1.Phn tch an ton khi ngi chm vo mt cc ca mng in n gin c in dung nh? 2. Phn tch an ton khi ngi chm vo mt cc ca mng in n gin c in dung ln? 3. Hy xc nh dng in qua ngi mng in 2 dy cch in i vi t in dung nh trong cc trng hp ngi chm vo:o o

ng thi 2 dy? Mt dy?

V cho bit ngi c nguy him khng trong tng trng hp, gii thch? Bit: - Mng in c in p U = 220V; - in tr cch in Rc = 30 k ; 4. Hy xc nh dng in qua ngi trong mng in 1 pha ca nc ta trong cc trng hp ngi chm vo:o o

ng thi 2 dy: dy pha v dy ni t (dy trung tnh)? Dy pha?

V cho bit ngi c nguy him khng trong tng trng hp, gii thch? Bit: - Mng in c in p U = 220V, f =50Hz ; - in tr ni t u ngun R0 = 4 ; - in tr ngi Rng = 1000 .*5 Hy xc nh dng in qua ngi khi ngi chm vo dy trung tnh ca mng in 1 pha nc ta trong cc trng hp:o o o o o

Ch chm cch ngun in 1 khong L1 = 30m? Ch chm ngay im u vi ph ti? Ch chm cch ngun in 1 khong L1 = 30m trong khi mng xy ra ngn mch ti ph ti? Ch chm ngay im u vi ph ti khi dy trung tnh b t ti u ngun? Chm khi dy pha b t?

* Cho bit ngi c nguy him khng trong cc trng hp trn, gii thch? * So snh mc nguy him khi chm in trong cc trng hp trn?

Bit rng: - Mng in c in p U = 220V, f =50Hz; dng dy ng mm M2 2,5 (r0 = 8,06 /km) di L = 50m cp in cho ph ti c cng sut 5,5 kW, cos = 0,85; - Gi thit in tr ni t u ngun R = 0 ; in tr ngi Rng = 1000 . 6. Hy xc nh dng in qua ngi khi ngi chm ng dy ti in cao p ti thi im va ct ra khi ngun c chiu di 1km k t ngun n ch chm in trong trng hp:o o

Chm vo mt dy? Chm vo c hai dy?

Bit: - in p gia 2 dy ti thi im t = 1s ngi chm in l 6kV; - Gi thit in dung gia 2 dy v 2 dy vi t cng bng 0,3 F/km. - in tr ngi Rng = 1,5k 7. Hy xc nh dng in qua ngi khi ngi chm vo hai cc ca mt t in ngay sau khi ct ra khi li in? Bit: - in p gia 2 cc ti thi im t = 0,5s ngi chm in l 3kV; - Gi thit in dung ca t bng 3 F. 8. Hy xc nh dng in qua ngi khi ngi chm vo mt dy ca mng in 2 dy cch in vi t cp in cho 1 ph ti ang lm vic cch ngun 500m? Bit: - in p ngun 6kV, f = 50Hz; - Ch chm in: ti im u vi ph ti. - Gi thit in dung gia cc dy vi t bng nhau v bng 0,3 F/km. - in tr ngi Rng = 1,5k .