2042results about "Protective switch details" patented technology

The present invention provides a GFCI that not only has ground fault protection, but also is capable of providing reverse wiring protection as well as detection of end of the service life of the GFCI by way of utilizing an end of life detection control circuit in connection with the reset button. In addition, the GFCI of the present invention provides a forcible mechanical tripping assembly by way of utilizing the test button. Finally, the present invention provides method for detecting whether the service life of the GFCI has ended.

A self test (ST) ground fault circuit interrupter (GFCI) provides a half wave rectifier for powering circuitry for determining and annunciating end of life (EOL) of the GFCI regardless of a shorted diode bridge or opening of a printed circuit board (PCB) trace. A fuse resistor is provided to open before an open PCB trace can occur. A microprocessor-controlled heat-conducting circuit is provided adjacent to a thermal fuse to controllably open the thermal fuse and remove power from face receptacle contacts and load terminals when EOL occurs.

The present invention is directed to an electrical wiring device that includes a plurality of line terminals, a plurality of load terminals, and a set of receptacle load terminals. The device includes a fixed contact and a first cantilever member including a first contact disposed thereon. A second cantilever member is disposed between the fixed contact and the first cantilever. The second cantilever member includes a dual contact disposed thereon. The dual contact is disposed between the fixed contact and the first contact. An actuator is configured to move between a closed position and a tripped position. The actuator is configured to urge the first cantilever toward the second cantilever to close the fixed contact, the first contact, and the dual contact such that the plurality of line terminals, the plurality of load terminals, and the set of receptacle load terminals are electrically continuous in the closed position. The actuator is also configured to release the first cantilever from the second cantilever to open the fixed contact, the first contact, and the dual contact. The plurality of line terminals, the plurality of load terminals, and the set of receptacle load terminals are decoupled in the tripped position.

An overvoltage protection device includes first and second electrically conductive electrode members, a varistor member formed of a varistor material and electrically connected with each of the first and second electrode members, and an electrically conductive, meltable member. The meltable member is responsive to heat in the device to melt and form a current flow path between the first and second electrode members through the meltable member.

The invention relates to a plastic case material for a breaker and a preparation method thereof. The material comprises the following components in parts by weight: 22-80 parts of nylon, 5-25 parts of glass fiber, 5-25 parts of needle-like filling material, 8-20 parts of fire retardant, 2-6 parts of auxiliary fire retardant and 0.1-2 parts of other auxiliaries. The preparation method comprises the following steps: evenly mixing the raw materials with a high-speed mixer at a high speed; and then bracing and pelleting the mixed materials with a screw extruder at the temperature of 220 DEG C-290DEG C to obtain the plastic case material. Compared with the prior art, the plastic case material has high breaking strength and elastic modulus, the strength of a compound material is barely influenced by a proper addition of the raw materials, and the obtained product has the advantages of no glass fiber rich surface, no buckling deformation, high strength and good heat resistance.

A hybrid air-gap / solid-state device protection device (PD) for use in an electrical power distribution system includes an air-gap disconnect unit connected in series with a solid-state device, a sense and drive circuit, and a microcontroller. Upon the sense and drive circuit detecting an impending fault or exceedingly high and unacceptable overvoltage condition in the PD's load circuit, the sense and drive circuit generates a gating signal that quickly switches the solid-state device OFF. Meanwhile, the microcontroller generates a disconnect pulse for the air-gap disconnect unit, which responds by forming an air gap in the load circuit. Together, the switched-OFF solid-state device and air gap protect the load and associated load circuit from being damaged. They also serve to electrically and physically isolate the source of the fault or overload condition from the remainder of the electrical power distribution system.

The present invention provides a set of circuits which is capable of performing an automatic check on main components of a circuit interrupting device when the circuit interrupting device is properly powered and the device is at a tripped state to determine whether these main components function normally. The results of the automatic check can be detected by depressing a reset button in the circuit interrupting device. If the reset button can be depressed, the main components function normally. Alternatively, the results can be automatically displayed by a showing on the face lid of the circuit interrupting device of either a green light, which means that the main components function normally, or a red or yellow light or no light, which means that at least one of the main components in the circuit interrupting device does not function properly. The present invention also provides an end-of-service-life detection integrated circuit chip capable of receiving and transmitting an automatic check signal and determining whether or not the circuit interrupting device can be reset. The preferred circuit interrupting device is a ground fault circuit interrupter (GFCI).

The present invention provides a circuit interrupting device, preferably a ground fault circuit interrupter (GFCI), which contains a dual-function test button having a short pole and a long pole positioned underneath the dual-function test button. When the GFCI is properly wired and powered, a depression of the dual-function test button allows the short pole to operatively connect to a conductive pin and generate a leakage current to test the components of the GFCI. If all of the components are functioned properly, the GFCI can be reset. If not, the GFCI cannot be reset. When the GFCI is miswired or reverse wired and not powered, a depression of the dual-function test button does not test the components of the GFCI. However, a further depression of the dual-function test button allows the long pole presses against a tripping lever on a locking member in a tripping device which mechanically trip the GFCI. The present invention further provides an end-of-life detection circuit which can automatically generates a simulated leakage current to test the components in the GFCI. If one or more components are not functioned properly, the end-of-life circuit prevents the GFCI from resetting.

A self testing fault detector having a line side and a load side and a conductive path there between, said apparatus is provided. The self testing fault detector includes a controller, adapted to perform periodic status tests on a protection circuit of the self testing fault detector without interrupting power to the load.

The present invention provides a circuit interrupting device, preferably a ground fault circuit interrupter (GFCI), which contains a dual-function test button having a short pole and a long pole positioned underneath the dual-function test button. When the GFCI is properly wired and powered, and preferably in a reset state, a first-level depression of the dual-function test button allows the short pole to close a flexible switch (KT) to electrically connect a power input end to a power output end and generate a leakage current to test the components of the GFCI. If all of the components are functioned properly, the GFCI can be reset. If not, the GFCI cannot be reset. When the GFCI is miswired or reverse wired and not powered, the first-level depression of the dual-function test button does not test the components of the GFCI. However, a second-level depression of the dual-function test button allows the long pole presses against a tripping lever on a locking member in a tripping device which mechanically trip the GFCI. The present invention further provides an end-of-life detection circuit which can automatically generates a simulated leakage current to test the components in the GFCI. If one or more components are not functioned properly, the end-of-life circuit prevents the GFCI from resetting.

The present invention provides to a circuit interrupting device, particularly a ground fault circuit interrupter (GFCI), with a test circuit which is capable of automatically generating a simulated leakage current to detect whether the service life of the circuit interrupting device has ended, i.e., whether the main components of the device are working properly, when the device is properly connected to power input terminals and in a tripped state. The test circuit contains an end-of-service-life integrated circuit chip, which is connected to a switch that interacts with the reset button, thereby, by observing whether the device is capable of resetting, a user can determine whether the service life of the device has ended, i.e., if the device can be reset, the device is working properly; if the device cannot be reset, the service life of the device has ended. Optionally, the circuit interrupting device contains an indicating light on the face of the device, thereby, by observing whether a normal status indicating light or a problem status indicating light is turned on and displayed on the face of the device, the user can determine whether the service life of the device has ended. The circuit interrupting device also possesses a forcible tripping mechanism through the operation of the test button to interrupt the power output to the device. The present invention also provides methods for detecting the end of service life of the circuit interrupting device.

This invention discloses a ground fault circuit interrupter capable of detecting its end of life, and is characterized by: a pair of flexible metal sheets connected to the power output end are added on the circuit board of the interrupter, and there is a pair of moving contacts on the metal sheets; there are two pairs of fixed contacts on the power output conductors; the two pairs of fixed contacts on the power output conductors respectively correspond to the moving contacts on the power input metal sheets and the moving contacts on flexible metal sheets, thus forming two groups and four pairs of switches. There is also a tripping apparatus on the circuit board, which can release / trip the interrupter, thus cutting off the power output of the interrupter. An end of life detection circuit has also been added to the circuit board. After the interrupter is energized, various components in the interrupter are automatically detected. If it is found that the interrupter has come to the end of its life, the reset button will be prevented from resetting, so that neither the load end of the interrupter nor the power output holes on the surface of the interrupter have any power output. This invention has powerful applications, with sound safety precautions, thus effectively ensuring the personal safety of the user as well as the safety of the appliances.

In a direct current cutoff switch1, a PTC 5, which is a non-linear resistor, is parallel connected to a contact circuit composed of a fixed contact 4-2 and a movable contact 8-2 via electrodes 5-1. When the switch is closed, no current flows in the PTC 5 with a prescribed resistance value at 25° C., since voltage between both the electrodes 5-1 is almost “0”. When the switch is opened in order to cut off current, the contacts form a closed circuit since the PTC 5 is parallel inserted between the fixed contact 4-2 and the movable contact 8-2. For this reason, it is difficult for surge voltage to occur and an arc hardly occurs between both the contacts. The PTC 5 instantaneously heats due to passing current, reduces the resistance value and passes peak current. Then, the resistance value rises and becomes stable in a high value such that weak current which is negligible at 42V, which is rated voltage. Thus, current is substantially cut off.

An arrangement for reducing pressure inside a circuit breaker caused by gas produced during an electrical interruption event, including a base, an interrupter assembly, and a trip unit base. A structure having a surface is positioned in the base at an angle relative to a vent opening of the interrupter assembly. The trip unit base includes a complementary structure opposing the structure to form a cavity. The base includes a chamber area adjacent to an opening of a vent chute that leads away from the circuit breaker. During an electrical interruption event, hot explosive gas, carbon, and molten metal debris are directed away from the vent opening of the interrupter assembly along the angled surface of the structure and toward the opening of the vent chute. In this manner, pressure in the circuit breaker is reduced during an electrical interruption event, and undesirable buildup of debris is reduced.

Disclosed is an end-of-life status alarm indication circuit and method for indicating the failure of the primary contacts of a ground fault circuit interruption (GFCI) device to open when a ground fault circuit is detected by the GFCI device. The GFCI device will protect against the situation where the primary contacts of a GFCI device become welded together and will not open when a ground fault circuit is detected by the device. The alarm indication may be either an audible or visual indication.