On a UL mercantile security system, how far can a switched personal door open without initiating an alarm?

In a UL mercantile security system, the specification regarding how far a switched personal door can open without triggering an alarm is crucial for maintaining security while allowing for controlled access. The correct distance is 2 inches. This means that if the door is opened up to 2 inches, the system will not initiate an alarm, permitting some degree of movement without responding to minor breaches.

This specification is essential as it helps to reduce false alarms caused by normal activity, such as people briefly opening a door or wind causing a door to move slightly. The 2-inch threshold is a balance between sensitive enough to detect unauthorized entry while also being tolerant of legitimate activities.

The other distances would either be too restrictive or too permissive in a commercial environment, which could lead to security vulnerabilities or unnecessary alarm activations, respectively. Understanding this parameter helps alarm technicians and users design and maintain their security systems effectively, ensuring that they provide proper protection without causing inconvenience in legitimate scenarios.