Single-Phase Compressor Soft Starters
Reduce Start Current by More than 50%
Thursday, October 22, 2020
by: Carlo Gavazzi

Section: Press Releases

October 21, 2020 – Buffalo Grove, IL - CARLO GAVAZZI has launched the RSBS Series, a compact, single-phase soft-starter. The RSBS is designed for single-phase compressors and is an ideal solution in single phase voltage networks that are prone to voltage fluctuations. The high inrush current caused by starting compressors in these conditions can cause light to flicker, fuses to trip, generators to stall, and other disturbances. The RSBS uses a current limiting algorithm to reduce compressor start current by more than 50% when compared to Direct Online (DOL) starters. Its control algorithm automatically detects when the compressor reaches full speed to make sure 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 special HP function ensures the compressor receives enough starting torque by allowing a maximum current of 80 Amps even when the pressures are not balanced.

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
  • 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.

Questions regarding this press release should be directed to:

CARLO GAVAZZI Inc., 750 Hastings Lane, Buffalo Grove, IL 60089
Phone: 847.465.6100 Fax: 800.222.2659 Email:

CARLO GAVAZZI (Canada) Inc., 2660 Meadowvale Blvd., Mississauga, ON L5N 6M6
Phone: 888.575.2275 Fax: 905.542.2248 Email:

CARLO GAVAZZI Mexico S.A. de C.V., Circuito Puericultores 22, Ciudad Satelite, Naucalpan de Juarez, EDOMEX CP, 53100
Phone/Fax: 52.55.5373.7042 Email:

CARLO GAVAZZI Automação Ltda., Av. Francisco Matarazzo, 1752 Conj 2018, 05001-200 São Paulo SP
Phone/Fax: 55.11.3052.0832 Email: