Soft start, soft stop and braking units – an overview
Soft start, soft stop and braking devices as a compact combination
While pure soft starters or pure braking units are only used for the respective function, more can be achieved with combination devices.
In so-called soft starter/braking units or soft start and braking device combinations, soft starting and DC braking are combined in one device.
This allows very compact, universally applicable solutions.
Applications
Soft start, soft stop and breaking units are used wherever motors – as mentioned above – need to be started and slowed down gently. Pumps, centrifuges and conveyor belts are obvious examples.
However, the following articles also show other areas of application:
Digital soft starter / Braking unit
LEKTROMIK® DS1
Features
- Microprocessor controlled
‣ One-button operation
‣ 2-line display - Optional interfaces (e.g. Ethernet, Profinet)
- 3 operating modes:
‣ Soft start – soft stop
‣ Soft start – braking
‣ Soft start – soft stop in delta connection - Ramp-up and ramp-down times separately adjustable
- Suitable for IE1, IE2 and IE3 motors
- Three-phase controlled soft start / soft stop
- Start with current limitation
- Integrated bypass relay to minimize losses
- Phase failure and rotating field monitoring
- Integrated DC brake: fully controlled, 2-phase
- Integrated stillstand detection
- Integrated evaluation of the motor winding temperature
- Predefined parameter sets for different applications
- 2 memories for user parameter sets
Applications
- Woodworking machines (saws, planing benches, grinding machines)
- Machines with gear, belt and chain drives
- Conveyors, fans, compressors and pumps
- Braking of machines with long stopping times
Soft start, soft stop and braking of squirrel cage motors
2.2 – 90 kW
LEKTROMIK® E
Features
- Electronic DC injection brake with a short delay time can be integrated in controller
- Compact unit easily retrofitted
- Shutdown on detection of phase failure during ramp up
- Controller inhibited when phase sequence is incorrect(E2, E4)
- Version for operation with two phase sequences forreversing drives available (E22, E42)
- Auxiliary module (OPTION I1) allows:
‣ Soft start with current limit
‣ Switch-on torque pulse
‣ Monitoring of power with overload trip
‣ Improvement of power factor at low load
Applications
- Machines with gearbox, belt or chain drives
- Drives using pole-change motors
- Conveyor belts (also high speed and high load transportation systems)
- Machines with high moments of inertia e.g. mills, compactors, centrifuges
- Grinding machines and circular saws
- Packing equipment
- Fans and compressors
- Pumps, in particular to reduce hydraulic shock waves
