The ABB 2TLA020070R1700 is a Type Safety Relay — the component that sits between the safety input devices (e-stop buttons, light curtains, interlock switches) and the power contactors or motor starters in a safety circuit. Its job is to monitor the inputs and, when a stop signal arrives, drop the outputs fast enough to meet the required Safety Integrity Level (SIL) or Performance Level (PL) for the guarded zone.
What the Type Rating Means for Fit
Being a Type Safety Relay means this unit is designed for safety-related control functions per IEC 61508 / EN 62061 / ISO 13849. It typically includes dual-channel input monitoring, cross-fault detection, and a forced-guided contact set on the outputs — so that a welded contact is mechanically prevented from closing the other channel. That matters when you are specifying a safety relay for a Category 3 or Category 4 architecture: the internal contact guidance is what lets you achieve the required fault-exclusion time. In a panel, the relay mounts on DIN rail and connects to the safety input chain and the load contactors. The wiring is straightforward for anyone familiar with the ABB safety relay range — spring-cage or screw terminals depending on the variant, with clear labeling for the reset/start configuration (automatic or monitored manual).