Automatic transfer switch for lighting loads with integral load shedding by dimming control
An automatic power transfer switch system includes a dimmable lighting load adapted to operate under a variable amount of power in dependence on a dimming control signal, an automatic transfer switch configured to connect a primary electrical power source to the dimmable lighting load under normal operating conditions of the primary electrical power source in a first mode, and to automatically disconnect the primary electrical power source from the load and connect an emergency electrical power source to the load under malfunctioning operating conditions of the primary electrical power source in a second mode, the automatic transfer switch further including an integrated load reduction dimmer configured to provide a dimming control signal to the dimmable lighting load. A load shedding controller communicatively coupled to the automatic transfer switch to provide a load shedding control signal to the automatic transfer switch, wherein the integrated load reduction dimmer develops the dimming control signal in response to the load shedding control signal.
1. An automatic power transfer switch system comprising:
a plurality of dimmable lighting loads each adapted to receive a respective dimming control signal and adjust a dimming level of that dimmable lighting load in dependence on the respective dimming control signal;
a plurality of automatic transfer switches each configured to connect a primary electrical power source to at least one of said plurality of dimmable lighting loads under normal operating conditions of said primary electrical power source in a first mode, and to automatically disconnect the primary electrical power source from said at least one lighting load and connect an emergency electrical power source to said at least one lighting load under malfunctioning operating conditions of said primary electrical power source in a second mode, each of said plurality of automatic transfer switches further including a respective integrated load reduction dimmer configured to selectively provide an integrated dimming control signal as the respective dimming control signal to said at least one dimmable lighting load; and
a load shedding controller communicatively coupled to each of said plurality of automatic transfer switches over a plurality of communication links, to provide respective load shedding control signals to respective ones of the plurality of automatic transfer switches, each integrated load reduction dimmer of said respective automatic transfer switches receiving said respective load shedding control signal and developing said integrated dimming control signal in response to said load shedding control signal.
2. The automatic power transfer switch system as set forth in claim 1 , further comprising;
an external dimmer controller configured to provide an external dimming control signal as the respective dimming control signal to at least one of said dimmable lighting loads; and
a relay configured to selectively connect either the external dimming control signal from said external dimmer controller or the integrated dimming control signal from the respective integrated load reduction dimmer of the automatic transfer switch associated with said at least one dimmable lighting load, in dependence on the mode of the associated automatic transfer switch.
3. The automatic power transfer switch system as set forth in claim 2 , wherein said relay is controlled by said associated automatic transfer switch.
4. The automatic power transfer switch system as set forth in claim 1 , wherein at least one of the plurality of communication links is a wired link.
5. The automatic power transfer switch system as set forth in claim 1 , wherein at least one of the plurality of communication links is a wireless link.
6. The automatic power transfer switch system as set forth in claim 1 , wherein said at least one of the plurality of communication links is a network link.
7. The automatic power transfer switch system as set forth in claim 6 , wherein said network comprises the Internet.
8. The automatic power transfer switch system as set forth in claim 1 , wherein said plurality of dimmable lighting loads are located in different areas of a building.
9. The automatic power transfer switch system as set forth in claim 1 , wherein said load shedding controller is configured to provide different load shedding control signals to different automatic transfer switches.
10. The automatic power transfer switch system as set forth in claim 1 , wherein at least one of said automatic transfer switches comprises a programmable controller configured to automatically detect normal and malfunctioning operating states of said primary power source and to selectively provide the respective integrated dimming control signal as the respective dimming control signal to at least one of said dimmable lighting loads when said emergency power source is connected to said at least one dimmable lighting load.
11. The automatic power transfer switch system as set forth in claim 1 , wherein at least one of said automatic transfer switches transitions between said first mode and said second mode over a period of time in dependence on at least one predetermined time delay.
12. The automatic power transfer switch system as set forth in claim 11 , wherein said at least one predetermined time delay is adjustable.
13. The automatic power transfer switch system as set forth in claim 1 , wherein at least one of said automatic transfer switches transitions between said first mode and said second mode over a period of time in dependence on a predetermined time delay.
14. The automatic power transfer switch system as set forth in claim 1 , wherein at least one of said automatic transfer switches further comprises a plurality of sensors for detecting the operation condition of said primary power source.
15. The automatic power transfer switch system as set forth in claim 1 , wherein at least one of the respective dimming control signals is 0-10V DC.