Fail-safe is mandatory on most stairwell doors and other code-designated egress paths — the lock must release on fire alarm or power loss to allow evacuation. Fail-secure on those doors is a code violation. Confirm the local fire code and AHJ requirements; commercial buildings in the U.S. follow NFPA 101 and the International Building Code, both of which detail egress lock behavior in detail.

Typical 12VDC electric strikes draw 200-500 mA continuous, with inrush spikes of 1-2A at engagement. Magnetic locks rated for 1,200 lbs holding force draw around 500 mA continuous at 24VDC. Power supplies need to handle simultaneous lock-down current — emergency lockdown events activate all locks at once. Size the supply with at least 25% headroom and confirm battery backup runtime requirements.

Most code-compliant electrified door installations require a REX sensor to shunt the alarm during authorized egress. Without REX, every egress event registers as a forced-door alarm. PIR motion sensors are the common choice and integrate with the door controller's REX input. Mechanical push-bar REX is also acceptable for hardware that includes that switch natively.

Yes — most electrified strikes and locks allow mechanical key override on the same door. Maintaining a master key for emergency mechanical access is required by code in many jurisdictions and recommended in all. Document the master key holders carefully; an uncontrolled master key program undermines the electronic audit trail.

Quality maglocks (Securitron M62, HES, von Duprin) typically last 15-20 years with no mechanical wear. Failure points are the connector, the armature plate-to-lock alignment, and contamination of the magnetic face. Plan for armature replacement at year 10 as a hedge against alignment drift. Strike-type locks with mechanical parts last 5-10 years before strike-plate wear becomes a reliability issue.