CML CML Access Control & Electromechanical Systems

Question 1

What is the primary difference between a fail-safe and a fail-secure electrified lock?

Accepted Answer

Fail-safe locks are unlocked when power is lost; fail-secure locks remain locked when power is lost

Answer

Fail-safe locks require a key to open; fail-secure locks do not

Answer

Fail-safe locks are used outdoors; fail-secure locks are used indoors

Answer

Fail-safe locks are cheaper than fail-secure locks

Question 2

An electric strike differs from an electromagnetic lock in that an electric strike:

Accepted Answer

Replaces the strike plate and releases mechanically, allowing the door hardware to remain passive

Answer

Requires continuous power to stay locked

Answer

Cannot be used on exterior doors

Answer

Only works with proximity card readers

Question 3

What is the standard voltage used for most low-voltage access control locking devices in the US?

Accepted Answer

24V DC or 12V DC

Answer

120V AC

Answer

48V DC

Answer

9V DC

Question 4

Which wiring configuration allows monitoring of a door contact's open, closed, and tampered (wire cut) states?

Accepted Answer

Supervised circuit with end-of-line resistors

Answer

Normally open (NO) wiring

Answer

Normally closed (NC) wiring

Answer

Double-pole double-throw (DPDT) wiring

Question 5

A mortise-style electrified lockset is typically preferred over a cylindrical electrified lockset for high-traffic commercial doors because:

Accepted Answer

Mortise locks have a heavier-duty body and integrate the latch, deadbolt, and electrical components more robustly

Answer

Mortise locks are less expensive

Answer

Mortise locks do not require a door prep

Answer

Mortise locks can be installed without cutting into the door edge

Question 6

When installing an electromagnetic lock on a door that must comply with ADA and fire code, the CML must ensure:

Accepted Answer

A request-to-exit (REX) motion sensor or push-plate is installed so the door can be opened without a credential

Answer

The magnet exceeds 1,500 lbs. holding force

Answer

The magnet is surface-mounted on the pull side only

Answer

The power supply is connected to the main electrical panel, not a dedicated circuit