Load interrupter system

• US 5,475,609 A
• Filed: 03/05/1993
• Issued: 12/12/1995
• Est. Priority Date: 03/05/1993
• Status: Expired due to Term

• Current Assignee: Square D Company (Schneider Electric SE)
• Original Assignee: Square D Company (Schneider Electric SE)
• Inventors: Apothaker, Richard L.
• Primary Examiner(s): Voeltz, Emanuel T.
• Assistant Examiner(s): KEMPER, MELANIE A
• Application Number:
  US08/026,864
• Time in Patent Office: 1,012 Days
• Field of Search: 364/480, 364/481, 364/483, 364/487, 364/492, 361/1, 361/18, 361/35, 361/78, 361/79, 361/86, 361/87, 361/30, 324/511
• US Class Current: 700/292
• CPC Class Codes: H02H 3/006 Calibration or setting of parameters

Abstract

An associative current interrupter system provides improved circuit protection and electrical safety. A test control unit (200) applies a regulated series of input voltage levels to the appliance (300) which is to be subsequently protected under a series of minimum and maximum load sequences. The resulting data series is logged and compressed into a format suitable for downloading into a programmable interrupter (100). A remote interface (217) is provided to allow device-specific data series to be input from alternative sources. When the appliance is connected in series with the interrupter (100), load current, line voltage, and time constraints are sampled and compared to the data series, thus providing a continuous solution to the determination of normal vs. abnormal currents. An output relay (103) provides a switching element and an internally accessible calibration port (111) allows monitoring combined non-linearities for correction during manufacture.

Claims

1. A load interrupter system, operable in a data acquisition mode and a normal operating mode, for protecting a device connected to an electrical system, said load interrupter system comprising:

a test control unit coupled to the device during the data acquisition mode, said test control unit including signal generation circuitry for applying test signals to the device and a storage medium for storing responses of the device to said test signals;

processing circuitry for formatting said responses into an operating profile representative of limits of normal operation of the device; and

an interrupter unit including a memory for receiving and storing said operating profile from said test control unit while connected thereto, said interrupter unit including an input connected to an input voltage source and an output connected to the device during the normal operating mode, said interrupter unit forming a current path between said input and said output and including a relay along said current path for breaking said current path, said interrupter unit including a load monitor for monitoring dynamic operating characteristics of the device relative to said operating profile and causing said relay to break said current path in response to said dynamic operating characteristics falling outside the limits of normal operation of the device.

2. The load interrupter system of claim 1, wherein said signal generation circuitry includes a line regulator and a multiple output transformer connected to an output of said line regulator, said line regulator providing said transformer with a stabilized output voltage in response to receiving a line voltage at an input of said line regulator.

3. The load interrupter system of claim 2, wherein said transformer includes selection taps controlled by respective drivers, and further including a controller for controlling said drivers to cause said transformer to generate a series of regulated voltage steps to the device while subjecting the device to varying load conditions.

6. The load interrupter system of claim 1, wherein said storage medium includes a random access memory.

7. The load interrupter system of claim 1, wherein said responses of the device to said test signals include data selected from the group consisting of voltage, current, load, and time data.

8. The load interrupter system of claim 1, wherein said processing circuitry includes means for compressing said responses.

9. The load interrupter system of claim 1, wherein said memory includes an electrically alterable read only memory (EAROM).

4. The load interrupter system of claim 4, wherein said signal generation circuitry includes means for applying said test signals as a series of regulated input voltage steps to the device while subjecting the device to varying load conditions.

5. The load interrupter system of claim 4, wherein said means for applying said test signals includes a line regulator and a multiple output transformer.

10. A method for protecting a device connected to an electrical system, comprising the steps of:

applying test signals to the device;

recording responses of the device to the applied test signals;

generating an operating profile for the device based on the recorded responses, the operating profile representing limits of normal operation of the device;

connecting the device to an input voltage source via an interruptible current path;

monitoring the interruptible current path by comparing dynamic operating characteristics of the device to the operating profile; and

interrupting the current path in response to the dynamic operating characteristics falling outside the limits of normal operation of the device.

11. The method of claim 10, wherein said step of applying test signals to the device includes applying a series of regulated input voltage steps to the device while subjecting the device to varying load conditions.

12. The method of claim 10, wherein said step of recording responses of the device to the applied test signals includes recording voltage, current, load, and time data.

13. The method of claim 10, wherein said step of generating an operating profile for the device includes compressing the responses.

14. A method for protecting a device connected to an electrical system, comprising the steps of:

connecting the device to an input voltage source via a first current path;

applying test signals to the device using the first current path;

monitoring the first current path for data responsive to the test signals applied to the first current path and storing the data in a memory;

formatting the data into an operating profile representative of limits of normal operation of the device;

connecting the device to the input voltage source via a second current path;

monitoring the second current path by comparing dynamic operating characteristics of the device to the operating profile; and

interrupting the current path in response to the dynamic operating characteristics falling outside the limits of normal operation of the device.

15. The method of claim 14, wherein said step of applying test signals to the device includes applying a series of regulated input voltage steps to the device while subjecting the device to varying load conditions.

16. The method of claim 14, wherein said data responsive to the applied test signals includes voltage, current, load, and time data.

17. The method of claim 14, wherein said step of formatting the data into an operating profile includes compressing the data.

18. A load interrupter system for protecting a device connected to an electrical system, said load interrupter system comprising:

means for applying test signals to the device and recording responses of the device to the applied test signals;

means for generating an operating profile for the device based on the recorded responses, the operating profile representing limits of normal operation of the device;

means for connecting the device to an input voltage source via an interruptible current path;

means for monitoring the interruptible current path by comparing dynamic operating characteristics of the device to the operating profile; and

means for interrupting the current path in response to the dynamic operating characteristics falling outside the limits of normal operation of the device.

19. A load interrupter system for protecting a device connected to an electrical system, said load interrupter system comprising:

a test control unit coupled to the device, said test control unit including signal generation circuitry for applying test signals to the device and a storage medium for storing responses of the device to said test signals;

processing circuitry for formatting said responses into an operating profile representative of limits of normal operation of the device;

an interrupter unit including a memory for receiving and storing said operating profile from said test control unit while connected thereto, said interrupter unit including an input connected to an input voltage source and an output said interrupter unit forming a current path between said input and said output and including a relay along said current path for breaking said current path, said interrupter unit including a load monitor for monitoring dynamic operating characteristics of the device relative to said operating profile and causing said relay to break said current path in response to said dynamic operating characteristics outside the limits of normal operation of the device; and

an external programming source connected to said test control unit for sending data to said control test unit, said data comprising electrical specifications and ratings of said device.