Today’s Quick Question is a great opportunity to explain the concept of “power assist” with regard to automatic operators:

For accessible public entrances serving certain buildings, the International Building Code (IBC) requires either a power-operated door or a low-energy power operated door; power-assist operators are not listed in the IBC as a permitted operator type.  I see that LCN offers a power assist feature on some of their automatic operators, can these operators be used on doors serving accessible public entrances?

The short answer – YES!  LCN operators can be used on accessible public entrances.  The confusion stems from the use of the same term – “power assist” – with two slightly different meanings.

In the BHMA and IBC definitions, along with the supporting description from the IBC Commentary, a power-assist door is one that is opened manually, but with reduced force.  The key is that these doors are opened manually (not automatically), which is why a power-assist operator is not listed in the IBC as one of the types that may be used on accessible public entrances.  Where required based on the occupancy type and occupant load, one door or one set of doors must open automatically (not manually).

BHMA A156.19: Power Assist Door. A manual door with a power mechanism that activates by pushing or pulling the door, reducing the opening resistance of a self-closing door to allow easier manual opening of the door. If the opening force on the door is released, the door shall come to a stop and either immediately begin to close, or begin to close after a predetermined time.

IBC: Power-assisted door. Swinging door which opens by reduced pushing or pulling force on the door-operating hardware. The door closes automatically after the pushing or pulling force is released and functions with decreased forces. See “Low-energy power-operated door” and “Power-operated door.”

IBC Commentary: Least common are power-assisted doors, which are required to comply with BHMA A156.19. These doors are swinging doors that open by reduced pushing or pulling force on the door-operating hardware, close automatically after the pushing or pulling force is released, and function with decreased forces. Power-assisted doors do not open automatically—the operators only reduce the opening force for easier manual operation.

The difference in the power-assist operators described above and the LCN power assist feature is that LCN operators DO open the door automatically AND the power assist feature helps to reduce the opening force when a user opens the door manually.  These operators do BOTH – they are low energy automatic operators with the added power assist feature, so they open the door automatically AND reduce the manual opening force.

From the Allegion Knowledge Center: 

The LCN Sr Swing IQ operators have a power assist feature available in the control box programming.  When turned on, the operator will assist with manual door opening.  The door will feel lighter by reducing the opening resistance of the motor gearbox.

The two very similar but slightly different uses of “power-assist” may be a little confusing, but once it’s explained, it’s a really nice perk to have that feature on LCN auto operators in addition to the fully-automatic function. This provides more application flexibility to cover your bases and accommodate all users, all with one operator.

You can learn more about LCN automatic operators here.

Any questions?

You need to login or register to bookmark/favorite this content.