INSTRUCTIONS
GE Industrial Control Systems
6KBU300
Braking Unit
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6KBU300 Braking Unit
Instruction Manual
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This book replaces the Instruction Book GEI-100350A Rev. 1.0 (9/97)
All rights reserved
These instructions do not purport to cover all details or variations in equipment, nor to provide every possible contin-
gency to be met during installation, operation, and maintenance. If further information is desired or if particular prob-
lems arise that are not covered sufficiently for the purchaser’s purpose, the matter should be referred to GE Industrial
Control Systems.
This document contains proprietary information of General Electric Company, USA and is furnished to its customer
solely to assist that customer in the installation, testing, operation, and/or maintenance of the equipment described.
This document shall not be reproduced in whole or in part nor shall its contents be disclosed to any third party without
the written approval of GE Industrial Control Systems.
© 1998 by General Electric Company, USA. All rights reserved.
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6KBU300
CONTENTS
1. GENERAL ———————————————————————————— 1
2. MAINS CHARACTERISTIC —————————————————————— 1
3. TECHNICAL DATA ————————————————————————— 1
3.1. DIMENSIONS AND WEIGHTS ———————————————————————— 1
3.2. HARDWARE SPECIFICATIONS ———————————————————————— 3
3.2.1. Power required —————————————————————————— 3
3.2.2. Internal fuses —————————————————————————— 3
3.2.3. Signalling LEDs —————————————————————————— 3
3.2.4. Terminal strip —————————————————————————— 3
3.2.5. Dip Switches description —————————————————————— 5
3.3. SELECTION OF THE INTERVENTION THRESHOLD ————————————————— 5
3.4. PARALLEL CONNECTION OF THE UNIT————————————————————— 5
3.5. OVERTEMPERATURE ALARM. ———————————————————————— 7
3.6. USE OF DC LINK DISCHARGE FUNCTION ———————————————————— 8
4. DIMENSIONING OF THE BRAKING UNIT AND CORRESPONDING RESISTANCE 1
4.1. SIMPLIFIED DIMENSIONING OF THE RESISTANCE ———————————————— 4
5. MINIMUM VALUE OF THE RESISTANCES THAT CAN BE UTILIZED ———— 1
6. STANDARD BRAKING RESISTANCES ————————————————— 1
7. EXTERNAL PANEL MOUNTED DC FUSE ———————————————— 1
8. BLOCKS DIAGRAM————————————————————————— 1
I
—————— CONTENTS ——————
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6KBU300
1. GENERAL
The braking unit 6KBU300 is basically composed by a static switch (IGBT) controlling the voltage of the intermediate
circuit of the inverter (DC Link), dissipating the energy generated by the motor (and correspondent load) connected
to the inverter while deceleration steps, by turning on and channeling excess energy through a resistor.
With this technique it is possible to obtain faster decelerations, operate overhauling loads avoid the tripping of the
“Overvoltage” protection of the inverter, which could be caused by a sudden increasing of the DC Link voltage.
Through a parallel connection of the units between terminals C and D, and a cascade connection of the braking
command (master/slave configuration), it is possible to parell four-units in connection.
A thermal protection contact input of the braking resistor with latched alarm is provided.
The latched alarm can be reset, once the alarm condition has been eliminated, by means of the button present on
the unit, or by a remote command, or switching off and on again the braking unit.
A quick discharge of the inverter’s intermediated circuit (DC Link) can be commanded.
This command must be directly interblocked with the contactors that supply the energy to the inverters
and suitably interlocked to not discharge while the drive is enabled.
1
1
—————— GENERAL ——————
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6KBU300
2. MAINS CHARACTERISTICS
-
-
-
-
-
-
Protection IP20
Max. working temperature 40°C (104°F) ambient (max 50°C (122°F) with a 20% of derating)
Costant switching on time (max. time ON) 3 minutes
Max.duty cycle admitted 50%
Supply of the circuit obtained by the DC Link
Possibility of parallel connection up to 3 units managed by a “MASTER” unit (4 slave units managed by a
drive set as master)
-
-
-
-
-
-
-
-
DC Bus threshold set by dip switches
Signaling of the +24V supply presence (Green diode led +24V)
Signaling of the Brake unit activity (Yellow diode led BR)
Signaling of alarm condition AL (Red diode led AL)
Signaling of OK condition (Green diode led OK)
OK relay dry contacts available for alarm sequences
Input to connect a resistor mounted klixon contact
Possibility of quick discharge of the DC Link.
1
2
—————— MAINS CHARACTERISTIC ——————
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6KBU300
3. TECHNICAL DATA
Model
Dissipated power @ Full load
Peak current
Average current
20 A
6KBU300-20
6KBU300-50
6KBU300-85
130 W
300 W
400 W
50 A
100 A
170 A
50 A
85 A
bu0005
WARNING!
The electronic circuit of the braking unit is directly connected to the DC Link whose voltage
value can reach up to 770Vdc.
When the cover of the drive is not removed, the live parts are not accessible (IP 20)
3.1. DIMENSIONS AND WEIGHTS
BR CR C D
b1
b
a1
c
a
Model
a
b
c
a1
b1
lbs/Kg
in/mm in/mm
in/mm
in/mm
in/mm
6KBU300-20
6KBU300-50
6KBU300-85
5.7/144 12.6/320 8.27/210
5.7/144 12.6/320 8.27/210
5.7/144 12.6/320 11.1/280
2.8/71 12.1/307
2.8/71 12.1/307
2.8/71 12.1/307
M 6
M 6
M 6
11.5/5.2
12.5/5.7
15/6.8
bu0045
1
3
—————— TECHNICAL DATA ——————
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GEI-100350A
+24V
BU-300
F2
75
76
75
NC
76
NC
NC
S3 RESET
1
2
+24V
0V24
TIM
3
4
RESET
MCMD
0V24(MCMD)
SIN
5
6
7
8
SIN
SOUT
SOUT
9
10
NC
400V
640V
680V
745V
S1
1. DC Link input power must be removed
and fully discharged before removing
cover, or performing maintenance or
inspection
DCHG
ON
2. Do not perform voltage test with meggar
on regulation card terminals
CAUTION
SLAVE
MASTER
MASTER
BR
GE Drive
OK
AL
Front view
2
3
—————— TECHNICAL DATA ——————
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6KBU300
3.2. HARDWARE SPECIFICATIONS
3.2.1. Power required
The supply of the braking unit is directly obtained by the DC Link and the maximum consumption is 15W.
3.2.2. Internal fuses
Denomination
Protection for
Switching input supply
Fuses
F1
F2
4A 500V slow 6 x 32 mm
315mA 250V slow 5 x 20 mm
+24V supply (terminals 1 and 2)
Master output command (terminals 5 and 6)
Supply of the internal fan (+24V)
F3
1A 250V slow 5 x 20 mm
bu0015
The fuse F2 for the +24V supply (terminals 1 and 2) and Master output command (terminals 5 and 6) is mounted
on the front panel.
Replacement vendor sources:
Fuse 1
Fuse 2
- Omega (Europe) GF632240
- Omega (Europe) ST520131
- Littlefuse 218315
Fuse 3
- Omega (Europe) ST520210
- Littlefuse 218001
3.2.3. Signalling LEDs
Denomination
Colour
green
yellow
yellow
green
red
Function
24 V
MASTER
BR
It shows presence of the power supply
The braking unit is set as master
The braking unit is active (braking)
OK relay status (closed = OK)
It shows the alarm condition
OK
AL
bu0020
3.2.4. Terminal strip
The power terminal strip is composed by the following terminals:
Terminals
C
Function
I/Q
Volt. max.
Curr. max.
Connection to the intermediate circuit of the
inverter
I
770Vdc
I peak
Connection to the intermediate circuit of the
inverter
D
I
770Vdc
I peak
CR
BR
PE
Connection to the braking resistor
Connection to the braking resistor
Ground connection
Q
Q
–
745V dc
745V dc
–
I peak
I peak
–
bu0025
3
3
—————— TECHNICAL DATA ——————
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GEI-100350A
Regulation board terminal strips:
Terminals
Name
+24V
Function
I/Q
Volt. max.
Curr. max.
200mA
–
1
2
Supply for commands TIM-RESET
0V potential of the +24V supply
Q
24V
–
0V 24V
Connection for the thermal contact of
resistor protection
3
4
TIM
I
15...30V
15...30V
3.2...6.4 mA
3.2...6.4 mA
RESET Remote Reset of alarm condition
MCMD Slave unit command (Master output)
I
5
6
Q
24V ± 5%
–
30 mA
–
0V 24V
SIN
0V potential of MCMD command
Slave unit input command
7
I
8...30V
8...30V
8...30V
8...30V
250Vca
250Vca
16 mA
16 mA
16 mA
16 mA
1 A
8
SIN
Slave unit input command
I
9
SOUT
SOUT
OK
Cascade connection of Slave units
Cascade connection of Slave units
OK relay dry contact (closed = OK)
OK relay dry contact (closed = OK)
Q
Q
Q
Q
10
75
76
OK
1 A
bu0030
Maximum cable sizes for power terminals C,D,CR,BR
Braking Unit type
Maximum Permissible Cable Cross-Section
[mm2]
AWG
flexible
10
multi-core
6KBU300-20
6KBU300-50
6KBU300-85
10
16
35
12
10
2
16
35
bu0031
Maximum cable sizes of the regulation section terminals
Terminals
1 ... 76
Maximum Permissible Cable Cross-Section
[mm2]
AWG
22 ... 16
flexible
multi-core
0.35 ... 1.5
0.35 ... 1.5
bu0032
4
3
—————— TECHNICAL DATA ——————
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6KBU300
3.2.5. Dip Switches description
Denomination
Function
S1-1
Enabling of the function for quick discharge of the DC link
Standard = OFF
S1-2 ... S1-5
Selection of intervention threshold of the braking unit
Braking threshold
400V dc
S1-2
OFF
OFF
OFF
ON
S1-3
OFF
OFF
ON
S1-4
OFF
ON
S1-5
ON
640V dc
OFF
OFF
OFF
680V dc
OFF
OFF
745V dc
OFF
S1-6
S2
Not used
MASTER = Selection of braking unit function as Master (standard)
SLAVE = Selection of braking unit as Slave
S3
Button Reset of alarm condition
bu0035
3.3. SELECTION OF THE INTERVENTION THRESHOLD
The DC threshold of the braking unit must be set accordingly to the supply voltage value of the connected
inverter, setting the switches as described in the following table.
NOTE:
It is possible to select only one braking threshold at a time.
Voltage
Braking threshold
[VBR
Position of the switches
supply
230Vac
400Vac
460Vac
]
S1-2
OFF
OFF
ON
S1-3
OFF
ON
S1-4
OFF
OFF
OFF
S1-5
ON
400Vdc
680Vdc
745Vdc
OFF
OFF
OFF
bu0010
3.4. PARALLEL CONNECTION OF THE UNIT
There is the possibility to connect up to four braking units in parallel. For this purpose, terminals C and D must be
parallel connected and one of the units must be set as Master function, while the others as Slave (through switch
S2).
Only the Master needs to be selected for the desired intervention threshold (through switches S1-2...S1-5).
Connect the braking units as showed in the picture, paying particular attention to the correspondance of the
terminals connection C and D. For the cascade’s command connections (terminals 5 ... 10) correspondence of
terminals polarity is not requested, but it is advisable to use twisted cables.
5
3
—————— TECHNICAL DATA ——————
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GEI-100350A
In this configuration, when the Master unit reaches the set intervention threshold, it manages also the intervention
of the first Slave unit by means of the command MCMD (output terminals 5 and 6), which is cascade connected
to the input SIN of it (terminals 7 and 8). At its turne, the second Slave will be enabled by the command SOUT
(output terminals 9 and 10) of the first Slave.
In case of inverters provided with internal command for external brake units, all the 6KBU300 units must be set
as Slave. The terminals MCMD and 0V24 of the drive have to be connected to the terminals 7 and 8 (SIN) of the
first 6KBU300, which will be of course connected to the next through its own terminals 9 and 10 (SOUT), as
described in the next page.
NOTE:
When a very close mounting of several braking units is needed, it is necessary to keep among
them a minimum distance of 5 centimeters (2 inches).
NOTE:
WRONG CONNECTIONS OF THE POWER PART CAN CAUSE THE DESTRUCTION
OF THE UNIT AND/OR OF THE CONNECTED INVERTERS IF DC LINK FUSES
ARE NOT SUPPLIED !!
AC Input
from C and D of inverter
*
*
INVERTER
MASTER
CR
BR
C
C
D
D
MASTER
9
10
5
7
6
8
7
8
C
CR
BR
*
*
*
*
C
CR
BR
D
SLAVE
D
SLAVE
10
9
7
10
9
7
8
8
CR
BR
C
*
*
*
*
CR
BR
C
D
SLAVE
D
SLAVE
9
10
9
10
* If supplied (see section 7)
** MCMD terminal is available only for Drives
having "Product configuration C1" or higher
Example of three units connected in parallel through 6KBU300 or inverter Master
6
3
—————— TECHNICAL DATA ——————
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6KBU300
The max. lenght of the connections between braking units and inverters must not exceed two meters, (the
twisted connection with the appropriate wire section, is always supplied together with the braking unit).
For the parallel connection of braking units, the user must always use a twisted cable; the units should however
be mounted side by side and the connections between terminals C and D should be kept as short as possible.
The power fuses of the correspondent inverters must be super fast.
3.5. OVERTEMPERATURE ALARM.
When the braking resistor reaches too high temperature, there is the possibility to trip out the braking unit. This
happen by means of the thermal relay (Klixon), and connecting its contact (normally closed) between the output
+24V (terminal 1) and the input protection TIM (terminal 3).
The contact of the thermal relay can be also externally supplied with a voltage between 15 and 30V whose 0V
potential must be connected to the 0V24V (terminal 2).
When there is the intervention of the thermal relay (opening of the contact) the braking unit is immediately tripped
, the red led AL lights on and the OK relay contact opens (terminals 75 76).
When an Overtemperature alarm occurs due to an overheating of the power module’s heatsink (opening of the
relative thermal relay), a BU trip occurs.
Once the alarm has been eliminated, it is possible to reset the braking unit using one of these modalities:
-
-
-
through button S3
through remote command inserted on the terminal 4
removing BU from DC BUS
The diagrams in the following pictures show a typical connection for protection with an external contact for the
alarm reset.
To the inverter
To the inverter
5
6
5
6
CR
BR
C
R
CR
BR
C
R
D
15…30Vdc
0V
D
3
2
4
3
1
PE
7
PE
4
10
8
9
Alarm reset
10
9
7
8
Alarm reset
Using the internal power supply of the braking unit
Using external power supply from the unit
7
3
—————— TECHNICAL DATA ——————
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GEI-100350A
3.6. USE OF DC LINK DISCHARGE FUNCTION
The braking unit can be used for discharging of DC Link with high capacitive value (e.g. in systems where the
DC Link is parallel connected) by a dipswitch setting.
In order set the switch S1-1 in position ON and bridge terminals 9 and 10.
In this condition the discharge of DC Link is obtained up to a value equal or lower than 60Vdc, applying an
external voltage between 10 and 30Vdc to the terminals 7 and 8 (SIN) or using the internal voltage present at the
terminals 1 and 2.
In order to avoid damages to the braking resistor, the user must pay particular attention to the inser-
tion sequence of this command. The signal must be supplied to the braking unit through an interblocked
contact with the contactors that supply the inverters.
8
3
—————— TECHNICAL DATA ——————
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6KBU300
4. DIMENSIONING OF THE BRAKING UNIT AND
CORRESPONDING RESISTOR
What below indicated should be meant in general, because point 6 reports a list of the normalised resistor which
must be used with the braking units of the series 6KBU300-.. for the supposed conditions.
Taking into account that:
PPBR [W]
PNBR [W]
EBR [J]
Peak power while braking
Rated power of the resistor
Braking energy
VBR [V]
Braking voltage threshold
Peak braking current
IPBR [A]
IAVBR [A]
IPBU [A]
Average braking current
Peak current of the braking unit
Initial and final speed
n1, n2 [RPM]
tBR, T [S]
JTOT [Kg* m2]
Braking time and cycle time
Total moment of inertia (referred to the motor shaft )
We will have:
n1-n2
tBR
2Π
60
*
PPBR = JTOT * n1 *
f001
JTOT
2
2Π
60
)2*(n12-n22)
EBR
=
*(
PPBR
VBR
IPBR
=
f003
VBR
IPBR
RBR = ≤
Ohmic value of the resistor:
f004
PPBR * tBR
2T
EBR
T
PNBR
=
=
Rated continuous power of the resistor:
f005
Attention! The value calculated here has to be considered carefully:
the formula calculates an average power value which may be considerably different
from the istantaneous power in case of very low duty-cycles.
Normally, resistors are not able to sustain a peak power greater than 5 to 10 times their rated
power. For this reason if the duty-cycles are less than 10%, the value calculated here can not
be used as rated power of the resistor and considerations made at 4.1 and 6 have to be taken
into account. Consult your resistor manufacturer for overload capability of resistors.
1
4
—————— DIMENSIONING... AND CORRESPONDING... ——————
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GEI-100350A
Being normally n2 = 0 (stop), we will have that:
1
2
EBR
=
PPBR * tBR
f006
IPBU ≥ IPBR
Braking unit features:
f007
This means that the peak current admissible by the 6KBU300-... must be equal or higher than the effective one.
Then for the average current we will have:
EBR
tBR * VBR
IAVBR
=
IAVBU ≥ IAVBR
f008
Sample calculation
Data:
- AC Input voltage
- Drive model
3 x 460 V
6KAV3015
15 HP
- Rated motor power
- Rated motor speed
- Moment of inertia of the motor
(PM)
(nn)
(JM)
(JL)
(MS)
(n1)
(n2)
(tBR)
(T)
3515 rpm
0.033 kgm2
0.95 kgm2
10% of motor nominal torque
3000 rpm
- Moment of inertia loading the motor shaft
- Friction of the system
- Initial braking speed
- Final braking speed
- Braking time
0 rpm
10 sec
- Cycle time
120 sec
We will have:
JTOT= JM + JL = 0.033 + 0.95 = 0.983 kgm2 and
∆ω = [2Π * (n1 - n2)] / 60 sec/min = 2Π * 3000 / 60 = 314 sec-1
Rated motor torque:
MM = PM / ωn = (15 * 745.7) / ( 2Π * 3515 / 60) = 30.4 Nm
MS = 0.1 MM = 3.04 Nm
it follows that
The braking energy is given by:
EBR = (JTOT / 2) * (2Π / 60)2 * (n12 -n22) = (0.983 / 2) * (0.10472)2 * 30002 = 48509 Joules or Wsec
2
4
—————— DIMENSIONING... AND CORRESPONDING... ——————
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6KBU300
But, if we want to take into account also the friction of the system, the braking energy that the braking unit will
need to dissipate is lower. To do this we can calculate EB as follows:
The required braking torque is
Mb = (JTOT * ∆ω) / tBR = 0.983 * 314 / 10 = 30.9 Nm
In reality the friction torque “helps” the motor, so we obtain
MbM = Mb - MS = 30.9 - 3.04 = 27.86 Nm
The brake process average power is given by
PAVE = (MbM * ∆ω) / 2 = 27.86 * 314 * 0.5 = 4374 W
And the new value of braking energy that we obtain in this way is
New EBR = PAVE * tBR = 4374 * 10 = 43740 Joules or Ws
which is obviously lower than the previous one.
The peak braking power is given by
PPBR = (JTOT * n1 * ∆ω * 2Π) / (tBR * 60) = 9.7 kW then we continue with
IPBR = PPBR / VBR = 9700 / 745 = 13A and
RBR ≤ VBR / IPBR = 745 / 13 = 57 Ω
Being IPBR = 13A, here we can already see that the unit 6KBU300-20 covers our needs. Now we have to
choose the resistor:
The nominal power of the resistor has to be
PNBR = (PPBR * tBR) / 2T = (9700 * 10) / 240 = 404 W
As we can see, the nominal power of the resistor is relative low due to a low duty-cycle (10 / 120) but the resistor
must be able to withstand the energy that is applied to it during the 10 seconds of braking. This energy is 43740
Joules. If we go on the table of normalized resistors, the type BRR 1K0T 49R has a nominal power that would
be sufficient but the value of EBR is too low (21kWsec).
For this reason our final choice is the type BRR 1K3T 31R that has EBR = 44kWsec.
3
4
—————— DIMENSIONING... AND CORRESPONDING... ——————
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GEI-100350A
4.1. SIMPLIFIED DIMENSIONING OF THE RESISTOR
In case all the above mentioned data were not available, it is possible to carry out the braking resistor calculation
in a simplest but approximately way.
This solution can lead to an overdimensioning of the resistor which has to be used.
For the calculation of different resistor values (to use e.g. with different threshold intervention values of the
braking unit) it is possible to use the following formula:
VBR [V]
RBR [Ω] =
IPBU [I]
f011
Where “VBR” means the intervention threshold of the braking unit and “IPBU” the max. peak current described
in the table.
Needing to calculate the value of the resistor for an inverter 6KAV3037 (100A peak current for the braking)
supplied with 400V (intervention threshold 680V with S1-3 ON) we will have:
680
RBR
=
= 6,8 ohm
100
f012
This formula shows the ohmic value, while about the resistor power the following consideration have to be taken
into account.
The braking resistor is normally used with intermittent cycle; it will be possible in this way to use a resistor able to
2
dissipate a costant power lower than the one given by the product RBR * IPBR
.
To decide the overload factor the following diagram can be used (such diagrams can be supplied from the
manufacturer of the resistor to use).
RESISTANCE POWER
1000
100
Pause time
15 seconds
30 seconds
10
1 minute
5 minutes
30 minutes
1
0,1
1
2
3
4
5
6
7
8
9
10
OVERLOAD FACTOR
4
4
—————— DIMENSIONING... AND CORRESPONDING... ——————
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6KBU300
To calculate the value of the costant power (or rated) of the braking resistor using this graphic, it will be possible
to apply the following formula:
regenerated power
continuative power RBR
=
overload factor
f013
Considering having to brake a 30KW motor with overload of 150%, the regenerated power will be at maximum
45KW.
Supposing a braking time of 5 seconds (overload time for the resistor) and 1 break minute, the graphic provides an
overload factor of 3,9, so the rated power of the resistor will be:
45000
= 11.5 kW
3.9
f014
NOTE:
The use of the normalized resistors reported at chapter 6 it is strongly reccomended
5
4
—————— DIMENSIONING... AND CORRESPONDING... ——————
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6KBU300
5. MINIMUM VALUE OF THE RESISTORS THAT CAN BE USED
Model
Value of intervention threshold
640V 680V
Minimum value of resistors
400V
745V
6KBU300-20
6KBU300-50
6KBU300-85
10 ohm
4 ohm
16 ohm
6.4 ohm
3.7 ohm
17 ohm
6.8 ohm
4 ohm
18.6 ohm
7.5 ohm
4.4 ohm
2.4 ohm
bu0040
The ohmic value indicated in the table, represents the absolute minimum value of the resistor connectable to
the different braking units in correspondence of the braking threshold set.
In case these values would not be available, it might be possible to use higher ohmic values.
E.g. with the braking unit 6KBU300-20 used with intervention threshold of 680V the indicated resistor value is
17Ω, if the commercial available ohmic value is 18Ω, it will be allowed its use with no problem (don’t use
16Ω).
The indication is for a best use of braking resistors when more parallelled resistors are used, case in which the
ohmic values indicated in the table should not be available.
ATTENTION!!
Units are not protected against direct short-circuit between terminals CR, BR. This
condition can lead to the destruction of the unit, if external DC fusing is not supplied.
1
5
—————— MINIMUM VALUE OF OF THE RESISTANCES ——————
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6KBU300
6. STANDARD BRAKING RESISTORS
In order to simplify the choice of the resistor that has to be used, here below the values of the normalized resistors
are reported, calculated on a criterion for a typical use.
POVL
Overload power that can be regenerated by the inverter, equal to the rated power mul-
tiplied by factor 1.36 (inverter’s overload = Icont x 1.36)
PAVBR
EBR
tOVLBR
tBR
Average power dissipated by the resistor, where the duty cycle is equal to 10%
Maximum instantaneous energy that the resistor can dissipate
Maximum continuative braking time in overload conditions (POVL
)
Maximum continuative braking time at drive rated load conditions
PNBR
Rated continuous power of the resistor which must be equal or greater than the average
power PAVBR
P,n
PPBR
EBR
n
t
TBR
TC
The ohmic value of the normalized resistors has been calculated in order to assure the braking current for the limit
use of 6KBU300, that is to say a 460Vac supply of the inverter (braking threshold 745Vdc).
1
6
—————— STANDARD BRAKING RESISTANCES ——————
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GEI-100350A
AV300
BU300
POVL
PAVBR
EBR
tOVLBR
tBR
PNBR
RESISTANCES OHMIC
MARK
VALUE
[KW]
[KW] [Kwsec] [sec]
[sec]
[KW]
3003
3005
3011
3015
3022
3030
3037
3045
3055
…-20
…-20
…-20
…-20
... -50
…-50
…-50
…-50
…-85
4
0.5
0.7
1.5
2
8.8
14
5
5
7
7
0.5
0.8
1.3
4
BRR 500T 100R
BRR 800T 68R
BRR 1K3T 31R
BDR 4K0T 23R
BDR 4K0T 15R4
BDR 4K0T 11R6
BDR 8K0T 9R2
BDR 8K0T 7R7
BDR 8K0T 6R2
2 x BDR 8K0T
9R2
100 Ω
68 Ω
6.8
15
20
30
40
50
60
75
44
3.5
8
5
31 Ω
80
11
8
23 Ω
3
120
70
6
4
15.4 Ω
11.6 Ω
9.2 Ω
7.7 Ω
6.2 Ω
4
4
5.5
10
8
4
5
180
220
140
7.5
6
8
6
8
7.5
4.5
6
8
3075
3090
3110
3132
3160
3250
3315
…-85
100
120
150
180
10
12
2 x 180
2 x 220
2 x 140
2 x 350
2 x 350
3 x 350
3 x 350
7.5
6
10
8
2 x 8
2 x 8
9.2 Ω
7.7 Ω
6.2 Ω
5.1 Ω
5.1 Ω
5.1 Ω
5.1 Ω
2 x BDR 8K0T
7R7
2 x …-50
2 x …-85
2 x …-85
2 x …-85
3 x …-85
3 x …-85
2 x BDR 8K0T
6R2
15
4.5
6
6
2 x 8
2 x BDR 12KT
5R1
18
8
2 x 12
2 x 12
3 x 12
3 x 12
180 *
(218)
272 *
(340)
272 *
(340)
2 x BDR 12KT
5R1
18
6
8
3 x BDR 12KT
5R1
27.2
27.2
6
8
3 x BDR 12KT
5R1
6
8
bu0055
NOTE:
the power ratings indicated with (*) have a value lightly below to the one calculated for POVL
(value between brackets) in order to avoid the introduction of further values of resistors.
Furthermore it must be take into consideration that with high power ratings as these ones, the
dynamic performances are generally lower and could even require the use of a regenerative
unit on the DC bus.
For 3250 and 3315 sizes, the use of the Line Regen Converter RS-300 should be more convenient.
Every resistor used having different features by the ones above mentioned, must be rated to support the power
POVL for a time equal to 1/10 of the one of an hypothetical cycle, where after the overload follows a period at zero
power for 9/10 of the whole time (10% duty cycle).
POVL x 0.1 T = PAVBR x T
The maximum duration of the braking time (and consequently the total duration of the cycle) will be determined
by the maximum energy pulse EBR admitted for the resistor during the braking moment, according to the following
relation:
tOVLBR and tBR = 0.1 T = EBR / POVL
Since the working temperature of the resistor is not known, the resistor itself must be provided with a normally
closed thermal dry contact (Klixon) see chapter 3.5.
2
6
—————— STANDARD BRAKING RESISTANCES ——————
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6KBU300
7. EXTERNAL PANEL MOUNTED DC FUSE
Recommended fuses that must be inserted on terminals C and D.
Model
Fuses
A70P80
FWP80
6KBU300-20
A70P150
FWP150
A70P200
FWP200
6KBU300-50
6KBU300-85
bu0050
Fuse Manufacturers:
A70P
FWP
Gold Shawmut
Bussman
1
7
—————— SUPERFAST DC FUSE TABLE ——————
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6KBU300
8. BLOCKS DIAGRAM
9
8
7
6
5
RBR
4
3
2
1
A
D
B
C
E
1
8
—————— BLOCKS DIAGRAM ——————
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GEI-100350A Rev. 2.0 (6/98)
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