Single-Phase Compressor Soft Starters

Oct. 22, 2020
These single-phase compressor soft starters from Carlo Gavazzi are said to reduce start current by more than 50%.

The RSBS Series compact, single-phase soft starter is designed for single-phase compressors in single-phase voltage networks prone to voltage fluctuations. The RSBS uses a current limiting algorithm to reduce compressor start current by more than 50% when compared to direct online starters. Its control algorithm automatically detects when the compressor reaches full speed to ensure that the internal bypass relay switches on when the current is at an optimum level. The RSBS can limit inrush currents up to 45 amps under balanced conditions with a maximum ramp-up time of 600 ms. Its HP function ensures the compressor receives enough starting torque by allowing a maximum current of 80 Amps. 

 Features of the RSBS include:

  • Single-phase 195.5 to 264.5 VAC, 50/60 Hz operating voltage range;
  • Current-limiting algorithm reduces inrush current by more than 50%;
  • Rated operational current: 37 Arms;
  • 4.4 kW / 5 HP rating at 40°C;
  • No user adjustments required;
  • Integrated diagnostics detect voltage dips, network interruptions and welded relay contacts;
  • Ideal for scroll compressors and piston compressors;
  • Anti-short cycling function with built-in delay between starts;
  • Auxiliary relay output with alarm status LED indication;
  • Choose from several different start capacitor sizes including an option for an external capacitor; and
  • Agency approvals: cULus Listing, CE certification.

The RSBS Series Soft Starters are the best choice for increasing reliability, reducing network interruptions and improving compressor operation.