If the SD-1250 Smoke Damper fails to operate within its specifications, replace the unit. For a replacement SD-1250 damper, contact the nearest Johnson Controls® representative.
Smoke dampers have round or oval connections for low or medium pressure.
Round connections are a minimum of 4 inches in diameter. The rectangular size of the damper is 2 inches larger than the connection dimension ordered.
Smoke dampers supplied with oval connections are a minimum of 6 inches wide x 4 inches high. The rectangular size of the damper is 2 inches larger than the width and height of the connection dimensions.
Note: The maximum dimension of the transition is 70 x 94 inches.
Figure 1. Transitions
