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

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.

Dynamic Braking Unit Manual
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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.

Dynamic Braking Unit Manual
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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

Dynamic Braking Unit Manual
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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

Dynamic Braking Unit Manual
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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

Dynamic Braking Unit Manual
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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)
5
400
390
740
720
1180
1160
2200
2170
6
Reserved
Reserve
d
Reserve
d
Reserve
d
Reserve
d
Reserve
d
Reserve
d
Reserve
d
7
Slave
mode
Slave
mode
Slave
mode
Slave
mode
Slave
mode
Slave
mode
Slave
mode
Slave
mode
Note:
If the grid voltage is 20% higher than the normal power supply, you shall set a larger
braking voltage.
Ensure that the braking starting voltage of the VFD matches with the device.
Do not perform the live operation. Do not adjust any setting until the
POWER indicator is utterly off.
5 Parallel operation
+ + + + +++
External braking
resistor RB
(+)
DC+
(-)
DC- BR1 BR2 PE
(-)
(+)
++ + + + ++
INVT/Other brands DBU
+ + +++
BR1 BR2 PE
(-)
(+)
DBU
External braking
resistor RB
PO1
PO2
PI
COM
Figure 5-1 Connection between braking units in parallel operation and the VFD

Dynamic Braking Unit Manual
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When more than two braking units are in parallel operation, connect the VFD, multiple
braking units and braking resistors according to Figure 5-1.
Control terminal wiring instruction
When multiple braking units are in parallel connection, take the first braking unit as the master
and the others as slaves. For the slave parameter setting, refer to item 7 of "Brake voltage
threshold setting" table in section 4.2. The braking ratios of the slave and the master shall be
consistent. The parallel output terminals PO1 and PO2 of the first braking unit are connected
to the parallel input terminals PI and COM of the second braking unit, and the parallel output
terminals PO1 and PO2 of the second braking unit are connected to the parallel input
terminals PI and COM of the third braking unit, and so on, so that the whole parallel braking
unit system can monitor each other's operation.
6 Fault analysis and handling
Item
Fault state
Cause
Handling method
1
Severe heating of
the braking resistor
occurs during
braking
The power of the braking
resistor is too small.
Replace a braking
resistor with larger
power.
2
Serious heating of
the braking resistor
occurs when not
braking
Main circuit power IGBT of
the braking unit is damaged
Replace the braking
unit.
The voltage setting of the
braking unit does not match
the voltage.
Reset
Braking unit fault.
Replace the braking
unit.
3
The VFD enables
the overvoltage
function.
The braking capacity of the
braking resistor is
insufficient.
Recheck the braking
conditions.
Improper wiring
Check and correct it.
The voltage setting of the
braking unit does not match
the voltage.
Reset
Braking unit fault
Replace the braking
unit.
4
The fault relay
outputs signals.
External fault input is valid
Recheck the operating
conditions

Dynamic Braking Unit Manual
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Item
Fault state
Cause
Handling method
The braking current is too
large while the braking
resistor is too small.
Select a resistor with
larger resistance.
Continuous braking time is
too long.
Reduce the braking
frequency.
Internal power fault.
Replace the braking
unit.
Note: The grid voltage is too high, you shall select larger voltage setting.
The control circuit of the braking unit is a non-isolated circuit. Disconnect
the connection between DC+ and DC-, and ensure there is no voltage
between DC+ and DC- before operating and checking the device.
7 Model selection specification
7.1 Braking voltage reference
The braking voltage shall be set to be high enough to avoid braking unit misoperation
caused by increase of grid voltage.
The braking voltage shall be set to be low enough. The VFD shall be operated at rated
voltage, ensuring safe operation of the equipment. A high braking voltage can ensure
that the braking unit does not operate mistakenly, but too high voltage has a great impact
on the long-term safe operation of the equipment.
7.2 Calculation of braking resistance and braking current (calculated by
100% braking torque)
The braking current indicates DC current flowing through the braking resistor and braking unit
during braking.
Calculated on the basis of a 380V standard AC motor.
P――――Rated motor power (kW)
V――――DC operating point of the braking unit, generally set to be 700V
I―――― Braking current (A)

――――Conversion efficiency of mechanical energy during feedback, generally set

= 0.7

Dynamic Braking Unit Manual
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Calculation basis: The braking resistor must completely absorb the regenerative electrical
energy of the motor.
Braking resistor absorbed power (V*I) = Motor regenerative electrical energy (watt) = 1000 *
P *

7.3 Calculation and selection of braking resistor (calculated by 100%
braking torque)
The value of the braking resistance indirectly reflects the value of the braking torque of the
system. If the braking torque is too small, the VFD still enables the overvoltage protection.
Calculation based on a standard 380V AC motor.
P――――Rated motor power (kW)
R
P
――――Rated dissipated power of the braking resistor (kW)
V――――DC operating point of the braking unit, generally set to be 700V
R――――Equivalent resistance of the braking resistor (Ω)

――――Conversion efficiency of mechanical energy during feedback, generally set

= 0.7.

――――Power dissipation safety factor of the braking resistor, set

= 1.4.
f
K
―――Braking frequency, indicating the time proportion that the regeneration process
accounts for the entire motor operation.
Generally, the values of
f
K
are as follows.
Uncoiling and reeling
f
K
＝50–60%
Oil pumping machine
f
K
＝10–20%
Elevator
f
K
＝10–15%
Centrifuge
f
K
＝5–20%
Crane whose lowering height exceeds 100m
f
K
＝20–40%
The load that brakes occasionally
f
K
＝5%
Others
f
K
＝10%
Resistance calculation basis: The braking resistor must completely absorb the regenerative
electrical energy of the motor.
Resistor absorbed power (V*V/R) = Motor regenerative electrical energy (watt) = 1000*P*

Resistor power calculation basis:

Dynamic Braking Unit Manual
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The regenerative electrical energy of the motor must be absorbed by the resistor, and
transformed into thermal energy for release.
R
P
=P*
f
K
*

*

=P*
f
K
*0.7*1.4
7.4 Input voltage class specifications and model selection for 380V VFDs
This table shows a model selection reference based on DC operating point 700V of the
braking unit.
Motor
power
(kW)
Braking
unit
model
Adaptive
braking
resistor
(Ω)
Dissipated power of braking
resistor (kW)
Min.
braking
resistance
(Ω)
Recommended
resistor model
100%
braking
torque
10%
braking
frequency
50%
braking
frequency
80%
braking
frequen
cy
18.5
DBU-055-4
26.5
2.59
12.95
20.72
6.4
20Ω@6000W
22
DBU-055-4
22.3
3.08
15.4
24.64
20Ω@6000W
30
DBU-055-4
16.3
4.2
21
33.6
20Ω@6000W
37
DBU-055-4
13.2
5.18
25.9
41.44
13.6Ω@9600W
45
DBU-055-4
10.9
6.3
31.5
50.4
13.6Ω@9600W
55
DBU-055-4
8.9
7.7
38.5
61.6
13.6Ω@9600W
75
DBU-055-4
Quantity:
Two
13*2
5.25*2
26.3*2
42*2
6.4*2
13.6Ω@9600W*
2
90
DBU-055-4
Quantity:
Two
10.8*2
6.3*2
31.5*2
50.4*2
13.6Ω@9600W*
2
110
DBU-055-4
Quantity:
Two
9*2
7.7*2
38.5*2
61.6*2
13.6Ω@9600W*
2
132
DBU-160-4
3.7
18.48
92.4
147.84
2.2
4Ω@30kW
160
DBU-160-4
3.1
22.4
112
179.2
4Ω@30kW
185
DBU-220-4
2.6
25.9
129.5
207.2
1.6
3Ω@40kW
200
DBU-220-4
2.4
28
140
224
3Ω@40kW

Dynamic Braking Unit Manual
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Motor
power
(kW)
Braking
unit
model
Adaptive
braking
resistor
(Ω)
Dissipated power of braking
resistor (kW)
Min.
braking
resistance
(Ω)
Recommended
resistor model
100%
braking
torque
10%
braking
frequency
50%
braking
frequency
80%
braking
frequen
cy
220
DBU-220-4
2.2
30.8
154
246.4
3Ω@40kW
250
DBU-315-4
2
35
175
280
1.1
4Ω@30kW*2
280
DBU-315-4
1.75
39.2
196
313.6
4Ω@30kW*2
315
DBU-315-4
1.56
44.1
220.5
352.8
4Ω@30kW*2
Note: The braking current shall not exceed the rated current.
7.5 Input voltage class specifications and model selection for 660V VFDs
This table shows a model selection reference based on DC operating point 1120V of the
braking unit.
Motor
power
(kW)
Braking unit
Model
Adaptive
braking
resistor
(Ω)
Dissipated power of
braking resistor (kW)
Min.
allowable
brake
resistanc
e (Ω)
Recommended
resistor model
100%
braking
torque
10%
braking
frequen
cy
50%
braking
frequenc
y
80%
braking
frequenc
y
75
DBU-090-6
16.73
10.5
52.5
84
12.4
24Ω@7500W
90
DBU-090-6
13.94
12.6
63
100.8
20Ω@9000W
110
DBU-160-6
11.40
15.4
77
123.2
7
16Ω@11kW
132
DBU-160-6
9.50
18.48
92.4
147.84
13.6Ω@13.2kW
160
DBU-160-6
7.84
22.4
112
179.2
11Ω@16kW
185
DBU-220-6
6.78
25.9
129.5
207.2
5.1
9.6Ω@18.5kW
200
DBU-220-6
6.27
28
140
224
9Ω@20kW
220
DBU-220-6
5.70
30.8
154
246.4
8Ω@22kW
250
DBU-350-6
5.02
35
175
280
3.2
7Ω@25kW

Dynamic Braking Unit Manual
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Motor
power
(kW)
Braking unit
Model
Adaptive
braking
resistor
(Ω)
Dissipated power of
braking resistor (kW)
Min.
allowable
brake
resistanc
e (Ω)
Recommended
resistor model
280
DBU-350-6
4.48
39.2
196
313.6
6.4Ω@28kW
315
DBU-350-6
3.98
44.1
220.5
352.8
5.6Ω@31.5kW
350
DBU-350-6
3.58
49
245
392
5.1Ω@35kW
Note: The braking current shall not exceed the rated current.
7.6 Braking resistor selection
It is recommended to use non-inductive resistors as braking resistors to reduce
inductance.
The braking resistor must be equipped with an overheating automatic isolation protection
device.
Ensure that no grounding fault to the braking resistor occurs, otherwise, major failure to
the device and VFD may occur.
The capacity of the braking resistor uses the reference value and is modified according
to load inertia, braking frequency, braking voltage threshold, and other characteristics. If
any questions, please contact us.
We have cement resistors, high power lacquered resistors, metal case, and other
non-inductive resistors available for purchase.
Note:
Braking units in parallel connection can expand the braking capacity.
The braking capacity of two braking units in parallel connection is twice that of a single
braking unit.
DBU-110-4=DBU-055-4*2

Energy Feedback Unit Manual
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Energy Feedback Unit Manual

Energy Feedback Unit Manual
-16-
Safety precautions
Read the manual carefully before installing, operating, servicing, and inspecting the energy
feedback 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.

Energy Feedback Unit Manual
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1 Overview
1.1 Overall technical characteristics
Voltage class
380V/660V/1140V
Braking torque
100% of rated torque: 1min (duty ratio: 25%). The energy
feedback units of 380V 90kW and higher & 660V 160kW
and higher can work continuously at 50% of rated torque,
and energy feedback units of other powers can work
continuously at 80% of rated torque.
AC-side power supply
380VAC/660VAC/1140VAC, 50/60Hz
AC-side power supply
voltage fluctuation
From +10% to -15% with phase imbalance of less than 2%
AC-side power frequency
fluctuation
Below 3Hz
Control mode
Current control method with the angle of 120 degrees
AC-side power factor
More than 0.9
Overload capacity
150% of rated current: 30s
Operation mode
External terminals, keypad
Fault output
Relay output
Status indication
LED keypad
Analog output
Voltage signal (0–10V)
Overcurrent protection
220% of rated current
Overload protection
150% of rated current: 30s
Overvoltage
830V/1250V/2400V on DC side
Overtemperature
Temperature resistance detection
AC-side phase loss fault
AC-side phase loss
AC-side frequency fault
Fluctuation is >3Hz
Power light indication
More than 50V on DC side