Chiyambi: Kufunika kwa Chitetezo cha Magetsi
Magetsi, moyo wosawoneka wa anthu amasiku ano, amalimbitsa nyumba zathu, mafakitale, ndi zatsopano. Komabe, mphamvu yofunikira imeneyi imakhala ndi zoopsa zachibadwa, makamaka kuopsa kwa kugwedezeka kwa magetsi ndi moto wobwera chifukwa cha zolakwika. Zida Zotsalira Zamakono (RCDs) zimakhala ngati alonda ovuta kwambiri polimbana ndi zoopsazi, zomwe zimadula mofulumira magetsi pamene awona kuti madzi akutuluka padziko lapansi. Ngakhale ma RCD osasunthika ophatikizidwa m'mayunitsi ogula amapereka chitetezo chofunikira pamabwalo onse, Socket-Outlet Residual Current Devices (SRCDs) imapereka chitetezo chapadera, chosinthika, komanso cholunjika kwambiri. Nkhani yonseyi ikufotokoza za dziko la SRCDs, ndikuwunika momwe amagwirira ntchito mwaukadaulo, kugwiritsa ntchito mosiyanasiyana, mawonekedwe ofunikira, ndi zabwino zomwe zimawapangitsa kukhala zida zofunika kwambiri zolimbikitsira chitetezo chamagetsi m'malo osiyanasiyana.

1. Kusokoneza SRCD: Tanthauzo ndi Lingaliro Lachikulu
SRCD ndi mtundu wina wa RCD wophatikizidwa mwachindunji mu socket-outlet (chotengera). Zimaphatikiza magwiridwe antchito a soketi yamagetsi yokhazikika ndi chitetezo chopulumutsa moyo cha RCD mkati mwa plug-in imodzi yokha. Mosiyana ndi ma RCD okhazikika omwe amateteza mabwalo onse kunsi kwa ogula, SRCD imapereka chitetezo chapafupikokhapazida zolumikizidwa molunjika. Ganizirani izi ngati mlonda wodzitetezera yemwe wapatsidwa mwachindunji pa socket imodzi.

Mfundo yofunikira pama RCDs onse, kuphatikiza ma SRCD, ndi Lamulo Lapano la Kirchhoff: zomwe zikuyenda mozungulira ziyenera kufanana ndi zomwe zikutuluka. Pazikhalidwe zogwirira ntchito, zowongolera zamoyo (gawo) ndi woyendetsa ndale ndizofanana komanso zotsutsana. Komabe, ngati cholakwika chikachitika - monga kuwononga chingwe chowonongeka, munthu kukhudza gawo lamoyo, kapena kulowetsa chinyezi - zina zamakono zimatha kupeza njira yosakonzekera padziko lapansi. Kusalinganika kumeneku kumatchedwa residual current kapena earth leakage current.

2. Momwe ma SRCDs Amagwirira ntchito: Njira Yowonera ndi Kuyenda
Chigawo chachikulu chomwe chimathandizira kuti SRCD igwire ntchito ndi thiransifoma yamakono (CT), nthawi zambiri imakhala yozungulira (yokhala ngati mphete) yozungulira ma conductor amoyo komanso osalowerera omwe amapereka socket-outlet.

1. Kuwunika Kopitilira: The CT imayang'anira kuchuluka kwa ma vector a mafunde omwe akuyenda m'makondakitala amoyo komanso osalowerera ndale. Munthawi yabwinobwino, yopanda cholakwika, mafundewa amakhala ofanana komanso amatsutsana, zomwe zimapangitsa kuti maginito aziyenda zero mkati mwa CT core.
2. Kuzindikira Kwakanthawi Kotsalira: Ngati cholakwika chipangitsa kuti magetsi atsike padziko lapansi (mwachitsanzo, kudzera mwa munthu kapena chipangizo cholakwika), zomwe zikubweranso kudzera pa kondakitala wosalowerera ndale zidzakhala zochepa poyerekeza ndi zomwe zikulowa panopa kudzera pa kondakitala wamoyo. Kusalinganika uku kumapangitsa kuti maginito azitha kuyenda pakatikati pa CT.
3. M'badwo wa Signal: Kusintha kwa maginito kumapangitsa kuti magetsi azizungulira pakatikati pa CT. Mphamvu yamagetsi imeneyi imayenderana ndi kukula kwa magetsi otsalira.
4. Electronic Processing: Chizindikiro chopangitsidwa chimadyetsedwa mumayendedwe owoneka bwino amagetsi mkati mwa SRCD.
5. Kusankha Kwaulendo & Kuyambitsa: Zipangizo zamagetsi zimafananiza mulingo wotsalira womwe wapezeka ndi SRCD's pre-set sensitivity threshold (mwachitsanzo, 10mA, 30mA, 300mA). Ngati mphamvu yotsalirayo idutsa malire awa, zozungulira zimatumiza chizindikiro ku cholumikizira chamagetsi chothamanga kwambiri kapena switch-state switch.
6. Kuyimitsa Mphamvu: Relay / switch nthawi yomweyo imatsegula zolumikizira zomwe zimapatsa ma conductor amoyo komanso osalowerera pa socket-outlet, kudula mphamvu mkati mwa milliseconds (nthawi zambiri zosakwana 40ms pazida za 30mA pazida zotsalira). Kumangika kofulumira kumeneku kumalepheretsa kugunda kwamagetsi komwe kungakhale koopsa kapena kuyimitsa moto womwe ukuyamba chifukwa cha mafunde otayikira omwe akudutsa muzinthu zoyaka.
7. Bwezeraninso: Cholakwacho chikachotsedwa, SRCD nthawi zambiri imatha kukhazikitsidwanso pamanja pogwiritsa ntchito batani la nkhope yake, kubwezeretsa mphamvu ku socket.

3. Zomwe Zimagwira Ntchito Zamakono a SRCDs
Ma SRCD amakono amaphatikiza zinthu zingapo zotsogola kupitilira kuzindikira zotsalira zomwe zilipo:

• Sensitivity (IΔn): Izi ndizomwe zimagwiritsidwa ntchito potsalira, mulingo womwe SRCD idapangidwira kuyenda. Zomwe zimakhudzidwa ndi izi:
  • High Sensitivity (≤ 30mA): Makamaka pofuna kuteteza kugwedezeka kwa magetsi. 30mA ndiye muyezo wachitetezo chamunthu aliyense. Mitundu ya 10mA imapereka chitetezo chokhazikika, chomwe chimagwiritsidwa ntchito m'malo azachipatala kapena malo omwe ali pachiwopsezo chachikulu.
  • Kukhudzika Kwapakatikati (monga, 100mA, 300mA): Kuteteza ku zoopsa zamoto zomwe zimadza chifukwa cha kuwonongeka kosalekeza kwa dziko lapansi, komwe nthawi zambiri kumagwiritsidwa ntchito pomwe kutayikira kwapansi kungayembekezeredwe (mwachitsanzo, makina a mafakitale, kuyika zakale). Ikhoza kupereka chitetezo cham'mbuyo.
• Mtundu wa Kuzindikira Kwaposachedwa: Ma SRCD adapangidwa kuti aziyankha kumitundu yotsalira yotsalira:
  • Type AC: Imazindikira mafunde otsalira a sinusoidal okha. Zodziwika bwino komanso zachuma, zoyenerera kuti zitheke, zowoneka bwino, komanso zonyamula popanda zida zamagetsi.
  • Mtundu A: Imazindikira mafunde onse a AC otsalirandikugwetsa mafunde otsalira a DC (mwachitsanzo, kuchokera pazida zowongoleredwa ndi theka la mafunde monga zida zina zamagetsi, zowunikira, makina ochapira). Zofunikira kumadera amakono okhala ndi zida zamagetsi. Kuchulukirachulukira kukhala muyezo.
  • Mtundu F: Wopangidwira mabwalo omwe amapereka ma drive othamanga a gawo limodzi (ma inverter) omwe amapezeka mu zida monga makina ochapira, ma air conditioners, ndi zida zamagetsi. Imawonjezera chitetezo chokwanira kuzovuta zapaulendo chifukwa cha mafunde othamanga kwambiri opangidwa ndi ma drive awa.
  • Mtundu B: Imazindikira AC, pulsating DC,ndimafunde otsalira osalala a DC (mwachitsanzo, ma inverter a PV, ma EV charger, makina akulu a UPS). Amagwiritsidwa ntchito makamaka m'mafakitale kapena ntchito zapadera zamalonda.
• Nthawi Yoyendayenda: Nthawi yochuluka pakati pa zotsalira zomwe zatsalira IΔn ndi kutsekedwa kwa mphamvu. Imayendetsedwa ndi miyezo (mwachitsanzo, IEC 62640). Kwa 30mA SRCDs, izi nthawi zambiri zimakhala ≤ 40ms ku IΔn ndi ≤ 300ms pa 5xIΔn (150mA).
• Zovoteledwa Pakalipano (Mu): Pakalipano mosalekeza soketi ya SRCD imatha kupereka bwino (mwachitsanzo, 13A, 16A).
• Chitetezo Chowonjezera (chosasankha koma Chofala): Ma SRCD ambiri amaphatikiza chitetezo chambiri, nthawi zambiri fuse (mwachitsanzo, 13A BS 1362 fuse mu mapulagi aku UK) kapena nthawi zina kachidutswa kakang'ono (MCB), kuteteza soketi ndi zida zomangidwira kuti zisachuluke komanso mafunde afupiafupi.Chofunika kwambiri, fuseyi imateteza dera la SRCD palokha; SRCD siyilowa m'malo kufunikira kwa ma MCB akumtunda mugawo la ogula.
• Tamper-Resistant Shutters (TRS): Zofunikira m'magawo ambiri, zotsekera zodzaza ndi masika izi zimalepheretsa kulumikizana ndi omwe akukhalapo pokhapokha mapini onse a pulagi ayikidwa nthawi imodzi, kuchepetsa kwambiri chiwopsezo cha kugwedezeka kwamagetsi, makamaka kwa ana.
• Batani Loyesera: Chinthu chovomerezeka chomwe chimalola ogwiritsa ntchito nthawi ndi nthawi kuyerekezera cholakwika chotsalira ndikuwonetsetsa kuti makina odumphira akugwira ntchito. Ayenera kupanikizidwa pafupipafupi (mwachitsanzo, pamwezi).
• Chizindikiro cha Ulendo: Zizindikiro zowoneka (nthawi zambiri zimakhala ndi batani lachikuda kapena mbendera) zimasonyeza ngati SRCD ili mu "ON" (mphamvu yomwe ilipo), "WOZIMA" (yozimitsa pamanja), kapena "Yotsekeredwa" (yomwe yazindikirika).
• Kukhazikika Kwamakina & Zamagetsi: Zapangidwa kuti zipirire kuchuluka kwa magwiridwe antchito amakina (mapulagi oyika / zochotsa) ndi ntchito zamagetsi (zozungulira zozungulira) molingana ndi miyezo (mwachitsanzo, IEC 62640 imafuna ≥ 10,000 ntchito zamakina).
• Chitetezo Chachilengedwe (Mayeso a IP): Imapezeka mumitundu yosiyanasiyana ya IP (Ingress Protection) m'malo osiyanasiyana (mwachitsanzo, IP44 ya kukana kuwonda m'khitchini/zipinda zosambira, IP66/67 yogwiritsa ntchito panja/mafakitale).

4. Ntchito Zosiyanasiyana za SRCDs: Chitetezo Chokhazikika Komwe Kukufunika
Mapulagi-ndi-sewero apadera a SRCDs amawapangitsa kukhala osinthika modabwitsa kuti apititse patsogolo chitetezo muzochitika zosawerengeka:

• Zokonda Panyumba:
  • Malo Owopsa Kwambiri: Kupereka chitetezo chowonjezera chofunikira m'mabafa, makhichini, magalaja, malo ogwirira ntchito, ndi zotsekera zakunja (minda, mabwalo) komwe chiwopsezo cha kugwedezeka kwamagetsi chimachulukitsidwa chifukwa cha kupezeka kwa madzi, pansi, kapena kugwiritsa ntchito zida zonyamula. Chofunika kwambiri ngati ma RCD akuluakulu ogula kulibe, olakwika, kapena akungopereka chitetezo chosunga zobwezeretsera (S Type).
  • Kubwezeretsanso Zoyikira Zakale: Kukweza chitetezo m'nyumba zopanda chitetezo chilichonse cha RCD kapena komwe kumapezeka pang'onopang'ono, popanda mtengo ndi kusokonezedwa kwa kuyimbanso kapena kusintha kwa ogula.
  • Chitetezo Chachindunji Chachindunji: Kuteteza zida zomwe zili pachiwopsezo chachikulu kapena zida zamtengo wapatali monga zida zamagetsi, zotchera udzu, makina ochapira, zotenthetsera zam'manja, kapena mapampu amadzi am'madzi mwachindunji pamalo omwe agwiritsidwa ntchito.
  • Zofunikira Zakanthawi: Kupereka chitetezo pazida zomwe zimagwiritsidwa ntchito pakukonzanso kapena ntchito za DIY.
  • Chitetezo cha Ana: Zotsekera za TRS zophatikizidwa ndi chitetezo cha RCD zimapereka zowonjezera chitetezo m'nyumba zomwe muli ana aang'ono.
• Malo Amalonda:
  • Maofesi: Kuteteza zida zodziwika bwino za IT, zotenthetsera zam'manja, ma ketulo, ndi zotsukira, makamaka m'malo omwe mulibe ma RCD osakhazikika kapena komwe kugwedezeka kwa RCD yayikulu kungakhale kosokoneza kwambiri.
  • Kugulitsa & Kuchereza: Kuonetsetsa chitetezo cha zida zowonetsera, zida zophikira zam'manja (zotenthetsera chakudya), zida zoyeretsera, ndi kuyatsa / zida zakunja.
  • Healthcare (Non-Critical): Kupereka chitetezo m'zipatala, maopaleshoni a mano (malo omwe si a IT), zipinda zodikirira, ndi malo oyang'anira zida zokhazikika. (Chidziwitso: Makina a IT azachipatala m'malo owonetsera amafunikira zosinthira zapadera, osati ma RCD/SRCD).
  • Mabungwe a Maphunziro: Zofunikira m'makalasi, ma laboratories (makamaka zida zonyamulika), ma workshop, ndi ma suites a IT kuti ateteze ophunzira ndi antchito. TRS ndiyofunikira pano.
  • Malo Opumula: Kuteteza zida m'malo ochitira masewera olimbitsa thupi, malo osambira (moyenera ndi IP), ndi zipinda zosinthira.
• Malo Opanga & Zomangamanga:
  • Kumanga & Kugwetsa: Chofunika kwambiri. Kugwiritsa ntchito zida zonyamulika, nsanja zowunikira, ma jenereta, ndi maofesi amasamba m'malo ovuta, onyowa, komanso osintha nthawi zonse pomwe kuwonongeka kwa chingwe kumakhala kofala. Ma SRCD onyamula kapena omwe amaphatikizidwa m'magulu ogawa amapulumutsa moyo.
  • Ma workshop & Maintenance: Kuteteza zida zonyamulika, zida zoyesera, ndi makina m'malo okonza fakitale kapena ma workshop ang'onoang'ono.
  • Kuyika Kwakanthawi: Zochitika, ziwonetsero, makanema apakanema - kulikonse komwe kumafunikira mphamvu kwakanthawi m'malo omwe angakhale oopsa.
  • Chitetezo Chosungira: Kupereka chitetezo chowonjezera kunsi kwa ma RCD osakhazikika, makamaka pazida zonyamulika.
• Mapulogalamu Apadera:
  • Ma Marine & Caravans: Zofunikira pakutetezedwa m'mabwato, ma yacht, ndi makaravani/ma RV komwe makina amagetsi amagwirira ntchito moyandikana ndi madzi ndi ma conductive hull/chassis.
  • Ma Data Center (Zipangizo Zoyang'anira): Kuteteza zowunikira, zida zowonjezera, kapena zida zosakhalitsa zolumikizidwa pafupi ndi ma seva.
  • Zowonjezera Mphamvu Zowonjezera (Zonyamula): Kuteteza zida zonyamula zomwe zimagwiritsidwa ntchito pokhazikitsa kapena kukonza ma solar panel kapena ma turbine ang'onoang'ono amphepo.

5. Ubwino Wotsimikizika wa Zogulitsa za SRCDs
Ma SRCD amapereka maubwino angapo omwe amalimbitsa gawo lawo munjira zamakono zachitetezo chamagetsi:

1. Chitetezo Chokhazikika, Chokhazikika: Ubwino wawo waukulu. Amapereka chitetezo cha RCDpokhapokhakwa chipangizo cholumikizidwa mwa iwo. Kulakwitsa kwa chipangizo chimodzi kumangoyendera SRCD yokhayo, ndikusiya mabwalo ena ndi zida zina zosakhudzidwa. Izi zimalepheretsa kutayika kwa magetsi kosafunikira komanso kosokoneza kuzungulira dera lonse kapena nyumba - vuto lalikulu ndi ma RCD osakhazikika ("kusokoneza zovuta").
2. Retrofit Kuphweka & Kusinthasintha: Kuyika kumakhala kosavuta monga kulumikiza SRCD muzitsulo zomwe zilipo kale. Palibe chifukwa chokhala ndi magetsi oyenerera (m'magawo ambiri amitundu yama plug-in), kusintha kwama waya ovuta, kapena kusintha kwa ogula. Izi zimapangitsa kukweza chitetezo kukhala kosavuta komanso kotsika mtengo, makamaka pazinthu zakale.
3. Kusunthika: Mapulagi-mu SRCD amatha kusunthidwa kupita kulikonse komwe chitetezo chimafunikira kwambiri. Tengani kuchokera kumalo ochitiramo garage kupita kumunda, kapena kuchokera ku ntchito yomanga kupita ku ina.
4. Kugwiritsa Ntchito Ndalama (Pa Mfundo Yogwiritsira Ntchito): Ngakhale mtengo wa unit wa SRCD ndi wapamwamba kusiyana ndi socket wamba, ndi wotsika kwambiri kuposa mtengo wa kukhazikitsa dera latsopano lokhazikika la RCD kapena kukweza gawo la ogula, makamaka pamene chitetezo chimangofunika pazigawo zochepa chabe.
5. Chitetezo Chowonjezera M'malo Owopsa: Kumapereka chitetezo chofunikira kwambiri pomwe chiwopsezo chili chachikulu (zipinda zosambira, zophikira, panja, malo ochitirako misonkhano), kuwonjezera kapena kulowetsa ma RCD okhazikika omwe sangakhudze madera awa payekhapayekha.
6. Kutsata Miyezo Yamakono: Imathandizira kukwaniritsa malamulo okhwima otetezedwa pamagetsi (mwachitsanzo, IEC 60364, malamulo oyendetsera mawaya adziko lonse monga BS 7671 ku UK, NEC ku US yokhala ndi zotengera za GFCI zomwe ndi zofanana) zomwe zimalamula kuti RCD itetezedwe pamasoketi ndi malo enaake, makamaka pakumanga ndi kukonzanso kwatsopano. Ma SRCD amadziwika bwino mumiyezo ngati IEC 62640.
7. Kutsimikizira Kwawogwiritsa Ntchito: Batani lophatikizana loyesa limalola ogwiritsa ntchito omwe si aukadaulo kutsimikizira mosavuta komanso pafupipafupi kuti chitetezo cha chipangizocho chikugwira ntchito.
8. Ma Tamper-Resistant Shutters (TRS): Chitetezo cha ana chophatikizika ndi chinthu chokhazikika, chochepetsa kwambiri chiwopsezo cha kugwedezeka kwa zinthu zomwe zimayikidwa mu socket.
9. Kukhudzika Kwachidziwitso Chachidziwitso: Kumaloleza kusankha kukhudzika koyenera (monga, 10mA, 30mA, Type A, F) pazida zomwe zikutetezedwa.
10. Kuchepetsa Chiwopsezo cha Kuyenda Mwangozi: Chifukwa amangoyang'anira kutayikira kwa chipangizo chimodzi, nthawi zambiri savutitsidwa ndi kutsika kophatikizana, kopanda vuto kwa zida zingapo pagawo lotetezedwa ndi RCD imodzi yokhazikika.
11. Chitetezo Chanthawi Yamagetsi: Njira yabwino yowonetsetsera chitetezo mukamagwiritsa ntchito njira zowonjezera kapena ma jenereta pazosowa kwakanthawi kamagetsi pamawebusayiti kapena zochitika.

6. SRCDs vs. Ma RCD Okhazikika: Maudindo Owonjezera
Ndikofunikira kumvetsetsa kuti ma SRCD salowa m'malo mwa ma RCD osakhazikika pagulu la ogula, koma yankho lothandizira:

• Ma RCD Okhazikika (mu Consumer Unit):
  • Tetezani mabwalo onse (mabokosi angapo, magetsi).
  • Amafuna akatswiri unsembe.
  • Perekani chitetezo chofunikira choyambirira cha mawaya ndi zida zokhazikika.
  • Kulakwitsa kumodzi kumatha kulumikiza magetsi kumalo ogulitsira / zida zingapo.
• SRCDs:
  • Tetezani chida chimodzi chokha chomwe chalumikizidwa.
  • Kuyika kosavuta kwa pulagi (mitundu yonyamula).
  • Perekani chitetezo chandandanda cha malo omwe ali pachiwopsezo chachikulu komanso zida zam'manja.
  • Cholakwika chimapatula chida cholakwika chokha.
  • Perekani kusuntha komanso kubweza mosavuta.

Njira yamphamvu kwambiri yachitetezo chamagetsi nthawi zambiri imagwiritsa ntchito kuphatikiza: ma RCD osasunthika omwe amapereka chitetezo chozungulira (mwina ngati ma RCBOs pakusankha dera la munthu aliyense) mothandizidwa ndi ma SRCD paziwopsezo zazikulu kapena pazida zinazake zonyamulika. Njira yosanjikiza iyi imachepetsa chiopsezo komanso kusokoneza.

7. Miyezo ndi Malamulo: Kuonetsetsa Chitetezo ndi Kuchita
Mapangidwe, kuyezetsa, ndi magwiridwe antchito a SRCDs amayendetsedwa ndi mfundo zokhwima zapadziko lonse lapansi komanso zamayiko. Mulingo wofunikira ndi:

• IEC 62640:Zipangizo zamakono zotsalira zokhala ndi chitetezo chowonjezera kapena chopanda ma socket-outlets (SRCDs).Mulingo uwu umatanthauzira zofunikira za SRCDs, kuphatikiza:
  • Zofunikira pakumanga
  • Mawonekedwe a magwiridwe antchito (kukhudzidwa, nthawi yopumira)
  • Njira zoyesera (makina, magetsi, chilengedwe)
  • Kulemba ndi zolemba

Ma SRCD akuyeneranso kutsatira miyezo yoyenera ya socket-outlets (mwachitsanzo, BS 1363 ku UK, AS/NZS 3112 ku Australia/NZ, masinthidwe a NEMA ku US) ndi miyezo ya RCD wamba (mwachitsanzo, IEC 61008, IEC 61009). Kutsatira kumatsimikizira kuti chipangizochi chikukwaniritsa zofunikira zachitetezo ndi magwiridwe antchito. Yang'anani zizindikiro zochokera ku mabungwe odziwika (monga CE, UKCA, UL, ETL, CSA, SAA).

Kutsiliza: Chigawo Chofunikira mu Safety Net
Socket-Outlet Residual Current Devices imayimira kusintha kwamphamvu komanso kothandiza paukadaulo wachitetezo chamagetsi. Mwa kuphatikiza zotsalira zotsalira zopulumutsira moyo molunjika kumalo komwe kuli ponseponse, ma SRCD amapereka chitetezo chokhazikika, chosinthika, komanso chosavuta kugwiritsa ntchito ku zoopsa zomwe zimachitika nthawi zonse za kugwedezeka kwa magetsi ndi moto. Ubwino wawo - kutetezedwa kwawoko komwe kumachotsa maulendo osokonekera adera lonse, kubwezeretsanso kosavutikira, kusuntha, kutsika mtengo kwa mfundo zinazake, komanso kutsatira malamulo achitetezo amakono - zimawapangitsa kukhala ofunikira kwambiri panyumba, malonda, mafakitale, ndi malo apadera.

Kaya mukukweza nyumba yakale yopanda ma RCDs, kuteteza zida zamagetsi pamalo omanga, kuteteza pampu ya dziwe la m'munda, kapena kungowonjezera chitetezo chowonjezera kuchipinda cha ana, SRCD imakhala ngati mlonda watcheru. Amapereka mphamvu kwa ogwiritsa ntchito kuwongolera mwachindunji chitetezo chawo chamagetsi pamalo ogwiritsira ntchito. Pamene machitidwe a magetsi akukhala ovuta kwambiri ndipo miyezo ya chitetezo ikupitirizabe kusinthika, SRCD mosakayikira idzakhalabe luso lamakono, kuonetsetsa kuti kupeza mphamvu sikumabwera pamtengo wa chitetezo. Kuyika ndalama mu SRCDs ndi ndalama popewa ngozi komanso kuteteza zomwe zili zofunika kwambiri.