Overview
The 3RB2283-4AC1 is a Siemens overload relay with 3 poles, rated for a switching current of 630 A and offering adjustable trip classes 5, 10, 20 and 30. It is housed in an IP20 enclosure for stand-alone installation and carries ATEX Ex II (2) GD certification for use in potentially explosive atmospheres.
Function & operation
This overload relay protects motors by monitoring current and tripping on overload. The adjustable trip class — selectable between CLASS 5, 10, 20 and 30 — lets the user match the relay's thermal response to the motor's starting characteristics: a CLASS 10 setting suits standard induction motors, while CLASS 20 or 30 accommodates longer acceleration times such as on high-inertia loads.
Applications
The 3RB2283-4AC1 is used in motor control centres, pump and fan drives, conveyor systems, and other industrial machinery where three-phase motor protection is required. Its adjustable trip class makes it suitable for both standard and high-inertia loads, and the ATEX certification extends its use to hazardous-area installations such as chemical processing, oil and gas, and grain handling.