INVT DBU-055-2 User manual

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Contents
Contents....................................................................................................................................i
Safety precautions ..................................................................................................................2
1 Inspection..............................................................................................................................3
2 Installation.............................................................................................................................3
2.1 Running environment ....................................................................................................3
2.2 Ambient environment.....................................................................................................3
2.3 Outline dimensions........................................................................................................4
3 Product name, model definition and use...........................................................................4
4 Installation instruction and parameter setting ..................................................................5
4.1 Regulation......................................................................................................................7
4.2 Voltage selection setup..................................................................................................7
5 Parallel operation .................................................................................................................8
6 Fault analysis and handling ................................................................................................9
7 Model selection specification ...........................................................................................10
7.1 Braking voltage reference............................................................................................10
7.2 Calculation of braking resistance and braking current (calculated by 100% braking
torque) ...............................................................................................................................10
7.3 Calculation and selection of braking resistor (calculated by 100% braking torque)....11
7.4 Input voltage class specifications and model selection for 380V VFDs ......................12
7.5 Input voltage class specifications and model selection for 660V VFDs ......................13
7.6 Braking resistor selection ............................................................................................14
Safety precautions ................................................................................................................16
1 Overview..............................................................................................................................17
1.1 Overall technical characteristics..................................................................................17
1.2 Nameplate description.................................................................................................18
1.3 Series models..............................................................................................................18
1.4 Outline dimensions......................................................................................................20
2 Unpacking inspection........................................................................................................21
3 Disassembly and installation ............................................................................................22
3.1 Running environment conditions .................................................................................22
3.2 Installation space and distance....................................................................................23
3.3 Installation dimensions of external keypad..................................................................24
3.4 Disassembly and installation of the cover plate...........................................................24
4 Wiring ..................................................................................................................................25
4.1 Wiring terminal diagram and function description .......................................................25
4.1.1 Main circuit terminals and function description...................................................25
4.1.2 Control circuit terminals and function description...............................................26

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4.2 Standard wiring diagram..............................................................................................27
4.2.1 380V 7.5kW-75kW..............................................................................................27
4.2.2 380V 90kW-220Kw/660V 55kW-250kW/1140V 55kW-160kW...........................28
5 Operations...........................................................................................................................29
5.1 Operation panel description.........................................................................................29
5.1.1 Panel diagram.....................................................................................................29
5.1.2 Key function description......................................................................................29
5.1.3 Indicator description............................................................................................30
5.2 Function parameter list................................................................................................31
5.3 Function description ....................................................................................................34
6 Troubleshooting .................................................................................................................36
7 Maintenance........................................................................................................................38
7.1 Routine maintenance...................................................................................................38
7.2 Periodic maintenance..................................................................................................38
7.3 Wearing part replacement ...........................................................................................39

Dynamic Braking Unit Manual
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Dynamic Braking Unit Manual

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Safety precautions
Read the manual carefully before installing, operating, servicing, and inspecting the dynamic
braking unit.
Safety precautions in the manual are classified as "Danger" and "Warning".
Danger
Serious physical injury or even death may occur if related
requirements are not followed.
Warning
Physical injury or damage to the equipment may occur if related
requirements are not followed.
Note
Actions taken to ensure proper running.
Warnings caution you about conditions that can result in severe injury or death and/or
equipment damage and advice on how to prevent dangers.
Note:
Do not use any incomplete or damaged braking unit or braking resistor.
Confirm that the braking unit and braking resistor are set properly.
Do not carry out a voltage-endurance test on the braking unit, otherwise, damage to the
semiconductor devices of the braking main circuit may occur.
Screws shall be tightened during wiring, otherwise, fire or leakage may occur.
When multiple braking units are installed in the same one chassis and used in parallel
connection, a fan or other cooling device shall be installed.
After the braking unit is wired, there is high voltage DC power supply inside it. Do not
touch the braking unit, internal components and printed boards with your hands,
otherwise, electric shock may occur.
The braking resistor shall be equipped with temperature protection and other
protections.
The braking unit and braking resistor shall be mounted on
flame-retardant mediums (e.g. metal).
Ensure all the power supplies are disconnected and fully discharged
before wiring.
Only professionals are allowed to carry out the wiring operation.
Check whether the wiring is proper before operation.
Check whether the master/slave selection and voltage class settings are
proper before operation.

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Ensure that the POWER indicator is completely off and confirm that the
charging voltage has dropped to zero with a voltmeter before adjusting
and servicing the braking unit.
Do not touch any components inside the braking unit during the
operation.
The braking unit is an accessory device of the VFD, so if it is used
improperly, the device failure and VFD fault may occur. Exercise caution
before using it.
If the VFD fails, regardless of whether it is related to the braking unit, we
will not bear any responsibility. The fuse for semiconductor is user
purchased.
1 Inspection
INVT braking units have been tested and inspected for quality before leaving the factory. After
receiving products, check whether the packing box is damaged due to careless transportation
and whether the product specifications and model are consistent with the purchased model. If
any problem is found, contact the INVT supplier.
Note: Only trained personnel are allowed to operate this device. Read the safety, installation,
operation and maintenance sections of this manual before use. The safe operation of the
device depends on proper transportation, installation, operation and maintenance.
2 Installation
2.1 Running environment
The braking unit shall be installed in a well-ventilated indoor place with wall mounting.
2.2 Ambient environment
Ambient temperature is -10°C to 40°C .
Prevent electromagnetic interference and keep away from interference sources.
Ensure foreign objects like dust, dirt, cotton wool, and metal powder will not fall into the
device.
Away from oil, salt, and corrosive gas.
Avoid vibration.
Away from high temperature and humidity, no rain, and humidity is less than 90%RH (no
condensation)
Away from flammable, combustible, explosive gas, liquid or solid.

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2.3 Outline dimensions
Figure 2-1 Outline dimensions (unit: mm)
Model
Range
L
L1
W
H
H1
H2
DBU-055-2
11-55kW
110
60
120
180
171
160
DBU-055-4
18.5-55kW
110
60
120
180
171
160
DBU-315-4
132-315kW
180
120
164
285
277
260
DBU-350-6
22-350kW
200
120
162
385
377
361
Note: The structure and dimensions of DBU-160-4, DBU-220-4 and DBU-315-4 are the same.
660V 22–350kW energy braking units use same structure and volume.
3 Product name, model definition and use
DBU–055–4
Voltage class
2: 220V
4: 380V
6: 660V
12: 1140V
Rated current
055: 55A
Dynamic braking
unit
8

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INVT dynamic braking unit is mainly used in cases where the VFD needs to be rapidly slowed
down, positioned and braked. When the VFD brakes, due to large load inertia, the kinetic
energy is transformed into electrical energy during braking, so that the DC bus voltage of the
VFD rises. In order not to affect the normal operation of the VFD, the braking unit is needed
to consume the regenerated electrical energy, otherwise, the VFD will enable the overvoltage
protection, affecting the normal operation of the VFD.
The braking unit can be applied in cases where the VFD driving a high-inertia load
decelerates abruptly, such as elevators, textile machines, paper machinery, centrifuges,
washing machines, wire-drawing machines, winding machines, proportional linkage systems,
overhead cranes and other systems.
4 Installation instruction and parameter setting
+ + + + +++
External braking
resistor RB
(+)
DC+
(-)
DC- BR1 BR2 PE
(-)
(+)
++ + + + ++
INVT/Other brands DBU
Figure 4-1 Main circuit wiring between the braking unit and the VFD
Note:
The connection cables between the VFD and the braking unit shall be shorter than 5m.
The connection cables between the braking resistor (Rb) and the braking unit shall be
shorter than 10m.
DC+ and DC- are "+" and "-" terminals of the DC bus inside the VFD. DC+ is positive
terminal while DC- is negative terminal.
The braking unit can continuously brake up to 5 minutes at 100% braking ratio. The
temperature of the chassis is high when braking continuously. Do not touch it with your
hands to avoid burns. If you require longer continuous braking time, you need to choose
a braking unit with larger power or operate the braking unit at 50% braking ratio, as

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shown in the following figure.
t/s
Braking
ratio
100%
50%
0 300
Figure 4-2 Derating of the braking unit
Improper main circuit wiring may cause damage to the braking unit and
the VFD.
Main circuit terminal description of the braking unit
BR1
BR2
(+)
(-)
PE
BR1, BR2-------------Terminals for connecting to the external braking resistor.
(+)------------------Positive terminal of the VFD DC bus
(-)------------------Negative terminal of the VFD DC bus
PE-----------------------Grounding terminal
Main control terminal description of the braking unit
RST
EFI
PI
COM
PO1
PO2
ROA
ROB
ROC
Control
terminal
Name
Description
RST
External reset terminal. Short connect to COM terminal for resetting
when a braking unit fault occurs.
EFI
External fault input terminal. When an external fault occurs, the braking
unit outputs a fault signal.
PI
Braking unit parallel input terminal. When multiple braking units are
used in parallel, this terminal can be used to monitor the operation of
other braking units.
COM
Common terminal of RST, EFI, PI

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PO1
PO2
Braking unit parallel output terminal. When multiple braking units are
used in parallel, this terminal outputs signals to enable other braking
units to monitor the operation.
ROA
ROB
ROC
Fault output terminal. When a braking unit fault occurs, the fault relay
acts to output a fault alarm signal.
ROA–ROB NC, ROA–ROC NO
When there is only one braking unit, connect the VFD, braking unit and braking resistor
according to Figure 4-1. Set the voltage class and braking threshold, and then the operation
starts.
4.1 Regulation
There is no need to adjust braking resistor units and braking units (except in the case of the
"voltage selection setting").
4.2 Voltage selection setup
Braking voltage threshold setting:
Set the braking unit voltage according to the VFD input power voltage. Disconnect the power
supply during voltage selection. The following table shows the relationship between the
voltage selection setting and braking starting/stopping voltage.
SN
S1 selection
220V system
380V system
660V system
1140V system
50% braking
ratio
100%
braking ratio
Braking
starting
value (V)
Braking
stoppin
g value
(V)
Braking
starting
value
(V)
Braking
stoppin
g value
(V)
Braking
starting
value
(V)
Braking
stoppin
g value
(V)
Braking
starting
value
(V)
Braking
stoppin
g value
(V)
0
330
320
640
620
1080
1060
1950
1920
1
350
340
660
640
1100
1080
2000
1970
2
(Factory
setting)
370
360
680
660
1120
1100
2050
2020
3
380
370
700
680
1140
1120
2100
2070
4
390
380
720
700
1160
1140
2150
2120