chuong 1

B GIO DC V O TOTRNG H S PHM K THUT TP HCMTRNG H S PHM K THUT TP.HCM

KHOA IN IN T

Gio trnh

TS. V VIT CNG

1

MC TIU MN HCGT An ton in c bin son cho SV khi ngnhCng ngh v K thut nhm:g g Trang b cho sinh vin nhngkin thc c bn v an ton incho ngi, thit b v cng trnh. Hnh thnh k nng lp t, sdng v vn hnh cc thit bin, in t ng quy cch. To cho SV thc an ton ltrn ht trong mi hot ng,

Trng H S phm K thut Tp.HCM _ Bi ging mn An ton in 2thao tc lin quan n in.

NI DUNG

Chng 1 : CC KHI NIM C BN

Chng 2 : PHN TCH DNG IN QUA NGIChng 2 : PHN TCH DNG IN QUA NGI

Chng 3 : H THNG NI T

Chng 4 :THIT B NG CT V BO V H P

Trng H S phm K thut Tp.HCM _ Bi ging mn An ton in 3

NI DUNG

Chng 5 : BO V AN TON CHO NGI

Chng 6 : BO V AN TON CHO THIT B

Chng 7 : BO V CHNG ST

Chng 8 :CNG C V QUN L AN TON IN

Chng 9 : S CU NGI B IN GIT


C 1Chng 1

CC KHI NIM C BN


Chng 1: CC KHI NIM C BN

MC TIU Cung cp cho sinh vinnhng thut ng, nhngkhi i b tkhi nim c bn trongmn hc ny.

Truyn t nhng kinthc c bn lm nn tngg bc tip vo nhngchng sau.


Chng 1: CC KHI NIM C BN

NI DUNG1.1 t vn 1.2 Tai nn in

1.3 Tc dng ca dng in vi c th ngi1.4 Cc yu t ng hng n tai nn in git

1.5 Dng in tn trong t1.6 in p bc1 7 i ti 1.7 in p tip xc1.8 Phn loi cng trnh v trang thit b in1 9 Nguyn nhn chnh gy ra tai nn in


1.9 Nguyn nhn chnh gy ra tai nn in

1.1. T VN in nng c s dng ph bin trong nhiu in nng c s dng ph bin trong nhiu lnh vc v nhiu ni:9 Sn xut thng9 Sn xut, thng mi, dch v9 Sinh hot dn dng9 Sinh hot dn dng9 Thnh th9 Nng thnNng thn

S ngi lm vic lin quan vi in ngy cng nhiu.g y g

in l 1 trong nhng nguyn nhn chnh gy ra cc tai nn v thm ha thng tm.

Trng H S phm K thut Tp.HCM _ Bi ging mn An ton in 8 Cn quan tm n vn an ton in

1.1. T VN Cc mi nguy him khc c th c bo trc hoc pht hin qua cc triu chng thy c nh:9 Mi kh c, s bc khi9 B phn quay xc xch,B phn quay xc xch, gy v9 Thanh kim loi nng Thanh kim loi nng Mi nguy him in ch cth bit khi tip tip xc ccth bit khi tip tip xc ccphn t mang in nhng nhvy l c th dn n cht

Trng H S phm K thut Tp.HCM _ Bi ging mn An ton in 9ngi.

1.1. T VN

- Thiu hiu bit v an ton inTai nn in

- trnh nhng nguy him c th xy ra cho bng g y ythn v cho nhng ngi xung quanh, ta phi hiumt s khi nim an ton in:

Tai nn in T d d i i h i Tc dng ca dng in vi c th con ngi Cc yu t nh hng n tai nn in git


1.2. TAI NN INin git; t chy in do h quang; n v ha hon1 in git1. in git Chm trc tip Chm gin tip

1 2 3 N 2 3 PE1

I : Dng in

Id : Dng in chm vIs : Dng in

qua ngiIs

Trng H S phm K thut Tp.HCM _ Bi ging mn An ton in 11Chm in gin tipChm in trc tip

1.2. TAI NN IN

2. t chy in: sinh ra do

Ngn mch ko theoht i h h ipht sinh h quang in.

Ngi n gn vtmang in p cao, tuycha chm nhng c thb b h ht d hb bng hay cht do hquang t chy da tht.


1.2. TAI NN IN

3. Ha hon, n

Dng in vt qu gii hn dy pht nng h quang y g ggy chy

Ha cht t gn thit b c Ha cht t gn thit b c dng ln, nhit cao n

Ha hon n xy ra mi Ha hon, n xy ra mi trng d chy n: bi bm, kh d chy, hi ha cht


y,

1.3. TC DNG CA DNG IN I VI C TH CON NGII VI C TH CON NGI

1. Tc dng kch thch g

H h hp, tun honC b t th ti- Cc c ngc b co rt, cc th c tim co

bp hn lonTim thiu oxy ngng p- Tim thiu oxy ngng p

H thn kinhS - Sc in phn ng mnh lc u

- Dn dn t lit m man t vong


1.3. TC DNG CA DNG IN I VI C TH CON NGI

2. Tc dng gy chn thng

I VI C TH CON NGI

g g y g

H quang in gy ra s hydit lp da bn ngoi Nngdit lp da bn ngoi. Nnghn l hy dit c bp, lp m,gn, xng.g , g

t chy do in gy nngton thn Nu gi tr dng lnton thn. Nu gi tr dng lnv thi gian tn ti di tvong.


g

1.3. TC DNG CA DNG IN I VI C TH CON NGI

3. Tc ng tm l

I VI C TH CON NGI

B in git c th nh hng n tm l ngib nn nh:

Chong vng, hong long S st Cnh gic hn khi tip xc vi thit b ing p Gy hu qu tm l, gnh nng gh gm chongi b nn, gia nh v cho c x hi.


ngi b nn, gia nh v cho c x hi.

1.4. CC YU T NH HNG N TAI NN IN GITTAI NN IN GIT

1 c t n dng in thi gian1. c tuyn dng in thi gian

2. c tuyn in p thi gian

3. in tr ca ngi

4 ng i dng in qua ngi4. ng i dng in qua ngi

5. Tn s dng in

6. Mi trng xung quanh

7 in p cho php


7. in p cho php

1.5. DNG IN TN TRONG T

U=U x /x

Khi mch chmt c dng chy

Umax = I/2.x1

U=Umax.x1/x

= k/x

g ytrong t chnhlch in p ti i kh

I

acc im khcnhau trong t. Vng

x1x I

Aoo Vngquanh ccni t gi

UA= I/2.x

ni t gil trngtn dng

Trng H S phm K thut Tp.HCM _ Bi ging mn An ton in 18Dng in tn trong tin.

1.5. DNG IN TN TRONG T Trng hp dy dn b t xung t, phn bin p c trnh by nh sau:

100

1. in cc ni t l 1 cc

in p trn cc ni t s tn hao:

68% t Ud(V)

1002. in cc ni t l h thng

- 68% trn on di 1m

- 24% trn on32

8

- 24% trn on di 110m

- 8% trn on di 80 1 8 20 X(m)

1020m Ngoi 20m xem 10Quan h Ud v khong

Trng H S phm K thut Tp.HCM _ Bi ging mn An ton in 19nh Ud = 0.

d gcch x t cc ni t

1.5. DNG IN TN TRONG T

Dng in tn t cc ni t c th xem l chytrong 1 dy dn(t) m tit din tng theo bc 2 cag y ( ) gbn knh qu cu q = 2x2.

q=2x12 q=2x22 q=2x32 in tr tn lnnht lp tphn cc ni t U ri max.

Cng xa cc

M hnh n gin dy dn t

gni t, in trgim U ri

i


M hnh n gin dy dn tgim.

1.6. IN P BC

U = I RUb =U - Ua

Ub = Ux Ux+aU = IRUb = Ia/2x(x+a)

RUb = 0

Cng xa im NMchm t Ub cng

gim.

Ub=0 nu 2 chnngi trn cng 1

Trng H S phm K thut Tp.HCM _ Bi ging mn An ton in 21in p bcvng ng p.

1.6. IN P BC

Gii hn cho php ca Ub khng quy nh. U nh khng nguy him do c tnh sinh l dng Ub nh khng nguy him do c tnh sinh l dng t chn qua chn.

T hi i U 100250V h th b Tuy nhin vi Ub=100250V, chn c th b co rt v s nguy him nu ng v lc ny dng i t tay qua chntay qua chn.

Khi xy ra chm t phi cm ngi n gn vi kh hkhong cch:9 4 5m i vi thit b trong nh

Trng H S phm K thut Tp.HCM _ Bi ging mn An ton in 229 8 10m i vi thit b ngoi tri

1.6. IN P BC

Bi tp v dTnh in p bc U lc ngi ng cch chTnh in p bc Ub lc ngi ng cch chchm t x = 15m dng in chm t I = 5kA, intr sut = 150 m, khong cch gia 2 bc chn , g gngi a = 0.8m?

Gii


1.7. IN P TIP XC

U = I.R

UT1 = U Ux1UT2 = U

2

Ux1 1

x1x2

1

in p tip xc trong vng ngn mch chm v


in p tip xc trong vng ngn mch chm v

1.7. IN P TIP XC

Khi ngi tip xc thit b(c ni t b chm v) th

UT 2.T hp cc cc ni t

(c ni t b chm v) thchu 1 in p tip xcUT = .U .

UT1UT2

T

Gii hn cho php caUT khng quy nh, thngT g q y , gUT

1.7. IN P TIP XC

2

U

U = I.RUT2 = UTB

RUIUx1 1

R

RngUngI

x1

RnUn

x2

S thay th mch Ung1 = U Ux1 UnU U U

Trng H S phm K thut Tp.HCM _ Bi ging mn An ton in 26in chm v Ung2 = U Un

1.8. PHN LOI CNG TRNH V TRANG THIT BTRANG THIT B

1. Phn loi cng trnh Cng trnh t nguy him: kh ro, khng nng(97%, to > 30oC, phn kim

Trng H S phm K thut Tp.HCM _ Bi ging mn An ton in 27loi ni t nhiu, sn dn in.

1.8. PHN LOI CNG TRNH V TRANG THIT B

2. Phn loi trang thit b

TRANG THIT B

Theo in p: trang thit b c in p cao U 1000V v trang thit b c in p thp U < 1000V

g

1000V v trang thit b c in p thp U < 1000V.

Theo b tr v tr cc trang thit b:- C nh

- Di ngDi ng

- Cm tay


1.9. NGUYN NHN CHNH GY RA TAI NN IN

1 i vi mng h p1.i vi mng h pDo ngi chm vo:

Dy dn ang mang in khng bc cch in Cch in b h hng xung cp Cch in b h hng, xung cp Hin tng chm v Khng c np che chn


1.9. NGUYN NHN CHNH GY RATAI NN IN

2. i vi mng cao pTAI NN IN

Nu n qu gn thit b hocng dy c in p cao(22KV 66KV 110KV ) d i(22KV, 66KV,110KV) d ngikhng chm nhng vn c thb tai nn do h quang inb tai nn do h quang in. Lc ny do khong cch giangi v vt mang in nhngi v vt mang in nhhn khong cch an ton phng in, t chy c th.


g y

1.9. NGUYN NHN CHNH GY RA

3. in p bc

TAI NN IN3. in p bc Khi dy mang in rt xungt, ti mi im ca t c 1t, ti mi im ca t c 1in th. Cng gn im chmt, in th cng cao.

Nu ngi i trong vng chmt s c mt in bc t ln 2 chn, dng in chy t chnny sang chn kia gy ra tai nn

Trng H S phm K thut Tp.HCM _ Bi ging mn An ton in 31in git.


4. Khng chp hnh quy trnh k thut an ton in

TAI NN IN

ton in T tro ln ct in, viphm hnh lang li in.p g Sa cha in trong nhkhng ct cu dao. S dng cc loi thit bkhng ng quy cch v khng

m bo cht lng. S dng in ba bi, khng h

Trng H S phm K thut Tp.HCM _ Bi ging mn An ton in 32ng mc ch.


5. Do ngi s dng in khng c ot t b ki th t i t

TAI NN IN

to, trang b kin thc v an ton in mtcch y v c h thng

6. Do trnh cn b t chc, qun l cngtc lp t, xy dng v sa cha cngt h i h tt

Trng H S phm K thut Tp.HCM _ Bi ging mn An ton in 33trnh in cha tt

TAI NN IN


1. c tuyn dng in - thi gian Gi tr dng qua ngi l mt trong nhng yu tgy nguy him cho ngi. Dng in xoay chiu tn s 50-60Hz c gi tr anton cho ngi phi nh hn 10 mA. Gi tr v thi gian tn ti dng in nh hngn tnh trng nguy him ca ngi b in git thhihin qua:

Quan h Imax v thi gian t tim khng ngng p

Dng in Imax(mA) 10 60 90 110 160 250

Thi gian in git t(s) 30 10 3 2 1 0,4


Thi gian in git t(s) 30 10 3 2 1 0,4

1. c tuyn dng in - thi gian

AC-4 1 AC-4 2AC-4.1 AC-4.2

AC-4.3Khng gy tc hi v

sinh l

Tim ngng p Ngng h hp

Xc sut nght

AC-1 AC-2 AC-3 AC-4

Bp tht co li

gtm tht 5%Xc sut nght tm tht 50%

Xc sut nghtKhng phn ng

p Kh th

Ri lon nhp tim

Xc sut nght tm tht > 50%

Trng H S phm K thut Tp.HCM _ Bi ging mn An ton in 37Vng tc ng ca thi gian v dng in ln c th ngi

2. c tuyn in p - thi gian c tuyn l

quan h gia inp tip xc UT(V)

5s

p tip xc UT(V)v thi gian dngqua ngi. Thi gian chophp qua ngi lv hn nu UT

3. in tr ca ngiI

B in git ngi tr thnh 1b phn ca mch in.

Ing

b phn ca mch in.

in tr ngi 2 u cc tipxc gm 3 phn:

R1C1

xc gm 3 phn:

- in tr R1 v in dung C1 lpda m dng I i vo

RngUng

da m dng Ing i vo

- in tr ni tng Rng R2C2

- in tr R2 v in dung C2 lpda m dng Ing i ra

IngS tng ng


g ngin tr ngi

3. in tr ca ngi

in tr ngi ZH phthuc vo:

thuc vo:

p sut tip xc, cng tn s v loi dng I

Phn trm dn s

, tn s v loi dng Ing,thi gian tip xc

Din tch v in p tip 95% Din tch v in p tipxc

5%

50%

Gi tr in tr ngi

Trng thi bnh l cangi


gtheo in p tip xc

3. in tr ca ngiGi t i t i th t h t ti Tnh trng

ti in tr ngi

Gi tr in tr ngi theo tnh trng tip xc

tip xc Kh m Chm ngn tay 40k1M 4k15k

Tay chm dy 10k50k

3k6k

Tay cm km 1k3kTay cm km5k10k

1k3k

Lng bn tay chm dy 3k8k 1k2kTay cm my khoan 1k3k 0.5k1.5kTay t - 200500

Trng H S phm K thut Tp.HCM _ Bi ging mn An ton in 41Chn t - 100300Phn ni tng khng k da - 2001000

4. ng i dng in qua ngi

nh gi mc nguyhim, da vo phn lnghim, da vo phn lngdng in chy qua tim.

Trng hp nguy him 0.31.3

1.5 Trng hp nguy himnht l dng in i t ngcn tay tri, tuy nhin t xy ra.

0.30.7

0.7

y , y y

Trng hp xy ra nhiunht l t tay phi n mtnht l t tay phi n mttrong hai chn.

10.8

Trng H S phm K thut Tp.HCM _ Bi ging mn An ton in 42Phn lng dng in qua tim

5. Tn s dng in D DC t hi h d AC bit l d Dng DC t nguy him hn dng AC c bit l dngAC tn s cng nghip 50Hz 60Hz. Tn s cng cao cng t nguy him Tn s cng cao cng t nguy him.

Gii tn s Tn gi ng dng Tc hiTc hi i vi ngi cc di tn s khc nhau

Gii tn s Tn gi ng dng Tc hi

DC -10kHz Tn s thp Mng dn Pht nhit phDC 10kHz Tn s thp Mng dn dng v CN

Pht nhit, ph hy t bo

100kHz- Tn s radio t in, Gia nhit in 100MHz

nhit in

mi t bo

100MHz- Sng L viba Gia nhit nc

Trng H S phm K thut Tp.HCM _ Bi ging mn An ton in 43100GHz Microwave

6. Mi trng xung quanh

m cng ln dn in ca lp das tng ln, tc in tr ngi gim xung.s tng ln, tc in tr ngi gim xung.

M hi, cc cht ha hc cng lm tng dn in ca dadn in ca da.

Nhit mi trng tng tuyn m hihot ng nhiu in tr ngi gim.

bn ca c th lm gim in tr ca bn ca c th lm gim in tr cada tng mc nguy him.


7. in p cho php Gi t i h h h th l i h th Gi tr in p cho php ph thuc loi h thngphn phi in v thi gian ngt s c.

H thng TT, U tip xc max l 50V. Thi gian ngt max vi h thng IT:in p danh nh U0/U (V)

tmax (s)Khng c dy trung tnh C dy trung tnh

g g g

Thi gian ngt

U0 (V) tmax (s)120 0 8Khng c dy trung tnh C dy trung tnh

120/240 0,8 5230/400 0 4 0 8

max vi h thng TN: 120 0,8230 0,4277 0 4230/400 0,4 0,8

400/690 0,2 0,4580/1000 0 1 0 2

277 0,4400 0,2

> 400 0 1


580/1000 0,1 0,2> 400 0,1

7. in p cho phpT i ki t thi i t lTrong iu kin m t, thi gian ngt lnnht c quy nh li nh sau:

H thng TN H thng ITH thng TN H thng ITin p

danh nhtmax(s)

in p danh nh

tmax (s)

Kh d C ddanh nh U0(V)

(s) danh nh U0/U(V)

Khng c dy trung tnh

C dy trung tnh

120 0 35 120/240 0 4 1120 0,35 120/240 0,4 1

230 0,2 230/400 0,2 0,5

277 0 2 277/480 0 2 0 5277 0,2 277/480 0,2 0,5

400,480 0,05 400/690 0,06 0,2

580 0 02 580/1000 0 02 0 08


580 0,02 580/1000 0,02 0,08

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