Grid Resistance Rotor Starter - Boltech Automation

GRID RESISTANCE ROTOR STARTER

Grid Resistance Rotor Starter is engineered for heavy-duty slip ring induction motors. Utilizing high thermal capacity metallic resistance banks (SS410), it ensures smooth, controlled, and stress-free motor acceleration with dust and vermin proof construction.

Switchgear Housing: Houses power contactors and other switchgear components securely.
Safe Operation: Provides safe and reliable operational performance under heavy loads.
Resistance Media: Features premium Metallic Resistance (SS410) material.
Thermal Design: Resistance designed for 350°C temperature rise with high thermal capacity.
Structural Integrity: Mounted on angle iron structure with proper support to absorb vibration and mechanical stress.
Integrated Layout: Rotor Regulator Contactor Panel and Resistance Box mounted in the same unit with an internal partition.

Cooling System: Well-ventilated, forced air-cooled compartment with adequate cooling fans.
Resistance Banks: Houses heavy-duty stainless steel coil type resistance banks.
Internal Wiring: Solid copper jumpers used for connections routed through polypropylene sheets.
Environmental Protection: Complete dust and vermin-proof enclosure construction.

Operating Principle

Grid Resistance Rotor Starter works on the principle of introducing external resistance into the rotor circuit of a slip ring induction motor during starting. The resistance is reduced in stages as the motor accelerates, providing the required starting torque while limiting starting current.

This ensures smooth and controlled motor acceleration with a predetermined torque profile, preventing sudden electrical and mechanical shocks to the drive system.

Mechanism & Control Layout

Specific resistance grids are connected in the rotor circuit at predefined motor speeds. The resistance values are calculated in advance according to the required torque at each stage.

Contactors and preset timers control the sequential switching of the resistance grids. At each timer interval, a portion of the rotor resistance is automatically cut off. The entire starting process is fully automatic and operated through a push-button, gradually removing all resistance until the motor reaches its rated speed.