Yadda Aiki Mai Karamin Yawan Rukuni (RCDs) Da Sabon Hukuma Da Su Ke Faru
Aiki mai karamin yawan rukuni (RCD), wanda ake kira da sunan leakage circuit breaker, ke faru idan ya sami shiga cikakken bayanan rukuni na biyu a kan live da neutral conductors. A cikin hanyoyin karamin zabe ta zamani, ko a cikin hanyoyin da ake tafiya zabe-babba ba su a taka taka, yana iya zama karfi da yake amfani da RCDs da gaskiya. Idan aikin ya yi aiki a baya, a lokacin da yawa ko yamma, RCD yana iya faru kadan-kadan. Samun abubuwan da suka faruwa da yankinan su yana da muhimmanci.
Wasu sun ce magana game da kawo RCD da kai tsakanin air circuit breaker na rating daban-daban—wadannan ke kontrola kawai live wire kafin ake haɗa neutral wires zuwa busbar na musamman. Idan wannan yana iya sauka aikin ya yi aiki da ba ya faru ba, wannan hanyar yana da dalilai mai yawa da maimaita. Wannan na iya kare ingantaccen babban al'amuran da ke taimaka, wanda ke dogara rayuwarsu da kayayyakin su a yawan sakewa.
Muhimmancinta Aiki Mai Karamin Yawan Rukuni (RCDs)
RCDs sun fiye da muhimmancin aikinsu a cikin hanyoyin karamin zabe na gida. Sun kare aiki na kusa da aikin kada a lokacin da suka sami shiga cikakken bayanan rukuni ko ground faults, wanda ke dogara darashe, tashoshin kayayyaki, da kuma kasa aikinsu. A cikin aiki na rana, aikin yana iya faru wasu irin abubuwa, wanda ke faru RCD. Idan kuna faru da aikin, ita ce da za a buƙata sababin da take faru don inganta dalilan da ke dogara dalili.
Tambayar yana nuna bayanai masu mahimmanci game da sabbin abubuwan da ke faru RCD.
RCDs sun faruwar aiki don kare abubuwan da ke faruwa ne don kudeta darashe a lokacin da yawan rukuni yana faru. Faruwar yana iya kula da labaran: faruwar da ya faru da faruwar da ba a faru ba.
RCD da rated tripping current na 30mA yana faru idan yawan rukuni a cikin aikin ya yi 25mA. Ingantacce yana da muhimmanci ga mutane (ba taimaka da darashe mai yawa ba) da kuma ba a kasa aikin ko taimaka da aiki na gaba-gaba. Amma, faruwar kadan-kadan a cikin wannan halin yana nuna cewa akwai abubuwan da ke faruwa a kan insulation da ya faru.
Wannan irin faruwar yana faruwar da defects a cikin RCD da kai, da kuma yana kula da labaran: failure to close (reset) da nuisance tripping.
Failure to Close:
Idan RCD ba a iya reset ba a lokacin da an sanar da aiki kawai ba ake taka load ba, wannan yana nuna cewa device na da defect. Ba a iya jin daidaita. RCDs da aka repair da suka bukatar testing na specialized equipment don tabbatar da aiki. Amfani da repaired device ba a testa ba yana da dalilai mai yawa.
Nuisance Tripping:
Faruwar kadan-kadan—mugali a ranar dubu ko lokacin da mutum ba a cikin gida ba—yana nuna cewa immunity a kan electromagnetic interference (EMI) yana da karfi. RCDs da suka faruwa da wannan yana buƙata cewa ake kawo da su da sabon device.
Yanzu, faruwar da ya faru da minor leakage (around 25mA) yana iya kunshi nuisance tripping. Wannan yana faruwar da aging insulation, inda moisture ke taimaka da leakage (faruwar a lokacin da yawa) amma ba a lokacin da yamma ba. Hanyar da ya fiye don kawo wannan abubuwa shine measuring insulation resistance of the circuit and equipment.
Standard requirement: Insulation resistance of each conductor must be ≥ 0.5 MΩ.
If the total measured insulation resistance of the load circuit is less than 8.8 kΩ (calculated as 220V ÷ 25mA = 8.8 kΩ), normal tripping is expected.
Poor Installation
Connections na terminal da suka da kafa yana iya yan furo, oxidize, da kuma kasa wire insulation a lokacin da yau. Wannan zai iya kasance arcing, burning smells, da kuma voltage drops, wanda ke taimaka da operation of circuit breaker.
Defective RCD
Internal component failure or manufacturing defects can cause malfunction.
Overloaded Circuit
Idan actual load yana fiye da rated current na circuit breaker—yanayi a cikin lokutan da ake sami fitowa high-power appliances like air conditioners or water heaters—replacement with a properly rated breaker is required.
Leakage or Short Circuit in Appliances or Wiring
Idan appliance yana karamin rukuni, kowace ka kawo da shi da kai reset breaker zai iya buƙata aiki.
Troubleshooting method:
Turn off all branch circuits.
Energize them one by one.
If the breaker trips when a specific circuit is energized, that branch contains the fault. Isolate and repair it before restoring power.
Excessively High Supply Voltage
Wannan yana da dalilai mai yawa da ake faruwar da shi a cikin "three-phase four-wire" residential systems.
Check:
Are both incoming lines live?
Are neighboring units also tripping?
Use a multimeter to measure input voltage.
Never force-reset the breaker. Doing so may destroy appliances or cause a fire.
Follow the sequence: main line → branches → endpoints.
Disconnect all branch circuits.
Energize the main line first. If it holds, the main line is fault-free.
Re-energize branches one by one.
The circuit that causes tripping upon energizing contains the fault. Focus your inspection there.
Inspect the protected area—including the RCD and connected wiring/equipment—for visible signs of damage. Pay special attention to:
Corners and bends
Junctions and splices
Overhead line crossings
Areas prone to moisture or mechanical damage
Use test instruments (e.g., multimeter, insulation resistance tester) to measure voltage, current, or insulation resistance. Compare results with baseline or expected values to locate faults.
Note: If the neutral wire has degraded insulation or is improperly grounded (repeated grounding), it may cause the main RCD to trip frequently while downstream (secondary) RCDs remain unaffected.
Used to determine if the RCD itself is faulty:
Turn off power.
Disconnect all load-side wires from the RCD’s zero-sequence current transformer.
Attempt to reset the RCD.
If it still won’t reset → RCD is faulty (repair or replace).
If it resets successfully → RCD is functional; the fault lies in the distribution panel or downstream wiring.
Then:
Disconnect all outgoing circuits.
If the RCD still fails to hold → fault is in the panel (check wiring, meters, etc.).
If it holds → fault is in the external circuit. Use the circuit isolation method to locate the exact point.
Safety Reminder:
Never bypass or remove an RCD for convenience. While it may stop nuisance tripping, it removes vital protection against electric shock and fire. Always diagnose and fix the root cause. When in doubt, consult a licensed electrician.