Motor protection relay for S10/S12 contactor systems
The Siemens 3RB1065-2GG0 is an electronic overload relay rated for motor currents from 55 A up to 250 A, with a Class 20 trip curve. It is designed for direct mounting on 3RT106 contactors (S10/S12 frame sizes) via the included connecting bars, or can be installed as a standalone unit with manual reset. The current lifecycle stage is active, meaning this order code remains in the current product portfolio.
What the ratings mean for your motor branch
The 55...250 A adjustment range covers large induction motors typically found on pumps, compressors, and conveyors in the 30–132 kW range at 400 V. Class 20 means the relay allows up to 20 seconds of locked-rotor current before tripping — matching NEMA and IEC motor starting profiles for standard-duty applications where the load accelerates in under 10 seconds. For high-inertia loads (fans, flywheels) that need longer starting times, a Class 30 or 40 relay would be the correct choice; this part is sized for the majority of industrial motor starts.
Mounting and integration
The relay mounts directly onto the 3RT106 contactor using the factory-supplied connecting bars, eliminating separate busbar wiring between the contactor and overload. This reduces panel wiring time and keeps the motor branch compact on the DIN rail or mounting plate. For retrofit or standalone use, the same unit installs independently with its own terminal connections.