ETC BA9026

Power Electronics
Softstarter with softstop BA 9026
Function diagram
Increases the life of squirrel cage motors and mechanical drives
Easily fitted to existing installations
3-phase control softstart and softstop
For motors up to 3 kW
Start current limited to 2 to 3 times rated motor current
Semiconductors bridged after softstart
Adjustable ramp time, starting torque and deceleration time
LED indication
DIN rail mounted
Galvanic isolation of control input and auxiliary power supply
Integrated overtemperature monitoring
Wide motor voltage range 200 to 460 V AC
Width 45 mm
Approvals and marking
X1 / X2
L1 / L2 / L3
A1 / A2
T1 / T2 / T3
Motor with gear, belt or chain drive
Fans, pumps, conveyor systems, compressors
Packaging machines, door-drives
Start current limiting on 3-phase motors
Reduces on off current on transformers and P.S.U's
M Mot
Softstarts are electronic devices designed to enable 1-phase or 3-phase
induction motors to start smoothly. The BA 9026 slowly ramps up the
current on three phases, therefore allowing the motor torque to build up
slowly. This reduces the mechanical stress or the machine and prevents
damage to conveyed material.
When the motor is up to full speed the semiconductors in BA 9026 are
bridged to prevent internal power losses and heat build up to addition
BA 9026 allows a softstop function prolonging the stop time of the motor
preventing high counter torques from abruptly stopping the motor.
t 0 : start
t0-t1 : ramp up time
t2-t 3 : ramp down time
LED green
LED yellow
LED red
power connected
power semiconductors bridged
Principle of operation
Block diagram
For direct on line or star delta applications, terminals L1, L2, L3 are
connected to the mains contactor, with the motor connected to terminals
T1, T2, T3. A 24 V DC auxiliary supply is connected to terminals A1, A2
and a 24 V DC control signal connected to terminals X1-X2.
When power is connected to terminals L1, L2, L3 and 24 V DC is present
at terminals X1-X2, the softstart will commence. Potentiometer
"tan " (0,5-5s) adjustst the ramp time (time motor takes to get to full speed)
and potentiometer "Man" adjusts the start voltage (50-80 % nomV). When
the softstart is complete the internal semiconductors are automatically
When 24 V DC is removed from terminals X1-X2, the softstop function will
commence for the deceleration time period set on potentiometer
"tab" (0,5-5s) and deceleration voltage level set on potentiometer
"Mab " (30-80 % nomV).
Motor load must always be connected as continuous operation of the
softstart with no load may cause overheating of the motor and softstart.
It is recomended that the softstart is protected by superfast semiconductor
fuses rated as per the current rating of the softstart of motor. However,
standard line and motor protection is acceptable, but for high starting
frequencies motor winding temperature monitoring is recommended.
All technical data in this list relate to the state at the moment of edition. We reserve the right
for technical improvements and changes at any time.
BA 9026 / 12.11.02 d
Technical data
Nominal voltage:
Nominal frequency:
Rated current:
Nominal motor power PN at
400 V:
200 V:
Min. motor power:
Start torque:
Ramp time:
Deceleration time:
Recovery time:
Switching frequency:
Auxiliary voltage A1/A2:
Power consumption:
Residual ripple:
Setup procedure
AC 200 V -10% ... 460 V +10%
50 / 60Hz
3 kW
1,5 kW
approx. 10 % of rated motor power
50 ... 80 %
0,5 ... 5 s
0,5 ... 5 s
200 ms
20 / h
(3 x I r, tacc = 5 s, Jv = 20 °)
DC 24 V
± 20 %
Control input
Voltage range X1+/X2:
- Attention: If the ramp-up time is adjusted to short, the internal bridging
contact closes before the motor is on full speed.
This may damage the bridging contactor or bridging relay.
DC: 0 ... 28,8 V
> 13 V
Temperature monitoring
General data
Temperature range:
Storage temperature:
Testing voltage:
Degree of protection:
Climate resistance:
Wire connection:
0 ... + 55°C
-25 ... + 75°C
2,5 kV
Housing: IP 40
IEC/EN 60 529
Terminals: IP 20
IEC/EN 60 529
0 / 055 / 04
IEC/EN 60 068-1
up to 2,5 mm2 stranded ferruled
DIN-rail mounting
300 g
Width x height x depth:
Set potentiometer "Man" to minimum (fully anti-clockwise).
Set potentiometer "Mab " to maximum (fully clockwise).
Set potentiometer "tan " to maximum (fully clockwise)
Set potentiometer "tab " to maximum (fully clockwise).
Start the motor and turn potentiometer "Man " up until the motor starts to
turn without excessive humming.
Stop the motor and restart.
Adjust potentiometer "tan " to give the desired ramp time.
Stop and restart the motor.
Adjust potentiometer "Mab" until the motor starts to visibly slow down at
the initiation of the softstop cycle.
Stop and restart the motor.
Adjust potentiometer "t ab" to give the desired deceleration time.
Stop and restart the motor, readjusting the potentiometers until the
desired starting/stopping characteristics are achieved.
45 x 74 x 121 mm
Standard type
BA 9026 3 AC 200 ... 460 V 50/60 Hz 3 kW
Article number:
• Nominal voltage:
3 AC 200 ... 460 V
• Nominal motor power:
3 kW
• Width:
45 mm
stock item
BA 9026 features overtemperature monitoring of its internal power
semiconductors. When the safe running temperature is exceeded the
power semiconductors will turn off and a red LED on the front of the unit
will illuminate. BA 9026 can be reset after the semiconductors have
cooled down by momentarily removing the auxiliary supply voltage.
Safety instructions
- Never clear a fault when the device is switched on
- Attention: This device can be started by potential-free contact, while
connected directly to the mains without contactor (see
application example). Please note, that even if the motor is
at rest, it is not physically separated from the mains.
Because of this the motor must be disconnected from the
mains via the corresponding manual motor starter.
- The user must ensure that the device and the necessary components
are mounted and connected according to the locally applicable
regulations and technical standards.
- Adjustments may only be carried out by qualified specialist staff and
the applicable safety rules must be observed.
Connection example
Ordering example
BA 9026 3AC 200 ... 460 V
50/60 Hz
3 kW
Nominal frequency
Nominal motor power
Nominal voltage
This units must be mounted on a vertical mounting area with the
connections in a vertical plane, i.e. top to bottom.
Ensure that no external heat source is placed below the unit and a
40 mm air gap is maintained above and below. Other devices may be
directly mounted either side of the unit.
A1 X1
L3 (+) (+)
Control input
If a voltage of more than 13 V DC is connected to terminals X1+/X2, the
device begins with softstart. If the voltage falls below 5 V DC the device
will softstop.
Softstart and softstop
E. DOLD & SÖHNE KG • D-78114 Furtwangen
e-mail [email protected] • internet
• Postf. 1251 • Tel. +49 7723 654 0 • Telefax +49 7723 654 356