DOLD softstarters ensure a soft and jerkless starting of your asynchronous motors. This reduces wearing and improves the service life of your motors and mechanical drive components. Application areas include:
Machines with geared, belt and chain drives
Conveyors, fans, pumps, compressors
Wood working machines, centrifuges
Cranes, travelling and slewing gear, elevators
Advantages
... at a glance
Easy installation by snapping on a top hat rail
Space-saving by compact design with integrated bypass relay
Improve safety by integrated temperature monitoring
Improve setting flexibility by separate setting of starting time, locked-rotor torque and deceleration time
More application flexibility, suited for a wide motor voltage range
Take off load from the supply system by reduction of starting currents
Technology
Starting methods for motors are the starting current as well as the starting torque
To get this under control it is the best to reduce the clamp voltage of the motor.
The following procedures have been developed until now:
starting transformer
starting resistor 3-pole
starting resistor 1-pole (KUSA- circuit)
star- delta switch
softstarter
Currents and torques during the start of motors
Direct Start
most simple method
IA = 6 ... 8 x IN
MA = 2 ... 3 x MN
Star / Delta
most usefull method
IA = 2 ... 3 x IN
MA = 0,7 ... 1 x MN
Transformator
no more importance
KUSA-Switching
rare, old
IA = 6 ... 8 x IN
MA = 0 ... 3 x MN
Softstarter
IA = 2 ... 5 x IN (adjustable)
MA = 0,15 ... 1 x MN (adjustable)
IA = initial current
MA = initial torque
MN = nominal moment
IN = nominal current
it is very easy to retrofit in already existing systems
EMC standard conformity according to DIN EN 60947-4-2
Power semiconductors (thistore, triacs) adjust continuously the supply voltage via phase- angle.
→ current and torque increase steadily.
Softstarters: Why are they used?
Problems with direct start of a drive with three-phase current motor
- Gears, belts, chains, couplings Mechanical wear
- Transport
Tapes/Bands upsetting or shifting of goods
- Pump
Plants Pressure shock in the line
- Electrical net
High initial current (6-8 times nominal current)
Exceeding of tariff limits
Overload of electrical installations
Voltage variations
- Environment
Loud startin noise
Softstarters remove and minimise the above- mentioned problems
DOLD softstarters ensure a soft and jerkless starting of your asynchronous motors. This reduces wearing and improves the service life of your motors and mechanical drive components. Application areas include:
