Rockwell Automation RELIANCE ELECTRIC INVERTRON DBU-50 User manual

INVERTRON DBU
Dynamic Braking Unit
Instruction Manual
Manual P/N. 899.05.26 User Manual: 49‘1328e (06)
Publication INVDBU-UM006F-EN-P
UL
CR

.

TABLE OF CONTENTS
49'1328 e DBU I
1. DESCRIPTION 1-1...1-2
Operation.......................................................................................................................1-1
Line voltage selection .................................................................................................... 1-2
Parameter setting on the inverter................................................................................... 1-2
Permissible loading of the electronics ............................................................................ 1-2
2. SPECIFICATIONS 2-1...2-4
Electrical specification of the Braking Unit ..................................................................... 2-1
Ambient conditions......................................................................................................... 2-1
Mechanical specification, dimensions ............................................................................ 2-2
Optional Diagnostic Card BUD....................................................................................... 2-3
3. MOUNTING AND CONNECTION 3-1...3-3
Mounting of the braking Unit .......................................................................................... 3-1
Short circuit protection fuses.......................................................................................... 3-1
Protection of braking resistors and conductors .............................................................. 3-1
Connection..................................................................................................................... 3-1
4. DESIGN INFORMATION 4-1...4-2
Calculation of braking power.......................................................................................... 4-1
Calculation of braking resistors ...................................................................................... 4-1
Example.........................................................................................................................4-2
Appendix A CE-Conformity A-1...A-4
EMC Directive ................................................................................................................A-1
Mounting instruction.......................................................................................................A-1
Wiring instruction ...........................................................................................................A-2
Cabinet mounted units ...................................................................................................A-2
Installation of standalone drives.....................................................................................A-4
Further documentation:
Instruction manual for GV3000/SE AC General Purpose and Vector Drive
Publication GV3000-UMxxxx-EN

GENERAL NOTES
II DBU 49'1328 e
Safety Instructions
DANGER, WARNING, and CAUTION point out potential trouble areas.
A DANGER alerts a person that high voltage is present which could result in severe bodily injury or
loss of life.
A WARNING alerts a person to potential bodily injury if procedures are not followed.
A CAUTION alerts a person that, if procedures are not followed, damage to, or destruction of
equipment could result.
DANGER:Before installing and/or operating this device, this manual must be understood by the
qualified electrical maintenance person who is familiar with this type of equipment and
the hazards involved. Failure to observe this precaution could result in bodily injury.
Machinery Directive
CAUTION:This device is a component intended for implementation in machines or systems for the
capital goods industry.
The start-up of this device in the European market is not permitted until it has been
confirmed that the machine into which the device is built is in conformance with the
regulations of the Council Directive Machinery 98/37/EWG.
Electromagnetic Compatibility (EMC-Directive)
CAUTION :The operating of this device in the European market is only permitted if the Council
Directive Electromagnetic Compatibility 89/336/EWG has been observed.
It is the responsibility of the manufacturer of the machine or system to observe the
immunity and emission limits, requested by the Council Directive EMC in the European
market. Guidelines for the installation according EMC-regulations - for shielding,
grounding, component arrangement as well as wiring instructions - are summarized in
Appendix A ‘CE-Conformance’ of this instruction manual.

DESCRIPTION
49'1328 e DBU 1 - 1
Operation
Frequency converters (Inverters) with DC bus and input diode rectifier bridge are suitable for the
operation of three phase AC-motors in two drive quadrants, motoring in both directions of rotation.
Braking with more than 10% of the rated inverter current is only possible with a braking unit.
Without a braking unit, an excessively rapid deceleration causes an increase in the DC bus voltage.
The regulator responds by
•shut-down due to DC bus overvoltage tripping (e.g. on GV3000: Fault HU)
•extending the set deceleration rate or increasing the output frequency depending on parameter
setting.
By the use of a Dynamic Braking Unit (DBU) and braking resistor the energy in the DC bus circuit can
be converted to heat.
The braking unit DBU is available in four sizes and two variants (Part No. in brackets):
DBU Size without Diagnostic card BUD with BUD built-in
37 kW DBU-50 (837.02.01) DBU-50-DIS (837.02.02)
75 kW DBU-100 (837.02.11) DBU-100-DIS (837.02.12)
150 kW DBU-200 (837.02.21) DBU-200-DIS (837.02.22)
300 kW - DBU-400 (837.02.41) *
* The Diagnostic card BUD is always built in on DBU-400 as a standard
NOTE: Until sept.1997 the units DBU-50 (837.02.00), DBU-100 (837.02.10) and DBU-200 (837.02.20)
with hysteresis type regulator BUA (813.25.00) have been delivered.
The new PWM type regulator BUC (813.01.00) is fully compatible to the BUA regulator.
45
47
48
47
PE
47
45
DBU
+
T
1)
Udc > 50V I > 0
3) Set DBU-DIS 839.25.41
24 V 0 - 20 mA
20 mA
24 V
29
101
T
0
115
M2)
BUC
813.01.00
BUS 813.03.00
2)
-+
X1 1 2 3 4 5 6
PE
Diagnostic Card BUD
1) If the resistor overheats, this contact operates a disconnect that removes AC power from the drive.
2) Fan on DBU-400 only 3) Diagnostic card BUD is built in on DBU-xx-DIS and DBU-400
Figure 1-1: Principle of operation of Inverter with braking unit

DESCRIPTION
1 - 2 DBU 49'1328 e
Line Voltage Selection
After removing the cover plate of the DBU the blue jumper plug with positions 460V / 415V is accessible
at the upper edge of the regulator card (middle on BUC, right on BUA).
This jumper plug defines the DC bus voltage at which the DBU switches the DB resistor to the DC bus.
When delivered from stock the DBU is adjusted for safety reasons to 460 V line voltage.
NOTE: If the blue jumper plug is missing, the DBU is set to 415V.
For the Inverters INVERTRON VTI / VCI / VGI type 415 V the blue jumper plug must be changed
from position 460 to 415.
Reason: On these inverters the max. permissible DC bus voltage is DC 720 V.
This fault trip level is fixed and assigned to the power semiconductors. It requests a DBU
turn-on voltage of 680 V, corresponding to 415 Vac line voltage selection.
For the GV3000 Inverters on line voltages up to 415 V the blue jumper plug must be set to position 415.
For the GV3000 Inverters on line voltages above 415 V and all the other inverters VTI / VCI / VGI type
460 V, GMI, GP2000 and SP500 the jumper must stay in position 460.
Parameter Setting on the Inverter
WARNING!
If an inverter drive is equipped with braking unit, the deceleration ramp extension or regenerative
torque limitation must be switched off depending on DC bus voltage. Please refer to the inverter
instruction manual.
Permissible Loading of the Braking Unit
To prevent thermal overload of the Braking Unit, assure that the unit works within the following limits:
In a time range of 10 minutes the permissible loading must be limited to the following current-time area
of any shape Imax x 2.5 minutes, with the following exception:
On DBU-400 current loading Imax (400 A) is permitted for 110 seconds every 10 minutes.
Examples:
1) Linear deceleration to zero speed of a drive with
high inertia connected (e.g. centrifuge)
2) Drive with active load (e.g. crane)
5 min.
10 min.
Pmax
5 min.
10 min.
Pmax
Pmax
2
Figure 1-2a Figure 1-2b

SPECIFICATIONS
49'1328 e DBU 2 - 1
Electrical Specification
Table 2-1: Power Ratings
DBU-50 DBU-100 DBU-200 DBU-400
Maximum braking current Imax 50 A 100 A 200 A 400 A*
Minimum braking resistor permitted
for max. braking power:
with 415V jumper 12.8 ohms 6.4 ohms 3.2 ohms 1.6 ohms
with 460V jumper 14.4 ohms 7.2 ohms 3.6 ohms 1.8 ohms
Continuous braking power at 460 V 9 kW 18 kW 36 kW 72 kW
Short-time braking power
with 415V jumper
with 460V jumper
34 kW
37.5 kW
68 kW
75 kW
135 kW
150 kW
270 kW*
300 kW*
Power loss (average) 250 W
*On DBU-400 current loading Imax (400 A) is permitted for 110 seconds every 10 minutes.
- Maximum DC bus voltage at terminals 45-47:........................................................................ DC 800 V
- Turn-on and Turn-off voltage of the DBU: ON OFF
a) with BUA: 415V jumper DC 680 V DC 650 V
460V jumper (default) DC 750 V DC 720 V
b) with BUC: Pulse width modulation PWM with 1 kHz switching frequency
Pulse width
720 750
100%
95%
0%
650 680
BUC
BUA
BUC
BUA
VDC
jumper 415V jumper 460V
Figure 1-3: DC bus voltage depending on pulse width (on BUC) respectively duty ratio (on BUA)
- Power consumption of the control circuits.................................................................................. 27 mA
Fan connection voltage and current consumption
only on DBU-400, terminals 0, 115. ................................................................... 115 V, 50/60 Hz, 0.2 A
Ambient Conditions
- Operation temperature .................................................................................................... 0 - 40 degr C
For temperatures higher than 40 degr C up to max 55 degr C,
the nominal continuous current Inom must be derated by ......................................1.5% per degr C
- Storage ........................................................................................................... -25 degr C....+55 degr C
- Transportation..................................................... -25 degr C....+70 degr C (+70 during max. 24 hours)
- Degree of protection....................................... .............................................................................. IP20

SPECIFICATIONS
2 - 2 DBU 49'1328 e
Mechanical Specification, Dimensions
121.5
ø6.5
220
7206
206
103
103
206
7
Weight: 3.1 kg
Figure 2-1: Dimensions and fixing holes for the Braking Units DBU-50 and DBU-100
80
8
350
157
PE 48 45 47 47
215
225
5
5
32
42 36 36 36 25 50
6.5
589
356
PE 47 47 45 48
1)
2)
3)
4)
310
0/115/
29/101
29 101
Type Weight: Power connections Control connections PE Fan
DBU-200 9 kg Terminal block below 1) Terminal block below 1) below without
DBU-400 10 kg Bus bars above 2) Terminals at fan carrier 3) above with 4)
Figure 2-2: Dimensions and fixing holes for the Braking Units DBU-200 and DBU-400

SPECIFICATIONS
49'1328 e DBU 2 - 3
Optional diagnostic card BUD
The diagnostic card BUD, (part No. 813.02.00) is incorporated on units DBU-xx-DIS and all DBU-400.
On units DBU-xx (with PWM-regulator BUC) the diagnostic card option set DBU-DIS (Part No. 839.25.41)
can be built in on site or used as a replacement part.
On DBU-400 units the BUD card is always built-in as a standard.
The BUD works independent from the DBU regulator based on separate DC bus voltage feedback
values and the voltage across the DB resistor. It replaced the DBU indication card BUB (set 839.25.00)
and contains besides the DC bus voltage and braking current indications two additional diagnostic
functions (available at terminals).
Udc > 50V I > 0
Set DBU-DIS
with Diagnostic Card BUD
24 V 0 - 20 mA
20 mA
24 V
-+
X1 1 2 3 4 5 6
DBU
Figure 2-3: Block diagram of the diagnostic card BUD (Set DBU-DIS)
Indications
•DC bus voltage: left LED lights when UDC > 50 V
•braking current : right LED lights when IB> 0
Switched output S1-2 (UDC > 50V)
Wearless transistor switch between terminals 1 (-) and 2 (+)
•S
1-2 is closed, when UDC > 50 V and IB= 0
•S
1-2 is open, when UDC > 50V and IB> 0, or when UDC < 50 V.
As shown in figure 2-4, switch S1-2 is closed after charging of the DC bus, at motor stand still or in
motoring operation mode.
motoring regenerative
operation operation
UDC
0
S1-2
Figure 2-4: Status of switch S1-2 depending on DC bus voltage
This switched output is a monitoring device for the DC bus and the function of the DBU, working
independent from the frequency converter and the DBU-regulator.
Loading of the transistor switch:........................................................................................ 24 V / 20 mA

SPECIFICATIONS
2 - 4 DBU 49'1328 e
Analog output A5-6
Signal A5-6 at terminals 5 and 6 is depending on the power P dissipated in the DB resistor.
The analog signal is generated through a filter circuit from the modulated voltage across the DB-
resistor. The indication range 0% to 100% pulse width (on BUC) respectively duty ratio (on BUA)
corresponds with 0 - 20 mA.
The scaling of the analog signal is depending on:
•jumpers 460V / 415V in relation with UDC and pulse width according to Figure 1-3,
•DB resistor selection, taking into account the minimum values according to Table 2-1,
•pulse width (on BUC) respectively duty ratio (on BUA) ED in %.
Calculation: P = ED x UDC
2/ R x 100 with 415V jumper: UDC = 650 V + (1.6 x analog signal [mA] )
with 460V jumper: UDC = 720 V + (1.6 x analog signal [mA] )
Example: jumper 460V, DB resistor 10 ohms
4 mA = 20% ED at 726V: 52.7 x 0.2 = 10.6 kW
19 mA = 95% ED at 750V: 55.4 x 0.95 = 53.4 kW (95%, 750 V are maximum values)
The analog output at terminals 5 and 6 must be supplied through an external DC current source at
terminals 4 (0 Volts) and 3 (24 V).

MOUNTING AND CONNECTION
49'1328 e DBU 3 - 1
Mounting of the Braking Unit
For free air circulation through the cooling fins of the power section, the braking unit must be screwed
onto a vertical panel according to figures 2-1 or 2-2. To prevent overheating due to heat build-up,
minimum clearances for air circulation of 100 mm above and below the unit must be observed.
Requested cooling air on forced ventilated DBU-400 is 158 m3/h (air flow direction from bottom to top).
Short Circuit Protection Fuses
A defective free wheeling diode will cause discharge of the Inverter-Bus into the braking unit. Therefore
the connections between inverter and braking unit (45-45 and 47-47) must be protected by the following
fuses:
Table 3-1: Short Circuit Protection Fuses
without Fuse Trip Indication with Fuse Trip Indication
Unit
Type 2 Fuses
Type: aR, 660 V
Fuse Holder 2 Fuses
Type: aR, 660 V
Fuse Holder
Part No. Type Part No. Part No. Type Part No.
DBU-50 50 A 553.15.00 22 x 58 511.27.13 63 A 553.44.00 27 x 60 512.32.02
DBU-100 100 A 553.18.00 22 x 58 511.27.13 100 A 553.44.02 27 x 60 512.32.02
DBU-200 200 A 553.44.05 27 x 60 512.32.00 200 A 553.44.05 27 x 60 512.32.02
DBU-400 400 A 553.32.15 DIN 80 511.24.00 400 A 553.32.15 DIN 80 511.24.00
Switch: 553.26.29
Terminal Protection Cover (Pair) for fuse holder Type 27 x 60: Part No. 512.32-10
Protection of Braking Resistors and Conductors
In case of a failed DBU (IGBT short circuit or constantly ON command) the rectified AC line voltage is
passed to the braking resistor. This fault is not detected with the temperature sensor on the heatsink of
the DBU, as the IGBT is not switching and therefore its temperature is not increased.
To inhibit possible damages due to overload on braking resistors, leads and input rectifier,
it is recommended to install:
•a thermal switch on the braking resistor heatsink or
•the optional indication card BUD with connection of switched output S1-2
The contact of the thermal switch should be wired in series with the thermal switch on the DBU.
Connections
Connect braking unit, fuses and braking resistors according to the wiring diagram in Figure 1-1.
Table 3-2: Control - and Signal Connections
Control terminal
Thermostat
Fan supply
29,101
0,115
Cable cross section max. 4 mm2 (AWG11)
Tightening torque 0,8 Nm
Press contact type
terminals at
BUD-Card
Signal outputs
1, 2
3, 4
5, 6
Cable cross section max. 1,5 mm2 (AWG16) Use screened
cable *
* Two cable clamps at the fan carrier (part of the BUD Option) serve as grounding of the shield as well
as pull-relief.

MOUNTING AND CONNECTION
3 - 2 DBU 49'1328 e
Power Connections
Refer also to the installation instructions according EMC regulations in Appendix A.
1. Connection leads between Inverter and DBU
During switching of the braking units IGBT the inductance of the lead between the DC bus capacitors of
the Inverter and the DBU generates short time (some µs) overvoltage peaks. These overvoltages ∆U,
which are damped by RC snubber circuits in the DBU, must not exceed 200 volts. This can be reached
on single motor drives (acc. to connection example a) by the following measures:
•limitation of the total cable length between Inverter and DBU to 1,5 m.
This must be strictly followed, specifically on DBU-200 and -400.
•The conductors must be bound together and run separated from other conductors or multi core cable
(EMC shielded) to reduce the cable inductance.
If a DBU is connected to several inverters, which are coupled through a common DC bus, ∆U must also
not exceed 200 volts. The inductance of the DC bus connection leads to the engaged DC bus capacitors
must be kept low by the following measures:
•short leads with low inductance,
•placing of the DBU between the biggest DC bus capacitors.
General applies: ∆U = L
C•∆I
∆U: local permitted overvoltage on the DBU: 200 V
L: effective inductance of the DBU input leads for the switched current ∆I
C: effective capacitance of the snubbers on the DBU according to Table 3-3
∆I: switched current, depending on jumper 415V / 460V and R.
Connection example
Connection of a DBU 400 to single motor drives
47
47
45
45
DBUGV3000 max. 1.5m

MOUNTING AND CONNECTION
49'1328 e DBU 3 - 3
2. Connection leads between DBU and DB resistor R
Because of the many different types of DB resistor constructions the inductance differs in a wide range.
High inductance (e.g. wire wound on ceramic core) at low resistance can limit the permitted lead length
especially for DBU-200 and -400.
General applies: τ= L/R including connection lead must be < 20 µs.
The inductance of the conductors can be reduced by bounding together single leads or using multi core
(EMC shielded) cable.
To connect the braking resistors, heat-resistant cables and cable sockets are to be used (min. 90°C).
For cable cross sections (mm2) depending on max. continuous braking current (rms) and tightening
torque see Table. 3-3
Table 3-3: Power connections
DBU-50 DBU-100 DBU-200 DBU-400
Max. mean rms braking current [A]
(Imax, 25% duty ratio) for cable selection 25 50 100 200
Capacitance of the built-in snubber [µF] 1 1 1 5
Connection No.
DC bus, braking
resistance
Terminals up to
352, bus bars
with bolts M10
above 352
45, 47,
47, 48
Maximum wire size mm2
AWG
Tightening torque Nm
16
6
2,5
16
6
2,5
35
2
2,5
95
4/0
10
Earth protection
Terminals up to
352, bolts M10
above 352
PE Maximum wire size mm2
AWG
Tightening torque Nm
16
6
2,5
16
6
2,5
16
6
2,5
95
4/0
10

DESIGN INFORMATION
49'1328 e DBU 4 - 1
Calculation of braking power
Calculation of the braking power P at linear braking rate tB
P [kW] =
Jnn
91200 tB
••
•
∆
J[kgm
2] : moment of inertia of the drive systems, relative to the motor shaft
n[min
-1] : speed before the braking process
∆n[min
-1] : difference in speed before and after the braking process during tB
tB[s] : braking time for ∆n
Please note that a linear braking rate at the beginning of the deceleration will require maximum braking
power (as calculated) and the braking power then decreases linear with speed.
The maximum braking power is an essential dimensioning criteria for DBU and DB resistor.
Calculation of the maximum braking power Pmax and minimum braking time tBmin
depending on maximum inverter current
Pmax [kW] = Un .Imax .cos ϕ.3. η/ 1000
Un [V] : nominal motor voltage
Imax [A] : maximum output current of inverter device
cos ϕ: cosine phi of the motor (0.86)
η: efficiency ( ≅0.9)
The minimum braking time can then be calculated as follows:
tBmin = Jnn
91200 Pmax
••
•
∆
If the moment of inertia J is not known, the braking time can be determined from the acceleration time.
To do this, accelerate the drive at a fast rate in current limit and measure the acceleration time.
The braking time must be selected to be smaller than this acceleration time.
Calculation of resistance value
The resistance value R ≥Rmin in ohms depending on max. braking power can be calculated as follows:
for 380/415 V: R = 439
P [kW] for 460 V: R = 534 P [kW]
NOTE: When selecting the actual resistance value and the DBU type, make sure that at maximum
braking power the duty ratio of the DBU is as high as possible.
Specification of the braking resistor
Please contact your braking resistor supplier.
The following information is required for specification of the braking resistor:
Duty cycle, braking time - cooling time
•maximum braking power, resp. max. braking current and duty ratio
•average braking power and duty ratio
- maximum DC bus voltage, see jumper 415/460, depending on inverter type.
- time constant of the braking resistor, ratio τ= L/R, specifically on resistors for
DBU-200 and DBU-400 with long resistor connection cables.

DESIGN INFORMATION
4 - 2 DBU 49'1328 e
Example
Roller table with 20 motors:
Each motor: 2.5 kW, 4.5 A, 460 V - 60 Hz
120 operations/h
Braking time: 1.8s
Braking torque = nominal torque
150% Overload capability required: 90 x 1.5 = 135 A
Total power: 20 x 2.5 kW = 50 kW / AC 90 A →GV3000 AC140
Braking resistance R = 534
50 kW =10 Ω→DBU 75 kW, Part No. 837.02.11 required
Order from qualified supplier a braking resistor with the following specifications:
Resistance value: 10 ohms
Braking power: 50 kW
Braking time: 1.8 s
Cooling time: 28 s
Max. DC voltage: 800 V

A - CE CONFORMITY
49'1328 e DBU A - 1
EMC Directive
This device is a component intended for implementation in machines or systems for the capital goods
industry. The units have been tested to meet Council Directive 89/336 Electromagnetic Compatibility
(EMC) and all applicable standards (listed in the technical construction file).
With the measures as described in this guidelines the DBU can be operated CE-conform according to
product standard EN 61800-3 or generic standards EN 50081-2, EN 50082-2 as follows:
Emission limits:
Class A, group 1 in the first environment (public LV supply network) on inverters with RFI filter,
Class A, group 2 in the 2nd environment (industrial supply network) on inverters with RFI filter,
group 2* in the 2nd environment (industrial supply network) on inverters with HF filter.
Immunity: Performance criteria A in the 2nd environment (industrial supply network).
For information about RFI- and HF-filters refer to the GV3000 Instruction manual.
CAUTION: The conformity of the device to any standard does not guarantee that the entire
installation will conform. Many other factors can influence the total installation and only
direct measurements can verify total conformity. It is therefore the responsibility of the
machine manufacturer, to ensure, that the EC-conformity is met.
Essential Requirements for Conforming Installation
The following items are required for CE conformance:
1. The complete drive system must be electromagnetically closed (Faraday cage).
2. This can be accomplished either by mounting all drive components (Inverter, RFI-Filter, DBU and
braking resistor) in a common cabinet (see Figure A-2) or in separate metallic enclosures (A-3).
3. Between the different drive components (inside or outside of enclosures) and the protection earth
of the line input (PE) an uninterrupted connection (green/yellow conductors) must be provided to
ensure correct grounding of the equipment.
4. All external power wiring (except line input) must be screened cable or run in a separate steel
conduit (e.g. DBU to braking resistor).
5. The braid of screened cables must be connected either to the common cabinet ground bus-bar or
to the enclosure by the use of suitable, EMC-tested cable glands.
Mounting Instructions
Cabinet Mounted Drives (see Figure A-2)
If the Drive Components are mounted in a cabinet, the following rules must be observed:
•If located in a common cabinet, all drive components must be screwed directly to a blank (not
painted) panel with good conductivity and the largest possible contact area.
•The support panel for the DBU and inverter with filters must be a conducting steel sheet, with a
common ground busbar at the bottom. This ground busbar, mounted in front of the terminals, must
be solidly connected to the panel, ensuring good conductivity.
•All cable screens, entering the cabinet must be solidly connected to the control cabinets ground
busbar or to the ground stud of the inverter with a large connection area and good conductivity to
ensure that the grounding represents a low impedance for HF-signals.
•Galvanized cable brackets as shown in Figure A-1 are recommended.
Standalone Drives in Enclosures (see Figure A-3)
•If the drive components (Inverter, RFI-Filter, DBU and braking resistor) are mounted in separate
enclosures, this must be metallic conductive and the diameter of ventilation holes should not
exceed 6 mm.
•The spacing between braking resistor assembly and enclosure shall be 100 mm minimum.

A - CE CONFORMITY
A - 2 DBU 49'1328 e
Wiring Instruction
General
•All the leads of a cable connection shall have the same cross section.
(earth conductors with cross section >162: min. 162 or 50% of phase lead)
•The connections between Inverter and DBU should be as short as possible!!
•Signal leads inside the cabinet must be distanced from Power leads.
Screened Cables entering the Control Cabinet (see Fig. A-2)
•The screen must be tinned copper braid or tinned steel braid.
•If screened cables are not available (limited by the obtainable cross sections) the individual
conductors and protective conductors must be run in steel conduits or enclosed metal cable ducts
also connected to earth at both ends.
•Signal and control leads (e.g. reference, feedback, relays) must be screened cable as specified in
Figure A-1. The individual conductors must be stranded, but twisted pairs are not required.
The screen must be grounded at both ends.
•The motor cable shall be 4-wire screened cable (3 phases and earth conductor green/yellow) as
specified in Figure A-1 or run in a separate steel conduit.
Power Connections between IP20 Enclosures (see Fig. A-3)
•The power cables between inverter - DBU enclosure and DBU enclosure - braking resistor
enclosure shall be 3-wire screened cable (+, - and earth conductor green/yellow) as specified in
Figure A-1 or run in a separate steel conduit.
•Between the different enclosures and the protection earth of the line input (PE) an uninterrupted
connection (green/yellow conductors) must be provided to ensure correct grounding of the
equipment.
•The braid of screened cables must be connected to the enclosures by the use of suitable, EMC-
tested cable glands.
Stranded copper wire
Plastic insulation
Inner plastic sheath
Compact screen of galvanized (tinned) copper or steel braid
Outer plastic jacket
Figure A-1: Specification for screened cable
Cable Glands
•Use suitable EMC-tested cable glands only.
•The conductivity of the screen earth connection is ensured by laying the braid over a plastic cone
which will press it to the inner side of the gland when mounted.
•It is important that the connection area is 360 degree around the cone.
•The cable glands provide pull-relief through the cable jacket.

A - CE CONFORMITY
49'1328 e DBU A - 3
Configuration
U,V,W L1- L3
U,V,W
M
PE
PE
2
1
5
3
4
G
R
DBU
45, 47
Cabinet
Panel
Braking resistor
Inverter
RFI-Filter
AC-Input line reactor
AC-Input contactor
AC-Input fuses
Terminals for 4-wire AC-input
cable (L1,L2,L3, PE)
Cabinet protection ground
busbar
➀Cable bracket
➁Shield
➂Shielded 4-wire
motor cable
➃Shielded signal
conductor cable
(feedback, reference)
➄EMC-tested armored
cable gland at terminal box
Figure A-2: Example for control cabinet configuration

A - CE CONFORMITY
A - 4 DBU 49'1328 e
Installation of Standalone Drives in IP20 Enclosure
U,V,W
R, S, T (L1, L2, L3)
U,V,W
M
PE
5
3
4
RFI
FILTER
5
INVERTER
1
G
L1, L2, L3
6
E
L1', L2', L3'
E'
45,47 R
DBU
45,47 47,48
PE
6 6
➀AC-Line input
➂Screened 4-wire motor cable
➃Screened signal conductor cable(feedback, reference)
➄EMC-tested armored cable gland at inverter and terminal box
!Screened cable with PE-conductor
Figure A-3: Example for standalone drive configuration