3Com MS40-717X warranty Mounting, Damper Actuator Sizing, Damper Shaft Sizing, Maximum

Mounting

Mount the TAC DuraDrive Actuator directly on the damper shaft in locations that clear the maximum dimensions of the actuator case and allow the actuator to be mounted flush to the surface of the terminal box and perpendicular to the damper shaft.

Note: Some terminal boxes have sheet metal screw heads or other protrusions near the damper shaft. In these cases, a spacer or shim may be added under the mounting tab of the actuator to make the actuator perpendicular to the shaft.

Caution: To remain in NEMA 2 compliance the MS40-715X and MS40-707X series actuators should be mounted with conduit end down.

Damper Actuator Sizing

Correct sizing of the actuator is necessary for proper control of dampers. The area of damper that can be controlled by a given actuator is dependent upon the quality of the damper, the pressure drop across the damper in the closed position, and the velocity of the air flow through the damper. To obtain actual damper torque requirements, contact the damper manufacturer.

Damper Shaft Sizing

Use the “Long Damper Shaft” mounting instructions if the damper shaft is at least 4-5/8" (117 mm) long.

Use the “Short Damper Shaft” mounting instructions if the damper shaft is shorter than 4-5/8" or the area around the damper shaft is too narrow to allow standard mounting, as described in the “Long Damper Shaft” mounting section. See Figure-9for minimum shaft length.

Min. 4-5/8" (117 mm)

Figure-9 Long Damper Shaft Dimensions.

Caution: The MS40-717X actuator is not designed to be used on aluminum damper shafts, solid steel shafts smaller than 1/2" diameter round or 1/2" square, or hollow steel shafts smaller than 3/4" round. The actuator can produce up to 545 in-lbs (61.8. N-m) maximum stall torque, which could result in the actuator snapping off an aluminum damper shaft or an improperly sized steel damper shaft. Refer to Table-2for nominal damper shaft sizes.

Table-2 Steel Damper Shaft Specifications.

Damper Shaft Shape	Damper Shaft Type	O.D. (Nominal)a	I.D. (Maximum)
	Solid bar	1/2" to 1"	0
		3/4"	0.375
		13/16"	0.683
Round	Hollow tubing	27/32"	0.626
		7/8"	0.805
		15/16"	0.808
		1"	0.930
Square	Solid bar	1/2" to 5/8"	0

aDamper shaft sizes over 1/2" (13 mm) O.D. require AM-753 universal mounting clamps.

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