Static field route #18934

What do I do when an FSD actuator hums but the blades do not move?

Fire/Smoke Dampers, Access Doors & Rated Assemblies🟥 STOP / VERIFYV189 answer-gap expansion

📖 Verified core answer

An actuator moving without blade movement is a life-safety/startup failure until proven otherwise. Stop, verify power/linkage/blade movement, and correct per manufacturer direction before passing commissioning.

Open in Field Rescue Open category

Field verification checklist

Identify damper tag, actuator model, fail position, and control signal/power status.
Check whether the actuator shaft/linkage is slipping or the blade pack is binding.
Verify blades move freely only by the approved/manual method.
Check sleeve/frame damage, incorrect orientation, or interference with retaining angles/wall.
Document and retest before cover/commissioning signoff.

Ask foreman

FSD [tag] actuator hums/turns but the blades do not move. I checked power/linkage and whether the blade pack is binding. Do you want controls/manufacturer startup involved, or should we correct linkage per the install sheet first?

Text to foreman

Route options

AMake the field correction only if it is within your assignment and the approved method.

BHold and document the condition if the fix affects airflow, access, life safety, pressure class, rated assemblies, equipment, or another trade.

CBring the foreman/detailer the location, what you checked, and what decision you need before cover, startup, or rework.

Do not do this

Do not mark an FSD passed because the motor makes noise.

Why this matters

If a life-safety damper does not actually open/close, it can fail commissioning and compromise smoke/fire control.

Verification basis

Approved drawings/specs, project coordination drawings, manufacturer instructions/submittals, shop standards, foreman/detailer direction, employer policy, and AHJ/code requirements.