בטיחות בחשמל
✦ בנוי על ידי פהד גאנם ✦
العربية
☀ מצב בהיר
1
▾
✕
P = I
2
·R |
P
2
P
1
=
I
2
2
I
1
2
| P(2·I) = 4·P(I) | FIRE = Q · O
2
· F
16 A
0
0
0
P₁ = I₁² · R = 16² · 0.1 = 256 · 0.1 = 25.6 W
P₂ = I₂² · R = 32² · 0.1 = 1024 · 0.1 = 102.4 W
P₂
P₁
=
I₂²
I₁²
=
102.4 W
25.6 W
= 4
2
▾
✕
I =
U
R
| U [V] · R [Ω] · I [A] | 1 A = 1000 mA | AC 50 Hz · IEC 60479
230 V
2000 Ω
115.0
mA
230
V
2000
Ω
0.0
s
U = 230 V , R = 2000 Ω
I =
U
R
=
230 V
2000 Ω
= 0.115 A
I = 0.115 A = 115 mA
115 mA > 100 mA
3
▾
✕
I
a
=
U
0
Z
s
| k =
I
a
I
n
| U
t
= U
0
·
Z
PE
Z
L
+ Z
PE
| U
0
= 230 V | f = 50 Hz
1.0 Ω
0.5 Ω
0.5 Ω
0
0
0
0
I
a
=
U
0
Z
s
=
230 V
1.0 Ω
= 230 A
k =
I
a
I
n
=
230 A
16 A
= 14.4
Z
s
= 5.0 Ω | I
a
=
230 V
5.0 Ω
= 46 A | k = 2.9
4
▾
✕
I
a
=
U
0
Z
s
|
230 V
0.5 Ω
= 460 A |
230 V
5 Ω
= 46 A |
460 A
46 A
= 10 | I
body
=
230 V
2000 Ω
= 115 mA
0.5 Ω
—
—
—
—
I
a
=
U
0
Z
s
I
a
=
230 V
0.5 Ω
= 460 A
I
a
=
230 V
5 Ω
= 46 A
460 A
46 A
= 10
460 A
16 A
= 28.8 |
46 A
16 A
= 2.9
5
▾
✕
I =
U
R
| ΔI = I
1
− I
2
| Φ
net
∝ I
1
− I
2
| I
1
= I
2
, Φ
net
= 0 | ΔI ≥ 30 mA | n =
ΔI
30 mA
2000 Ω
6.0 A
0.0
0.0
0.0
0.0
I =
U
R
I =
230 V
2000 Ω
= 0.115 A
0.115 A = 115 mA
n =
115 mA
30 mA
= 3.8
6
▾
✕
I =
U
R
=
230 V
2000 Ω
= 115 mA | I
let-go
≈ 10 mA | P = I²·R
1.6 s
—
—
—
I =
U
R
=
230 V
2000 Ω
= 0.115 A = 115 mA
7
▾
✕
R =
ρ · L
A
| ρ
Cu
= 0.0175 Ω·mm²/m | U = I · R | I
leak
=
U
R
ins
| ΣI
Δ
= n · I
1
| I
Δn
= 30 mA
25 m
2.5 mm²
1 A
500 V
10 MΩ
5
2 mA
0
0
0
0
R =
ρ · L
A
R =
0.0175 Ω·mm²/m · 25 m
2.5 mm²
= 0.175 Ω
U = I · R = 1 A · 0.175 Ω = 0.175 V = 175 mV
A = 1.5 mm² | R =
0.0175 Ω·mm²/m · 25 m
1.5 mm²
= 0.2917 Ω
8
▾
✕
0
0
—
10
0
0
—
0:00
→
🏠
♿