摘要:
A compact switchgear system employing a number of modular components that plug into their mating interface and are maintained in electrical isolation employing solid insulation in a manner that substantially shields the electrical conducting portions of the assembly from contact with lower voltage portions of the system. The assembly is primarily made up of five modules. A multi-phase load connector having integral current monitoring transformers for each of the respective phases; a voltage monitoring transformer which plugs into the load connector; an in-line actuator and vacuum interrupter module, provided for each phase, which plugs into the load connector; a three position vacuum switch connected between the vacuum interrupter module and the line or ground; and an electronic control module which receives inputs from the current and voltage monitors, circuit relays, vacuum interrupter/in-line actuator module, and temperature sensors, and provides programmed, controlling outputs to the in-line actuators of the respective vacuum interrupter modules.
摘要:
A modular three position vacuum isolator switch that is operable to connect a stationary contact to either of two moveable contacts or an intermediate position which is out of electrical engagement with either of the moveable contacts. One of the moveable contacts is grounded and the other is connected a power source. The stationary contact is connected to two electrical connectors. One of the two electrical connectors is connected to a breaker and the second is connected to a corresponding input on a second similar isolator switch model, which itself is connected to a second line source. The stationary contact is connected to the circuit interrupter for connecting the circuit interrupter to either of the two line sources, to ground, or to isolate the circuit interrupter by placing the isolator switch module in the intermediate position.
摘要:
A load connector module for connecting a multi-phase load to a circuit interrupter which includes all the multi-phase connectors, a current transformer for each respective phase, and a voltage transformer coupling, in an integral, solid, insulated unit.
摘要:
A photovoltaic (PV) power system is disclosed that includes hybrid DC contactors corresponding to each of a plurality of PV strings, with each hybrid DC contactor having main contacts, a solid state switching unit positioned in parallel with the main contacts, and sensors configured to measure a voltage and current on respective PV strings. A controller is provided in the PV power system that is configured to receive voltage and current data on the PV strings, detect a fault condition on a respective PV string based on the voltage and current data, cause the main contacts of a respective hybrid DC contactor to remain closed on each PV string for which a fault condition is detected, and cause the main contacts of a respective hybrid DC contactor to open on each PV string for which no fault condition is detected, so as to clear the fault condition.
摘要:
A system and method for detecting incipient mechanical motor faults by way of current noise cancellation is disclosed. The system includes a controller configured to detect indicia of incipient mechanical motor faults. The controller further includes a processor programmed to receive a baseline set of current data from an operating motor and define a noise component in the baseline set of current data. The processor is also programmed to repeatedly receive real-time operating current data from the operating motor and remove the noise component from the operating current data in real-time to isolate any fault components present in the operating current data. The processor is then programmed to generate a fault index for the operating current data based on any isolated fault components.
摘要:
Molded case circuit breaker having collapsible toggle linkage with rectangular cross section knee pin non-rotatably held within open rectangular slots in upper link, bifurcated movable contact fingers loosely guided for pivotal movement about fixed pin to break contact welds, helical compression springs biasing bifurcations against faces of a stationary connector, trapezoidal cross section shaft biasing shaft against a fixed corner of clamping strap and frame, increasing clamping force and increasing tool clearance, operating handle which changes pivot point moving to RESET position, reducing lateral force component of operating springs for reliable return of handle to OFF position, dual stops for movable contact fingers to spread impact forces along fingers, greater contact separation in poles not containing operating mechanism, slot motor laminations providing metal reinforcement to separate arc chamber housing which is cooperatively interlocked with base to distribute structural strength, terminal cover with arc vent extension angled downwardly, extended lug cover with second arc vent extension interlocked to terminal cover and arc chamber housing for no-fastener securement, trip unit armature pivoted in crested surface of molded pocket and connected to trip bar by wire bail for space-efficient location of parts, and accessory devices supported on and secured to trip unit housing have throw-away pin locking operator lever in correct position during installation.
摘要:
A hybrid switch (2) having a solid state circuit (2a) including a thyristor (SCR) for closing and reopening a supply circuit (S,4,6) to a load (L) and contacts including an isolating contact (S1) for connecting power to and disconnecting power from the solid state circuit (2a), a control contact (S2) for initiating turn-on and turn-off of the thyristor (SCR), and a bypass contact (S3) for shunting the solid state circuit (2a) after the load has been energized. A zero voltage crossover circuit (ZVC) allows turn-on of the thyristor (SCR) only when the A.C. supply voltage is below a preset value to avoid arcing at the contacts on closing. The inherent zero current crossing turn-off characteristic of the thyristor (SCR) avoids arcing at the contacts on opening. A pushbutton switch (8,10) provides a mechanically controlled time delay of a minimum of the time of one-half cycle of the power supply voltage between the closing of the control contact (S2) and the closing of the bypass contact (S3) and also between the opening of the control contact (S2) and the opening of the isolation contact (S1) to allow operation of the thyristor (SCR) at zero voltage or zero current thereby to avoid arcing for long contact life and elimination of EMI (electromagnetic interference).
摘要:
Stationary contacts (12) of a multi-pole disconnect or safety switch are arranged to be engaged by one of a rotatably movable bridging contact (2) before engagement of the other end thereof with a second set of stationary contacts (10). Stationary contacts (12) of adjacent switch poles are positioned on alternate ends for increasing the phase-to-phase failure distance, and one stationary contact (10a) may be arranged to close one or two milliseconds late to produce single phasing for a short time under fault current conditions during which time current limiting fuses (14) begin to open the circuit.
摘要:
A hybrid D.C. power controller of the relay/circuit breaker type that uses a hybrid arrangement of hard contacts (4) and power FET's (18, 20) in cooperative functional combination as the arc quenching means for 270 volt D.C. power systems in low atmospheric pressure environments such as at 80,000 feet altitude in aircraft applications. Also, the relay is provided with arc horns (44c, 48b, 48c, 46c), magnetic field amplifiers (60, 62) looped stationary contacts (44, 46), arc splitters (64, 66), and gas ablating insulating members (60b, 62b, 72, 74, 64b, 66) to enable the relay to interrupt the power circuit if necessary without the help of the power FET's. The power FET's are controlled in both opening and closing the power circuit to afford arcless contact operation in normal load make-break situations. Current and voltage sensing (28, 32) and sampling (CS, VS) circuits determine when to turn the power FET's on after contact arcing has provided the required values. The power contacts (4) can be closed and opened by manual switch (TS) control and opened automatically under overload or short circuit conditions by instantaneous trip detector (ITD) control. Isolation contacts (2) in the power circuit are controlled by delay means (MMV4, MMV8) to close last and open first with respect to the power contacts.
摘要:
In a molded case circuit breaker with an interchangeable thermalmagnetic trip unit, the C-shaped heater transformer core is permanently held in place in the casing by a load bus strap with the gap in the core facing the trip unit. When the interchangeable trip unit is inserted into the molded casing, a magnetically permeable member mounted in the trip unit is aligned in the gap in the heater transformer core. The bimetal of the trip unit is fixed at one end to an electrically conductive sleeve surrounding the magnetically permeable member and forming the secondary of the heater transformer. The length of the magnetically permeable member is selected to establish the current conditions at which the bimetal trips the circuit breaker. The bus strap has an off-set section forming a first shoulder against which one wall of the housing of the interchangeable trip unit seats, and a second shoulder against which a pole piece backed by the heater transformer core seats to fix a gap between the pole piece and the armature in the interchangeable trip unit providing the instantaneous magnetic trip function.