Product Description
Benefits & Applications
The Siemens 3SB3400-0B is a high-quality 1NO (Normally Open) auxiliary contact block designed for use with Siemens 3SB3 modular pushbuttons, selector switches, and signaling devices. Built for industrial reliability, this auxiliary block delivers consistent performance in automation systems, motor control circuits, and machine panels that require dependable NO contact signaling.
With its secure snap-on mounting system, the 3SB3400-0B installs quickly behind compatible operator heads, providing a simple and efficient way to expand control logic or replace worn auxiliary contacts without modifying the main operator assembly.
Typical Applications
- Start circuits and enable functions
- PLC input and automation signaling
- Machine control and OEM operator stations
- Motor starters and interlock circuits
- Commercial and industrial control panel assemblies
Technical Advantages
- 1 Normally Open (1NO) auxiliary contact
- Fast, tool-free snap-on design
- High mechanical durability for frequent operation
- Reliable low-level switching for PLC input circuits
- Compact modular design suited for dense control panels
- Compatible with Siemens 3SB3 and SIRIUS ACT operator heads
Compatibility Notes
The Siemens 3SB3400-0B fits directly behind operator units in the 3SB3 modular pushbutton series and is compatible with:
- Pushbuttons (illuminated and non-illuminated)
- Selector switches and key switches
- Mushroom-head and emergency stop operators
- SIRIUS ACT devices within the same mounting interface
If your Siemens control station requires a dependable 1NO auxiliary contact, the 3SB3400-0B is the correct OEM module for expansion or replacement.
Frequently Asked Questions
Q: What does “1NO” mean for the 3SB3400-0B?
“1NO” indicates a Normally Open auxiliary contact that closes only when the operator device is actuated.
Q: Is the 3SB3400-0B compatible with SIRIUS ACT pushbuttons?
Yes. It is compatible with Siemens 3SB3 and SIRIUS ACT operator heads using the same mounting interface.
Q: Can I stack multiple auxiliary contacts?
Yes. Siemens 3SB3 auxiliary contacts can be stacked to create multi-contact configurations for advanced control logic.
Q: Is this auxiliary block suitable for PLC inputs?
Absolutely. The 3SB3400-0B provides reliable low-level switching ideal for PLC I/O and automation circuits.
Q: What is the difference between 3SB3400-0A and 3SB3400-0B?
The difference is typically the mounting orientation or mechanical stacking arrangement. Electrically, both provide a 1NO function. Always check your operator assembly before selecting a replacement.
