Muhimman Yadda Differenciyar: IEE-Business da IEC Vacuum Circuit Breakers

Matsayin Ikkilanta Daga Vacuum Circuit Breakers na IEEE C37.04 zuwa IEC/GB Standards

Vacuum circuit breakers da aka fadada shiga standard IEEE C37.04 na Amurka ta Nauwaci suna iya haɗa daban-daban a matsayinta da funktiyoyin gaba tare da wadannan da suka ci gaba da standards IEC/GB. Wannan ikkilinta yana faruwa ne kafin haka daga tsari, ingantaccen aiki da sabbin lamarin da ke samar da yanke da kullum a cikin North American switchgear practices.

1. Trip-Free Mechanism (Anti-Pumping Function)

"Trip-free" mechanism—ko anti-pumping function—yana tabbatar da idan aika mai trip (trip-free) an yi da ya faruwa a gaba da aika mai sauya (electrical ko manual), wannan breaker ba zai iya sauya, hata a lokacin da ya faruwa ba.

• Idan aika mai trip an faruwa, mafi girman kontakta zai zo waɗanda yake da shi a kan birnin da ya faruwa, kafin a faruwa a gaba da aika mai sauya.

• Wannan mechanism yana iya buƙatar aika masu spring energy a lokacin da ake amfani da shi.

• Amma, a lokacin da wannan aiki, ba za a iya haɗe gabas kontakta daga 10%, ko kuma bude ability da shi ke da ita don maɗara voltage ga gabas. Kontaktun zai ci a kan birnin da ya faruwa, ba a kan birnin da ya sauya ba.

• Duka electrical da mechanical interlocks suna buƙata a sauya a kan wannan alamomin.

Tsunufin Yadda Ake Yi:

• Electrical Interlock: Solenoid yana buƙata a sauya. Idan aika mai trip (manual ko electrical) an faruwa, Microswitch 1 (da aka nuna a Fig. 2) yana buƙata closing coil. Tare, plunger na solenoid yana faruwa don kuɗe aikan mai sauya. Ba tare, Microswitch 2 yana faruwa, tare da normally open contact da take taka a cikin closing coil circuit, don buƙata a sauya electrical.

• Alternative Mechanical Design: Akan mai sauya yana iya faruwa, amma energy da ke cika a spring yana faɗa a jirgin sama (i.e., ba da load), ba a kan main shaft don sauya vacuum interrupter ba. Wannan yana tabbatar da dalilai a cikin aiki da a kan mechanical actuation ba a sauya.

2. Automatic Spring Discharge (ASD)

ASD (Auto Spring Discharge) yana daya daga cikin abubuwan dalilai masu muhimmanci a kan IEEE standards. Yana tabbatar da circuit breaker ba zai a kan charged (spring-energized) state a lokacin da ake racking in ko out of its compartment—ko a lokacin da ake karɓa daga test to service position, ko a lokacin da ake karɓa fitar da switchgear cubicle.

• Wannan yana buƙatar a bangaren personnel da ake buƙata a kan high-energy spring mechanisms a lokacin da ake aiki, tare da a buƙatar accidental energy release.

• Saboda haka, breaker yana da kyau a faruwa a kan birnin da ya faruwa, ba a kan birnin da ya sauya ba, a lokacin da ake faruwar aiki.

• Akwai automatic energy release mechanism da ya faruwa don faɗa stored spring energy a lokacin da ake karɓa fitar da connected position.

• Idan energy an faɗa a bayan karɓa, electrical interlock yana buƙata automatic re-energization of the spring, don tabbatar da breaker yana da kyau a lokacin da ake aiki.

Wannan feature yana saukarci dalilai da ake buƙata a cikin North American safety protocols for metal-clad switchgear.

3. MOC – Main Contacts Position Indicator (C37.20.2-7.3.6)

Yawan IEC/GB breakers, inda auxiliary switches (e.g., S5/S6) da suka nuna main contact position suna daidai a cikin enclosure na operating mechanism na breaker da suka faruwa a kan main shaft via linkage (simple and reliable), IEEE standards sun tabbatar da Main-Open/Main-Closed (MOC) auxiliary switches suna daidai a cikin fixed switchgear compartment, ba a cikin breaker ba.

Dalilan Yadda Ake Buƙa Tsarin:

• Enable Secondary System Testing Without the Breaker: Yana ba technicians a wayar da breaker position (open/closed) a cikin test probe ko simulator, don a duba protection relays, control circuits, da signaling systems—even when the breaker is removed from the cubicle.

• Support High-Current Auxiliary Circuits: Control systems na farko suna buƙatar high-current signaling (e.g., >5A), wanda standard secondary plug contacts (typically rated for 1.5 mm² wire) ba zan iya faruwa ba. Fixed MOC switches sun ba da kyau a yi aiki a cikin heavier gauge wiring within the compartment.

Abubuwan Dalilai Masu Tsarin:

• Main shaft na breaker yana da kyau a faruwa fixed MOC switch a both test and service positions.

• Drive linkage (top, bottom, or side-mounted) yana da kyau a faruwa motion daga moving breaker to stationary switch.

• Wannan yana buƙatar movable coupling, ba rigid connection, don a saukarci mechanical complexity.

• Saboda high impact forces during operation and potential alignment tolerances, reliability and mechanical endurance suna da kyau.

• IEEE yana tabbatar da minimum of 500 mechanical operations for MOC mechanisms, amma a cikin practice, suna da kyau a gaba da full mechanical life na breaker (often 10,000 operations).

• Linkage mass yana iya haɗe closing and especially opening speed, don haka, lightweight, low-inertia components suna da kyau don a haɗe performance impact.

4. TOC – Test and Connected Position Indicator (C37.20.2-7.3.6)

Yawan IEC/GB breakers, inda position indicators (e.g., S8/S9) suna daidai a cikin chassis na breaker da suka faruwa a kan racking screw, IEEE standards sun tabbatar da Test and Connected (TOC) position switches suna daidai a cikin switchgear compartment.

• Wannan switches suna nuna physical position na breaker truck: whether it is in the Connected (Service), Test, or Disconnected (Withdrawn) position.

• Being fixed in the compartment yana ba da consistent, reliable indication independent of the breaker’s internal condition.

• Wannan yana ba da safe interlocking (e.g., preventing closing when not fully connected) and enables remote monitoring of breaker position.

5. Mechanical Contact Wear Indicator for Vacuum Interrupters

Yawan SF₆ circuit breakers, vacuum interrupters suna da sealed units with face-to-face contacts and no arcing horns or pre-insertion contacts. Both interrupting fault currents and normal mechanical operations cause contact erosion and wear.

• Contact wear yana daya daga cikin abubuwan dalilai masu muhimmanci a kan electrical life na vacuum breaker.

• While many algorithms estimate electrical life based on number of operations, short-circuit current levels, and arcing time, these are largely theoretical or empirical.

• Due to variations in first-pole-to-clear, current phase, and individual unit differences, predicted life often does not correlate precisely with actual physical wear.

• There remains a gap between software-based predictions and real-world physical degradation.

Therefore, the North American market demands a mechanical contact wear indicator directly integrated into the vacuum interrupter or operating mechanism.

• This visual or mechanical gauge allows maintenance personnel to directly observe the degree of contact wear during inspection.

• It provides a reliable, physical measurement of remaining contact life, enhancing predictive maintenance and ensuring timely replacement before failure.