Q I live in Pennsylvania. What would you recommend and do you know of any code that addresses a scenario that involves an elevator lobby with stair doors located inside the tenant?s space and the entry doors secured by card access?
A There is not a simple answer to your question. If the lock on the door you seek to control is in the path of the egress, you can't lock it in such a way that egress is prevented.
There are two issues:
- How someone gets from the interior space to the elevator.
- How someone gets out of the elevator lobby if the elevator fails.
How you do it is all up to the AHJ. The number of exits required will depend on occupancy and the number of expected occupants. I have not met an AHJ yet who would allow a person to be trapped in an elevator lobby if the elevator failed, especially since the elevator may not be operational in the event of a fire. So, if the door in question is in the path between the lobby and the stairwell, it can't be mechanically or electrically locked. If the AHJ allows the door to be locked, it can only be locked in a way that complies with the code adopted in that jurisdiction.
In general, this means:
- A sensor shall be provided on the egress side arranged to detect an occupant approaching the doors. The doors shall be arranged to unlock by a signal from or loss of power to the sensor.
- Loss of power to that part of the access control system which locks the doors shall automatically unlock the doors.
- The doors shall be arranged to unlock from a manual unlocking device located 40 inches (1016 mm) to 48 inches (1219 mm) vertically above the floor and within 5 feet (1524 mm) of the secured doors. Ready access shall be provided to the manual unlocking device and the device shall be clearly identified by a sign. When operated, the manual unlocking device shall result in direct interruption of power to the lock independent of the access control system electronics and the doors shall remain unlocked for a minimum of 30 seconds.
- Activation of the building fire alarm system, if provided, shall automatically unlock the doors, and the doors shall remain unlocked until the fire alarm system has been reset.
- Activation of the building's automatic sprinkler or fire detection system, if provided, shall automatically unlock the doors. They shall remain unlocked until the fire alarm system has been reset.
- Entrance doors in buildings within some occupancy groups may not be secured from the egress side during periods when the building is open to the general public.
Consider leaving the doors unlocked and secure the elevator; it would allow egress at all times in all directions and restrict entry by the elevator to those with a credential.
Q How are access control systems programmed and what are the major considerations? Can you also include features commonly performed by the central computer?
A Some systems are programmed with an integrated keypad and others can be programmed with hand-held computers. The most common method is programming access control systems via a computer. When a computer is used, it's usually also used to record a history of events, including who goes where and when.
Access control is accomplished through a combination of time zones, access levels and holidays. Time zones allow you to determine the time and day that something occurs. Access levels allow you to determine where something occurs. Holidays allow you to make exceptions to accommodate varied schedules on holidays.
Other features that are possible: