초록 ▼

A damper actuator for a ventilation damper serves as both a control device for the ventilation damper and a fire and smoke rated device for the ventilation damper. The damper actuator includes a modulating motor controller, a two-point motor controller, and a thermal switch or switch like device tha

A damper actuator for a ventilation damper serves as both a control device for the ventilation damper and a fire and smoke rated device for the ventilation damper. The damper actuator includes a modulating motor controller, a two-point motor controller, and a thermal switch or switch like device that is operative to switch control of the motor from the modulating motor controller used during normal operation, to the two-point motor controller during a fire and smoke condition. The damper actuator provides an automatic and permanent disabling (by-passing) of the modulating motor controller functions the first time a pre-determined temperature level (switch point) is reached via the thermal switch or switch like device. Once the modulating motor controller is disabled, the actuator no longer supports the advanced motor control functions (i.e. the modulating control). Thereafter, the thermal switch or switch like device enables a two-point motor controller that is operative to put the damper into either a fully open or a fully closed position.

대표청구항 ▼

What is claimed is: 1. A damper actuator comprising: a motor adapted to control a ventilation damper; a thermally actuated switch coupled to said motor; first motor control circuitry coupled to said switch; and second motor control circuitry coupled to said switch; said thermally actuated switc

What is claimed is: 1. A damper actuator comprising: a motor adapted to control a ventilation damper; a thermally actuated switch coupled to said motor; first motor control circuitry coupled to said switch; and second motor control circuitry coupled to said switch; said thermally actuated switch having a first state wherein said first motor control circuitry is coupled to said motor for operational control of said motor and said second motor control circuitry is decoupled from operational control of said motor, and a second state wherein said second motor control circuitry is coupled to said motor for operational control thereof and said first motor control circuitry is decoupled from operational control of said motor. 2. The damper actuator of claim 1, wherein said second motor control circuitry is configured to cause said motor to put the damper in one of a fully open position and a fully closed position. 3. The damper actuator of claim 1, wherein said first motor control circuitry is configured to cause said motor to put the damper into a first position, a second position, and at least one position intermediate said first position and said second position. 4. The damper actuator of claim 1, wherein said thermally actuated switch is operative to change from said first state to said second state when said thermally actuated switch reaches approximately a pre-determined temperature. 5. The damper actuator of claim 1, wherein said first state of said thermally actuated switch is a normal state of operation and said second state of said thermally actuated switch is a fire control state of operation. 6. The damper actuator of claim 1, wherein said thermally actuated switch comprises a one-way thermostatic switch. 7. A ventilation damper actuator comprising: a motor configured to control a ventilation damper; a modulating controller adapted to control said motor; a two-point controller adapted to control said motor; and a switch having a first input connected to said modulating controller, a second input connected to said two-point controller, and an output connected to said motor, said switch normally coupling said modulating controller to said motor for operational control of said motor and responsive to a pre-determined thermal condition wherein said modulating controller is de-coupled from said motor and said two-point controller is coupled to said motor for operational control of said motor. 8. The ventilation damper actuator of claim 7, wherein said two-point controller is operative to cause said motor to put the ventilation damper in either a fully open position or a fully closed position. 9. The ventilation damper actuator of claim 7, wherein said modulating motor controller is operative to cause said motor to put the ventilation damper into a fully open position, a fully closed position, and a plurality of positions intermediate said fully open and said fully closed positions. 10. The ventilation damper actuator of claim 7, wherein said switch comprises a thermally actuated switch. 11. The ventilation damper actuator of claim 10, wherein said thermally actuated switch comprises a one-way thermostatic switch. 12. A method of controlling a ventilation damper comprising the steps of: providing a damper actuator, the damper actuator having a motor configured to control the ventilation damper, a modulating controller adapted to control the motor, a two-point controller adapted to control the motor, and a switch having a first input connected to the modulating controller, a second input connected to the two-point controller, and an output connected to the motor, the switch having a first state wherein the modulating controller is coupled to the motor for operational control thereof and a second state wherein the two-point controller is coupled to the motor for operational control thereof; operating the damper actuator with the switch in the first state in the absence of a fire event; and operating the damper actuator with the switch in the second state during a detected fire event. 13. The method of claim 12, wherein the step of operating the damper actuator with the switch in the second state first includes the step of setting the switch into the second state during a fire event. 14. The method of claim 12, wherein the switch comprises a thermally actuated switch. 15. The method of claim 14, wherein the thermally actuated switch comprises a one-way thermostatic switch. 16. The method of claim 12, wherein the damper actuator further includes a spring return operative to bias the damper into the fully closed position; and the method further includes the step of allowing the spring return to bias the damper into the fully closed position during a power interrupt. 17. The method of claim 12, wherein said two-point controller is operative to cause said motor to put the ventilation damper in either a fully open position or a fully closed position. 18. The method of claim 12, wherein said modulating motor controller is operative to cause said motor to put the ventilation damper into a fully open position, a fully closed position, and a plurality of positions intermediate said fully open and said fully closed positions.