What is fail-safe vs fail-secure?
Simple definition
Fail-safe generally unlocks when power is removed, while fail-secure generally remains locked when power is removed.
Why it matters in wiring diagrams
This distinction is critical for strikes, maglocks and egress design.
When reading a wiring diagram, this term usually affects cable choice, power path, signal path, device selection or commissioning notes.
Common mistakes
- Assuming the term means the same thing across all brands.
- Ignoring the actual terminal names in the manufacturer manual.
- Not documenting how the term applies to the final installed system.