Product Description
Benefits & Applications
The Siemens 3SB3400-0E is a high-reliability changeover auxiliary contact block (1CO) that provides both 1 Normally Open (1NO) and 1 Normally Closed (1NC) contact in a single compact module. Designed for use with Siemens 3SB3 and SIRIUS ACT pushbuttons, selector switches, and key operators, this dual-contact design supports flexible control logic such as start/stop circuits, interlocks, feedback loops, and PLC input signaling.
Built for demanding industrial environments, the 3SB3400-0E features long mechanical endurance, secure mounting, and reliable low-level switching. It installs quickly behind compatible operator heads, making it ideal for both OEM machine builders and maintenance teams upgrading or expanding existing control panels.
Typical Applications
- Start/stop control circuits
- Interlock and safety logic
- PLC input and automation feedback
- Motor starter auxiliary signaling
- Industrial and commercial operator station panels
Technical Advantages
- Changeover contact (1NO + 1NC) in one module
- Tool-free, snap-on mounting behind operator heads
- High electrical and mechanical endurance
- Reliable low-current switching for PLC and control circuits
- Compact modular format ideal for tight panel designs
- Compatible with Siemens 3SB3 and SIRIUS ACT platforms
Compatibility Notes
The 3SB3400-0E integrates with the following Siemens operator ranges:
- 3SB3 pushbuttons (metal and plastic versions)
- SIRIUS ACT pushbuttons and selector switches
- Key-operated switches and emergency stop operators
- Control stations and OEM industrial panels
If your control system requires a changeover auxiliary contact (1CO) to provide both NO and NC logic, the 3SB3400-0E is the correct Siemens OEM accessory.
Frequently Asked Questions
Q: What does “1CO” mean for the 3SB3400-0E?
“1CO” stands for 1 Changeover contact, which includes both 1NO and 1NC switching elements in a single contact block.
Q: Is the 3SB3400-0E compatible with SIRIUS ACT?
Yes. The 3SB3400-0E is fully compatible with SIRIUS ACT pushbuttons, selector switches, and key switches using the same mounting interface.
Q: Can this auxiliary block be stacked with additional contacts?
Yes. Siemens 3SB3 auxiliary blocks can be stacked to create expanded NO/NC combinations for more complex control circuits.
Q: Is the 3SB3400-0E suitable for PLC inputs?
Absolutely, the module provides clean, reliable NO and NC signal switching for PLC digital input circuits.
Q: How is this different from 3SB3400-0B or 3SB3400-0C?
3SB3400-0B = 1NO contact only
3SB3400-0C = 1NC contact only
3SB3400-0E = 1NO + 1NC (changeover)
