Rockwell Automation AK DBU User Manual
AK DBU Dynamic Braking
Unit
600/690 VAC
User Manual
Important User Information
Solid state equipment has operational characteristics differing from those of
electromechanical equipment. “Safety Guidelines for the Application, Installation
and Maintenance of Solid State Controls” (Publication SGI-1.1 available from
your local Rockwell Automation Sales Office or online at
www.rockwellautomation.com/literature
between solid state equipment and hard-wired electromechanical devices. Because
of this difference, and also because of the wide variety of uses for solid state
equipment, all persons responsible for applying this equipment must satisfy
themselves that each intended application of this equipment is acceptable.
In no event will Rockwell Automation be responsible or liable for indirect or
consequential damages resulting from the use or application of this equipment.
The examples and diagrams in this manual are included solely for illustrative
purposes. Because of the many variables and requirements associated with any
particular installation, Rockwell Automation cannot assume responsibility or
liability for actual use based on the examples and diagrams.
No patent liability is assumed by Rockwell Automation with respect to use of
information, circuits, equipment, or software described in this manual.
Reproduction of the contents of this manual, in whole or in part, without written
permission of Rockwell Automation is prohibited.
Throughout this manual, when necessary we use notes to make you aware of safety
considerations.
WA R NI NG : Identifies information about practices or circumstances
that can cause an explosion in a hazardous environment, which may
!
lead to personal injury or death, property damage, or economic loss.
) describes some important differences
http://
Important: Identifies information that is critical for successful application and
understanding of the product.
ATTENTION: Identifies information about practices or
circumstances that can lead to personal injury or death, property
!
damage, or economic loss. Attentions help you:
• identify a hazard
• avoid the hazard
• recognize the consequences
Shock Hazard labels may be located on or inside the equipment
(e.g., drive or motor) to alert people that dangerous voltage may be
present.
Burn Hazard labels may be located on or inside the equipment
(e.g., drive or motor) to alert people that surfaces may be at dangerous
temperatures.
PowerFlex is a registered trademark of Rockwell Automation.
Preface Overview
Who Should Use this Manual?. . . . . . . . . . . . . . . . . . . . . . . . P-1
Reference Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P-1
Manual Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P-2
General Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P-2
Catalog Number Explanation. . . . . . . . . . . . . . . . . . . . . . . . . P-3
Description and Block Diagram. . . . . . . . . . . . . . . . . . . . . . . P-4
Line Voltage Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P-7
Permissible Loading of the DBU. . . . . . . . . . . . . . . . . . . . . . P-8
Chapter 1 Installation/Wiring
Minimum Mounting Clearances . . . . . . . . . . . . . . . . . . . . . . 1-1
Grounding Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Fuses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Protection of Brake Resistors and Conductors . . . . . . . . . . . 1-3
Power Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
Control Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
CE Conformity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
Chapter 2 Start Up / Troubleshooting
Start-Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
DC Power on LED. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
Table of Contents
Appendix A Specifications
DBU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1
Dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3
Diagnostic Card BUB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-4
Resistor Specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-4
Fuse Ratings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-4
Appendix B CE Conformity
General Installation & Wiring Guidelines for CE Conform. . B-1
Essential Requirements for CE Compliance . . . . . . . . . . . . . B-2
Mounting Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-3
Wiring Instruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-4
Configuration Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-6
Appendix C Design Information
Determining Dynamic Brake Requirements . . . . . . . . . . . . . C-1
Determine Values of Equation Variables . . . . . . . . . . . . . . . . C-4
Selecting the Brake Resistor . . . . . . . . . . . . . . . . . . . . . . . . . C-7
Example Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-10
2 Table of Contents
Preface
Overview
The purpose of this manual is to provide the necessary information for
the installation, start-up and trouble shooting of the AK Dynamic
Braking Unit.
For information on…
Who Should Use this Manual?
Reference Materials P-1 Description and Block Diagram P-4
Manual Conventions P-2 Line Voltage Selection P-7
General Precautions P-2 Permissible Loading of the DBU P-8
See
page For information on…
P-1 Catalog Number Explanation P-3
See
page
Who Should Use this Manual?
This manual is intended for personnel qualified in the installation,
programming, and operation of adjustable Frequency Drives and their
use in common DC bus systems.
Reference Materials
The following manuals are recommended for general drive information:
Title Publication Available Online at …
Wiring and Grounding Guide for
PWM AC Drives
Preventive Maintenance of
Industrial Control and Drive
System Equipment
Reactors and Isol. Transformers 1321-TD001D-EN-P
Guarding Against Electrostatic
Damage
Safety Guidelines for the Appli-
cation, Installation and Maintenance of Solid State Control
A Global Reference Guide for
Reading Schematic Diagrams
DRIVES-IN001A-EN-P
www.ab.com/manuals/dr
DRIVES-SB001A-EN-E
8000-4.5.2
www.ab.com/manuals/gi
SGI-1.1
0100-2.10 Not available online, contact
your local RA Sales Office
For detailed PowerFlex Inverter information including specifications:
Title Publication Available . . .
PowerFlex
Reference Manual
Common Bus Application
Guide
PFLEX-RM001D-EN-E on the CD supplied with the drive
TBD TBD
or at
www.ab.com/manuals/dr
P-2 Overview
Manual Conventions
• In this manual we refer to the AK Dynamic Braking Unit as DBU
and to the Adjustable Frequency AC Drive (AFD) as; drive, inverter
or PowerFlex Drive.
• The following words are used in the manual to describe an action:
Word Mean ing
Can Possible, able to do something
Cannot Not possible, not able to do something
May Permitted, allowed
Must Unavoidable, you must do this
Shall Required and necessary
Should Recommended
Should Not Not Recommended
General Precautions
ATTENTION: This DBU contains ESD (Electrostatic Discharge)
sensitive parts and assemblies. Static control precautions are required
!
when installing, testing, servicing or repairing this assembly.
Component damage may result if ESD control procedures are not
followed. If you are not familiar with static control procedures,
reference A-B publication 8000-4.5.2, “Guarding Against Electrostatic
Damage” or any other applicable ESD protection handbook.
ATTENTION: An incorrectly applied or installed DBU can result in
component damage or a reduction in product life. Wiring or application
!
errors, such as, incorrect or inadequate AC supply, or excessive ambient
temperatures may result in malfunction of the system.
ATTENTION: Only qualified personnel familiar with AFD’s and
associated machinery should plan or implement the installation,
!
start-up and subsequent maintenance of the system. Failure to comply
may result in personal injury and/or equipment damage.
ATTENTION: To avoid an electric shock hazard, verify that the
voltage on the DC bus terminals (which are connected to the DC bus
!
capacitors of the Inverter) has discharged before performing any work
on the DBU. Measure the DC bus voltage at the +DC and -DC terminal
of the Output Power Terminals. The voltage must be zero.
ATTENTION: Second source of power for cooling blower is present.
To avoid an electric shock hazard or moving blades, verify the
!
AC-power supply has been removed prior to performing any
maintenance or repairs.
Overview P-3
Catalog Number Explanation
The catalog numbering scheme for the AK Dynamic Braking Unit is
shown below.
AK DBU F 300 N E
Product Voltage Rating Rating Enclosure Documentation
Product
Name Cat.Code
AK Dynamic Braking Unit AK DBU
Version & Voltage Rating
Input Voltage
600/690 VAC 950/1090 VDC F
Full On
Vo lt ag e
Rating - Output Peak Current
Amps Voltage Cat. Code
300.0 600/690 VAC 300
Cat.
Code
Enclosure Type & Conformal Coating
Rating Conf. Coating Cat. Code
Open / IP00 No N
Documents & Shipping Carton
Document(s) Ship. Carton Cat. Code
English U. M. Yes E
P-4 Overview
Description and Block Diagram
The DBU includes the following main components:
The Chopper Transistor
(IGBT). The Chopper Transistor is either ON or OFF. When in the
ON state the Dynamic Brake Resistor connects to the inverter’s DC
bus and dissipates regenerated energy from the load. When in the
OFF state, the Dynamic Brake Resistor is electrically isolated from
the inverter’s DC bus and no energy regeneration occurs. Several
transistor ratings are used in the available DBUs. The most important
rating is the collector current rating of the Chopper Transistor that
contributes in determining the minimum ohmic value used for the
Dynamic Brake Resistor.
is an Isolated Gate Bipolar Transistor
Chopper Transistor Voltage Control BUC (PWM type) regulates
the voltage of the DC Bus during regeneration. The average DC bus
voltage is 950V DC for 600V AC input and 1090V DC for 690V AC
input.
DBU Overtemperature Sensor located in the heat-sink for thermal
protection of the DBU.
Power Resistor (customer supplied) or resistor assembly with
Overtemperature Sensor for thermal protection. If the resistor
overheats, this contact disables the connected drive(s).
RC-snubber circuit
Cooling Fan that must be connected to a customer supplied 115V AC
Power Supply. The fan must run if the inverter is energized.
Diagnostic card BUB
The breaking unit includes the BUB diagnostic card with the two
indicating LEDs DC Power on and Brake on.
Overview P-5
Figure P.1 shows the block diagram of the DBU with the Dynamic Brake
Resistor. The DBU is shown connected to the positive (DC+) and negative (DC-) terminals of an AC PWM Drive.
Figure P.1 Block diagram of Inverter with Dynamic Braking Unit
DC+
Inverter
DC-
Field
installed
Fuses
F1
F2
DC+
Transist or
Control
BUC
DC-
BUB
DC Power on Brake on
DBU
to customer grounding scheme
or earth gr ound
PE
BR1
BR2
RC
Snubber
>°C
115
M
to inverter's main
contactor circuit
to customer's
suppl ied
115 VAC
0
power source
11
to inverter's
main contactor
10
circuit
PE
R
>°C
P-6 Overview
Theory of Operation
When the rotor of an induction motor is turning slower than the
synchronous speed set by the drive’s output power, the motor is
transforming electrical energy obtained from the drive into mechanical
energy available at the drive shaft of the motor. This process is referred
to as motoring. When the rotor is turning faster than the synchronous
speed set by the drive’s output power, the motor is transforming
mechanical energy available at the drive shaft of the motor into electrical
energy that can be transferred back into the utility grid. This process is
referred to as regeneration.
Most AC PWM drives convert AC power from the fixed frequency utility
grid into DC power by means of a diode rectifier bridge or controlled
SCR bridge before it is inverted into variable frequency AC power.
Diode and SCR bridges can only handle power in the motoring direction.
Therefore, if the motor is regenerating, the bridge cannot conduct the
necessary negative DC current. Depending on parameter setting, the
drive regulator will either increase the DC bus voltage and cause a Bus
Overvoltage trip at the drive, or extend the set deceleration rate or
increase the output frequency.
When a drive is dissipating regenerative electrical energy on an
occasional or periodic basis, a DBU connected to the DC bus of a drive
and feeding a power resistor can be specified. When a drive is
consistently operating in the regenerative mode, a regenerative unit or
RGU should be used to transform the DC regenerated energy to the fixed
frequency utility energy.
Parameter Setting on the Inverter
ATTENTION: When the braking unit is connected to a drive, the drive
Bus Regulation should be turned off. In addition the Regen Power Limit
should be set to the motor power limit or the braking unit power limit,
whichever is greater.
For example on a PowerFlex 700
• Parameters 161/162 [Bus Reg. Mode A/B] must be set to 0 (Disabled)
• Parameter 163 [DB Resistor Type] must be set to 2 (None)
• Parameter 153 [Regen Power Lim] must be set to the motor power
limit or braking unit power limit, whichever is greater.
Overview P-7
-
Line Voltage Selection
After removing the cover plate of the DBU, a red jumper plug located on
the BUC card allows for the line voltage selection of 690V / 600V.
The selection of this jumper plug defines the DC bus voltage at which
the DBU switches the brake resistor to the DC bus.
Figure P.2 Jumper plug location on the BUC card
BUC-Card
600V
Figure P.3 Pulse Width (Jumper Setting) in Relation to DC Bus Voltage
100%
95%
0%
Jumper at 600: 913V
690V
Jumper plug on rear side,
shown in position for 600V AC line
VDC
950V
690: 1047V 1090V
The default jumper voltage selection shipped from the factory is
690V AC line voltage.
ATTENTION: Without the jumper plug in place, the default line
voltage selection of the DBU is set to 600V AC. When operating on a
!
690V AC line the brake resistor will be constantly switched on. This
can cause an overtemperature trip on the DBU and/or the brake resistor.
Verify the jumper plug is present and has been properly selected for the
application.
P-8 Overview
Permissible Loading of the DBU
To prevent thermal overload of the Braking Unit, it must operate within
the following limits:
In a time range of 10 minutes the permissible loading must be limited
to the maximum peak current of the DBU (300A) up to a maximum of
2.5 minutes.
This maximum current-time area of 750 Amp.-minutes can be of any
shape, as long as 300A is not exceeded.
The peak current (I
(maximum current with R
) in the following two examples is 300 Amp
Peak
= 3.2 ohm at 600 VAC line) and the
min
current-time area also meets the 750 Amp.-minutes requirement.
Figure P.4 Examples for Permissible Loading of the DBU
1) Linear deceleration to zero speed of
a drive with high inertia connected
(e.g. centrifuge)
I
Peak
300A
0
5
10
minutes
Current-time area:
(300 * 5) / 2 = 750 Amp-Min.
2) Drive with active load
(e.g. crane)
I
Peak
300A
112.5A
0
t
4
1
Current-time area:
(300 * 1) + (112.5 * 4) = 750 Amp-Min.
10
t
minutes
Chapter
Installation/Wiring
This chapter provides the information needed for the installation and
wiring of the Allen-Bradley Dynamic Braking Module.
1
For information on…
Minimum Mounting Clearances
Grounding Requirements 1-2 Control Wiring 1-8
Fuses 1-3 CE Conformity 1-9
Protection of Brake Resistors and Conductors 1-3
Most start-up difficulties are the result of incorrect wiring. Every
precaution must be taken to assure that the wiring is done as instructed.
All items must be read and understood before the actual installation
begins.
ATTENTION: The following information is merely a guide for proper
installation. The Rockwell Automation Company cannot assume
!
responsibility for the compliance or the noncompliance to any code,
national, local or otherwise for the proper installation of this device or
associated equipment. A hazard of personal injury and/or equipment
damage exists if codes are ignored during installation.
See
page For information on…
1-1 Power Wiring 1-4
Minimum Mounting Clearances
For free air circulation through the cooling fins of the power section, the
braking unit must be mounted in the vertical position only. In order to
prevent overheating due to heat build-up, minimum clearances for air
circulation of 100 mm (25 in) above and below the unit must be
observed.
The rate of cooling air for the forced ventilated DBU is 158 m
with a bottom to top of the unit air flow.
See Appendix
A, Figure A.3 for detailed dimension information.
3
See
page
/h,
1
-2
Installation/Wiring
Grounding Requirements
The Safety Ground terminal (PE) must be connected to the building
grounding scheme. Ground impedance must conform to the
requirements of national and local industrial safety regulations and/or
electrical codes. The integrity of all ground connections should be
periodically checked.
For installations within a cabinet, a single safety ground point or ground
bus bar connected directly to building steel should be used. All circuits
should be grounded independently and directly to this point/bar.
Figure 1.1 Typical Grounding
Ground Gr id, Girder or Ground
Rod (Building Ground Potential)
R (L1)
S (L2)
T (L3)
Drive
+DC
-DC
PE
+DC
-DC
DBU
PE
Safety Ground Terminal - PE
The DBU safety ground (PE) must be connected to the customer
grounding scheme or earth ground. This is the safety ground for the
DBU that is required by code. This point must be connected to adjacent
building steel (girder, joist, a floor ground rod, bus bar or building
ground grid) see Figure 1.1. Grounding points must comply with
national and local industrial safety regulations and/or electrical codes.
For additional information refer to publication DRIVES-IN001A-EN-P.
Installation/Wiring 1-3
Fuses
National and local industrial safety regulations and/or electrical codes
may determine additional requirements for these installations.
ATTENTION: The DBU does not provide DC Bus branch short
circuit protection. Specifications for the recommended fuse to provide
!
protection against short circuits are provided in Appendix
A.
Protection of Brake Resistors and Conductors
In case of a failed DBU (IGBT short circuit or a constantly ON
command), the rectified AC line voltage is passed to the brake resistor.
Since the IGBT in the DBU is not switching and therefore its
temperature is not increasing, this fault will not be detected by the
temperature sensor located on the heat sink of the DBU.
To prevent possible damages due to the overloading of the brake
resistors, leads and input rectifier, the installation of a thermal switch on
the brake resistor heat sink is recommended:
The contact of the thermal switch on the brake resistor should be wired
in series with the thermal switch on the DBU to the drives main
contactor control circuit. Refer to Figure 1.5
.
1
-4
Installation/Wiring
Power Wiring
ATTENTION: National Codes and standards (NEC, VDE, BSI etc.)
and local codes outline provisions for safely installing electrical
!
equipment. Installation must comply with specifications regarding wire
types, conductor sizes, and disconnect devices. Failure to do so may
result in personal injury and/or equipment damage.
Recommendations for the selection and wiring of power cables
• Cable must have copper conductors only
• Cable with 1,000V rating or greater is required
• Shielded cable is preferred
• For unshielded cable allow a spacing of 0.3 meters (1 foot) for every
10 meters (32.8 feet) of length. Long parallel runs must be avoided.
• Do not use cable with an insulation thickness less than or equal to
15 mils (0.4 mm/0.015 in.).
• See “Use of Unshielded Cable”
Use of Unshielded Cable
THHN, THWN or similar wire is acceptable for drive installation in dry
environments provided adequate free air space and/or conduit fill rates
limits are provided. Do not use THHN or similarly coated wire in wet
areas. Any wire chosen must have a minimum insulation thickness of
15 mils and should not have large variations in insulation concentricity.
EMC Compliance
Refer to Appendix B for details.
Cable Trays and Conduit
If cable trays or large conduits are to be used, refer to guidelines
presented in the PowerFlex 700 Reference Manual.
ATTENTION: To avoid a possible shock hazard caused by induced
voltages, unused wires in the conduit must be grounded at both ends.
!
For the same reason, if a drive sharing a conduit is being serviced or
installed, all drives using this conduit should be disabled. This will help
minimize the possible shock hazard from “cross coupled” motor leads.
Connect DBU, fuses and brake resistors according to the block diagram
in Figure P.1
for CE Conformity on page B-1.
. Refer also to General Installation and Wiring Guidelines
Installation/Wiring 1-5
Connection leads between Inverter and DBU
During switching of the braking unit’s IGBT the inductance of the leads
between the DC bus capacitors of the inverter and the DBU generates
short time (milliseconds) bus over voltage peaks.
These bus over voltages, which are dampened by the RC snubber circuits
in the DBU, must not exceed 200 volts.
Drives Connected to a Single Motor
For drives connected to a single motor this can be accomplished by the
DC+
):
DBU
BR1
Cable length
max.30m
DB-Resistor
Assembly
following measures (see Figure 1.2
• The conductors must be bound together and run separatedly from
other conductors or multi-core cables (EMC shielded). This is to
reduce the cable inductance.
• Limiting the total cable length between the drive and the DBU to a
maximum of 3 m (120 in)
Connection example
Figure 1.2 Connection to single motor drive
AC-Drive
DC+
Cable length
max.3m
F1
R
DC- DC-
F2
Field
Installed
Fuses
BR2
10 11
Multiple Drives Coupled through a Common DC Bus
For a DBU that is connected to several drives which are coupled through
a common DC bus, the bus over voltages must also not exceed 200 V.
The inductance of the DC bus connection leads to the engaged DC bus
capacitors must be kept low by adhering to the following measures:
• Use short leads with low inductance.
• Locate the DBU as close as possible to the largest DC bus capacitors.
• Wires should be twisted
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