Ponena za kutentha kovomerezeka kwa nthawi yayitali kwa ma cable cores, kutchinjiriza kwa rabara nthawi zambiri kumakhala pa 65°C, kutchinjiriza kwa polyvinyl chloride (PVC) pa 70°C, ndi kutchinjiriza kwa polyethylene (XLPE) pa 90°C. Pa ma short-circuits (okhala ndi nthawi yayitali yosapitirira masekondi 5), kutentha kwakukulu kovomerezeka kwa conductor ndi 160°C pa kutchinjiriza kwa PVC ndi 250°C pa kutchinjiriza kwa XLPE.
I. Kusiyana pakati pa Zingwe za XLPE ndi Zingwe za PVC
1. Zingwe za Low Voltage Cross-Linked (XLPE), kuyambira pomwe zinayamba kugwiritsidwa ntchito pakati pa zaka za m'ma 1990, zakula mofulumira, zomwe tsopano zikuyimira theka la msika pamodzi ndi zingwe za Polyvinyl Chloride (PVC). Poyerekeza ndi zingwe za PVC, zingwe za XLPE zimakhala ndi mphamvu yonyamula mphamvu zambiri, mphamvu yochulukirapo, komanso moyo wautali (nthawi yogwiritsa ntchito kutentha kwa chingwe cha PVC nthawi zambiri imakhala zaka 20 pansi pa mikhalidwe yabwino, pomwe nthawi yogwiritsa ntchito chingwe cha XLPE nthawi zambiri imakhala zaka 40). PVC ikayaka, imatulutsa utsi wakuda wambiri ndi mpweya woopsa, pomwe kuyaka kwa XLPE sikupanga mpweya woopsa wa halogen. Kupambana kwa zingwe zolumikizidwa kumazindikirika kwambiri ndi kapangidwe ndi ntchito.
2. Zingwe za PVC wamba (zotetezera kutentha ndi chidebe) zimayaka mofulumira ndi kuyaka mwachangu, zomwe zimawonjezera moto. Zimataya mphamvu zamagetsi mkati mwa mphindi imodzi mpaka ziwiri. Kuyaka kwa PVC kumatulutsa utsi wakuda wambiri, zomwe zimapangitsa kuti pakhale zovuta kupuma komanso mavuto otuluka. Chofunika kwambiri, kuyaka kwa PVC kumatulutsa mpweya woopsa komanso wowononga monga hydrogen chloride (HCl) ndi dioxin, zomwe ndi zomwe zimayambitsa imfa pamoto (zomwe zimapangitsa 80% ya imfa zokhudzana ndi moto). Mpweya uwu umawononga zida zamagetsi, zomwe zimawononga kwambiri magwiridwe antchito a chitetezo cha kutentha ndipo zimayambitsa zoopsa zina zomwe zimakhala zovuta kuzithetsa.
II. Zingwe Zosagwira Moto
1. Zingwe zoletsa moto ziyenera kukhala ndi makhalidwe oletsa moto ndipo zimagawidwa m'magulu atatu oletsa moto A, B, ndi C malinga ndi IEC 60332-3-24 “Kuyesa pa zingwe zamagetsi zomwe zili pamoto.” Gulu A limapereka magwiridwe antchito apamwamba kwambiri oletsa moto.
Mayeso ofanana a kuyaka pa mawaya oletsa moto ndi osaletsa moto adachitika ndi US Standards and Technology Research Institute. Zotsatira zotsatirazi zikuwonetsa kufunika kogwiritsa ntchito zingwe zoletsa moto:
a. Mawaya oletsa moto amapereka nthawi yothawirako yochulukirapo nthawi zopitilira 15 poyerekeza ndi mawaya osaletsa moto.
b. Mawaya oletsa moto amayatsa theka la zinthu zomwe zimagwiritsidwa ntchito poyerekeza ndi mawaya osaletsa moto.
c. Mawaya oletsa moto amaonetsa kuchuluka kwa kutentha komwe kumatuluka gawo limodzi mwa magawo anayi okha a mawaya osaletsa moto.
d. Mpweya woipa wochokera ku kuyaka ndi gawo limodzi mwa magawo atatu okha a zinthu zosaletsa moto.
e. Kuchuluka kwa utsi komwe kumatulutsa sikukuwonetsa kusiyana kwakukulu pakati pa zinthu zoletsa moto ndi zinthu zosaletsa moto.
2. Zingwe Zopanda Halogen Zopanda Utsi Wochepa
Zingwe zopanda utsi wochepa zomwe sizili ndi halogen ziyenera kukhala ndi makhalidwe oletsa moto omwe alibe halogen, utsi wochepa, komanso oletsa moto, ndipo izi ndi izi:
IEC 60754 (mayeso opanda halogen) IEC 61034 (mayeso opanda utsi wambiri)
Kutumiza kuwala kochepa
PH≥4.3 r≤10us/mm T≥60%
3. Zingwe Zosagwira Moto
a. Zizindikiro zoyesera kuyaka kwa chingwe zosagwira moto (kutentha ndi nthawi ya moto) malinga ndi muyezo wa IEC 331-1970 ndi 750°C kwa maola atatu. Malinga ndi chikalata chatsopano chaposachedwa cha IEC 60331 kuchokera ku mavoti aposachedwa a IEC, kutentha kwa moto kumakhala pakati pa 750°C mpaka 800°C kwa maola atatu.
b. Mawaya ndi zingwe zosagwira moto zitha kugawidwa m'magulu awiri: zingwe zosagwira moto zomwe sizingapse ndi zingwe zosagwira moto zomwe sizingapse ndi moto kutengera kusiyana kwa zinthu zopanda chitsulo. Zingwe zosagwira moto zapakhomo zimagwiritsa ntchito makamaka ma conductor okhala ndi mica-coated ndi extruded lawi-insulation ngati kapangidwe kake kakakulu, ndipo zambiri zimakhala zinthu za Gulu B. Zomwe zimakwaniritsa miyezo ya Gulu A nthawi zambiri zimagwiritsa ntchito matepi apadera a mica opangidwa ndi mineral insulation (copper core, copper sleeve, magnesium oxide insulation, yomwe imadziwikanso kuti MI) zingwe zosagwira moto.
Zingwe zotetezedwa ndi mchere zomwe zimayaka moto sizimayaka, sizipanga utsi, sizimazizira, sizimapha poizoni, sizimakhudzidwa ndi moto, ndipo zimakana kupopera madzi. Zimadziwika kuti zingwe zotetezedwa ndi moto, zomwe zimasonyeza kuti zimagwira ntchito bwino kwambiri poteteza moto pakati pa mitundu ya zingwe zomwe sizimayaka moto. Komabe, njira yopangira zingwezo ndi yovuta, mtengo wake ndi wokwera, kutalika kwake kopanga ndi kochepa, ma radius ake opindika ndi akulu, kutchinjiriza kwawo kumakhala kosavuta kunyowa, ndipo pakadali pano, zinthu zamtundu umodzi zokha za 25mm2 ndi kupitirira apo ndi zomwe zingaperekedwe. Ma terminal okhazikika ndi zolumikizira zapakati ndizofunikira, zomwe zimapangitsa kuti kukhazikitsa ndi kumanga zikhale zovuta.
Nthawi yotumizira: Sep-07-2023