Siemens 3TK2820-1CB30 SIRIUS Safety Relay - Expansion Unit
Siemens SIRIUS safety relay, expandable to PL e / SIL 3.
The Siemens 3TK2821-1CB30 is a SIRIUS safety relay with relay enabling circuits (EC), designed for use as an expansion unit. It operates on 24 V AC/DC and features a 22.5 mm width with screw terminals. This unit offers 3 instantaneous normally open (NO) EC contacts and 1 normally closed (NC) safety contact (SC). While functioning as a basic device, it offers PL 'c' and SIL 1, but when used as an expansion unit, it contributes to achieving up to PL 'e' and SIL 3.
This safety relay is particularly useful for expanding the functionality of existing safety systems or for applications requiring more complex safety interlocking scenarios. It is widely applied in machine building, automation lines, and safety control systems where modular expansion is needed.
Stanlo Automation, a veteran-owned surplus parts distributor, provides access to essential components like the Siemens 3TK2821-1CB30. We help you maintain and enhance your industrial automation setups with reliable and cost-effective surplus solutions.
| Voltage | 24 V AC/DC |
| Width | 22.5 mm |
| Terminals | Screw |
| EC Instantaneous | 3 NO |
| EC Delayed | 0 |
| SC | 1 NC |
| Autostart/Manual start | Yes |
| Basic Device SIL | 1 |
| Basic Device PL | c |
| Expansion SIL | 3 |
| Expansion PL | e |