Busbars ug Connectors sa HV ug EHV installations

Busbars ug Connectors sa Indoor ug Outdoor Installations

Unsa ang Electric Busbar?

Ang electric busbar gitakda isip usa ka single conductor o grupo sa mga conductor nga nagserbisyo sa propieto sa pag-collect sa electrical power gikan sa incoming feeders ug pag-distribute nia sa outgoing feeders. Sa esensya, kini naglakip sa importante nga junction diin ang currents gikan sa incoming ug outgoing feeders mag-converge, efektibong nag-aggregate sa electrical power sa usa ka punto sa electrical system. Kini nga function gigahum sa busbars isip essential nga komponente aron mopasabot sa efficient flow ug distribution sa electricity sa uban-uban nga power-related setups.

Busbars para sa Outdoor Installations

Sa high-voltage (HV), extra-high-voltage (EHV) installations, sama usab sa outdoor medium-voltage (MV) installations, kasagaran gamiton ang bare busbars ug connectors. Ang conductors nga gamiton sa sitwasyon niining duha ka pangunaa nga klase: tubular o stranded wires.

Ang tubular busbars kasagaran supported sa column insulators, nga kasagaran gihimo sa ceramics. Kasagaran importante ang role sa mga insulators aron mapreserba ang electrical isolation tali sa busbars ug supporting structure, siguradohon ang safe ug proper functioning sa electrical system. Sa lahi na bahin, ang stranded-wire busbars secured sa lugar pinaagi sa dead-end clamps, nga matigayon molhok sa wires ug prevent ang movement o loosening nga mahimong disrupt sa electrical connection.

Ang Figures 1 ug 2 naghatag og visual examples nga illustrate ang concepts nga gi-describe sa itaas, showcasing ang typical appearance ug installation sa outdoor busbars ug ilang associated components.

Busbars para sa Switchgear Installations

Ang busbars nga gamiton sa switchgear installations kasagaran fabricated gikan sa copper, aluminium, o aluminium alloys sama sa Al-Mg-Si (aluminium-magnesium-silicon) alloys. Ang materials niini napili alang sa ilang electrical conductivity, mechanical properties, ug cost-effectiveness, nagpabilin sila suitable aron efficiently distribute electrical power sa switchgear systems.

Main Characteristics sa Bare Busbars

• Physical Dimensions: Para sa tubular conductors, ang diameter mao ang critical parameter, samtang para sa stranded-wire conductors, ang cross-sectional area mao ang primary importance. Kini nga dimensions directly influence ang current-carrying capacity ug electrical resistance sa busbar. Ang mas dako nga diameter o cross-section allows for the transmission sa mas taas nga currents ngadto sa mas baba nga losses.

• Mechanical Properties: Ang bare busbars kinahanglan adunay adequate mechanical strength aron tubagon ang uban-uban nga forces encountered sa operation. Key mechanical parameters include tensile strength (ability to resist stretching), compressive strength (resistance to squeezing), bending strength (ability to withstand bending forces), ug buckling strength (resistance to deformation under compressive loads). Additional, moments of resistance ug inertia crucial aron maunsa ang busbar will respond sa mechanical stresses, ensuring its structural integrity over time.

• Rated Current: Ang rated current sa busbar indicates ang maximum continuous current nga safely carry without excessive heating or degradation of its performance. This value determined based on factors such as material properties, cross-sectional area, ug ambient operating conditions. Selecting a busbar with an appropriate rated current essential aron prevent overheating ug potential failures in the electrical system.

Importante nga ipahibalo nga tungod kay wala insulated ang bare busbars, ang concept sa rated voltage dili applicable sa same way sa insulated conductors. Sa connecting sa busbars sa equipment terminals, specialized connectors must be used. These connectors, as exemplified in Figure 3, ensure a secure, low-resistance electrical connection, facilitating the reliable transfer of electrical power between the busbars and other components of the switchgear system.

Busbar Connection ug Insulated Busbar Systems

Busbar Connection

Sa making connections tali sa busbars, ang choice of connectors crucial ug depends sa materials sa busbars being joined. Para sa copper-to-copper connections, bronze connectors typically employed. These connectors offer excellent electrical conductivity ug mechanical strength, ensuring a reliable connection. Para sa aluminium-to-aluminium connections, aluminium alloy connectors ideal choice. They specifically designed match the properties of aluminium busbars, providing a secure ug stable connection while minimizing risk of corrosion.

Sa case of copper-to-aluminium connections, bi-metallic connectors essential. Using these connectors necessary aron prevent corrosion can occur due to electrolytic effect when two different metals come into contact in presence of electrolyte (such as moisture in air). The electrolytic reaction between copper ug aluminium can lead to degradation of connection over time, potentially causing electrical failures. Bi-metallic connectors engineered mitigate this issue, ensuring long-lasting ug reliable connection between copper ug aluminium busbars.

Insulated Busbars & Trunking Systems

Sa indoor medium-voltage (MV) ug low-voltage (LV) installations, where high currents involved ug space at a premium, insulated busbars ug trunking systems often utilized. Sa setups, busbars enclosed within metallic enclosures, which serve dual purposes of providing mechanical protection ug electrical insulation. The enclosures safeguard busbars from physical damage, such as accidental impacts or contact with foreign objects, ug also prevent electrical shocks isolating live conductors from surrounding environment.

However, this enclosure comes with trade-off. The presence of enclosure reduces heat dissipation of busbars. It restricts flow of cooling air around busbars decreases radiation losses, important for dissipating heat generated during current flow. As result, current ratings of busbars within enclosures often significantly lower compared to those exposed to free air.

To address this issue minimize reduction in current-carrying capacity, ventilated enclosures used. These enclosures designed with openings vents allow better air circulation, facilitating more efficient heat dissipation. This helps maintain higher current ratings while still providing necessary mechanical protection insulation.

Figure 4 provides illustrative example of enclosed busbar, showcasing typical structure appearance of system highlighting how enclosure integrated with busbars meet requirements of indoor electrical installations.

Isolated Busbars ug Trunking Systems

Isolated Busbars

Isolated busbars typically constructed using flat bars of copper or aluminium. The number of bars per phase vary, depending on magnitude of current required carry. Setup, each individual phase or pole encased within separately earthed sheath. Ends of sheath connected by bar rated for full short-circuit current.

Primary function of sheath prevent occurrence of inter-phase short-circuit currents. Additionally, offers important advantage related to magnetic fields. When current flows through conductors, generates strong magnetic fields. However, equal opposite current induced in enclosure sheath, almost completely cancels out magnetic fields. Cancellation of magnetic fields helps reduce electromagnetic interference minimize potential for unwanted effects on nearby electrical electronic equipment.

Commonly employed insulating materials for isolated busbars include air sulfur hexafluoride (SF6). Air readily available cost-effective option, while SF6 offers superior insulating properties, suitable applications where higher levels of insulation electrical performance required.

Trunking Systems

In low-voltage (LV) installations, one cost-effective approach to power distribution, as well as supplying power to multiple pieces of equipment facilitating interconnections between switchboards or between switchboard transformer, use of trunking system. As illustrated in Figure 5, trunking systems provide structured efficient way route electrical conductors, protecting from physical damage simplifying installation maintenance of electrical systems.

Trunking Systems: Features ug Advantages

A trunking system consists of pre-assembled flat bar conductors (including phase neutral conductors) enclosed within single metallic casing. Design offers streamlined organized approach electrical power distribution.

In feeder trunking systems, power extraction from busbar trunking achieved through use of tap-off units. Units connected specific, predefined locations along busbar trunking. Enable safe controlled removal of power from system, typically via appropriate protective devices such circuit breakers fuses. Setup ensures electrical power distributed precisely various loads required.

Trunking systems present several significant advantages over traditional cable-based systems:

• Cost-effectiveness Ease of Installation: Trunking systems more economical implement simpler install, especially dealing high-current applications. Scenarios, achieving necessary current ratings single-core cables often requires using multiple cables meet voltage drop voltage dip specifications. Increases complexity cost cable installation raises risk overheating between cables, potentially lead short circuits. Contrast, trunking systems provide more efficient reliable solution high-current power distribution.

• Mechanical Strength Installation Efficiency: Exhibit superior mechanical strength over long distances minimal need fixings. Characteristic significantly reduces installation times, fewer supports fasteners required compared cable runs. Robustness trunking systems ensures greater durability reliability during operation.

• Space-saving Simplified Design: Eliminate need multiple cable runs along associated supporting metalwork, simplifying overall electrical infrastructure. Reduction complexity saves space makes system easier manage maintain.

• Reduced Termination Requirements: Demand less termination space within switchboards. Crucial advantage, especially switchboard designs space at premium, allowing compact efficient electrical panel layouts.

• Eliminating Need for Cable Jointers: Since trunking systems pre-assembled do not require on-site cable splicing, need specialized cable jointers eliminated. Reduces labor costs minimizes potential errors associated cable joining, enhancing overall quality reliability electrical installation.

• Flexibility in Power Distribution: Multiple tap-off outlets provide flexibility adapt changes power requirements after initial installation, subject rating busbar trunking. Feature allows easy reconfiguration electrical system accommodate new loads changes load demands, making trunking systems highly adaptable evolving electrical needs.

• Ease of Repositioning Extension: Repositioning distribution outlets straightforward process trunking systems. Moreover, system easily extended electrical requirements facility grow, offering scalable solution power distribution.

• Aesthetic Appeal: Areas electrical system visible, trunking systems offer aesthetically pleasing appearance compared bundles cables. Sleek uniform design enhance visual appeal building's interior, making preferred choice commercial public spaces.

• Reusability: Busbar trunking systems dismantled reused areas, providing cost-effective solution facilities undergoing renovation expansion. Reusability factor reduces waste offers significant savings terms material installation costs.

• Enhanced Fire Resistance: Provide better resistance spread fire compared traditional cable systems. Metallic enclosure trunking helps contain fire prevent spreading through electrical system, contributing improved fire safety buildings.