................................................................................................................................39
3U Drive Status Display Codes ..........................................................................................................................39
Status LEDs (for older and newer revision) 3U042............................................................................................40
Amplifier stops and displays a code....................................................................................................................41
APPENDIX A.............................................................................................................................................................42
PWM Cable Ordering Information..........................................................................................................................42
Mating Connector and Cable Kits ...........................................................................................................................42
Connector and pins Part numbers ......................................................................................................................42
Motor Cable Drawing..............................................................................................................................................43
3U042 (CABKIT3C) ...........................................................................................................................................43
APPENDIX B.............................................................................................................................................................44
Regenerative Resistor: GAR78/48 .........................................................................................................................44
APPENDIX C.............................................................................................................................................................46
3U Rack DIMENSIONS .........................................................................................................................................46
Table of Contents
iii
3U Servo Amplifier
Table of Contents
iv
3U Servo Amplifier
Table of Contents
v
3U Servo Amplifier
INTRODUCTION
This document provides user data and support for the 3U Geo Direct PWM drives 3U042. Geo drives are
brushless drive amplifier modules designed and manufactured by Delta Tau Data Systems, Inc.
The 3U042 is a 3U size Geo Direct PWM amplifier designed to drive up to two axis with 4A RMS
continuous and 8A RMS peak (2 seconds). These drives are low power amplifiers designed to drive
permanent magnet brushless (rotary or linear), AC induction and DC Brush type motors from PWM
(pulse width modulated) command signals. These drive systems are designed to fit into a standard 3U
rack. The 3U Geo Direct PWM drives will operate directly off the power mains wired to the backplane,
typically 230VAC or 110VAC, three phase or single phase with the appropriate derating. An external
power supply of +24 VDC @1A (unregulated) is required for logic power allowing the user to control
motor power separately from control logic power. The amplifiers are interfaced to a PMAC controller via
ACC-24E2, ACC-24E2M, ACC-8F or ACC-8FS or other digital output servos.
These drive amplifiers are designed to receive logic-level direct digital PWM motor voltage command
from the controller and convert them to high voltage for motor control. They provide the power
conversion, motor current sense feedback to the controller, and comprehensive system protection. Each
drive also accepts motor thermal overload sensors for drive shut down on motor over temperature. The
host controller provides all other motor control functions.
Product Features:
• Simple wiring
•
High power density
•
Extensive fault protection
•
Locking motor connectors
•
Closed loop hall effect current sensors
•
Direct line connection with Soft Start
•
Separate logic and motor power control
•
3U format for small size and easy support
•
Full isolation for PMAC and user interfaces
•
Direct PWM control for best performance and cost
•
Shunt Regulator (requires external Resistor) for Bus power control
•
Auto ranging Shunt Regulator automatically selects for 115 or 230V operation
The 3U Geo Direct PWM drives consist of three basic components: 3U format Drive Module, backplane
that gives access for the power supply and associated metal work with fan for keeping the drive cool.
Both the drive modules and backplane may be purchased separately as spares. This family of products is
further supported with the availability of cable or connector kits and compatible shunt regulator resistor
(regen resistor).
The amplifier has many protection features to ensure the proper operation and protection of all of the
components connected to the unit. When the amplifier detects a fault, the unit will display a character
indicating the type of fault. Even though backup protection is provided, the PMAC controller should
have the I2 T protection variables set up to protect the amplifier from over current over time.
The following is a list of the faults detected by the logic of the amplifier:
• Instantaneous over current
• Integrated current over time (I2 T)
Backplane Board
1
3U Servo Amplifier
•
•
•
•
•
•
•
•
Motor over temperature (input from motor)
Under voltage
IGBT thermal failure
PWM fault
Over voltage
Ground fault
Minimum dead time protection
Shoot through protection
Note:
The 3U drive products are available in kit-form. The electronics on these products are
subject to damage by static electricity. Handle it as little as possible. Use ground wrist
straps when handling. Do not allow static-charge holding materials (paper, plastic, etc.)
to come in near proximity of the product.
Typically, the position feedback is fed to the PMAC controller via the available accessories and is not part
of the 3U drive amplifier. Thus, the position feedback is not to be connected to the amplifier in any
way.
Compatible Motors
The 3U Geo Direct PWM product line is capable of interfacing to a wide variety of motors. The 3U Geo
Direct PWM drives can be used with almost any type of three-phase brushless motor, including DC
brushless rotary, AC brushless rotary, induction, and brushless linear motors. Motor selection for an
application is a science in itself and cannot be covered in this manual. However, some basic
considerations and guidelines are offered. Motor manufacturers include a host of parameters to describe
their motor.
Some basic equations can help guide an applications engineer to mate a proper drive with a motor. A
typical application accelerates a load to a speed, running the speed for a while and then decelerating the
load back into position.
Maximum Speed
The motor’s maximum rated speed is given. This speed may or may not be achievable in a given system.
The speed could be achieved if enough voltage and enough current loop gain are available. Also,
consider the motor’s feedback adding limitations to achievable speeds. The load attached to the motor
also limits the maximum achievable speed. In addition, some manufacturers will provide motor data with
their drive controller, which is tweaked to extend the operation range that other controllers may be able to
provide. In general, the maximum speed can be determined by input voltage line-to-line divided by Kb
(the motor’s back EMF constant). It is wise to de-rate this a little for proper servo applications.
Torque
The torque required for the application can be viewed as both instantaneous and average. Typically, the
instantaneous or peak torque is calculated as a sum of machining forces or frictional forces plus the forces
required to accelerate the load inertia. The machining or frictional forces on a machine must be
determined by the actual application. The energy required to accelerate the inertia follows the equation: t
= JA, where t is the torque in pound-feet required for the acceleration, J is the inertia in pound-feetsecond squared, and A is in radians per second per second. The required torque can be calculated if the
desired acceleration rate and the load inertia reflected back to the motor are known. The t-JA equation
requires that the motor’s inertia be considered as part of the inertia-requiring torque to accelerate.
Once the torque is determined, the motor’s specification sheet can be reviewed for its torque constant
parameter (Kt). The torque required at the application divided by the Kt of the motor provides the peak
Backplane Board
2
3U Servo Amplifier
current required by the amplifier. A little extra room should be given to this parameter to allow for good
servo control.
Most applications have a duty cycle in which the acceleration profile occurs repetitively over time.
Calculating the average value of this profile gives the continuous rating required by the amplifier.
Applications also concern themselves with the ability to achieve a speed. The requirements can be
reviewed by either defining what the input voltage is to the drive, or defining what the voltage
requirements are at the motor. Typically, a system is designed at a 230 or 480V input line. The motor
must be able to achieve the desired speed with this voltage limitation. This can be determined by using
the voltage constant of the motor (Kb), usually specified in volts-per-thousand rpm. The application
speed is divided by 1000 and multiplied by the motor’s Kb. This is the required voltage to drive the
motor to the desired velocity. Headroom of 20% is suggested to allow for good servo control.
Peak Torque
The peak torque rating of a motor is the maximum achievable output torque. It requires that the amplifier
driving it be able to output enough current to achieve this. Many drive systems offer a 3:1 peak-tocontinuous rating on the motor, while the amplifier has a 2:1 rating. To achieve the peak torque, the drive
must be sized to be able to deliver the current to the motor. The required current is often stated on the
datasheet as the peak current through the motor. In some sense, it can also be determined by dividing the
peak amplifier's output rating by the motor’s torque constant (Kt).
Continuous Torque
The continuous torque rating of the motor is defined by a thermal limit. If more torque is consumed from the
motor than this on average, the motor overheats. Again, the continuous torque output of the motor is subject
to the drive amplifier’s ability to deliver that current. The current is determined by the manufacturer’s
datasheets stating the continuous RMS current rating of the motor and can also be determined by using the
motor’s Kt parameter, usually specified in torque output per amp of input current.
Motor Poles
Usually, the number of poles in the motor is not a concern to the actual application. However, it should
be noted that each pole-pair of the motor requires an electrical cycle. High-speed motors with high motor
pole counts can require high fundamental drive frequencies that a drive amplifier may or may not be able
to output. In general, drive manufacturers with PWM switching frequencies (16KHz or below) would
like to see commutation frequencies less than 400 Hz. The commutation frequency is directly related to
the number of poles in the motor.
Motor Inductance
Typically, motor inductance of servomotors is 1 to 15 mH. The Geo drive product series can drive this
range easily. On lower-inductance motors (below 1mH), problems occur due to PWM switching where
heating currents flow through the motor, causing excessive energy waste and heating. If an application
requires a motor of less than 1mH, external inductors are recommended to increase that inductance.
Motors with inductance in excess of 15mH can still be driven, but are slow to react and typically are out
of the range of high performance servomotors.
Motor Resistance
Motor resistance is not really a factor in determining the drive performance, but rather, comes into play
more with the achievable torque or output horsepower from the motor. The basic resistance shows up in
the manufacturer’s motor horsepower curve.
Motor Back EMF
The back EMF of the motor is the voltage that it generates as it rotates. This voltage subtracts from the
bus voltage of the drive and reduces the ability to push current through the motor. Typical back EMF
ratings for servomotors are in the area of 8 to 200 volts-per-thousand rpm. The Geo drive product series
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3U Servo Amplifier
can drive any range of back EMF motor, but the back EMF is highly related to the other parameters of the
motor such as the motor inductance and the motor Kt. It is the back EMF of the motor that limits the
maximum achievable speed and the maximum horsepower capability of the motor.
Motor Torque Constant
Motor torque constant is referred to as Kt and usually it is specified in torque-per-amp. It is this number
that is most important for motor sizing. When the load that the motor will see and the motor’s torque
constant is known, the drive amplifier requirements can be calculated to effectively size a drive amplifier
for a given motor. Some motor designs allow Kt to be non-linear, in which Kt will actually produce less
torque per unit of current at higher output speeds. It is wise to de-rate the systems torque producing
capability by 20% to allow headroom for servo control.
Motor Inertia
Motor inertial comes into play with motor sizing because torque to accelerate the inertia of the motor is
effectively wasted energy. Low inertia motors allow for quicker acceleration. However, consider the
reflective inertia from the load back to the motor shaft when choosing the motor’s inertial. A high ratio of
load-to-motor inertia can cause limited gains in an application if there is compliance in the transmission
system such as belt-drive systems or rubber-based couplings to the systems. The closer the rotor inertia
matches the load’s reflected inertia to the motor shaft, the higher the achievable gains will be for a given
system. In general, the higher the motor inertia, the more stable the system will be inherently.
Mechanical gearing is often placed between the load and the motor simply to reduce the reflected inertia
back to the motor shaft.
Motor Cabling
Motor cables are an integral part of a motor drive system. Several factors should be considered when
selecting motor cables. First, the PWM frequency of the drive emits electrical noise. Motor cables must
have a good-quality shield around them. The motor frame must also have a separate conductor to bring
back to the drive amplifier to help quench current flows from the motor due to the PWM switching noise.
Both motor drain wire and the cable shield should be tied at both ends to the motor and to the drive
amplifier.
Another consideration in selecting motor cables is the conductor-to-conductor capacitance rating of the
cable. Small capacitance is desirable. Longer runs of motor cable can add motor capacitance loading to
the drive amplifier causing undesired spikes of current. It can also cause couplings of the PWM noise
into the earth grounds, causing excessive noise as well. Typical motor cable ratings would be 50 pf per
foot maximum cable capacitance.
Another factor in picking motor cables is the actual conductor cross-sectional area. This refers to the
conductor’s ability to carry the required current to and from the motor. When calculating the required
cable dimensions, consider agency requirements, safety requirements, maximum temperature that the
cable will be exposed to, the continuous current flow through the motor, and the peak current flow
through the motor. Typically, it is not suggested that any motor cable be less than 14 AWG.
The motor cable’s length must be considered as part of the application. Motor cable length affects the
system in two ways. First, additional length results in additional capacitive loading to the drive. The
drive’s capacitive loading should be kept to no more than 1000 pf. Additionally, the length sets up
standing waves in the cable, which can cause excessive voltage at the motor terminals. Typical motor
cable length runs of 200 feet for 230V systems and 50 feet for 480V systems are acceptable. Exceeding
these lengths may put other system requirements in place for either a snubber at the motor end or a series
inductor at the drive end. The series inductor at the drive end provides capacitance loading isolation from
the drive and slows the rise time of the PWM signal into the cable, resulting in less voltage overshoot at
the motor.
Backplane Board
4
3U Servo Amplifier
RECEIVING AND UNPACKING
Delta Tau products are thoroughly tested at the factory and carefully packaged for shipment. When the
3U Geo Direct PWM Drive is received, there are several things to be done immediately:
1. Observe the condition of the shipping container and report any damage immediately to the
commercial carrier that delivered the drive.
2. Remove the control from the shipping container and remove all packing materials. Check all
shipping material for connector kits, documentation, CD ROM, or other small pieces of equipment.
Be aware that some connector kits and other equipment pieces may be quite small and can be
accidentally discarded if care is not used when unpacking the equipment. The container and packing
materials may be retained for future shipment.
3. Verify that the part number of the drive received is the same as the part number listed on the purchase
order.
4. Inspect the drive for external physical damage that may have been sustained during shipment and
report any damage immediately to the commercial carrier that delivered the drive.
5. Electronic components in this amplifier are design-hardened to reduce static sensitivity. However,
use proper procedures when handling the equipment.
6. If the 3U Geo Direct PWM Drive is to be stored for several weeks before use, be sure that it is stored
in a location that conforms to published storage humidity and temperature specifications stated in this
manual.
Use of Equipment
The following restrictions will ensure the proper use of the 3U Geo Direct PWM Drive:
• The components built into electrical equipment or machines can be used only as integral components
of such equipment.
• The 3U Geo Direct PWM Drives are to be used only on grounded three-phase industrial mains supply
networks (TN-system, TT-system with grounded neutral point).
• The 3U Geo Direct PWM Drives must not be operated on power supply networks without a ground or
with an asymmetrical ground.
• If the 3U Geo Direct PWM Drives are used in residential areas, or in business or commercial
premises, implement additional filter measures.
• The 3U Geo Direct PWM Drives may be operated only in a closed switchgear cabinet, taking into
account the ambient conditions defined in the environmental specifications.
Delta Tau guarantees the conformance of the 3U Geo Direct PWM Drives with the standards for
industrial areas stated in this manual, only if Delta Tau components (cables, controllers, etc.) are used.
Environmental Specifications
Description
Unit
Operating Temperature
°C
Rated Storage Temperature
Humidity
Shock
Vibration
Operating Altitude
°C
%
Air Flow Clearances
Backplane Board
Feet
(Meters)
in (mm)
Specifications
+0 to 45°C. Above 45°C, derate the continuous peak output current by 2.5%
per °C above 45°C. Maximum Ambient is 55°C
-25 to +70
10% to 90% non-condensing
Call Factory
Call Factory
To 3300 feet (1000 meters). Derate the continuous and peak output current
by 1.1% for each 330 feet (100meters) above the 3300 feet
3" (76.2mm) above and below unit for air flow
5
3U Servo Amplifier
Electrical Specifications
Output Circuits (axes)
Nominal Input Voltage (VAC)
Rated Input Voltage (VAC)
Rated Continuous Input Current (A ACRMS)
Rated Input Power (Watts)
Frequency (Hz)
Phase Requirements
Charge Peak Inrush Current (A)
Main Bus Capacitance (µf), backplane
board
Rated Output Voltage (V)
Rated Cont. Output Current per Axis
Peak Output Current (A) for 2 seconds
Rated Output Power per Axis (Watts)
Nominal DC Bus
Over-voltage Trip Level (VDC)
Under-voltage Lockout Level (VDC)
Turn-On Voltage (VDC)
Turn-Off Voltage (VDC)
Maximum Current (A)
Recommended Current (A)
Minimum Resistance (Ohms)
Maximum Power (W)
Recommended Load Resistor (300 W
Max.)
Input Voltage (VDC)
Input Current (A)
Inrush Current (A)
Resolution (bits)
Full-scale Signed Reading (±A)
Maximum PWM Frequency (kHz) @ rated
current
Minimum Dead Time (µs)
Charge Pump Time (% of PWM period.)
2
230
97-265
5.28
2103
50/60
1Φ or 3Φ
940
138
4
8
956
325
410
10
392
372
GAR48
20-27
1
2
12
13.01
12
1
5
Recommended Fusing and Wire Gauge
Model
Recommended Fuse (FRN/LPN) Recommended Wire Gauge*
3U042
20
* See local and national code requirements
12 AWG
Wire Sizes
3U Geo Direct PWM Drive electronics create a DC bus by rectifying the incoming AC electricity. The
current flow into the drive is not sinusoidal but rather a series of narrow, high-peak pulses. Keep the
incoming impedance small so that these current pulses are not hindered. Conductor size, transformer size,
and fuse size recommendations may seem larger than normally expected. All ground conductors should
be 8AWG minimum using wires constructed of many strands of small gauge wire. This provides the
lowest impedance to high-frequency noises.
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3U Servo Amplifier
Physical Specifications
L x W x H (inches)
Width (3U rack slots)
Weight: drive only with front panel
(w/o backplane and side panels)
Backplane
Backplane Width (3U rack slots)
Backplane Weight
Terminal Connections
Backplane Board
3U042
6.30 x 2.40 x 5.08
3
0.9kgs (2.0lbs)
3UBP8A
3
0.275kgs (0.6lbs)
Torque to 20 in-lb
7
3U Servo Amplifier
MOUNTING
The 3U Geo Direct PWM drives are designed to be installed in an enclosure whose ambient temperature
does not exceed 55 °C. It must not be exposed to conductive dust or humidity in excess of 90% noncondensing. Corrosive gasses, corrosive dust, and other contaminants must be kept out of the drive
enclosure.
6.30
2.39
DELTA
TAU
2-AXIS PWM AMPLIFIER
230 VAC INPUT - 4A rms CONT/8A rms PEAK
MOTOR
O.T .
AMPLIFIER
STATUS
P WM
ENA 1
INPUT
1
U
V
ENA 2
PWR
W
U
P WM
INPUT
2
V
W
M
O
T
O
R
1
5.08
3.94
M
O
T
O
R
2
MODEL 3U42
FACEPLATE
3 SLOT
The drive rack is mounted to a back panel. The back panel should be unpainted and electrically
conductive to allow for reduced electrical noise interference. The back panel is machined to accept the
mounting bolt pattern of the drive. Make sure that all metal chips are cleaned up before the drive is
mounted so there is no risk of getting metal chips inside the drive.
The 3U rack is mounted to the back panel through 4 x 0275”x0.400” obround, user needs to provide
screws and internal-tooth lock washers to attach at the cabinet. It is important that the teeth break through
any anodization on the drive's mounting gears to provide a good electrically conductive path in as many
places as possible. Mount the 3U rack on the back panel so there is airflow (at least three inches) at both
the top and bottom areas of the drive.
If multiple 3U Geo drives are used, they can be mounted side-by-side, leaving at least one-tenth of an
inch clearance between drives in the 3U rack. It is extremely important that the airflow is not obstructed
by the placement of conduit tracks or other devices in the enclosure.
Caution:
Units must be installed in an enclosure that meets the environmental IP rating of
the end product (ventilation or cooling may be necessary to prevent enclosure
ambient from exceeding 113° F [45° C]).
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8
3U Servo Amplifier
SYSTEM WIRING
GARxx
SHUNT
RESISTOR
EARTH
BLOCK
WHT
Motor#1
3U042 Geo Direct PWM drive
BLK
BLK
WHT
BLU
WHT
GRN\YEL
SCREW HEAD
EARTH
FRAME
Optional
EMI FILTER
Motor#2
BLK
U V W
Motor #2
MCR
BLK
U V W
Motor #1
MAIN
POWER
BLU
WHT
3UBP8A
Backplane
300-603730 -10x
TB1
Fusing
L2
L1
24V
POWER
SUPPLY
+24 V
RED
Twisted Wires
24 V RET
BLK
BLK
RED
AC INPUT
L3
Twisted Wires
FAN J3
GND
24V
J2
GND
+24V
TB2
SHUNT
EARTH
SHUNT RTN
WARNING:
Installation of electrical control equipment is subject to many regulations including
national, state, local, and industry guidelines and rules. General recommendations
can be stated but it is important that the installation be carried out in accordance
with all regulations pertaining to the installation.
Fuse and Circuit Breaker Selection
In general, fusing must be designed to protect the weakest link from fire hazard. Each Geo drive is designed
to accept more than the recommended fuse ratings. External wiring to the drive may be the weakest link as
the routing is less controlled than the drive’s internal electronics. Therefore, external circuit protection, be it
fuses or circuit breakers, must be designed to protect the lesser of the drive or external wiring.
High peak currents and high inrush currents demand the use of slow blow type fuses and hamper the use
of circuit breakers with magnetic trip mechanisms. Generally, fuses are recommended to be larger than
what the rms current ratings require. Remember that some drives allow three times the continuous rated
current on up to two axis of motion. Time delay and overload rating of protection devices must consider
this operation.
Use of GFI Breakers
Ground Fault Interrupter circuit breakers are designed to break the power circuit in the event that
outgoing currents are not accompanied by equal and opposite returning currents. These breakers assume
that if outgoing currents are not returning then there is a ground path in the load. Most circuit breakers of
this type account for currents as low as 10mA PWM switching in servo drives coupled with parasitic
capacitance to ground in motor windings and long cables generate ground leakage current. Careful
installation practices must be followed. The use of inductor chokes in the output of the drive will help
keep these leakage currents below breaker threshold levels.
Transformer and Filter Sizing
Incoming power design considerations for use with Geo Drives require some over rating. In general, it is
recommended that all 3-phase systems using transformers and incoming filter chokes be allotted a 25%
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3U Servo Amplifier
over size to keep the impedances of these inserted devices from affecting stated system performance. In
general, it is recommended that all single-phase systems up to 1kW be designed for a 50% overload. All
single-phase systems over 1kW should be designed for a 200% overload capacity.
Noise Problems
When problems do occur often it points to electrical noise as the source of the problem. When this
occurs, turn to controlling high-frequency current paths. If following the grounding instructions does not
work, insert chokes in the motor phases. These chokes can be as simple as several wraps of the individual
motor leads through a ferrite ring core (such as Micrometals T400-26D). This adds high-frequency
impedance to the outgoing motor cable thereby making it harder for high-frequency noise to leave the
control cabinet area. Care should be taken to be certain that the core’s temperature is in a reasonable
range after installing such devices.
Operating Temperature
It is important that the ambient operating temperature of the 3U Geo Direct PWM drive must be kept
within specifications. The 3U Geo Direct PWM drive should be installed in an enclosure such as a
NEMA spec. cabinet. The internal temperature of the cabinet must be kept under the Geo Drive Ambient
Temperature specifications. It is sometimes desirable to roughly calculate the heat generated by the
devices in the cabinet to determine if some type of ventilation or air conditioning is required. For these
calculations the 3U Geo Direct PWM drive’s internal heat losses must be known. Budget 100W per axis
for 1.5A drives, 150W per axis for 3A drives, 200W per axis for 5A drives, 375W per axis for 10A
drives, 500W per axis for 15A drives, and 650W per axis for 20A drives (A are for continuous rating).
From 0°C to 45°C ambient no de-rating required. Above 45°C, de-rate the continuous and peak output
current by 2.5% per °C above 45°C. Maximum ambient is 55°C.
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3U Servo Amplifier
Amplifier Cooling Considerations
The drive amplifiers produce heat that must be removed. The installation requires that a fan blows air up
through the vertical fins of the product’s heat sink. The 3U Geo Direct PWM drive systems include the
metal plates that go around the unit as part of the rack’s metal panel work and a 24VDC (2.6W) fan. The
fan must be positioned at the bottom side of the drive unit and attached to the fan connector, J3 for
3U042, on the backplane for power.
Caution:
Do not operate the amplifier without an operational fan.
Do not impede airflow through the unit.
Single Phase Operation
Due to the nature of power transfer physics, it is not recommended that any system design attempt to
consume more than 2kW from any single-phase mains supply. Even this level requires careful
considerations. The simple bridge rectifier front end of the Geo Drive, as with all other drives of this
type, require high peak currents. Attempting to transfer power from a single-phase system getting one
charging pulse each 8.3 milliseconds causes excessively high peak currents that can be limited by power
mains impedances. The 3U Geo Direct PWM Drive output voltage sags, the input rectifiers are stressed,
and these current pulses cause power quality problems in other equipment connected to the same line.
While it is possible to operate drives on single-phase power, the actual power delivered to the motor must
be considered. Never design expecting more than 1.5 HP total from any 115V single-phase system and
never more than 2.5 HP from any 230V single-phase system.
Check the table below on how to calculate how to derate at single phase.
110VAC single phase
3U042
10%
230VAC single phase
Not needed
Note: Output Wattage derrates @ single phase.
Power Supply Considerations
The 3U Geo Direct PWM Amplifiers require an external mains connection to the barrier block on the
back side of the backplane to create the motor bus power. This connection can be single phase or threephase AC power at 115 or 230Vac. A single-phase system cannot provide more than 1500-2000 watts.
The form factor of the current becomes exaggerated perhaps allowing the internal rectifier bridge to be
damaged and electrical noise to interfere with other electronic equipment. These connections must be
fused with slow blow (i.e., FRN) fuses. Recommended fusing is 20A for the 3U042.
The logic power for the amplifier is derived from a separate external 24VDC @1A power supply. The
3U Drives have internal DC-to-DC converters that isolate the drive from this power supply and create all
the internally required logic voltages. Startup current from this power external power supply is isolated
with a soft start circuit
A Protective Earth Ground must be connected to the backplane (3UBP8A) and to the 3U rack itself. The
ground should be a low impedance path directly returning to the main earth distribution block within the
machine enclosure.
Wiring AC Input
The main bus voltage supply is brought to the Geo drive through connector TB1 on the backplane board.
If single phase is used, derrating needs to be calculated. It is acceptable to bring the single-phase power
into any two of the three input pins on connector TB1. Higher-power drive amplifiers require three-phase
input power. It is extremely important to provide fuse protection or overload protection to the input
power to the Geo drive amplifier. Typically, this is provided with fuses designed to be slow acting, such
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11
3U Servo Amplifier
as FRN-type fuses. Due to the various regulations of local codes, NEC codes, UL and CE requirements,
it is very important to reference these requirements before making a determination of how the input power
is wired.
Additionally, many systems require that the power be able to be turned on and off in the cabinet. It is
typical that the AC power is run through some kind of main control contact within the cabinet, through
the fuses, and then fed to a Geo drive. If multiple Geo drives are used, it is important that each drive has
its own separate fuse block.
Whether single- or three-phase, it is important that the AC input wires be twisted together to eliminate
noise radiation as much as possible. Additionally, some applications may have further agency noise
reduction requirements that require that these lines be fed from an input filtering network.
The AC connections from the fuse block to the Geo drive are made via a cable that is connected at the
backplane with screw terminals.
TB1: AC Input Connector Pin-out on the backplane
Pin #
Symbol
Function
1
2
3
L1
L2
L3
Input
Input
Input
Description
Notes
Line Input Phase 1
Line Input Phase 2
Line Input Phase 3
Not used for single phase input
3UBP8A, 300-603730-10x
If DC bus is used, use L3 for DC+ and L2 for DC return
Wiring Earth-Ground
Panel wiring requires that a central earth-ground location be installed at one part of the panel. This
electrical ground connection allows for each device within the enclosure to have a separate wire brought
back to the central wire location. Usually, the ground connection is a copper plate directly bonded to the
back panel or a copper strip with multiple screw locations. The Geo drive is brought to the earth-ground
via a wire connected to the stud on the front panel through a heavy gauge, multi-strand conductor to the
central earth-ground location.
Earth Grounding Paths
High-frequency noises from the PWM controlled power stage will find a path back to the drive. It is best
that the path for the high-frequency noises be controlled by careful installation practices. The major
failure in problematic installations is the failure to recognize that wire conductors have impedances at
high frequencies. What reads 0 ohms on a DVM may be hundreds of ohms at 30MHz. Consider the
following during installation planning:
1. Star point all ground connections. Each device wired to earth ground should have its own conductor
brought directly back to the central earth ground plate.
2. Use unpainted back panels. This allows a wide area of contact for all metallic surfaces reducing high
frequency impedances.
3. Conductors made up of many strands of fine conducts outperform solid or conductors with few
strands at high frequencies.
4. Motor cable shields should be bounded to the back panel using 360-degree clamps at the point they
enter or exit the panel.
5. Motor shields are best grounded at both ends of the cable. Again, connectors using 360-degree shield
clamps are superior to connector designs transporting the shield through a single pin. Always use
metal shells.
6. Running motor armature cables with any other cable in a tray or conduit should be avoided. These
cables can radiate high frequency noise and couple into other circuits.
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3U Servo Amplifier
Wiring 24 V Logic Control
An external 24VDC power supply is required to power the logic portion of the 3U Geo Direct PWM
drive. This power can remain on, regardless of the main AC input power, allowing the signal electronics
to be active while the main motor power control is inactive. The 24V is wired into connector J2 at the
3UBP8A backplane. The polarity of this connection is extremely important. Carefully follow the
instructions in the wiring diagram. This connection can be made using 16 AWG wire directly from a
protected power supply. In situations where the power supply is shared with other devices, it may be
desirable to insert a filter in this connection.
The power supply providing this 24V must be capable of providing an instantaneous current of at least
0.8A to be able to start the DC-to-DC converter in the 3U Geo Direct PWM drive. In the case where
multiple drives are driven from the same 24V supply, it is recommended that each drive be wired back to
the power supply terminals independently. It is also recommended that the power supply be sized to
handle the instantaneous inrush current required to start up the DC-to-DC converter in the Geo drive.
J2: 24VDC Input Logic Supply Connector
Pin #
Symbol
1
+24VDC
2
RET
Function
Description
Notes
Input
Control power input
24V+/-10% @ 1A
Common
Control power return
Connector is located at the backplane
3UBP8A, 300-603730-10x
Regen (Shunt) Resistor Wiring
The regen circuit is also known as a shunt regulator. Its purpose is to dump power fed back into the drive
from a motor acting as a generator. Excessive energy can be dumped via an external load resistor. The
Geo product series is designed for operation with external shunt resistors of 48 Ω for the 10A, 15A and
20A.These are available directly from Delta Tau as GAR48 and GAR78, respectively. These resistors are
provided with pre-terminated cables that plug into the connector at the backplane.
Caution:
The black wires are for the thermostat and the white wires are for the regen resistor
on the external regen resistor (pictured in Appendix). These resistors can get very
hot. It is recommended that they be mounted away from other devices and near the
top of the cabinet.
The regen resistors incorporate a thermal overload protection device available through the two black leads
exiting the resistor. It is important that these two leads be wired in a safety circuit that stops the system
from operating should the thermostat open.
TB2: Regen Resistor Connector
Pin #
1
2
Symbol
SHUNT RTN
SHUNT
Function
Description
Output
Regen Resistor output
Output
Regen Resistor Return
Connector is located at the backplane
3UBP8A, 300-603730-10x
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3U Servo Amplifier
Shunt Regulation
When the motor is used to slow the moving load, this is called regenerative deceleration. Under this
operation, the motor is acting as a generator consuming energy from the load while passing the energy
into the DC Bus storage capacitors. Left unchecked, the DC Bus voltage can raise high enough to
damage the drive. For this reason there are protection mechanisms built into the Geo Drive product such
as shunt regulation and over-voltage protection.
The shunt regulator monitors the DC Bus voltage. If this voltage rises above a present threshold (Regen
Turn On Voltage), the Geo Drive will turn on a power device intended to place the externally mounted
regen resistor across the bus to dump the excessive energy. The power device keeps the regen resistor
connected across the bus until the bus voltage is sensed to be below the Regen Turn Off voltage at which
time the power device removes the resistor connection.
Minimum Resistance Value
The regen resistor selection requires that the resistance value of the selected resistor will not allow more
current to flow through the Geo Drive’s power device than specified.
Maximum Resistance Value
The maximum resistor value that will be acceptable in an application is one that will not let the bus
voltage reach the drive’s stated over voltage specification during the deceleration ramp time. The
following equations defining energy transfer can be used to determine the maximum resistance value.
Energy Transfer Equations
Regen, or shunt, regulation analysis requires study of the energy transferred during the deceleration
profile. The basic philosophy can be described as follows:
• The motor and load have stored kinetic energy while in motion.
• The drive removes this energy during deceleration by transferring to the DC bus.
• There are losses during this transfer, both mechanical and electrical, which can be significant in some
systems.
• The DC bus capacitors can store some energy.
• The remaining energy, if any, is transferred to the regen resistor.
Kinetic Energy
The first step is to ascertain the amount of kinetic energy in the moving system, both the motor rotor and
the load it is driving. In metric (SI) units, the kinetic energy of a rotating mass is:
EK =
1
Jω 2
2
where:
EK is the kinetic energy in joules, or watt-seconds (J, W-s)
J is the rotary moment of inertia in kilogram-meter2 (kg-m2)
ω is the angular velocity of the inertia in radians per second (1/s)
If the values are not in these units, first convert them. For example, if the speed is in revolutions per
minute (rpm), multiply this value by 2π/60 to convert to radians per second.
When English mechanical units are used, there are additional conversion factors must be included to get
the energy result to come out in joules. For example, if the rotary moment of inertia J is expressed in lbft-sec2, the following equation should be used:
E K = 0.678 Jω 2
If the rotary moment of inertia J is expressed in lb-in-sec2, the following equation should be used:
E K = 0.0565 Jω 2
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3U Servo Amplifier
In standard metric (SI) units, the kinetic energy of a linearly moving mass is:
EK =
1
mv 2
2
where:
EK is the kinetic energy in joules (J)
m is the mass in kilograms (kg)
v is the linear velocity of the mass in meters/second (m/s)
Here also, to get energy in Joules from English mechanical units, additional conversion factors are
required. To calculate the kinetic energy of a mass having a weight of W pounds, the following equation
can be used:
E K = 0.678
W 2
v = 0.0211Wv 2
g
where:
EK is the kinetic energy in joules (J)
W is the weight of the moving mass in pounds (lb)
g is the acceleration of gravity (32.2 ft/sec2)
v is the linear velocity of the mass in feet per second (ft/sec)
Energy Lost in Transformation
Some energy will be lost in the transformation from mechanical kinetic energy to electrical energy. The
losses will be both mechanical due to friction and electrical due to resistance. In most cases, these losses
will comprise a small percentage of the transformed energy and can be safely ignored especially because
ignoring losses leads to a conservative design. However, if the losses are significant and the system
should not be over-designed, calculate these losses.
In metric (SI) units, the mechanical energy lost due to Coulomb (dry) friction in a constant deceleration to
stop of a rotary system can be expressed as:
E LM =
1
T ωt
2 f d
where:
ELM is the lost energy in joules (J)
Tf is the resistive torque due to Coulomb friction in newton-meters (N-m)
ω is the starting angular velocity of the inertia in radians per second (1/s)
td is the deceleration time in seconds (s)
If the frictional torque is expressed in the common English unit of pound-feet (lb-ft), the comparable
expression is:
E LM = 0.678T f ωt d
In metric (SI) units, the mechanical energy lost due to Coulomb (dry) friction in a constant deceleration to
stop of a linear system can be expressed as:
E LM =
1
F vt
2 f d
where:
ELM is the lost energy in joules (J)
Tf is the resistive force due to Coulomb friction in newtons (N)
v is the starting linear velocity in meters/second (m/s)
td is the deceleration time in seconds (s)
If the frictional force is expressed in the English unit of pounds (lb) and the velocity in feet per second
(ft/sec), the comparable expression is:
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3U Servo Amplifier
E LM = 0.678 F f vt d
The electrical resistive losses in a 3-phase motor in a constant deceleration to stop can be calculated as:
E LE =
3 2
i rms R pp t d
2
where:
ELE is the lost energy in joules (J)
irms is the current required for the deceleration in amperes (A), equal to the required deceleration torque
divided by the motor’s (rms) torque constant KT
Rpp is the phase-to-phase resistance of the motor, in ohms (Ω)
td is the deceleration time in seconds (s)
Capacitive Stored Energy in the Drive
The energy not lost during the transformation is initially stored as additional capacitive energy due to the
increased DC bus voltage. The energy storage capability of the drive can be expressed as:
EC =
(
1
2
2
C V regen
− V nom
2
)
where:
EC is the additional energy storage capacity in joules (J)
C is the total bus capacitance in Farads
Vregen is the DC bus voltage at which the regeneration circuit would have to activate, in volts (V)
Vnom is the normal DC bus voltage, in volts (V)
Evaluating the Need for a Regen Resistor
Any starting kinetic energy that is not lost in the transformation and cannot be stored as bus capacitive
energy must be dumped by the regeneration circuitry in to the regen (shunt) resistor. The following
equation can be used to determine whether this will be required:
E excess = E K − E LM − E LE − E C
If Eexcess in this equation is greater than 0, a regen resistor will be required.
Regen Resistor Power Capacity
A given regen resistor will have both a peak (instantaneous) and a continuous (average) power dissipation
limit. It is therefore necessary to compare the required peak and continuous regen power dissipation
requirements against the limits for the resistor.
The peak power dissipation that will occur in the regen resistor in the application will be:
P peak =
2
V regen
R
where:
Ppeak is peak power dissipation in watts (W)
Vregen is the DC bus voltage at which the regeneration circuit activates, in volts (V)
R is the resistance value of the regen resistor, in ohms (Ω)
However, this power dissipation will not be occurring all of the time, and in most applications, only for a
small percentage of the time. Usually, the regen will only be active during the final part of a lengthy
deceleration, after the DC bus has charged up to the point where it exceeds the regen activation voltage.
The average power dissipation value can be calculated as:
Pavg = P peak
%on − time
100
where:
Pavg is average power dissipation in watts (W)
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3U Servo Amplifier
%on-time is the percentage of time the regen circuit is active
Note:
The Turn On voltage for the shunt circuitry for all Geo drives is 388.5V. There is
a Hysteresis of 20V, so if the regen turns on @ 388.5V it will not turn off until it
drops to 367.5V.
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3U Servo Amplifier
Bonding
The proper bonding of shielded cables is imperative for minimizing noise emissions and increasing immunity
levels. The bonding effect is to reduce the impedance between the cable shield and the back panel.
Power input wiring does not require shielding (screening) if the power is fed to the enclosure via metal
conduit. If metal conduit is not used in the system, shielded cable is required on the power input wires
along with proper bonding techniques.
Filtering
CE Filtering
Apply proper bonding and grounding techniques, described earlier in this section, when incorporating
EMC noise filtering components to meet this standard.
Noise currents often occur in two ways. The first is conducted emissions passed through ground loops.
The quality of the system-grounding scheme inversely determines the noise amplitudes in the lines.
These conducted emissions are of a common-mode nature from line-to-neutral (ground). The second is
radiated high-frequency emissions that usually are capacitively coupled from line-to-line and are
differential in nature.
When mounting the filters, make sure the enclosure has an unpainted metallic surface. This allows more
surface area to be in contact with the filter housing and provides a lower impedance path between the
housing and the back plane. The back panel should have a high frequency ground strap connection to the
enclosure frame and earth ground.
Input Power Filtering
Caution:
To avoid electric shock, do not touch filters for at least 10 seconds after removing the
power supply.
The Geo Drive electronic system components require EMI filtering in the input power leads to meet the
conducted emission requirements for the industrial environment. This filtering blocks conducted-type
emissions from exiting onto the power lines and provides a barrier for power line EMI.
Adequately size the system. The type of filter must be based on the voltage and current rating of the
system and whether the incoming line is single or three-phase. One input line filter may be used for
multi-axis control applications. These filters should be mounted as close to the incoming power as
possible so noise is not capacitively coupled into other signal leads and cables. Implement the EMI filter
according to the following guidelines:
• Mount the filter as close as possible to the incoming cabinet power.
• When mounting the filter to the panel, remove any paint or material covering. Use an unpainted
metallic back panel.
• Filters are provided with a ground connection. All ground connections should be tied to ground.
• Filters can produce high leakage currents; they must be grounded before connecting the supply.
• Do not touch filters for a period of ten seconds after removing the power supply.
Motor Line Filtering
Motor filtering may not be necessary for CE compliance of Geo Drives. However, this additional
filtering increases the reliability of the system. Poor non-metallic enclosure surfaces and lengthy,
unbonded (or unshielded) motor cables that couple noise line-to-line (differential) are some of the factors
that may lead to the necessity of motor lead filtering.
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3U Servo Amplifier
Motor lead noise is either common-mode or differential. The common-mode conducted currents occur
between each motor lead and ground (line-to-neutral). Differential radiated currents exist from one motor
lead to another (line-to-line). The filtering of the lines feeding the motor provides additional attenuation
of noise currents that may enter surrounding cables and equipment I/O ports in close proximity.
Differential mode currents commonly occur with lengthy motor cables. As the cable length increases, so
does its capacitance and ability to couple noise from line-to-line. While every final system is different
and every application of the product causes a slightly different emission profile, it may become necessary
to use differential mode chokes to provide additional noise attenuation to minimize the radiated
emissions. The use of a ferrite core placed at the Geo Drive end on each motor lead attenuates differential
mode noise and lowers frequency (30 to 60 MHz) broadband emissions to within specifications. Delta
Tau recommends a Fair-Rite P/N 263665702 (or equivalent) ferrite core.
Common mode currents occur from noise spikes created by the PWM switching frequency of the Geo
Drive. The use of a ferrite or iron-powder core toroid places common mode impedance in the line
between the motor and the Geo Drive. The use of a common mode choke on the motor leads may
increase signal integrity of encoder outputs and associated I/O signals.
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3U Servo Amplifier
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3U Servo Amplifier
3U DRIVE CONNECTIONS
PWM Input Connector
Axis #1 PWM input connector
P1 (36-pin Mini-D Connector)
Pin #
Symbol
Function
Description
Notes
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
FC0
Feedback
1 of 4 fault code bits
FC2
Feedback
1 of 4 fault code bits
ADC_CLK1+
Command
A/D converter clock
ADC_STB1+
Command
A/D converter strobe
CURRENTA+
Feedback
Phase A actual current data
Serial digital
CURRENTB+
Feedback
Phase B actual current data
Serial digital
AENA1+
Command
Amplifier enable
High is enable
FAULT1+
Feedback
Amplifier fault
High is fault
PWMATOP1+
Command
Phase A top Cmd
High is on command
PWMABOT1+
Command
Phase A bottom Cmd
High is on command
PWMBTOP1+
Command
Phase B top Cmd
High is on command
PWMBBOT1+
Command
Phase B bottom Cmd
High is on command
PWMCTOP1+
Command
Phase C top Cmd
High is on command
PWMCBOT1+
Command
Phase C bottom Cmd
High is on command
GND
Common
Reference voltage
+5V
Power
+5v power
From controller
Reserved
Reserved
FC1
Feedback
1 of 4 fault code bits
FC3
Feedback
1 of 4 fault code bits
ADC_CLK1Command
A/D converter clock
ADC_STB1Command
A/D converter strobe
CURRENTAFeedback
Phase A actual current data
Serial digital
CURRENTBFeedback
Phase B actual current data
Serial digital
24
25
AENA1Command
Amplifier enable
Low is enable
26
FAULT1Feedback
Amplifier fault
Low is fault
27
PWMATOP1Command
Phase A top Cmd
Low is on command
28
PWMABOT1Command
Phase A bottom Cmd
Low is on command
29
PWMBTOP1Command
Phase B top Cmd
Low is on command
30
PWMBBOT1Command
Phase B bottom Cmd
Low is on command
31
PWMCTOP1Command
Phase C top Cmd
Low is on command
32
PWMCBOT1Command
Phase C bottom Cmd
Low is on command
33
GND
Common
Reference voltage
34
+5V
Power
+5v power
From controller
35
Reserved
36
Reserved
A Mini-D 36-pin connector for first digital amplifier command outputs and current feedbacks. This
connector provides the interface to a fully digital amplifier for the first channel.
Note that current feedback data must be in serial digital form, already converted from analog in the
amplifier.
For Cables see Appendix A
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3U Servo Amplifier
Axis #2 PWM Input connector
P2 (36-pin Mini-D Connector)
Pin #
Symbol
Function
Description
Notes
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
FC0
Feedback
1 of 4 fault code bits
FC2
Feedback
1 of 4 fault code bits
ADC_CLK2+
Command
A/D converter clock
ADC_STB2+
Command
A/D converter strobe
CURRENTA+
Feedback
Phase A actual current data
Serial digital
CURRENTB+
Feedback
Phase B actual current data
Serial digital
AENA2+
Command
Amplifier enable
High is enable
FAULT2+
Feedback
Amplifier fault
High is fault
PWMATOP2+
Command
Phase A top Cmd
High is on command
PWMABOT2+
Command
Phase A bottom Cmd
High is on command
PWMBTOP2+
Command
Phase B top Cmd
High is on command
PWMBBOT2+
Command
Phase B bottom Cmd
High is on command
PWMCTOP2+
Command
Phase C top Cmd
High is on command
PWMCBOT2+
Command
Phase C bottom Cmd
High is on command
GND
Common
Reference voltage
+5V
Power
+5v power
From controller
Reserved
Reserved
FC1
Feedback
1 of 4 fault code bits
FC3
Feedback
1 of 4 fault code bits
ADC_CLK2Command
A/D converter clock
ADC_STB2Command
A/D converter strobe
CURRENTAFeedback
Phase A actual current data
Serial digital
CURRENTBFeedback
Phase B actual current data
Serial digital
24
25
AENA2Command
Amplifier enable
Low is enable
26
FAULT2Feedback
Amplifier fault
Low is fault
27
PWMATOP2Command
Phase A top Cmd
Low is on command
28
PWMABOT2Command
Phase A bottom Cmd
Low is on command
29
PWMBTOP2Command
Phase B top Cmd
Low is on command
30
PWMBBOT2Command
Phase B bottom Cmd
Low is on command
31
PWMCTOP2Command
Phase C top Cmd
Low is on command
32
PWMCBOT2Command
Phase C bottom Cmd
Low is on command
33
GND
Common
Reference voltage
34
+5V
Power
+5v power
From controller
35
Reserved
36
Reserved
A Mini-D 36-pin connector for first digital amplifier command outputs and current feedbacks. This
connector provides the interface to a fully digital amplifier for the first channel.
Note that current feedback data must be in serial digital form, already converted from analog in the
amplifier.
Note:
The dual axis unit, 3U042, has two jumpers on the logic board (603728-10x
/bottom board). If these Jumpers are ON then the shield of the PWM cable
connects directly to the GND, if the jumper is OFF (default) there is a 0.1mfd
capacitor in the way to the GND. These jumpers are E2 and E3, for channels #1
and #2 respectively. For revisions -104 and above.
Backplane Board
22
3U Servo Amplifier
Motor Output Connector
The cable wiring must be shielded and have a separate conductor connecting the motor frame back to the
drive amplifier. The cables are available in cable kits (CABKIT3C) from Delta Tau. (See Appendix A.)
Motor phases are conversed in one of three conventions. Motor manufacturers will call the motor phases
A, B, or C. Other motor manufacturers call them U, V, W. Induction motor manufacturers may call them
L1, L2, and L3. The drive’s inputs are called U, V, and W. Wire U, A, or L1 to the drive’s U terminal.
Wire V, B, or L2 to the drive’s V terminal. Wire W, C, or L3 to the drive’s W terminal.
The motor’s frame drain wire and the motor cable shield must be tied together at the mounting stud (5mm
thread) on the front of the Geo drive product.
Motor #1 Output Connector Pin-out
Pin #
Symbol
Function
Description
1
U
Output
Phase1 Axis 1
Notes
2
V
Output
Phase2 Axis 1
3
W
Output
Phase3 Axis 1
Rake : Connect to motor frame and cable drain, Chassis Ground
CONKIT3C
CABKIT3C
Motor #2 Output Connector Pin-out
Pin #
Symbol
Function
Description
1
U
Output
Phase1 Axis 1
Notes
2
V
Output
Phase2 Axis 1
3
W
Output
Phase3 Axis 1
Rake : Connect to motor frame and cable drain, Chassis Ground
CONKIT3C
CABKIT3C
Backplane Board
23
3U Servo Amplifier
Wiring the Motor Thermostats
Some motor manufacturers provide the motors with integrated thermostat overload detection capability.
Typically, it is in one or two forms: a contact switch that is normally closed or a PTC. These sensors can
be wired into the Geo drive's front panel MTR TEMPERATURE SWITCH. Motor 1 thermostat is wired
to MTR1 PTC RET and MTR1 PTC. And Motor 2 thermostat can be wired to MTR2 PTC RET and
MTR2 PTC. These contacts have to be low impedance for the drive to be operational.
If the motor overload protection is not required, these pins (MTR1 PTC and MTR1 PTC RET, MTR2
PTC and MTR2 PTC RET) should have the jumpers ON (default) so as to disable this function in the
drive. Otherwise, the drive status display will show immediately an error code “1E6” for motor #1 over
temperature or a “2E6” for motor #2 over temperature.
When the motor over temperature error code is tripped, the drive will immediately write a value of “06”
at the ADC A register for the axis on the PMAC, bits 11:4. It is recommended that the user writes a
special PLC, so as to react accordingly to this error code. After 60 seconds in this condition, the amplifier
will fault and motion will stop. The seven-segment display will change the fault code from “1E6” or
“2E6” to “1F6” for motor #1 and “2F6” for motor #2.
Motor Temperature Switch
Pin
Symbol
Function
1
2
MTR1_PTC
MTR1_PTC_RETURN
Input
Input
If motor does not have overtemp sensor output
must jump pin 1 to pin 2 (as sent from factory)
3
4
MTR2_PTC
MTR2_PTC_RETURN
Input
Input
If motor does not have overtemp sensor output
must jump pin 3 to pin 4 (as sent from factory)
Note: If the input is not used, then a regular jumper can be used.
4-pin Molex Connector .100 spacing, 22-28AWG
DeltaTau p/n: 200-000R04-LHM
MOLEX p/n: 22-01-3047(housing), 08-50-0114(pins)
Backplane Board
24
3U Servo Amplifier
GEO 3U PWM BACKPLANE CONNECTIONS
3UBP8A, 300-603730-10x
J1
1
2
3
4
5
6
7
J3
8
F AN
9
RET
J2
L3
+ 24V
L2
10
L1
11
SHUNT TB2
RET
SHUNT
TB1
EART H
J1: 3U Geo Drive backplane slot
J1: Connector
Pin
1
2
3
4
5
6
7
8
9
10
11
Backplane Board
Description
BUS+/ Shunt+
BUS+/ Shunt+
SHUNT RTN
BUSBUS+24V RTN
+24V
L3 3 phace AC input
L2 3 phace AC input
L1 3 phace AC input
GND
25
3U Servo Amplifier
J2: 24V Input Molex Connector
J2: 24V Input Molex Connector .200 spacing, 22-30AWG
Pin
Description
1
+24VDC @ 1A
2
24V RETURN (GND)
DeltaTau p/n: 200-C30F02-LHM
MOLEX p/n: 10-01-3026(housing), 08-70-1028(pins)
J3: FAN output Molex Connector
J3: Fan Molex Connector .100 spacing, 22-28AWG
Pin
Description
1
Fan+ (+24V)
2
Fan RTN (GND)
DeltaTau p/n: 200-00F002-HSG
MOLEX p/n: 10-11-2023 (housing), 08-50-0114(pins)
TB1: AC input Power and Regen Resistor Connector
TB1 – 3 Position Screw Terminal Block
Pin
Description
1
2
3
Line Input Phase 1
Line Input Phase 2
Line Input Phase 3
TB2: Regen Resistor Connector
TB2 – 2 Position Screw Terminal Block
Pin
Description
1
2
Backplane Board
SHUNT
SHUNT RTN
26
3U Servo Amplifier
Backplane Board
27
3U Servo Amplifier
DIRECT PWM COMMUTATION CONTROLLER SETUP
The 3U amplifier must have the proper controller setup to command the amplifier/motor system. This
section summarizes the key variables of both Turbo and Non Turbo PMAC2 controllers that would have
to be modified for use with the amplifier. The Delta Tau setup software such as Turbo Setup will help set
these parameters for the system automatically. For details about direct commutation of brushless and
induction motors, read the PMAC2 or Turbo PMAC2 User Manual. To find out the details about these
variables, refer to the PMAC2 or Turbo PMAC2 Software Reference Manual.
Key Servo IC Variables
Non-Turbo
Turbo
Type
Description
I900
I901
I7m00
Clock
Max phase clock setting
I7m01
Clock Divisor
Phase clock divisor
I7m02
Clock Divisor
Servo clock divisor
I902
I903
I7m03
Clock
Hardware clock settings
I904
I7m04
Clock
PWM dead time
I905
I7m05
Strobe
DAC strobe word
*
I7m06
Strobe
ADC strobe word (Must be set to $3FFFFF for Geo drives.)
I9n0
I7mn0
Channel
Encoder decode for channel
I9n6
I7mn6
Channel
Output mode for channel (Must be set to 0.)
* To change the ADC strobe word for a non-Turbo PMAC2 controller, issue a write command directly to the
memory location of the Gate array channel connected to the amplifier, I7m06. For non-Turbo PMAC2 channel
1-4, use memory location X:$C014. For non-Turbo PMAC2 channel 5-8, use memory location X:$C024.
For example: WX:$C014,$3FFFFF or I7006=$3FFFFF for Turbo.
Key Motor Variables
Caution:
The ADC Strobe Word, X:$C014 (non-Turbo) or I7m06 (Turbo), must be set to
$3FFFFF for proper operation. Failure to set I7m06 equal to $3FFFFF could result in
damage to the amplifier.
Non-Turbo
Turbo
Type
Ix00
Ix01
Ix25
Ix70
Ix71
Ix72
Ix77
Ix78
Ix83
Ix61
Ix62
Ix66
Ix76
Ix82
Ix84
Ix57
Ixx00
Ixx01
Ixx24 Ixx25
Ixx70
Ixx71
Ixx72
Ixx77
Ixx78
Ixx83
Ix61
Ix62
Ix66
Ix76
Ix82
Ix84
Ixx57
Ixx58
General
General
General
Commutation
Commutation
Commutation
Commutation
Commutation
Commutation
Current Loop
Current Loop
Current Loop
Current Loop
Current Loop
Current Loop
I2T
I2T
Ix58
Controller Setup
Description
Motor enable
Commutation enable
Motor flag setup
Number of commutation cycles per Ix71
Counts per commutation cycle per Ix70
Commutation phase angle
Induction motor magnization current
Induction motor slip gain
On-going phase position
Current loop integrator gain
Current loop forward path proportional gain
PWM scale factor
Current loop back bath proportional gain
Current loop feedback address
Current loop feedback ADC mask word
Continuous limit for I2T
Integrated current limit
28
3U Servo Amplifier
DC BRUSH MOTOR DRIVE SETUP WITH NON-TURBO PMAC
It is possible to use PMAC2’s direct PWM and digital current loop for control of DC brush motors, both
those with permanent-magnet fields, and those with wound fields. Because PMAC2’s digital current loop
and commutation algorithms are combined, it is necessary to activate PMAC2’s commutation algorithm
for the motor, even though it is not commutating the motor.
The sine-wave commutation is effectively disabled in this technique by telling PMAC2 that the motor has
a commutation cycle of 1 count. Each of the counts received causes a 360oe phase increment, leaving the
phase angle constant at all times for DC control. With the phase angle always at zero, PMAC2’s
quadrature, or torque-producing, output voltage and feedback current are always equivalent to the motor’s
rotor, or armature, voltage and current. PMAC2’s direct, or magnetization field, voltage and current are
always equivalent to the motor’s stator, or wound field, voltage and current (if any).
Hardware Connection
In this technique, the rotor (armature) current is commanded by PMAC2 phases A and C. The motor
armature leads should be connected between the two half-bridges of the amplifier driven by PMAC2
phases A and C, together forming a full H-bridge.
The armature current sensor should feed an A/D converter that is connected to one of the serial ADC
inputs for the channel on PMAC2. If there is a wound field, the armature current reading must be fed into
ADC A and the field current reading must be fed into ADC B.
If there is a permanent magnet field only, the armature current reading can be fed into either ADC A or
ADC B, with Ix82 telling PMAC2 which one is used. If ADC A is used, the serial digital input for ADC
B (+signal only) should be tied to GND so a zero feedback value is forced (alternately a background PLC
can zero the direct current integrator register periodically). If ADC B is used, then PMAC uses the
Compare A read/write register for the (non-existent) direct current feedback; in this case, a zero value
should be written into this register on power-on/reset, and no other value should be written to it during the
application.
If there is a wound field, it must be commanded from PMAC2’s B phase, and the current feedback must
be brought back into PMAC2’s B-phase. If only uni-directional voltage and current are required for the
field, the field windings can be commanded from a single half-bridge. If bi-directional voltage or current
is required, a full H-bridge must be used, with PMAC2’s B-phase commanding the two half bridges in
anti-phase mode (also the command for the top of one half is used for the bottom of the other half).
I-Variable Setup
To set up a motor for this technique, the following I-variable settings must be made:
•
Ix00 = 1 to activate the motor
•
Ix01 = 1 to activate commutation algorithms
•
Ix02 should contain the address of the PWM A register for the output channel used (this is the
default), just as for brushless motors
•
Ix70 = 4, Ix71 = 4: This defines a commutation cycle size of 4/4 = 1 count. The use of 4/4 instead of
1/1 allows us to rotate the angle +90o for test and tuning purposes.
•
Ix72 = 64 or 192 for 1/4 or 3/4 cycle between the armature (rotor) and field (stator). If a positive
voltage output number creates a negative current feedback number, use 64; otherwise use 192.
•
Ix73 = 0, Ix74 = 0: No power-on phase search will be required
•
Ix75 = 0: Zero offset in the power-on phase reference
•
Ix77 = 0 for motors without wound field. With a wound field, Ix77 determines the strength of the
field; with field weakening functionality, Ix77 will be a function of motor speed.
Controller Setup
29
3U Servo Amplifier
•
•
•
•
•
•
•
Ix78 = 0 for zero slip in the commutation calculations
Ix81 = $80770: This tells PMAC2 to read the low 8 bits of Y:$0770 for the power-on phase position.
This register is forced to zero on power-on/reset, so this setting forces the phase position to zero.
Ix82 should contain the address of ADC B register for the feedback channel used (just as for
brushless motors) when the ADC A register is used for the rotor (armature) current feedback. If there
is a wound field, the stator field current feedback should be connected to ADC B. If there is a
permanent magnet field, there will be no feedback to ADC B.
Ix82 should contain the address one greater than that of the ADC B register for the feedback channel
used when the ADC B register is used for the rotor (armature) current feedback. This is suitable for
motors with only a permanent magnet field.
Ix83 does not really matter here, because the commutation position is defeated by the single-count
cycle size. However, it is fine to use the default value.
Ix84 is set just as for brushless motors, specifying which bits the current ADC feedback uses.
Ix61, Ix62, and Ix76 current loop gains are set just as for brushless motors.
Controller Setup
30
3U Servo Amplifier
DC BRUSH MOTOR DRIVE SETUP WITH TURBO PMAC
Commutation Phase Angle: Ixx72
Ixx72 controls the angular relationship between the phases of a multiphase motor. When Turbo PMAC is
closing the current loop digitally for Motor xx, the proper setting of this variable is dependent on the
polarity of the current measurements.
If the phase current sensors and ADCs in the amplifier are set up so that a positive PWM voltage
command for a phase yields a negative current measurement value, Ixx72 must be set to a value less than
1024: 683 for a 3-phase motor, or 512 for a DC brush motor. If these are set up so that a positive PWM
voltage command yields a positive current measurement value, Ixx72 must be set to a value greater than
1024: 1365 for a 3-phase motor, or 1536 for a DC brush motor. The testing described below shows how
to determine the proper polarity.
The direct-PWM algorithms in the Turbo PMAC are optimized for 3-phase motors and will cause
significant torque ripple when used with 2- or 4-phase motors. Delta Tau has created user-written phase
algorithms for these motors; contact the factory if interested in obtaining these.
Note:
It is important to set the value of Ixx72 properly for the system. Otherwise, the
current loop will have unstable positive feedback and want to saturate. This could
cause damage to the motor, the drive, or both, if over current shutdown features do
not work properly. If unsure of the current measurement polarity in the drive,
consult the Testing PWM and Current Feedback Operation section of this manual.
For commutation with digital current loops, the proper setting of Ixx72 is unrelated to the polarity of the
encoder counter. This is different from commutation with an analog current loops (sine-wave control), in
which the polarity of Ixx72 (less than or greater than 1024) must match the encoder counter polarity.
With the digital current loop, the polarity of the encoder counter must be set for proper servo operation;
with the analog current loop, once the Ixx72 polarity match has been made for commutation, the servo
loop polarity match is guaranteed.
Special Instructions for Direct-PWM Control of Brush Motors
Special settings are needed to use the direct-PWM algorithms for DC brush motors. The basic idea is to
trick the commutation algorithm into thinking that the commutation angle is always stuck at 0 degrees, so
current into the A phase is always quadrature (torque-producing) current. These instructions assume:
• The brush motor’s rotor field comes from permanent magnets or a wound field excited by a separate
means; the field is not controlled by one of the phases of this channel.
• The two leads of the brush motor’s armature are connected to amplifier phases (half-bridges) that are
driven by the A and C-phase PWM commands from Turbo PMAC. The amplifier may have an
unused B-phase half-bridge, but this does not need to be present.
The following settings are the same as for permanent-magnet brushless servo motors with an absolute
phase reference:
• Ixx01 = 1 (commutation directly on Turbo PMAC) or Ixx01=3 (commutation over the MACRO ring)
• Ixx02 should contain the address of the PWM A register for the output channel used or the MACRO
Node register 0 (these are the defaults), just as for brushless motors.
• Ixx29 and Ixx79 phase offset parameters should be set to minimize measurement offsets from the A
and B-phase current feedback circuits, respectively.
• Ixx61, Ixx62, and Ixx76 current loop gains are set just as for brushless motors.
Controller Setup
31
3U Servo Amplifier
•
Ixx73 = 0, Ixx74 = 0: These default settings ensure that Turbo PMAC will not try to do a phasing
search move for the motor. A failed search could keep Turbo PMAC from enabling this motor.
• Ixx77 = 0 to command zero direct (field) current.
• Ixx78 = 0 for zero slip in the commutation calculations.
• Ixx82 should contain the address of ADC B register for the feedback channel used (just as for
brushless motors) when the ADC A register is used for the rotor (armature) current feedback. The B
register itself should always contain a zero or near-zero value.
• Ixx81 > 0: Any non-zero setting here makes Turbo PMAC do a “phasing read” instead of a search
move for the motor. This is a dummy read, because whatever is read is forced to zero degrees by the
settings of Ixx70 and Ixx71, but Turbo PMAC demands that some sort of phase reference be done.
(Ixx81=1 is fine.)
• Ixx84 is set just as for brushless motors, specifying which bits the current ADC feedback uses.
Usually, this is $FFF000 to specify the high 12 bits.
Special settings for brush motor direct PWM control:
• Ixx70 = 0: This causes all values for the commutation cycle to be multiplied by 0 to defeat the
rotation of the commutation vector.
• Ixx72 = 512 (90oe) if voltage and current numerical polarities are opposite, 1536 (270oe) if they are
the same. If the amplifier would use 683 (120oe) for a 3-phase motor, use 512 here; if it would use
1365 (240oe) for a 3-phase motor, use 1536 here.
• Ixx96 = 1: This causes Turbo PMAC to clear the integrator periodically for the (non-existent) direct
current loop, which could slowly charge up due to noise or numerical errors and eventually interfere
with the real quadrature current loop.
Settings that do not matter:
• Ixx71 (commutation cycle size) does not matter because Ixx70 setting of 0 defeats the commutation
cycle
• Ixx75 (Offset in the power-on phase reference) does not matter because commutation cycle has been
defeated. Leaving this at the default of 0 is fine.
• Ixx83 (ongoing commutation position feedback address) doesn’t matter, since the commutation has
been defeated. Leaving this at the default value is fine.
• Ixx91 (power-on phase position format) does not matter, because whatever is read for the power-on
phase position is reduced to zero.
Testing PWM and Current Feedback Operation
WARNING:
On many motor and drive systems, potentially deadly voltage and current levels
are present. Do not attempt to work directly with these high voltage and current
levels unless fully trained on all necessary safety procedures. Low-level signals on
Turbo PMAC and interface boards can be accessed much more safely.
Most of the time in setting up a direct PWM interface, there is no need to execute all of the steps listed in
these sections (or the Turbo Setup program will do them automatically). However, the first time this type
of interface is setup, or there are problems, these steps will be of assistance.
For safety reasons, all of these tests should be done with the motor disconnected from any loads. All
settings made as a result of these tests are independent of load properties, so will still be valid when the
load is connected.
Controller Setup
32
3U Servo Amplifier
Before testing any of Turbo PMAC’s software features for digital current loop and direct PWM interface,
it is important to know whether the hardware interface is working properly. PMAC’s M-Variables are
used to access the input and output registers directly. The examples shown here use the suggested MVariable definitions for Motor 1.
Purpose
The purpose of these tests is to confirm the basic operation of the hardware circuits on PMAC, in the
drive, and in the motor, and to check the proper interrelationships. Specifically:
• Confirm operation of encoder inputs and decode
• Confirm operation of PWM outputs
• Confirm operation of ADC inputs
• Confirm correlation between PWM outputs and ADC inputs
• Determine proper current loop polarity
• Confirm commutation cycle size
• Determine proper commutation polarity
Preparation
First, define the M-Variables for the encoder counter, the three PWM output registers, the amplifierenable output bit, and the two ADC input registers. Using the suggested definitions for Motor 1, utilizing
Servo IC 0, Channel 1:
M101->X:$078001,0,24,S
M102->Y:$078002,8,16,S
M104->Y:$078003,8,16,S
M107->Y:$078004,8,16,S
M105->Y:$078005,8,16,S
M106->Y:$078006,8,16,S
M114->X:$078005,14
;
;
;
;
;
;
;
Channel
Channel
Channel
Channel
Channel
Channel
Channel
1
1
1
1
1
1
1
Encoder position register
PWM Phase A command value
PWM Phase B command value
PWM Phase C command value
Phase A ADC input value
Phase B ADC input value
Amp Enable command bit
Note:
The ADC values are declared as 16-bit variables even though typically, 12-bit
ADCs are used; this puts the scaling of the variable in the same units as Ixx69,
Ixx57, Ixx29, and Ixx79.
It is useful to monitor these values in the Watch window of the Executive program. Therefore, add the
variable names to the Watch window which causes the program to repeatedly query Turbo PMAC for the
values and display them. Then the hardware can be exercised with on-line commands issued through the
Terminal window.
To prepare Turbo PMAC for these tests:
1. Set I100 to 0 to deactivate the motor.
2. Set I101 to 0 to disable commutation (This allows for manual use of these registers.)
3. Make sure that I7000, I7004, I7016, and I7017 are set up properly to provide the PWM signals desired.
4. If the Amplifier Enable bit is 1, set it to zero with the command M114=0.
5. Set Ixx00 and Ixx01 for all other motors to zero.
Controller Setup
33
3U Servo Amplifier
Position Feedback and Polarity Test
If the PWM command values observed in the Watch window are not zero, set them to zero with the
command:
M102=0 M104=0 M107=0
The motor can be turned (or pushed) freely by hand now. As the motor is turned, monitor the M101 value
in the Watch window. Look for the following:
• It should change as the motor is moved.
• It should count up in one direction, and count down in the other direction.
• It should provide the expected number of counts in one revolution or linear distance increment.
• As the motor is returned repeatedly to a reference position, it should report (approximately) the same
position value each time.
If these things do not happen, check the encoder/resolver operation, its connection to Turbo PMAC and
the Turbo PMAC decode variable I7mn0. Double-check that the sensor is powered. In addition, look at
the encoder waveforms with an oscilloscope.
If the direction of motion to be the positive direction is known, check this here. If the direction is
incorrect, invert it by changing I7mn0, usually from 7 to 3, or from 3 to 7. If the direction is not known,
change it later, but make another change at that time to maintain the proper commutation polarity match;
usually by exchanging two of the motor phase leads at the drive.
Note:
Because I100 has been set to 0, and I103 may not yet have been set properly, any
change of position will not be reflected in the motor position window.
PWM Output and ADC Input Connection
WARNING:
Make sure before applying any PWM commands to the drive and motor in this
fashion that the resulting current levels are within the continuous current rating of
both drive and motor.
First, enable the amp, then apply a very small positive command value to Phase A and a very small
negative command value to Phase B with the on-line commands:
M114=1
; Enable amplifier
M102=I7000/50 M104=-I7000/50 M107=0 ; A pos, B neg, C zero
This provides a command at 2% of full voltage into the motor; this should be well within the continuous
current rating of both drive and motor. It is a good idea to make the sum of these commands equal to zero
so as not to put a net DC voltage on the motor; putting all three commands on one line causes the changes
to happen virtually instantaneously.
With power applied to the drive and the amplifier enabled (M114=1), current readings should be received
in the ADC registers as shown by the M-Variables M105 and M106 in the Watch window.
Since the M-Variables are defined as +/-32,768 for full current range, which should correspond
approximately to the instantaneous current limit. Make sure that the value read does not exceed the
continuous current limit, usually which is about 1/3 of the instantaneous limit. If well below the
continuous current limit, increase the voltage command to 5% to 10% of maximum. For example:
M102=I7000/10 M104=-I7000/10 M107=0 ; 10% of maximum
Controller Setup
34
3U Servo Amplifier
PWM/ADC Phase Match
Command values from Turbo PMAC’s Phase A PWM outputs should cause a roughly proportionate
response of one sign or the other on Turbo PMAC’s Phase A ADC input (whatever the phase is named in
the motor and drive). The same is true for Phase B.
If no response is received on either phase, re-check the entire setup, including:
• Is the drive properly wired to Turbo PMAC, either directly or through an interface board?
• Is the motor properly connected to the drive?
• Is the drive properly powered, both the power stage, and the input stage?
• Is the interface board properly powered?
• Is the amplifier enabled (M114=1 on Turbo PMAC and indicator ON at the drive)?
• Is the amplifier in fault condition? If so, why?
If only an ADC response is received on one phase, the phase outputs and inputs may not be matched
properly. For example, the Phase B ADC may be reading current from the phase commanded by the
Phase C PWM output. Confirm this by trying other combinations of commands and checking which
ADC responds to which phase command. If there is not a proper match, change the wiring between
Turbo PMAC and the drive. Changing the wiring between drive and motor will not help here.
Synchronous Motor Stepper Action
With a synchronous motor, this command should cause the motor to lock into a position, at least weakly,
like a stepper motor. This action may be received temporarily on an induction motor, due to temporary
eddy currents created in the rotor. However, an induction motor will not keep a holding torque
indefinitely at the new location.
Current Loop Polarity Check
Observe the signs of the ADC register values in M105 and M106. These two values should be of
approximately the same magnitude, and must be of the opposite sign from each other. (Again, remember
that these readings may appear noisy. Observe the base value underneath the noise.) If M105 is positive
and M106 is negative, the sign of the PWM commands matches the sign of the ADC feedback values. In
this case, the Turbo PMAC phase angle parameter I172 must be set to a value greater than 1024 (1365 for
a 3-phase motor).
If M105 is negative and M106 is positive, the sign of the PWM commands is opposite that of the ADC
feedback values. In this case, I172 must be set to a value less than 1024 (683 for a 3-phase motor).
Make sure your I172 value is set properly before attempting to close the digital current loops on Turbo
PMAC. Otherwise positive feedback will occur, creating unstable current loops which could damage the
amplifier and/or motor.
If M105 and M106 have the same sign, the polarities of the current sense circuitry for the two phases is
not properly matched. In this case, something has been miswired in the drive or between Turbo PMAC
and the drive to give the two phase-current readings opposite polarity. One of the phases will have to be
fixed.
Do not attempt to close the digital current loops on Turbo PMAC until the polarities of the current sense
circuitry for the two phases have been properly matched. This will involve a hardware change in the
current sense wiring, the ADC circuitry, or the connection between them. As an extra protection against
error, make sure that Ixx57 and Ixx58 are set properly for I2T protection that will shut down the axis
quickly if there is saturation due to improper feedback polarity.
Troubleshooting
If not getting the current readings expected, probe the motor phase currents on the motor cables with a
snap-on hall-effect current sensor. If the current is not seen when commanding voltages, check for phaseto-phase continuity and proper resistance when the motor is disconnected.
Controller Setup
35
3U Servo Amplifier
SETTING I2T PROTECTION
It is very important to set the I2T protection for the amplifier/motor system for PMAC2 direct PWM
commutation. Normally, an amplifier has internal I2T protection because it is closing the current loop.
When PMAC2 is closing the current loop, the amplifier cannot protect itself or the motor from over
heating. Either set up the I2T protection using one of the Setup Programs or manually set the Ixx69,
Ixx57 and Ixx58 variables based on the following specifications:
Parameter
Description
Notes
MAX ADC Value
Maximum Current output of amplifier relative to a
value of 32767 in Ixx69
The lower of the amplifier or motor system
3U042 = 13.01A
Instantaneous Current
RMS or Peak*
Limit
Continuous Current
The lower of the amplifier or motor system
Usually RMS
Limit
I2T protection time
Time at instantaneous limit
Usually two seconds
Magnetization Current
Ixx77 value for induction motors
Only for induction motors
Servo Update
Default is 2258 Hz.
Frequency
* If specification given in RMS, calculate this value by 1.41 to obtain peak current for calculations.
Example Calculations for Direct PWM commutated motor:
MAX ADC = 13.01A
Instantaneous Current Limit = 8A Peak, for RMS need to multiply with
Continuous Current Limit = 4A RMS
I2T protection time = 2 seconds
Magnetization Current (Ixx77) = 0
Servo Update = 2.258 kHz
Ixx69 =
Instantaneous Limit (Peak)
MAX ADC
2
× 32767 × cos(30°)
if Calculated Ixx69>32767 then Ixx69 equals 32767
Ixx57 =
ContinuousLimit
xIxx69
Ins tan tan eousLimit
2
2
2
Ixx69 + Ixx77 − Ixx57
Ixx58 =
× ServoUpdateRate( Hz ) × PermittedTime(sec onds )
2
32767
Based on the above data and equations, the following results: Ixx69=24677
Ixx57=8725
Ixx58=2240
For details about I2T protection, refer to the safety sections of the User Manual. Details about the variable
setup can be found in the Software Reference manual.
Setting Protection
36
3U Servo Amplifier
CALCULATING MINIMUM PWM FREQUENCY
The minimum PWM frequency requirement for a system is based on the time constant of the motor.
Calculate the minimum PWM frequency to determine if the amplifier will properly close the current loop.
Systems with very low time constants need the addition of chokes or in-line inductive loads to allow the
PMAC to properly close the current loop of the system. In general, the lower the time constant of the
system, the higher the PWM frequency must be.
Calculate the motor time constant by dividing the motor inductance by the resistance of the phases.
L
τ motor = motor
R motor
The relationship used to determine the minimum PWM frequency is based on the following equation:
τ >
20
2π × PWM ( Hz )
∴ PWM ( Hz ) =
20
2πτ
Example:
Lmoto r = 5.80 mH
Rmotor = 11.50 Ω
τ motor =
Therefore, PWM ( Hz ) =
5.80 mH
11.50 Ω
= 0.504 m sec
20
= 6316 Hz
2π × ( 0.504 m sec)
Based on this calculation, set the PWM frequency to at least 6.32kHz.
PWM Drive Command Structure
37
3U Servo Amplifier
PWM DRIVE COMMAND STRUCTURE
The amplifier functions in two modes: Default and Enhanced.
Default Mode
Default Mode is the mode the amplifier is in when it is first powered on or the power is re-cycled for any
reason. Default mode is compatible with the full series of Delta Tau amplifiers and the A/D converters
used on these amplifiers.
In this mode, the amplifier returns not only the currents for phases A and B but also the fault codes for the
axes associated with those currents. The fault codes occupy the lower 12-bits on each phase.
For Default mode to work correctly, make sure that the A/D strobe word for the axis is set to the correct
value for the A/D on the amplifier. For instance, the current Delta Tau amplifiers use a 12-bit Burr
Brown part requiring a strobe word of $3FFFFF; this word is written to
X:$C014 as WX:$C014, $3FFFFF for non-Turbo. For Turbo PMAC I7m06= $3FFFFF.
This value can be saved to PMAC memory and sent to the amplifier on boot automatically.
Enhanced Mode
Enhanced mode is available on the Geo series of Delta Tau amplifiers and offers many more options.
Like the Default mode, Enhanced mode requires that a special strobe word be written to the amplifier, and
like Default mode, this word may be saved to PMAC memory and issued each boot automatically.
Enhanced mode axes and Default mode axes may not be mixed on the same amplifier.
Enhanced mode not only offers the fault codes associated with any axis on bits 11:4 of the current
feedback, but also reading both bus voltage and IGBT temperatures.
To enter Enhanced Mode, the Strobe Word must be set according to the table below.
ADC Strobe Word
WX:$C014 or I7m06
Value
Description
$300FFF
$301FFF
$3FDFFF
$3FEFFF
$3FFFFF
IGBT Temperature reported on phase B for each axis
Bus Voltage reported on phase B for each axis
Firmware Major version number in 00.00 (major.minor) format
Firmware Minor version number in 00.00 (major.minor) format
Default mode
At present, the commands sent to axis one are active on all axes of the amplifiers, that is, if bus voltage
from axis one is requested, bus voltage from all axes on that amplifier will be received.
IGBT temperature:
For every 2.13 degrees Celsius there is an additional count at the ADC register, +1h. The baseline
temperature is set at 25°C, which means the ADC has a value of 21h. The maximum IGBT temperature
for the drive is 150° Celsius.
Bus Voltage:
For every 5.25Volts there is an additional count at the ADC register, +1h. The maximum Bus Voltage for
the 3U042 drive is 420VDC, (296VAC) before over voltage fault, which means the ADC has a value of
50h. The Shunt resistor turn on voltage is 388.5V, the value is 4Ah, and the turn off voltage is 367.5, a
value of 46h.
PWM Drive Command Structure
38
3U Servo Amplifier
TROUBLESHOOTING
Error Codes
In most cases, the Geo Drive communicates error codes with a text message via the serial port to the host.
Some error codes are also transmitted to the Status Display. The same message is saved in the EEPROM
under an error history log (FLTHIST, ERR) so nothing is lost when power is removed. Not all errors reflect
a message back to the host. In these cases, the no-message errors communicate only to the Status Display.
The response of the Geo Drive to an error depends on the error's severity. There are two levels of
severity:
1. Warnings (simply called errors and not considered faults and do not disable operation).
2. Fatal errors (fatal faults that disable almost all drive functions, including communications).
Note:
The Geo Drive disables automatically at the occurrence of a fault.
3U Drive Status Display Codes
The 7-segment display on the current model, 16 numeric
codes plus two decimal points, provides the following codes:
D1
14
3
6
11
2
7
8
10
13
1
VCC
VCC
DPR
G
F
E
D
C
B
A
5082-7730
Display
Fault code
ADC bits Description
11:4
Fault
code
Axis faults : n stands for axis number (n=1-2)
nF1
01
Axis n Peak Current Fault – indicates the peak current was excessive long
enough to trip the peak current fault, but there was not enough current to
cause a nF3 fault (described below). Check for overshoots in the current
loop, make sure Ixx69 is less or equal to 24676
nF2
02
Axis n RMS Current Fault – indicates the continuous or RMS current
rating of the drive has been exceeded. Check for binding in motor, check
if the motor is properly phased.
nF3
03
Axis n Short Circuit Fault – indicates high output current has been
detected (fast acting). Unplug the Motor lead connectors and, if the fault
persists, send the drive for RMA. Else check your motor and cable. Do not
reset until unplugging motor cable and checking out the cause for the fault
or permanent damage could result!
nF4
-Reserved for future use
nF5
05
Power Stage (IGBT) Over-Temperature Fault – indicates excessive
temperature has been detected. Check ambient temperature that it does not
exceed the limits. Power off the drive and let it cool down. If the drive is
cool and the fault persists, send the drive for RMA
nE6
06
Motor #n Over temperature Eror Code (warning), if it insists for more than
60 seconds it will trip the Over temperature Fault.
nF6
06
Motor #n Over temperature Fault Code, amplifier disables
nF7-nFF
- -Reserved for future use
0
FF
Axis Enabled, drive is functioning properly.
Troubleshooting
39
3U Servo Amplifier
Global Faults
AF1
04
AF2
AF3
0B
0D
AF4
0E
AF5
AFb
0F
07
AFd
09
AFU
08
AFL
0C
PWM over frequency fault – indicates the PWM frequency detected by the
drive exceeds specified limits. Check your settings (I-vars)
Strobe Word Fault – not valid strobe word $3FFFFF
EEPROM Communication Fault – make sure the drive is properly
grounded. If problem persists, send the drive for RMA.
Shunt RMS Fault – The shunt will stay on continuously for only 2
seconds.
Soft Start Fault – Check the AC mains, if fault persists, send for RMA
Bus Over-Voltage Fault – indicates either that excessive bus voltage has
been detected, or no bus voltage at all has been detected, so check your
bus supply, regen resistors (GARxx).
Shunt Short Circuit Fault – check the shunt resistor leads for short. If the
connector is unplugged and the error persists, send the drive for RMA.
Bus Under-Voltage Fault – indicates that not enough bus voltage has been
detected, check the DC bus to ensure that more than 10V exists.
AC Line monitor – check the AC mains for more than 97VAC.
Status LEDs (for older and newer revision) 3U042
Color
Description
ENA1
LED
Red/Green
ENA2
Red/Green
PWR
For 3U042
Green
Green when axis enabled. Red when
drive is at fault. (Unlit does not
necessarily mean fault.)
Green when axis enabled. Red when
drive is at fault. (Unlit does not
necessarily mean fault.)
Lit when Logic has power.
Note:
There are currently two versions of the 3U042 (DAD3U) drive, the old version which
was up to revision-103 (603729) and the newer revision, which is -104 and above.
The easiest way to recognize the two versions is the period LED on the seven-segment
display. If the period is blinking, then the drive is the newer version; if the period is
not blinking, it is the older one. You can also check the revision number at the boards
Troubleshooting
40
3U Servo Amplifier
Amplifier stops and displays a code
Amplifier Fault
If a 3U amplifier displays other digit than 0, please refer to the appropriate table from above for an
explanation of fault codes.
Amplifier is dark
If the amplifier status display, +5V, +12V, -12V, ENA1, and ENA2 are not illuminated, verify that DC
bus is connected to the 3U amplifier.
If the condition described above is present, and the 3U amp is used in a UMAC rack along with a power
supply, verify that AC line is connected to the power supply.
Motor does not move upon a command
Verify that PWM cables and motor leads are correctly connected to 3U amplifier.
Is motor properly phased? Is the BUS voltage ON?
Cannot phase a motor
Verify that PMAC is properly configured and reads the motor’s feedback. Power cycle the drive and the
controller.
Notes
If a shunt (regen) resistor is required, use the shunt terminals on the backplane.
If the 3U amplifier is not used in Delta Tau UMAC rack, it is a user’s
responsibility to assure that the proper cooling is provided for the IGBTs. Delta
Tau suggests a fan capable of at least 100 CFM placed as close to the heatsink as
possible.
If the bus connection to the 3U amp is not done via Delta Tau backplane, a de-coupling capacitor (about
120 µF) for + and – bus should be used.
Troubleshooting
41
3U Servo Amplifier
APPENDIX A
PWM Cable Ordering Information
Cable
Length
600mm 900mm 1.5m 1.8m
(24")
(36") (60") (72")
2.1m
(84")
3.6m
(144")
√
CABPWM-1
CABPWM-2
CABPWM-3
CABPWM-4
CABPWM-5
CABPWM-6
√
√
√
√
√
Part Numbers
200-602739-024X
200-602739-036x
200-602739-060x
200-602739-072x
200-602739-084x
200-602739-144x
Mating Connector and Cable Kits
Cable sets can be purchased directly from Delta Tau to make the wiring of the system easier. Available
cable kits (CABKITxx) are listed below.
However, for those who wish to manufacture their own cable sets, the table below provides Connector
Kits to use with each drive. Connector Kits (CONKITxx) include the MOLEX connectors and pins for
the motor outputs, and 24VDC power supply connector.
Cable kits have terminated cables on the drive end and flying leads on the other.
CONKIT3C
Mating Connector Kit for the 3U042 drives: Includes Molex Connector kit for
two motors, and 24V power connection for the backplane.
Requires Molex Crimp Tool for proper installation.
Molex Tool Part #
63811-0400 for the Motor Output
CABKIT3C
Includes Molex mating connectors pre-crimped for dual axis drives up to 5amp continuous rated For 3U042
(1) 3 ft. 24VDC Power Cable
(2) 10 ft. shielded Motor Cable
Connector and pins Part numbers
CONKIT3C
Connector
Motor (x2)
3pins
24V
2pins
Appendix B
D/T part number
200-000F03-HSG
200-C30F02-LHM
D/T part number
individuals
Molex part number
Housing: 014-000F03-HSG
44441-2003
Pins: 014-043375-001
43375-0001
Housing: 014-C30F02-LHM
10-01-3026
Pins: 025-701030-MCT
08-70-1030
42
3U Servo Amplifier
Motor Cable Drawing
3U042 (CABKIT3C)
Appendix B
43
3U Servo Amplifier
APPENDIX B
Regenerative Resistor: GAR78/48
Appendix B
44
3U Servo Amplifier
Appendix B
45
3U Servo Amplifier
APPENDIX C
3U Rack DIMENSIONS
R E V IS IO N S
DESCRIPTION
REV .
--
DATE
NEWDRAWINGRELEASE
6-19- 03
CHGD
APPROVED
N.G .
D.D .
MINIMUM OF (1) 1 -SLOT
BLANK FOLLOWED
BY2-SLOT FILLERS
MUST START
W/1 1/4 -SLOT BLANK
TOP VIEW
A
C
B
8.580
2. 250
1. 475
1. 400
MINIMUM OF (2) 1 -SLOT
BLANK FOLLOWED
BY2-SLOT FILLERS
MINIMUM OF (1) 1-SLOT
BLANK FOLLOWED
BY 2 -SLOT FILLERS
MUST START
W/ 1 1/4 -SLOT BLANK
FRONT VIEW
BOTTOM VIEW
RACK SIZES
WIDTH
UNLESSOTHERWISESPECIFIED
AVAILABLE IN
A
42T - 10 1/2 SLOT WIDE
63T - 15 3/4 SLOT WIDE
84T - 21 SLOT WIDE
8.75
12.95
17.15
B
C
9. 90
14 .10
18 .30
10.60
14.80
19.00
NOTE:
FRACTIONS
±
PLACE CARD GUIDES@ .8 0 INCREMENTS
(FOR1 -SLOT BOARDS) STARTING WITH
THE POWER SUPPLY
.
DECIMALS
.XX= ± .03
.010
ANGLES
± .
P ROJ E CT
U MA C R A C K
DELTA TAU
NEXT L EVEL
A P PROV A L S
6- 16- 03
CHECKED
SI ZE
A P P ROV E D
CUSTOM RACKS AVAIL ABLE UPON REQUEST
DO NO T SCALE DRAWI NG
F IL E
584- 4269- 0.DWG
DWG . NO .
DX
6- 16- 03
DATA SYSTEM S , INC.
3 U RACK ASSY
, " UMAC"
21-SLOT STANDARD
DAT E
D R A WN
FINISH
SCALE
NONE
584- 604269
DASH NO .
SHEET
-100
1O F 1
3U Rack Sizes
Width
A
B
C
D1 - 10 ½ Slot wide
22.23cm (8.75in)
25.15cm (9.9in)
26.92cm (10.6in)
D2 – 15 ¾ Slot wide
32.89cm (12.95in)
35.81cm (14.10in)
37.60cm (14.8in)
D3 – 21 Slot wide
43.56cm (17.15in)
46.48cm (18.30in)
48.26cm (19in)
Note: All dimensions on the drawing are in inches
The 3U rack is mounted to the back panel through 4 x 0275”x0.400” obround
Appendix C
46
REV
--