OVERVIEW

Official designation: Siemens 3TK2825-1BB40 (SIRIUS, Safety Relay)

Role/Application: A dual-channel safety relay providing three instantaneous safety outputs and two auxiliary outputs for critical machine safety functions like emergency stop and guard door monitoring, compliant with SIL 3 / PL e.

KEY SPECS SUMMARY

Power: 24 V DC (Operating range 0.85 to 1.1 times rated voltage)

Interfaces / Ports: Screw terminals, Dual-channel input monitoring

Indicators: Refer to the latest manufacturer manual.

Operating Temp: -25 to 60 degrees C (Ambient)

Platform / Compatibility: Suitable for Category 4, SIL 3, PL e, DIN rail mounting

Limit: Instantaneous Safety Contacts (EC): 3 NO, Auxiliary Contacts (SC): 2 NC

Lifecycle: Product Discontinued (Successor is 3SK1111-1AB30)

FREQUENTLY ASKED QUESTIONS

Technical Specifications:

Q: What are the rated switching capacity limits for the safety outputs (NO contacts) at 230 V AC?

A: The safety contacts have a maximum switching current of 6 A at 230 V AC (AC-15).

Wiring & Installation:

Q: What are the physical dimensions of the 3TK2825-1BB40 for control cabinet placement?

A: The dimensions are 138.5 millimeters high, 44.8 millimeters wide, and 120 millimeters deep.

Troubleshooting & Compatibility:

Q: What is the minimum pulse duration required for the ON pushbutton input for a monitored start?

A: The minimum pulse duration for the ON pushbutton input is 25 milliseconds.

Replacement & Upgrades:

Q: Which safety relay is the preferred successor for the discontinued 3TK2825-1BB40 model?

A: The preferred successor is the Siemens 3SK1111-1AB30, which has one less signaling circuit.