Carlo Gavazzi’s RSGD Series Provides an Innovative Soft Starting for Squirrel Cage Induction Motors
- Published: Tuesday, 08 October 2013 17:32
Carlo Gavazzi has launched the RSGD series of compact general purpose soft starters complete with monitoring, protection and self-learning features all in a compact 45mm housing and is suited to fixed speed motors up to 45Amp (22kW).
During the starting of an induction motor, current levels may reach values of 5 to 8 times the rated motor current. Following the Energy using Products (EuP) directive, in recent years higher efficiency motors have been introduced onto the market. Starting such motors via contactors may result in currents as high as 15 times the rated motor current, increasing the occurrence of electrical and mechanical disturbances.
The RSGD (2-phase controlled) soft starter series reduces the starting current down to 3 – 4 times the rated motor current, resulting in smoother starting and stopping of motors, thereby increasing the lifetime of the motor and reduces the electrical disturbances on the supply network. In certain applications, such as water pumps, soft starters are required to reduce certain phenomena such as water hammering, which may cause premature failure of the pumps. Thanks to its extremely compact size, the RSGD series can fit limited sized panel spaces, providing easier access for replacement of mechanical contactor’s.
The RSGD is offered in a 45mm wide IP20 housing for DIN or panel mounting. Controlling 2-phases, the unit is internally by passed to reduce heat dissipation inside the panel. The starting parameters can be easily set-up via the user friendly push buttons and red, yellow and green LEDs for easy identification of supply, alarm and ramping/bypass status.
RSGD provides a number of diagnostic functions including phase sequence, over- and under-voltage monitoring and locked rotor protection. Optional relays for alarm and bypass indication are provided as an option. For higher starts/hr, the RSGD 37A and 45A versions can also be equipped with a fan which is available as an accessory.
This series also includes auto-adaptive algorithm for optimal inrush current reduction and current balancing whilst the intelligent algorithm reacts to a stalled motor. The RSGD40: 220 – 400VAC (Internally supplied) / RSGD60: 220 – 600VAC (Externally supplied). This series is approved by CE, cULus with CCC (Pending).