A key part of the life safety system in any building is the fire and smoke dampers. When working as designed these dampers help prevent the spread of fire and smoke throughout the building in the event of a fire. The fire dampers usually do not have control actuators and close when a rise in temperature to about 165 degrees causes a fusible link to open, causing the fire damper to close and stop the fire from passing through a barrier. Smoke dampers and combination dampers do have actuators like those made by Belimo.
These smoke and fire damper actuators become an important maintenance consideration because failure to
have written documentation that these actuators have been checked out and are working properly can put the building owner in a very bad position legally should there be a fire and the owner is not able to prove the actuators were working properly.
So let’s look at the smoke dampers which require a smoke damper actuator like the Belimo smoke damper actuator. A smoke damper must open and close when required to provide fresh air or to stop smoke passage. Your geographic area and the smoke control mandated by your local codes determine how you will control the smoke damper. Usually a smoke detector(s) in the duct will close the damper via the smoke damper actuator and shut down the fans. Perhaps the best way to see this is to check out this video of a smoke damper actuated system when smoke is sensed.
Another type of fire and smoke damper you might have in your building is the combination fire and smoke damper. These combination dampers use fire and smoke damper actuators, and just like smoke only actuators, must be tested as part of a maintenance routine. These combination dampers are fire rated and their blades must be in a barrier wall, which means the actuator cannot be in the wall. So mounting these actuators can be a little tricky in that you will need to use a jackshaft and linkage so that the actuator is connected outside the damper sleeve. Not to worry Belimo has great mounting instructions.
If you have tested your fire and smoke damper actuator and have found it defective or if the actuator is obsolete then you will need to replace it. Before you replace it make sure it is your actuator that is the problem and not a malfunctioning damper. If it is the damper you will need to replace the damper with a UL listed damper assembly that includes a factory installed actuator by the damper manufacturer.
If the damper is okay and you need to replace your damper actuator, then you must make sure that the mounting of the actuator does not require any changes to the damper itself. When in doubt about this contact the damper manufacturer to see if the damper needs to be replaced. Also make sure that the current draw of the actuator is the same or less than the original actuator and that the voltage and the timing are the same. Your Stromquist customer service representative can help you with this information.
You also need to be in compliance with your local code. Inspectors usually are looking for “Equal or Better” replacement actuators and actuators that are UL555S listed with the damper manufacturer. In that Belimo is one of the major suppliers of smoke and damper actuators they are a safe bet.
If you have not checked your fire and smoke dampers and actuators get on it and contact Stromquist or Belimo should you have any questions.