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Siemens SIRIUS Safety Relay 3TK2828-2AJ21: 115V AC, 45mm Width

Siemens SIRIUS safety relay with relay enabling circuits.

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ManufacturerSiemens

Part number3TK2828-2AJ21

Coil Voltage 115 V AC

Width 45 mm

Enabling Circuits (EC) 2 NO instantaneous, 2 NO delayed (0.05-3s)

Safety Circuit (SC) 1 NC

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115V AC coil 45mm slim design 2 NO instantaneous EC contacts 2 NO delayed EC contacts (0.05-3s) 1 NC safety contact High safety ratings (SIL 3, PL e)

Product description

The Siemens SIRIUS safety relay (3TK2828-2AJ21) is designed to monitor safety functions in industrial machinery. It operates with a 115V AC coil voltage and has a compact 45mm overall width. The relay provides two relay enabling circuits (EC) that are instantaneous (2 NO contacts) and two that are delayed (2 NO contacts), with an adjustable delay from 0.05 to 3 seconds. It also includes one normally closed (NC) safety contact (SC).

This safety relay is suitable for applications requiring high safety integrity, such as emergency stop functions, light curtains, and safety gate monitoring. It achieves a Safety Integrity Level (SIL) of 3 and a Performance Level (PL) of e/d, ensuring reliable protection for personnel and machinery in manufacturing plants, automotive industry, and material handling systems.

Stanlo Automation, your veteran-owned source for industrial parts, offers the Siemens SIRIUS safety relay 3TK2828-2AJ21. Count on us for quality surplus components and efficient service.

Technical specifications

Coil Voltage	115 V AC
Width	45 mm
Enabling Circuits (EC)	2 NO instantaneous, 2 NO delayed (0.05-3s)
Safety Circuit (SC)	1 NC
Autostart	Yes
Maximum SIL	3
Maximum PL	e/d

Common applications

Emergency stop circuits

Safety gate monitoring

Light curtain safety

Two-hand control

Machine guarding

Industrial safety systems

Compatible systems

Siemens SIRIUS devices Industrial safety circuits Emergency stop systems Safety gate interlocks

Also known as

Siemens SIRIUS safety module 3TK2828-2AJ21 relay Siemens safety control

Replaces / compatible with

This SIRIUS safety relay is a standard component for safety circuits and does not typically replace a specific older part number but rather fulfills safety requirements.

Technical note

Expert tip

Ensure the connected safety devices (e.g., E-stop buttons, light curtains) meet the required SIL and PL ratings compatible with this relay.

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Frequently asked questions

What safety integrity level (SIL) and performance level (PL) does the Siemens 3TK2828-2AJ21 achieve?

The Siemens SIRIUS safety relay 3TK2828-2AJ21 achieves a maximum Safety Integrity Level (SIL) of 3 and a Performance Level (PL) of e/d, indicating a high degree of reliability for safety-critical applications.