Selection Charts - Johnson Controls - LIT-1900638 - LIT-1900638

SD-1250 Smoke Dampers Catalog Page

Johnson Controls
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Catalog Page
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About this task

Use the following to select the product:


  1. Determine required size and type of damper.
  2. Select the features from the Smoke Damper Ordering Template that match the operation and performance required.
  3. Enter width and height of damper.
  4. Enter options required.


Smoke Dampers include 16-gauge galvanized steel blades, stainless steel bearings, and stainless steel side seals.

Maximum size and area limitations are determined by past UL testing. Future testing may include additional actuators or expand present limits. Actual damper size is 1/4 inch less than nominal. For example, a damper ordered 24 inches wide x 32 inches high is shipped 23-3/4 inches wide x 31-3/4 inches high.

Table 1. SD-1250 Panel Size Limits
Damper Width x Height

Maximum, 1 Panel

36 in. x 48 in.

Table 2. SD-1250 Options List


Option Description


Exact size, no undercut


Factory-Installed Blade Position Switch Kit


20-gauge galvanized steel sleeve, 20 in. length


Internal mount actuator


Transition to round or oval duct

Minimum size is 6 x 4 in. Maximum size is 70 x 94 in.

Note: Dampers have a maximum of two factory-installed options.
Note: One kit provided for each damper opening, not one kit for each actuator or shipped section.
Note: Minimum size for an electric actuator is 12 x 21 in. Minimum size for a pneumatic actuator is 18 x 24 in.
Table 3. SD-1250 Smoke Damper Ordering Template
Specification Code Number Field


S = Smoke


Blade Operation

O = Opposed (greater than 12 inches)

P = Parallel


Blade Type

E = Class I Aluminum Frame and Blade (SD-1250)



S = Standard (stainless steel/silicone)


Actuator Type

A = 120 VAC 250°F

B = 24 VAC 250°F

C = 120 VAC 350°F

D = 24 VAC 350°F

O = Pneumatic 250 ° F (8-13# spring range)

P = Pneumatic 350°F (8-13# spring range)

Width Dimensions

008 to 144, 1-inch increments

- www x
Height Dimensions

006 to 096, 1-inch increments


Factory-installed Options

See Options List for selection and combinations.

Note: Standard product includes the actuator mounted outside the air stream on a 12 inch wide side plate. Specific damper and actuator combinations have been evaluated and found suitable for volume control use. As such, use dampers marked Also Suitable For Use As Volume Control Damper for volume control applications.
Note: Mutiple panel assemblies with a maximum width of 0 to 72 inches have a maximum height of 192 inches.
Note: Mutiple panel assemblies with a maximum width of 73 to 144 inches have a maximum height of 96 inches.
Note: Mutiple panel assemblies with a maximum width of 145 to 288 inches have a maximum height of 48 inches.


Example: SOESB-020x020 is an SD-1250 smoke damper that has 16-gauge blades, opposed blade operation, stainless steel bearings, high-temperature blade seals, and side seals. Its dimensions are 20 inches wide x 20 inches high, with a 250°F 24 VAC electric actuator.