To reduce starting loads, two devices are used: frequency converter or soft starter (soft starter). They solve similar problems, but in different ways. Let's figure out what to choose.
Soft start device (SFD)
The soft starter smoothly increases the voltage at start-up, reducing the starting current and shock. After acceleration, the engine operates directly from the network.
- Pros: cheaper, more compact, simpler.
- Cons: does not regulate the speed during operation, only makes starting easier.
Frequency converter (FC)
The frequency converter controls the speed of the engine throughout operation, changing the frequency of the current.
- Pros: soft start + speed control + savings energy.
- Disadvantages: more expensive, more complex, loads the insulation.
Comparison
| Possibility | User | Frequency control |
|---|---|---|
| Soft start | Yes | Yes |
| Regulation speed | No | Yes |
| Energy saving | No | Yes (pumps, fans) |
| Price | Lower | Higher |
What to choose
If you only need a soft start (for example, for a conveyor or pump with a constant speed) - a soft starter is sufficient. If you need to regulate speed and save energy (pumps, fans with variable flow) - choose frequency converter. To work with inverters, reinforced winding insulation is desirable, which is taken into account when rewinding.
Don’t know what to choose for your motors in Tashkent? Elektromotors engineers will advise and prepare the engine - contact us.