12 INCH ROUND MOTORIZED ZONE DAMPERS This line of round, motorized dampers is ideal for zoning, sub-zoning or local switch application for your home's heating/cooling system. They have a 3-wire connection through a "phone" type jack. Uses power to open and close. They are available in 8", 10" or 12" diameters. We have tested these high quality units to over 100,000 cycles without failure (more than 20 years operating 10 times a day). The damper blades create a nearly 100% seal. Installation is simple and fast, with no duct collars or sensitive special handling necessary. The asynchronous motor is a three wire model rated at 24VAC, 500mA with integral limit switches at the fully open and fully closed positions. The barrel is made of rigid polymeric resin with extra stiffing beads to insure its roundness. The motor area is insulated with 1/2" of polyurethane foam insulation.
