Product Overview

ManualsBrandsBarber Colman ManualsDampers4" Post Mount Damper Actuator w/ Positioner (8-13 PSI)

b. For a normally open damper, apply air pressure to the

actuator equal to the high end of its spring range, e.g.:

13 psig (90 kPa) for an 8 to 13 psig (55 to 90 kPa)

spring, then close the damper blades against their

stops. Clamp the crank arm to the extension shaft as

described above. Signal pressure above the spring

range will then provide additional close-off force.

Figure-2 M556 Actuator Mounting Dimensions & External Installation Detail.

Note:

If an actuator is furnished with a positive positioning

relay, the final installation steps described above should be

done with the positioner’s output line disconnected and the

signal air applied directly to the actuator housing. (See

Positive Positioner Adjustment.)

Miscellaneous Mounting

M556 actuators may be utilized for other applications, such

as:

Internal Air Damper Control

These applications are non-standard. When required, internal

mounting of M556 actuators should be coordinated with the

damper manufacturer.

Fan Scroll Inlet Van Control

These field applications must be custom-engineered, utilizing

the fan manufacturer’s data for torque, stroke, mounting and

linkage requirements.

Centrifugal Refrigeration Machine Inlet Vane Control

These OEM applications are pre-engineered and the

actuators are factory installed.

M573 & M574

External Mounting

See Figures 3 and 4

Whenever feasible, M573 or M574 piston actuators operating

air control dampers should be mounted on the external

surface of ducts by means of right angle brackets (See

Figure-4). By selection of the proper model number (See

Specification Table-1), actuators of the proper size (effective

area and stroke), spring range and positioner option can be

obtained complete with the right angle bracket. the necessary

linkage components for driving damper shafts are purchased

separately, see Replacement Part and Accessories.

When ordered properly, a control damper will have one or

more shaft extensions for the required number of actuators.

These extensions will be in their retracted or “stored” positions

when shipped and must be extended and locked in position

with their set screws or through bolts.

Next, the “normal” position of the damper blades (open or

closed when signal air is removed and the actuator piston

retracts) and direction of shaft rotation as the piston is

extended must be determined to establish the mounting

position of the actuator bracket. The standard right angle