Ducts and Duct Systems:Troubleshooting Damper Motors

Troubleshooting Damper Motors

Although damper motors are completely sealed, they do malfunction from time to time. The principal malfunctions, their possible causes, and suggested remedies are listed in Table 7-4.

Some manufacturers produce special compact control units for mounting on damper motors. These control units (for example, the Honeywell W859 Economizer shown in Figure 7-21) give damper motors the capacity to regulate the outside and recirculated air dampers for the following applications:

• To bring in outside air (when it is colder than the inside air) for cooling or ventilating

• To close outdoor air dampers to minimum position during the heating cycle

• To prevent short cycling of the cooling compressor to avoid coil icing