1. What is the total area of the damper? (square feet)
2. Opposed blade or Parallel blade control construction? (L” x W” = Total sq inches/144 = total sq feet)
Opposed Blade w/o seals 3 in-lb/sq feet*
Opposed Blade w/ seals 5 in-lb/sq feet
Parallel Blade w/o seals 4 in-lb/sq feet
Parallel Blade w/ seals 7 in-lb/sq feet
*Less than 1,000 feet per minute
3. Are there blade and edge seals on the damper? This will impact the proper selection as the seals add resistance requiring more torque. If unknown, use a worst case scenario, parallel blade with seals.
4. For the damper in question, what does the manufacturer specify as the torque rating? If this information is not available refer to the “typical damper requirements and sizing” chart below.
5. What is the air velocity, static pressure, or design CFM? System above 1,000 FPM required additional actuator torque.
6. Is fail-safe actuation required?
7. What is the supply voltage to the actuator?
• 24 VAC/DC
• 120 VAC
• 230 VAC single phase
8.What is the control signal to the actuator?
• 2 position
• Floating point
• Modulating
• Sequencing
• “Non-standard” voltage signals
This will be a critical component to the selection of an actuator. Consider the …MFT actuator product range and the flexibility of its application.
9. Can you direct couple to a damper shaft? Direct-coupling has become the industry standard. Some retrofit applications do not allow direct coupling. Refer to the Belimo “Mounting & Methods Guide” for application details.
10. Are there additional accessories required? For example, some applications require the addition of an auxiliary switch for proof of position; a retrofit application may require an additional mounting bracket and linkage kit. We advise that you identify these needs prior to leaving the job site or ordering products.
