Operation
How the Smoke Guard system works
Ready
The system connects to an auxiliary relay in the smoke detector for the elevator landing.
The smoke containment curtain is rolled into a housing located above the elevator door.
Alarm
There are two alarm conditions that deploy the smoke containment curtain:
smoke detector goes into alarm (but NOT in response to a general fire alarm)
continued loss of power
Under alarm conditions, the curtain automatically unrolls and magnetically attaches to
auxiliary rails or ferrous elevator door frame. The curtain stops when it reaches the floor.
An aluminum tube creates a seal at the floor when the curtain is fully deployed.
Deployed
When the unit is deployed, it remains deployed until you reset the smoke detector or re-
establish power to the unit (see “Rewind” below). The curtain may bow slightly in or out
due to the direction of the airflow. While the curtain is deployed, anyone who needs to
move through the opening can press a rewind switch to retract the curtain temporarily.
The curtain then unwinds to the fully deployed position if alarm conditions still exist;
otherwise, it rewinds fully and remains in ready mode.
NOTE: The system is designed so there is a delay of several seconds after the unit has
deployed before the rewind switch will operate.
Rewind
The curtain rewinds automatically when you reset the smoke detector or reestablish
power to the unit. (Pressing the rewind switch rewinds the curtain only temporarily as
long as an alarm condition exists.)
What makes up the Smoke Guard system
Housing
The housing is a sheet metal box, with a dust cover, mounted above the elevator door.
The housing holds the curtain , the control circuit board (see below), up-limit switch,
clutch, viscous governor, and rewind motor. In addition, the housing contains the
electrical connections to 120VAC, the smoke detector, and the rewind switch.
Auxiliary rails (required for most installations)
Auxiliary rails attach to the wall next to the elevator door frame. These rails attract the
magnets on the curtain and form a seal. In some installations, the elevator frame is of a
ferrous metal and the auxiliary rails are not necessary.
Curtain
The curtain material is reinforced transparent polyimide plastic film. The film is attached
to a flexible magnet along each vertical edge by means of an elastomeric sealant that
allows the film to expand under differential air pressures likely found in an elevator shaft.