Hng dn la chn dy cp in trong xy dng nhGi: VNTnh ton la chn dy dn in cho nh l mt ic c!n thi"t #$an trng% th& nh't l 'n ( an t)an cho ng*i ti +,n% th& hai l ti"t -im ./ c0 th1 trnh 2cic ph,i tho ra lm l3i -hi th'y -h4ng ph5 h2p67 Hng dn ny trnh by mt cch ngn gn v vn ny, ng hu gp cho ng dng tu tn v d dng hon trong vc ua chn dy dn n cho nh o. Trong hng dn ny, cu trc v tn g cua cc oa dy p at trong nh (xem 3.3) oc tham kho theo tu chun TCVN 2103; cc oa cp ngo tr v cp n ke (xem 3.1 v 3.2) oc tham kho theo tu chun cua ngnh n uc cng nh cc nh sn xut cp uy tn o Vt nam hn nay.Hng dn gom cc muc nh sau:- Cc nguon n su dung cho nh o- Mt so cch dy v oa dy tong ng, thng dung- Cc oa dy dn thch hop cho nh o- Cng sut ch}u t cua cc oa dy cp n thng su dung cho nh o- Cch tnh ton v ua chn dy dn- Cc u cho h thong n nh o- Nhng tc ha kh dng dy & cp n km cht ong- Nhng knh nghm ua chn dy n cho nh o1. Cc ngun in s dng cho nh 1.1 Ngun in 1pha 2dy (thng dng nht)Nguon 1pha 2dy gom c 1 dy pha v 1 dy trung tnh (cn oc g 1 dy nng v 1 dy ngu). y nguon n cho nh o thng dung nht ta Vt Nam hn nay.1.2 Ngun in 1pha 3dyNguon n 1pha 3dy gom c 1 dy pha 1 dy trung tnh v 1 dy no t (cn oc g 1 dy nng, 1 dy ngu v 1 dy bo v). O Vt Nam hn nay nguon n ny bt u p dung o cc ta nh cao tng, bt thu, budng, khch san, cc no c su dung cc my mc thet b} quan trng hoac cc nh o cao cp hon.1.3 Ngun in 3pha 4dy (t gp)Nguon n 3pha 4dy gom c 3 dy pha v 1 dy trung tnh (cn oc g 3 dy nng, 1 dy ngu). O Vt Nam hn nay nguon n ny t gap trong nh o, tr kh chu nh c }nh su dung thet b} n 3pha.1.4 Ngun in 3pha 5dy (rt t gp)Nguon n 3pha 5dy" gom c 3 dy pha 1 dy trung tnh v 1 dy no t bo v (cn oc g 3 dy nng, 1 dy ngu v 1 dy bo v). O Vt Namhn nay nguon n ny rt t gap trong nh o, tr kh chu nh c }nh su dung thet b} n 3pha v c yu cu thm v dy bo v.2. Mt s cch i dy v loi dy t!ng "ng# th$ng dng2.1 i dy ni! Dy & cp n oc uon trong cc ong nhua hoac nep nhua v oc co }nh trn tng, trn nh. So ong dy trong ong cn xem xt saocho ng qu cht e c the rt dy, uon dy kh cn thet sua cha thay the.Cc oa dy nh VCm, VCmd, VC thch hop cho cch dy no.2.2 i dy " t#$ng% " tr&n% " '(n! Dy & cp n oc uon trong cc ong nhua (ong tron kh thng, ong rut g kh chuyen hng) at m trong tng, trn hoac sn nh. So ong dy trong ong cn xem xt sao cho ng qu cht e c the rt dy, uon dy kh cn thet sua cha thay the. Cc oa dy n nh VC, CV, CVV thch hop cho cch dy m.2.3 i dy ng&"! o v cc cng trnh ngoa v, khng dnh n v nh, dy & cp n oc uon trong cc ong nhua cng hoac ong thp ch}u uc, khng thm nc v chn ngm d t o su khoang 0,7mt. Cc oa cp c o gp thp hoac oc bc km oa th c the chn truc tep trong t m khng cn uon trong ong. Cn thet ph chn cc oa dy / cp c kh nang chong thm nc, chong cn trng cho ng dy ngm.%. Cc loi dy d&n th'ch h() cho nh Theo thng cua ngnh n uc cng nh thuc te hn nay o Vt Nam, hng dn ny chn nguon n "1 pha 2 dy" e trnh by cho muc ch nh o. Hng dn ny cha h thong dy cho nh o ra m 3 phn v tong ng vm phn hng dn ny a ra cc ngh} v cc oa dy dn c the oc dng nh sau:3.1 )*n dy ng)(i #$ng +() &u nh( ()*n dy ng)(i tr$i)oan dy ny dy no t n }a phong vo en nh, thng thng oan dy ny nm han tan ngo tr (ngoa tr mt so rt t nh o su dung cp ngm th oan dy ny oc chn d t). oan dy ngo tr ny oc ngh} su dung mt trong cc oa dy/cp sau y:Cp Duplex rut ng, cch in PVC (Duplex Du-CV)Cp Dupex Du-CV c 2 rut dn bng ong, rut dn 1 so ong ac hoac 7so ong oc xon a v nhau, m rut dn oc bc cch n PVC sau xon v nhau. Cp n p cua cp 450/750V hoac 0,6/1kV.Cp Duplex rut ng, cch in XLPE (Duplex Du-CX)Cp Dupex Du-CX c 2 rut dn bng ong, rut dn 1 so ong ac hoac 7so ong oc xon a v nhau, m rut dn oc bc cch n XLPE mu en sau xon v nhau, mt trong ha c gn no e phn bt pha. Cp n p cua cp 0,6/1kV.3.2 )*n dy t, &u nh( +() in -. ()*n /0p in -.)oan dy ny dy no t u cuo oan dy ngo tr (oc n o muc 3.1) en n ke (ong ho o n nang tu thu). Thng thng oan dy ny nmmt nua dc theo tng, mt nua trong nh (v thng thng n ke oc attrong nh). oan dy ny oc ngh} su dung mt trong cc oa dy/cp sau y:Cp in k rut ng, cch in PVC (!-CVV)Cp n ke rut ong cch n PVC cn g cp Muer rut ong cch n PVC, cp c 2 hoac nhu hon 2 rut dn, rut dn 1 so ong ac hoac7 so oc xon a v nhau, m rut dn oc bc cch n bng vt u PVC, mt p bc t PVC, mt p bang nhm (e chong trm n) v p vo bc PVC bo v bn ngo, cp n p cua cp 450/750V hoac 0,6/1kV.Cp in k rut ng, cch in XLPE (!-CXV)Cp n ke rut ong cch n XLPE cn g cp Muer rut ong cch n XLPE, cp c 2 hoac nhu hon 2 rut dn, rut dn 1 so ong ac hoac 7 so oc xon a v nhau, m rut dn oc bc cch n bng vt u XLPE mu trng-trong (mu tu nhn), mt trong ha c bang mu hoacsc mu e phn bt pha, mt p bc t PVC, mt p bang nhm (e chongtrm n) v p vo bc PVC bo v bn ngo, cp n p cua cp 0,6/1kV.3.3 1y d2n t, in -. .n /0/ thi.t 34 ti5u th in (dy d2n tr)ng nh()O Vt Nam, hu nh 2 oan dy cp o muc 3.1 v 3.2 u do ngnh n uc tu ua chn v p at neu chu nh khng c yu cu g rng. Cn cc dy dn t n ke en cc thet b} tu thu n, hu het do chu nh tu quyet }nh o u, y cng vc m hng dn ny cho chu nh cn thet ph quan tm. Cc dy dn ny oc ngh} su dung mt trong cc oasau y.3.3.1 1y 6n /7ng (89)Dy on cng (VC) dy c rut dn 1 so ong, bc cch n PVC. Cp n p cua dy 600V.Ngo ra, cn c Dy on cng khng ch (LF-VC), khng tc ha cho con ngv m trng bng cch su dung vt u PVC khng ch (LF-PVC), ph hop quy }nh RoHS (Restrcton of Hazardous Substances) cua chu Au.3.3.2 1y 6n ":" (89")Dy on mm (VCm) dy c rut dn gom nhu so ong oc xon v nhau, bc cch n bng vt u PVC. Cp n p cua dy 250V.Ngo ra, cn c Dy on mm khng ch (LF-VCm), khng tc ha cho con ng v m trng bng cch su dung vt u PVC khng ch (LF-PVC).3.3.3 1y i ":" d;t (89"d)Dy mm det (VCmd) dy c 2 rut dn, m rut dn gom nhu so ong xon a v nhau, 2 rut dn ny oc bc cch n PVC v phn cch n cua 2 rut dn dnh v nhau tao ra mt dy det c 2 rut dn cch n song song v nhau. Cp n p cua dy 250V.Ngo ra, cn c Dy mm det khng ch (LF-VCmd), khng tc ha cho conng v m trng bng cch su dung vt u PVC khng ch (LF-PVC).3.3.4 1y i ":" Da chn < tr-nJ:. Cc lu ; cho h thng in nh - Nn cha ng n phn pho trong nh o thnh nhu nhnh e thun tncho vc ngt n kh cn sua cha, thay the.- Cc dy pha (dy nng) c cng mu v tot nht mu o, mu cam hoac mu vng. h c nhu nhnh chung mt tuyen m kch c gong nhau th mu cua tng nhnh nn khc nhau e d phn bt.- Dy cho h thong no t nn c mu rng bt v tt c cc dy khc v nn chn dy mu xanh- sc- vng hoac vng- sc- xanh.- h uon dy trong ong hoac trong nep, ph chn kch thc ong, nep u rng sao cho d uon, d rt m khng h ha en dy dn.- hng nn dy no m thp hoac qu gn cc nguon nht, ha cht.- Mo no dy ph chat, tep xc tot e khng gy ra m-ve nac ua kh mang t.- hng oc no truc tep rut dn ong v nhm v nhau.- oan dy trong ong khng nn c mo no.- hng nn dy m trong nn cua tng trt neu nn khng m bo co }nh v tng kh nn b} n.- hng nn su dung dy c tet dn nho hon 0.5mm2.ng tc hi ?hi d@ng dy A c) in ?B8 ch+t l(ng#hi :u>t )?ng !@* cht l0Ang h,Bc !hng ) ti"t %in cC thD g&' :a cc tc hEi sau- Dn n km, gy sut p trn ng dy m cho thet b} hat ng khng hu qu, tuo th thet b} gm nhanh.- Pht nng qu mc trn ng dy, gy h ha p cch n, gy cham chp chy no.- Rut ong km cht ong rt d gy, kh no, kh p vo cc phu kn nkhc.#hi l1p cch )in !@* cht l0Ang cC thD g&' :a cc tc hEi sau- Nt cch n, ho rut dn, gy n gt cho ng.- Ran nt cch n sau mt th gan ngn, gy r n, ton tht n nang, cham chp chy no.- hng ch}u oc nht cho php cua rut dn, chy nho gy ra cham chp chy no.- hng tu tt kh b} pht chy bo tc nhn bn ngo.- Mt mu sau mt th gan ngn, gy nhm n cc dy v nhau kh sua cha, thay the.C. =h>ng ?inh nghi8 l2/ ch3n dy din cho nh Nhng knh nghm oc nu o y chu yeu hng t cc oa dy dng trongnh (nh muc 3.1 cp).V rt nhu cc oa dy n trn th} trng hn nay, tot c, xu c, tht c,g c, thm ch c kh gap dy chng c nhn mc, tn nh sn xut g c. Vvy, mt ng khng chuyn th vc ua chn dy no, nhn hu no m c the tn cy oc mt vc khng d dng g. ng mt v knh nghm cua ng bn soan, hng dn ny a ra mt so khuyen ngh} v nhng ch du e hy vng rng ng dng c the trnh oc cc sn phm dy/ cp n km cht ong.- hng nn chn dy khng c nhn mc trn bao b, khng c tn nh sn xut, khng }a ch r rng.- hng nn chn dy m trn dy khng c cc thng tn co bn nh: nhn hu, tn oa dy, tet dn, cu trc rut dn (so so v ng knh m so), tu chun sn xut.- Dy tot thng c b ngo cua vo nhua bng, ng.- Lp nhua cch n cua dy tot rt do, kh tuot ra kho rut dn, c the ko gn gp , gp ba chu d ban u m cha b} t. Dy c the b gp nhu n hoac xon gt nhng b mat cch n khng b} rang nt.- C the kem tra rut dn, bng cch em so so nho bn trong so v so so oc gh bn ngo. ng knh cua cc so nho bn trong rt kh kem tra, v ph c thc chuyn dng m o oc. Tuy nhn, v mt thong hu uy tn, trn dy c gh cu the cu trc rut dn (so so v ng knh m so) th c the tn tong oc.- Dy tot th c rut dn sng, bng, neu dy ong th rut dn rt mm do. o v dy rut dn ong c nhu so nho th c the dng ha ngn tay xon rut dn d dng m cc so nho khng bung, khng gy, khng m vo tay. o v dy rut dn c mt so th c the b gp rut ong en v chuc n m khng gy.- Thng thng, dy tot c g cao hon dy dom v cng c oa