The present disclosure relates generally to the field of hardware and control systems for fire damper equipment. More specifically, the present disclosure relates to an actuator system that may be coupled to a fire damper to allow the damper to be remotely actuated for operational testing purposes without damaging the fire damper fusible link.
One implementation of the present disclosure is a fire damper actuation system in an HVAC system. The fire damper actuation system includes a damper system and an actuator system. The damper system includes damper blades rotatable between an open configuration and a closed configuration, a crank arm assembly configured to drive the damper blades, a spring assembly configured to be held in a loaded condition when the damper blades are in the open configuration, a temperature-activated fusible link, and a fusible link arm coupling the temperature-activated fusible link to the crank arm assembly. The actuator system includes a motor and a drive device. The drive device is coupled to the crank arm assembly and the temperature-activated fusible link. Operation of the drive device by the motor between a first end stop location and a second end stop location simultaneously rotates the crank arm assembly and the temperature-activated fusible link to complete a test inspection procedure.
In some embodiments, the drive device is coupled to the temperature-activated fusible link using a U-joint component.
In some embodiments, the fire damper actuation system includes a remote inspection tool communicably coupled to the actuator system and configured to transmit a control signal initiating the test inspection procedure. In other embodiments, the remote inspection tool is configured to receive motor current measurement data from the actuator system and to detect an abnormal operating condition based on the motor current measurement data. In still further embodiments, the abnormal operating condition is a broken spring assembly, an obstruction in a path of the plurality of damper blades, a broken temperature-activated fusible link, or a missing temperature-activated fusible link. In other embodiments, the remote inspection tool is a dedicated handheld device, a fire alarm system control panel component, a mobile phone, or a tablet device.
In some embodiments, the first end stop location corresponds to the open configuration of the damper blades and the second end stop location corresponds to the closed configuration of the damper blades.
In some embodiments, the crank arm assembly includes a shaft, a first pivoting linkage, and a second pivoting linkage. The second pivoting linkage is coupled to the first pivoting linkage and a damper blade to drive the damper blades between the open configuration and the closed configuration.
In some embodiments, the spring assembly includes a torsion spring.
In some embodiments, the temperature-activated fusible link is fabricated from a fusible metallic alloy.
Another implementation of the present disclosure is a method of testing a fire damper system having multiple damper blades in an HVAC system. The method includes receiving a signal to initiate a test inspection procedure from a remote inspection tool, operating a drive device between a first end stop location and a second end stop location to simultaneously rotate a crank arm assembly and a temperature-activated fusible link, measuring a current through a motor operating the drive device between the first end stop location and the second end stop location, and transmitting the motor current measurement data to the remote inspection tool.
In some embodiments, the method is performed by an actuator system.
In some embodiments, the first end stop location corresponds with an open configuration of the damper blades, and the second end stop location corresponds with a closed configuration of the damper blades.
In some embodiments, the remote inspection tool is a dedicated handheld device, a fire alarm system control panel component, a mobile phone, or a tablet device.
In some embodiments, the remote inspection tool is configured to detect an abnormal operating condition based on the motor current measurement data. In other embodiments, the abnormal operating condition is an obstruction in a path of the plurality of damper blades, a broken temperature-activated fusible link, or a missing temperature-activated fusible link.
Yet another implementation is a fire damper actuation system in an HVAC system. The fire damper actuation system includes a damper system, an actuator system, and a remote inspection tool. The damper system includes multiple damper blades rotatable between an open configuration and a closed configuration. The damper blades are normally retained in the closed configuration by a temperature-activated fusible link. The actuator system includes a motor and a drive device. The drive device is coupled to the temperature-activated fusible link and is configured to drive the damper blades between the open configuration and the closed configuration. The remote inspection tool is communicably coupled to the actuator system and is configured to transmit a control signal initiating a test inspection procedure to the actuator system. The test inspection procedure includes rotation of the temperature-activated fusible link while the damper blades are simultaneously driven between the open configuration and the closed configuration.
In some embodiments, the remote inspection tool is further configured to receive motor current measurement data from the actuator system and to detect an abnormal operating condition based on the motor current measurement data. In other embodiments, the abnormal operating condition is an obstruction in a path of the damper blades, a broken temperature-activated fusible link, or a missing temperature-activated fusible link.
In some embodiments, the remote inspection tool is a dedicated handheld device, a fire alarm system control panel component, a mobile phone, or a tablet device.
Before turning to the FIGURES, which illustrate the embodiments in detail, it should be understood that the disclosure is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology is for the purpose of description only and should not be regarded as limiting.
Referring generally to the FIGURES, an actuator system for life safety fire dampers is shown, according to some embodiments. Fire dampers are passive fire protection devices used in HVAC ducts to prevent the spread of fire inside the ductwork. In normal operation, the dampers are continuously held open by a temperature-activated fusible link. When a rise in temperature occurs due to a fire, the fusible link is designed to fail and allow a spring assembly to close the dampers, restricting airflow though the duct and limiting the ability of the fire to spread.
Depending on the local building code, fire dampers must undergo periodic operational testing. Per the National Fire Protection Association (NFPA) standard 80 that is referenced by most municipalities, every fire damper must be tested and inspected one year after installation, and then every four or six years depending on the building type. Operational testing of fire dampers can be highly resource-intensive—since the dampers are located in ceiling ductwork, access can be difficult and messy. For example, when the testing is completed in hospitals, building zones must be selectively masked off in order to protect patients from unsettled dust and debris when ceiling panels are disturbed. Once the dampers are accessible to technicians, test cycling of the dampers involves removing the fusible link, confirming that the damper closes completely without assistance, and returning the damper to a fully open position, taking care to ensure that the fusible link is not damaged in the process. Often, building owners are faced with the choice of complying with the onerous testing procedure or taking the risk of noncompliance with building codes.
The actuator system depicted in the FIGURES is a low cost addition to an existing fire damper system that permits a building owner to remotely confirm the operational status of the dampers without visual verification of their operation. Instead of manually removing the fusible link and confirming proper closure of the dampers, an actuator system rotates the dampers to a closed position and back without damaging or requiring removal of the fusible link. Control signals for the actuator system may be sent remotely via wired or wireless means, either from a handheld test verification tool or an existing fire alarm panel.
Referring to
Remote inspection tool 400 may be a device that permits a user to initiate a damper test and determine whether the test was successfully completed using wired or wireless communications without necessitating a view of the damper itself. For example, remote inspection tool 400 may include one or more components configured to receive user input (e.g., a “Begin Test” button, a “Pause Test” button). Remote inspection tool 400 may further include a visible test indicator or interface (e.g., red and green colored lights, a status and/or parameter display screen, an error display screen) that indicate the results of the test and/or the damper status. For example, the parameter display screen may indicate whether the damper system 200 is in an open configuration, a closed configuration, or a partially closed configuration. In various embodiments, remote inspection tool may be a dedicated handheld device or an integrated component of a fire alarm system control panel. Power for the actuator system 300 may be supplied from the handheld device or the control panel. In other embodiments, remote inspection tool 400 may be a mobile device (e.g., a mobile phone, a tablet), and actuator system 300 may include a smart actuator configured to receive and transmit wireless signals to and from the mobile device or a building automation system (BAS) controller.
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The spring assembly 204 may be configured to work in concert with the crank arm assembly 210. In some embodiments, the spring assembly 204 includes a torsion spring that is coupled to the shaft 212. When the fire damper actuator system 100 is in its open configuration, the spring assembly 204 may be held in a wound or loaded state. Upon failure of the fusible link 208 and subsequent release of fusible link arm 206, the spring assembly 204 may unwind and cause the crank arm assembly 210 to drive the damper blades 202 to the closed position. In some embodiments, fusible link 208 may be fabricated in whole or in part from a fusible metallic alloy that is designed to melt (i.e., fail) at a specific temperature (e.g., 165° F., 212° F.).
Actuator system 300 may include a U-joint 302 rotatable by the drive device of the actuator. Actuator system 300 may further include securing hardware 304 used to couple U-joint 302 to fusible link 208. In some embodiments, securing hardware 304 may include one or more bolts, pins, nuts, and washers. As U-joint 302 rotates from an open blade position (with its end pointing away from the damper blades 202, as depicted in
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In various embodiments, parameters 810-840 may be displayed on the a user interface (e.g., a display screen) of the remote inspection tool 400. In other embodiments, another computing device (e.g., a laptop, a tablet, a mobile device) may be communicably coupled to the remote inspection tool 400 to display the parameters 810-840. In some embodiments, the fire damper actuator system 100 includes feedback sensors to measure and communicate the actuator position 820 and the damper position 830 to the remote inspection tool 800. In other embodiments, the fire damper actuator system 100 does not include feedback sensors that directly measure the actuator position 820 and the damper position 830. Rather, as described below, the actuator and/or damper positions may be determined based on the actuator motor current 810. Monitoring of the actuator and/or damper positions via the actuator motor current 810 may permit the detection of a variety of faults in the actuator system 100 without the added expense of additional feedback sensors.
Thus, in some embodiments, the actuator motor current 810 may be the sole monitored parameter to ensure proper functioning of the fire damper actuator system 100. For example, when the damper blades 202 are traveling from the open configuration to the closed configuration, the motor current 810 increases as the damper blades 202 close because the spring assembly 204 is unwinding from its loaded state. There is less aiding load on the actuator system 300 as it drives, which is more torque at the actuator motor. Similarly, when the damper blades 202 travel from the closed configuration to the open configuration, the motor current 810 increases because spring assembly 204 is rewinding and causing an increase of torque at the actuator motor. In other words, the slope(s) of the measured motor current 810 may provide an indication that the fire damper actuator system 100 is not experiencing mechanical problems.
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At step 1206, the actuator system 300 measures the current supplied to the actuator motor as the drive device is operated between its end stop locations. In some embodiments, the measured motor data is identical or substantially similar to the motor current data presented in plots 800-1100 described above with reference to
The construction and arrangement of the systems and methods as shown in the various exemplary embodiments are illustrative only. Although only a few embodiments have been described in detail in this disclosure, many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.). For example, the position of elements may be reversed or otherwise varied and the nature or number of discrete elements or positions may be altered or varied. Accordingly, all such modifications are intended to be included within the scope of the present disclosure. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes, and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present disclosure.
The present disclosure contemplates methods, systems and program products on any machine-readable media for accomplishing various operations. The embodiments of the present disclosure may be implemented using existing computer processors, or by a special purpose computer processor for an appropriate system, incorporated for this or another purpose, or by a hardwired system. Embodiments within the scope of the present disclosure include program products comprising machine-readable media for carrying or having machine-executable instructions or data structures stored thereon. Such machine-readable media can be any available media that can be accessed by a general purpose or special purpose computer or other machine with a processor. By way of example, such machine-readable media can comprise RAM, ROM, EPROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to carry or store desired program code in the form of machine-executable instructions or data structures and which can be accessed by a general purpose or special purpose computer or other machine with a processor. When information is transferred or provided over a network or another communications connection (either hardwired, wireless, or a combination of hardwired or wireless) to a machine, the machine properly views the connection as a machine-readable medium. Thus, any such connection is properly termed a machine-readable medium. Combinations of the above are also included within the scope of machine-readable media. Machine-executable instructions include, for example, instructions and data which cause a general purpose computer, special purpose computer, or special purpose processing machines to perform a certain function or group of functions.
Although the figures show a specific order of method steps, the order of the steps may differ from what is depicted. Also two or more steps may be performed concurrently or with partial concurrence. Such variation will depend on the software and hardware systems chosen and on designer choice. All such variations are within the scope of the disclosure. Likewise, software implementations could be accomplished with standard programming techniques with rule based logic and other logic to accomplish the various connection steps, processing steps, comparison steps and decision steps.
This application claims the benefit of and priority to U.S. Provisional Patent Application No. 62/491,748, filed Apr. 28, 2017, the entire disclosure of which is incorporated by reference herein.
Number | Date | Country | |
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62491748 | Apr 2017 | US |