Diagramma na yankin kudin kasa da take sauki da ayyuka daban-daban

Diagram of Circuit Breakers Control Circuit Functions Description

• Maimaito mai Circuit Breaker: Wadannan ba su shiga cikin circuit na kontrol. Su ne suna da muhimmanci wajen kawo ko fuskantar hanyar tashar karamin kware.

• Mechanism na Kudin: Wani mechanism wanda yake gargaɗe energia da ke bukatar don kawo maimaito mai karamin kware daga babban zuwa tsakiyar ta. Yana iya zama daidai da cikin circuit na kontrol. Mutanen yakin ya fi yawa a kan kawo maimaito mai karamin kware, wanda yana da muhimmanci wajen kawo ko fuskantar hanyar tashar karamin kware.

• Sistem na Kudin wa Energy: Sistem na kudin wa energy yana bayyana energy don mechanism na kudin. A cikin systems da take da hydraulic, spring, ko pneumatic energy storage, yana iya kasance da motor na karamin kware, motor - operated pump, ko compressor. Wannan sistem yana taka da dalilin da ke bukatar don kudin mechanism na kudin, masu muhimmanci wajen kawo da fuskanta maimaito mai karamin kware, bane da zama da ita da yawan kawo.

Monitor na Density da Maimaiton Monitor na Density: Wadannan devices suna da muhimmanci wajen kula insulation da/ko arc - extinguishing media, wadanda suka fi sani SF6 ko mixed gas a cikin circuit breakers na zamani. Da yauwarsa, suke amfani da pressure switches da suka samun temperature - compensated. Sun yi aiki da auxiliary relays don kare circuit breaker daga tripping ko closing idan density na SF6 gas a cikin enclosure ya zama da kyau da critical levels. Switches da maimaiton yana da biyu masu muhimmanci:

• Aiki na Warning/Alarm: Sun bayyana warning ko alarm idan density na SF6 gas a cikin enclosure ya zama da kyau amma ya zama da kyau da lockout level. Wannan alert na kadan yana ba operator da wani lokacin da ya fi yawa don kawo karfin da aka fara bago circuit breaker ya ci lockout da ya zama da kyau da operational capabilities.

• Aiki na Interlocking/Prohibiting: Idan density na SF6 gas ya zama da "lockout level," inda safe operation ya zama da kyau, wadannan components suke interlock ko prohibit aiki na circuit breaker. Operator yana da zama da option don configure circuit breaker don either automatically trip and lockout idan wannan level an samu (wanda yake da some safety risks) ko ci lockout a matsayin yadda yake a lokacin.

Close Coil: Close coil yana cikin solenoid device. Idan circuit breaker yake samu valid closing signal, close coil yake energize. Wannan energization yana kawo mechanism, wanda yake kawo maimaito mai karamin kware na circuit breaker. Idan circuit breaker ya zama da closed position, auxiliary switch contacts a cikin closing circuit suka zama open, de - energizing closing coils. Duk da yake da close coil na biyu a cikin control circuit don taka da single, coordinated closing operation.

Open Coils: Open coils na da su cikin solenoid devices. Idan circuit breaker yake samu valid opening signal, suke energize. Wannan energization yana kawo mechanism, wanda yake kawo maimaito mai karamin kware na circuit breaker. Idan circuit breaker ya zama da open position, auxiliary switch contacts a cikin trip coil circuits suka zama open, de - energizing trip coils. Duk da yake da biyu trip coils wadanda suke yi aiki daga independent power supplies. Operation of just one trip coil yana da zama da zai iya kawo circuit breaker. Provision of two coils yana taimaka wajen minimize risk of a failure to trip, enhancing the reliability of the circuit - breaking process.

• Position Auxiliary Switch: Driven by the operation of the circuit breaker, these contacts serve multiple purposes. They interrupt the current of the close and trip coils to de - energize them once the operation (closing or opening) is complete. Additionally, they are used for indicating and monitoring the position of the circuit breaker. They also play a role in interlocking control and protection operations at the bay or station level, preventing incorrect switching operations. These switches can be utilized in any function where the position of the circuit breaker is a critical parameter.

• Anti - Pumping: The anti - pumping feature is designed to prevent a re - closing operation when a previous close command is still active while the circuit breaker has been opened. This mechanism stops the circuit breaker from repeatedly closing and opening, which could lead to damage and safety hazards. Typically, the close command energizes an anti - pumping relay via an auxiliary switch contact (a Normally Open (NO) contact). One contact of the anti - pumping relay interrupts the circuit to the close coil, while a second contact latches or "seals in" the anti - pumping relay until the close command is removed from the circuit.

• Energy Limit Contact: The energy limit contacts are set to activate when the stored energy in the mechanism is depleted, either due to operation or losses. Usually, they trigger a motor to start, aiming to restore the energy of the mechanism to its normal operating level, such as re - compressing a spring or replenishing hydraulic/pneumatic pressure. For spring mechanisms, recharging typically occurs after every close operation, whereas other mechanism types may be able to perform several operations before recharging is needed. Pneumatic and hydraulic systems have a switch that monitors the pressure and energizes a compressor when the pressure falls below a critical level. Once the energy level is restored, a switch opens, stopping the motor. The motor is generally equipped with protection against thermal overload and a time - limit relay, which stops the motor (or a motor - operated pump or compressor) in case of a malfunction. The switches or contacts monitoring the stored energy perform the following functions:

• Closing Lockout: They lock out the close operation if the circuit breaker lacks sufficient energy to close and re - open safely.

• Opening Lockout: They lock out the open operation if the circuit breaker does not have enough energy to open safely. This is particularly relevant for hydraulic or pneumatic circuit breakers, although it may not apply in the same way to spring - operated breakers, where a successful closing charges the opening spring(s).

• Charging Control: They control (start and stop) the charging circuit of the energy storage device (e.g., a spring).

• Local/Remote Switch: This is a selector switch that allows the operator to disable remote control and operate the circuit breaker only locally. It serves as a safety feature to prevent remote operation of the circuit breaker during maintenance, ensuring the safety of maintenance personnel.

• Disconnect/Fuse Element: These devices are used to cut off the power supply to the control system during maintenance work or when there is a fault in the control circuit. Disconnection is usually achieved through knife switches or removable fuses/links, which provide visual confirmation that the control circuit is open. They can also be locked in the open position to prevent unauthorized re - connection. In cases where short - circuit protection is required, Mini Circuit Breakers (MCB) can be used as an alternative to simple fuses.

• Local Control and Indication: This function provides an indication of the circuit breaker's position and the status of the local/remote control facility. These indicators are mainly for maintenance purposes or emergency operations, depending on local safety regulations, enabling personnel to quickly assess the circuit breaker's condition.

• Pole Discrepancy/Pole Disagreement Circuit: For Independent Pole Operation (IPO) circuit breakers, where each phase has its own operating mechanism, it is possible for one phase of the circuit breaker to be in a different position (open or closed) compared to the other phases. This situation, known as pole discrepancy or pole disagreement, can lead to an unsymmetrical primary current. When a pole discrepancy occurs, auxiliary switch contacts in each phase are used to energize a time - delay relay. If the discrepancy persists after the preset time delay (usually between 1.5 to 5 seconds, depending on specific grid conditions and the allowable duration of asymmetric primary circuit operation, which should be longer than the one - phase auto - reclose time and shorter than the negative phase sequence protection of generation), an attempt will be made to trip all phases of the circuit breaker. If the pole discrepancy was due to a failure to close one pole, the trip is likely to succeed. However, if the initial discrepancy was due to a failure to open, the failed pole may not respond to subsequent opening commands, and opening other circuit breakers may be necessary.

• Heating: Space heaters are commonly installed in each of the operating mechanism and control housings. Their purpose is to reduce condensation, which can cause corrosion and malfunctions in the equipment, thereby ensuring the reliable operation of the circuit breaker components.