Product Description
Benefits & Applications
The Siemens 3SB3400-0C is a high-reliability 1NC (Normally Closed) auxiliary contact block engineered for use with Siemens 3SB3 and SIRIUS ACT pushbuttons, selector switches, and operator devices. Built for industrial environments, the 3SB3400-0C provides dependable signaling for stop circuits, safety interlocks, and PLC input logic requiring a normally closed function.
The compact snap-on design allows quick installation behind operator heads, helping panel builders and technicians expand or replace auxiliary contact functions without altering the primary operator assembly. Its rugged construction ensures stable operation even under high mechanical cycling or vibration.
Typical Applications
- Stop circuits and emergency shutdown functions
- Safety interlock and machine disable logic
- PLC input and automation feedback signals
- Motor starter auxiliary signaling
- Industrial OEM machinery and control panels
Technical Advantages
- 1 Normally Closed (1NC) auxiliary contact
- Tool-free snap-on mounting for fast replacement
- High mechanical endurance for frequent operation
- Reliable low-level switching suitable for PLC circuits
- Compact modular design ideal for dense control panels
- Compatible with Siemens 3SB3 and SIRIUS ACT operators
Compatibility Notes
The Siemens 3SB3400-0C integrates with the following product ranges:
- 3SB3 modular pushbuttons (metal and plastic versions)
- SIRIUS ACT pushbutton and selector switch operators
- Key switches, mushroom-head operators, and emergency stops
- Control stations and OEM panel assemblies requiring NC logic
If your system requires a dependable 1NC auxiliary contact for Siemens operator devices, the 3SB3400-0C is the correct OEM accessory.
Frequently Asked Questions
Q: What does “1NC” mean on the 3SB3400-0C?
“1NC” means the contact is Normally Closed and opens only when the operator is actuated, ideal for stop, safety, and interlock applications.
Q: Is the 3SB3400-0C compatible with SIRIUS ACT devices?
Yes. The 3SB3400-0C works with SIRIUS ACT pushbuttons and selector switches using the same mounting interface.
Q: Can this auxiliary contact be stacked with others?
Yes. Siemens 3SB3 auxiliary blocks can be stacked to build multi-contact logic (NO + NC combinations).
Q: Is this suitable for PLC input circuits?
Absolutely, the 3SB3400-0C provides clean, reliable switching for PLC digital inputs and low-voltage control signaling.
Q: What is the difference between 3SB3400-0B and 3SB3400-0C?
3SB3400-0B = 1NO contact
3SB3400-0C = 1NC contact
Choose based on whether the circuit requires a normally open or normally closed function.
