Ni jinsi gani earthing (Grounding) kwenye nyumba ya umeme ina complete circuit?

PD_Magumba

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Kwa mjibu wa basics za Physics, electric current itapita na kufanya kazi kama tu kuna closed path(Complete circuit).

Kwa maana hiyo kifaa chochote cha umeme kitafanya kazi kama kipo kwenye complete circuit.

Sasa naomba kujua katika lugha ya kawaida kabisa ni jinsi gani ile earth rod kwenye mfumo wa umeme humo ardhini ina complete circuit ili kufanikisha kazi ya ku-dump excess au dangerous current (s)?
 
niseme tu kwamba Earthing system haipo kwaajili ya kucomplete circuit,

Earthing system yenyewe ndo inakuwa inalinda circuit kwa kuhakikisha hakuna umeme unaovuja kwenye circuit ikisaidiwa na ELCB na RCCB ambazo zinadetect kuvuja kwa umeme kwenye sakiti (mf. Live ikagusa waya wa Earth au metal box ambazo zimeungwa na earth), ndipo zitakata umeme kwa usalama zaidi
 
Mechanism ya ulinzi wa umeme yani Circuit Breaker (CB)
ni kuhakikisha kuwa tofauti ya voltage (+e) inayopita kwenye waya wenye umeme (live wire) inalingana na tofauti ya voltage (-e) inayopita kwenye waya wa neutral (urudiako kwenye chanzo chake). Kwa hiyo, ikitokea tofauti ya voltage imevuja kutoka live kwenda kwenye grounding wire kwasababu labda mtumiaji ameweka kifaa kibovu au waya zimechubuka na kugusana au tatizo lolote,, ELCB itapokea tofauti ya voltage chache kuliko ilivyotoa (+e). Hii inaashiria kuwa sehemu ya umeme imeelekea kwenye grounding, na hivyo, kutokea kwa upungufu wa elektroni na kupelekea kutrip kwa circuit breaker.

Kwa kifupi, kazi ya wire ya Earthing ni kusaidia kukuhakikisha usalama wa mfumo na kuchukua umeme unaovuja na kwenda aridhini, kwa kufanya hivyo utamlinda mtumiaji kutokana madhara ya umeme na kitendo hicho kina kamilisha mechanism ya protection.
 
kagua vizuri kwenye nguzo za transformer(inayolisha umeme kwako) utaona kuna wire wa 50mm2 wa kijani unaelekea chini, ardhini, kule chini kuna earth rod ndefu kabisa mithili ya mnazi

hii ndiyo inayopokea ile leakage current inayofyonzwa na earth rod ya home kwako, hence circuit completed
 
Hicho ulichonandika si sahihi mkuu, napingana nawe kuhusu ground kuwa ina complete circuit, na ground iliyopo kwenye transformer hilo sio kweli kabisa. Naomba utafakari swali langu hili: ikiwa nazalisha umeme kupitia generator kisha nikachomeka umeme kwenye main switch yangu live na neutral, je, ni kweli kwamba kama umeme utavuja na kwenda ardhini, basi CB haitatrip kwa sababu hakuna complete circuit kati ya Earthing rod yangu na generator? Unachanganya mambo mkuu, Earth rod ya transformer ina kazi nyingine nje ya kucomplete circuit
 
Generator nyingi na hata hizi invetor za solar zina sehemu ya kufunga earth rod ila huwa hatuzingatii hilo
 
Kinacho nichanganya mimi Layman kwenye hili ni kwamba. Umeme unawezaje kuflow mpaka ardhini kupitia hiyo earth rod pasipo na complete circuit?
 
JMF said:
Generator nyingi na hata hizi invetor za solar zina sehemu ya kufunga earth rod ila huwa hatuzingatii hilo
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Upo sahihi, lakini nachopinga mm ni kuwa iyo Earth ya generator ina complete circuit na Earth rod ya nyumba (mtumiaji) ilo tu ndio napinga mimi mkuu.
 
PD_Magumba said:
Kinacho nichanganya mimi Layman kwenye hili ni kwamba. Umeme unawezaje kuflow mpaka ardhini kupitia hiyo earth rod pasipo na complete circuit?
Click to expand...
jibu la kilayman ni kwamba umeme unaokwenda kule unatupwa kwa kubadilishwa form nadhani joto.ndio sababu wanaweka ile nondo ya shaba baada ya waya kuingia ardhini.

wanashuri hiyo copa zaidi na sio msumari au nondo kama akina fundi maiko wanavyofanyaga kirahisisha mambo.
 
Transformer has two conductors grounded.

1. Neutral (black)
2. Earth wire(s) (green)


Earth wire(s) is for protection of transformer na associated components.

Neutral is for user ELCB customer protection again leakages.

Let's go:

Technically it's advisable to install earth rods 2m deep for both transformer (both for N and E) and houses.

The number of earth rods may increase or adding charcoal and salt until required resistance is obtained (below 0.5 Ohm )

This way we can achieve below 1 Ohm ground canductivity making underground electrical path easier.

At now Transformer grounded Neutral and houses earth rods are at the same potential (low voltage).


How now ELCB trips?

Kama inadvertently lives (L) wire imegusana na any metal that connects to ground or wall itself in the house then earth were ata conduct way down to the earth rod and then being at the same potential, transformer rods specifically neutral wire ata carry on hii leakage and then itapita na kurudia Kwenye LV ABC bundles (400V au 230V) along the way to your meter and to your main switch. At this point your house Neutral has leakage.


Let's brake here:
-------------
ELCB ina trip Kwa electromagnetic au thermal tripping or combination of both.


Most of them ni electromagnetic tripping. That Neutral na Live zimezungushwa each on one leg of transformer or inductor in several turns around electroagnetic core.


Kama wire zote zinapitisha current sawa (go for L and return for N) then magnetic field produced ina cancel out and hence rod plunge haiexperience push or pull force ku break circuit.
--------

Get back to our breakpoint above.


This time now Neutral ina leakage therefore magnetic field generated Za N zitamu edge out Zile Za Live and hence extra magnetic field zinazarisha force (according to Fleming left hand rule) consequently hii force ina push or pull rod plunge same as solenoid works breaking electrical connection automatically. It will keep tripping until leakage issue is solved.


That makes sense right?
 
Earth wire ni chombo cha usalama cha kumlinda mtumiaji wa umeme pale ambapo chombo anachokitumia
kitakuwa kimepata itilafu, na waya wa moto( live wire) ukagusana na bati, Badala ya huo umeme uliopotea njia
kumdhuru mtumiaji kwa kumpitia kwenda ardhini ndo huo waya unafanya kazi ya kupeleka umeme huo ardhini.
Kama hakuna tatizo kwenye mfumo,huo waya unawezasema ''hauna kazi'' kama ilivyo air bag kwenye magari

Lakini unawekwa kwa ajili ya usalama au tuseme ajali haina kinga,ni lazima uwekwe kwa usalama wa mtumiaji wa umeme na ndo maana TANESCO wanahakikisha nyumba yako imewekewa kabla hawajakuunganishia umeme.
N.B Nyumba hata kama imefungiwa ELCB,kama hujaweka earth wire hiyo ELCB haisaidii kitu.

Kuna mdau amegusia ule waya mkubwa unaowekwa kwenye transforma
Ule una kazi ya kukupatia neutral ya system yako (-ve) yako, kama utaangalia vizuri utagundua
kwenye transformer zinaingia nyaya tatu ambazo zote ni za moto,lakini waya zinapotoka pale kwenda kwa watumiaji zinatoka nne. Ule waya wa nne ndo unaofanya kazi hiyo uliyoiita kucomplete circuit.

Samahani mimi siyo mwalimu sijui kama nimeeleweka.
 
uchumi2018 said:
ule waya wa nne ndo unaofanya kazi hiyo uliyoiita kucomplete circuit.
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Weka clear kidogo, huo waya wa nne kutoka kwenye transformer unaodai unacomplete circuit ya earthing system unaitwaje?(L, N au G?)
 
PD_Magumba said:
Weka clear kidogo, huo waya wa nne kutoka kwenye transformer unaodai unacomplete circuit ya earthing system unaitwaje?(L, N au G?)
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Wewe acha kushabikia yanga ndio utaelewa!


Na ili kukuchanganya zaidi, jifunze hii mifumo inayotumika kutengeneza Transformer na pia kusuka AC motors

Delta- Wye



Wye - Delta



Wye - Wye

 
Mkuu kuhusu mpira naipenda sana Yanga.
Kuhusu hizo electrical circuits (including Delta na Star) na hata Electrical Energy Production and Supply niko nondo sana theoretically.
Swali la msingi ambalo sijapata majibu. Je, earthing system ususani kwenye domestic electrification ina complete circuit au haina complete circuit? Kama ipo ni ipi hiyo?
Au mkuu unataka nikubali kwamba earthrod ina-complete circuit na supplying transformer?
 
Mkorintho hapa naweza kukubaliana na wewe (it makes sense). Itapendeza mkuu ukifafanua kidogo ya kua ni vipi inawezekana ku-convert electrical energy into other form of energy with only Live as input to the converting device(sytem).
 
PD_Magumba said:
Kuhusu hizo electrical circuits (including Delta na Star) na hata Electrical Energy Production and Supply niko nondo sana theoretically.
Click to expand...
Haya nijie hapa....
Nikitaka kufunga Three phase motor iendeshe mtambo unaohitaji umeme mwingi katika kuanza mzunguko na baadae ikisha changaya ibadilishe na kutumia umeme wa kawaida au vice versa, niifunge kwa mtindo upi na kutumia vifaa gani ?

PD_Magumba said:
Je, earthing system ususani kwenye domestic electrification ina complete circuit au haina complete circuit?
Click to expand...
Wapi kwenye electrical systems yeyote inasema earthing system inakamilisha circuit?, hii umetoa wapi
Kwenye kukamilisha circuit ni pale tu, nyumba yako ina earthing systems na kifaa chako cha umeme kinachotumia earthing pin kina hitilafu ya live wire imegusa conducting parts na kuweza kukulinda mtumiaji kwa kukusanya hio leakage current na kupeleka kwenye ground, na kama nyumba yako ina Earth Leakage Circuit Breaker, hii tayari ingeshakuwa imezima umeme kama ukichomeka kifaa chenye hitilafu ya earth.

Earthing system inatumika kwa vifaa vya aina ya Class 1 Electrical devices (nenda kajifunze hii)- Pasi, Jiko, Fridge...
Kwa sababu kuna vifaa vingi tu vingine visivyohitaji earthing connection, hivi vinaitwa Class 2 Electrical device(kajifunze hii), Radio, TV.......
Earthing ni jukumu lako kujilinda, unapojenga nyumba, lazima uwe na hii na kisheria (angalia picha), na pia inasaidia kuzuia static electricity inayotokana na radi(lightining) ama sivyo nyumba yako itawaka moto.


 
Maelezo mazuri sana mkuu lakini nahisi hujaelewa swali langu. Si maanishi kwamba earthing system inakamilisha circuit kwenye nyumba.
Natambua fika Earthing system ipo mahsusi ku-dump dangerous current (volt) na hivyo kulinda uhai na vifaa.

Nacho uliza ni jinsi gani huu mfumo una achieve jukumu hilo (mechanism) kwa input ya Live tu(in case earth wire ita carry umeme basi ni Live) bila neutral?

Mambo ya motor start current na operating current tuyaache kidogo mkuu.
 
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