Mechanical and Electronic Lock Servicing
Core concepts
This domain splits into mechanical servicing (rekeying, repairing, lubricating, and adjusting cylinders, mortise locks, and deadbolts) and electronic access control (keypads, card readers, electric strikes, electromagnetic locks, and stand-alone electronic cylinders). Know the difference between fail-safe and fail-secure hardware: fail-safe unlocks on power loss (life-safety egress), fail-secure stays locked. Understand request-to-exit devices, door position switches, and how power transfer reaches a door.
Servicing practice
Rekeying means changing key pins (and often drivers) to match a new key while keeping the cylinder functioning; master-keying adds a second shear line via additional pins. Lubrication should be graphite-free for many modern cylinders-use manufacturer-approved lubricant sparingly, since excess attracts debris. Electronic systems demand attention to wiring polarity, voltage, and the difference between normally open and normally closed circuits.
Traps
Questions love to invert fail-safe and fail-secure, or to imply an electromagnetic lock is appropriate where free egress is required without a release device. Another trap: assuming a keypad alone provides security-codes can be shared, so audit trails and code management matter. Don't confuse a strike (frame side) with a latch (door side), or a request-to-exit sensor with a door position switch.
Worked example
A maglock on a stairwell door must release on fire alarm and allow free egress. Because maglocks are inherently fail-safe (they release when de-energized), wire the lock so loss of power or an alarm signal de-energizes it, and add a request-to-exit device plus a manual release. Verify the door complies with life-safety code before signing off.