Technical information
4/27
In [A]
180
175
170
165
160
155
150
145
140
135
130
125
120
T [°C]
40 45 50 55 60 65 70
1SDC21068GF0001
1SDC210033D0202
The electronic overcurrent trip units do not undergo any variations in performance as the temperature
varies.
However, even if heating does not affect the trip thresholds of the electronic trip units, in the case of
temperatures exceeding +40°C it is advisable to reduce the maximum setting for protection against
overloads (L) to preserve the copper parts of the circuit-breaker against high temperatures.
The same considerations can be done about the switch-disconnectors and magnetic only circuit-
breakers.
The table and graph below show the maximum adjustment at which the threshold I
1
of the overcurrent
protection (L) must be set according to the ambient temperature and to the type of terminals used.
XT1 - Fixed circuit-breakers with only magnetic trip unit or switch-disconnectors
40°C 50°C 60°C 70°C
Imax [A] Imax [A] Imax [A] Imax [A]
F-EF-ES-FCCu-R
160 160 153 140
F = Front flat terminals EF = Extended front ES = Extended spreaded FCCu = Front for copper cables R = Rear
XT4 with thermomagnetic trip units
T amb (°C) 10 20 30 40 45 50 60 70
In [A]
MIN[A] MAX [A] MIN[A] MAX [A] MIN[A] MAX [A] MIN[A] MAX [A] MIN[A] MAX [A] MIN[A] MAX [A] MIN[A] MAX [A] MIN[A] MAX [A]
16
13 19 13 18 12 17 11 16 11 15 10 14 9 13 8 12
20
19 27 17 24 16 23 14 20 14 19 12 17 11 15 9 13
25
21 30 20 28 19 27 18 25 17 24 16 23 15 21 13 19
32
26 43 24 39 25 36 22 32 22 31 19 27 17 24 15 21
40
33 48 32 45 30 43 28 40 27 39 26 37 24 34 21 30
50
37 62 35 58 38 54 35 50 34 48 32 46 29 42 27 39
63
53 75 50 71 47 67 44 63 43 61 41 58 37 53 33 48
80
59 98 55 92 60 86 56 80 54 77 52 74 46 66 41 58
100
83 118 79 113 74 106 70 100 68 97 67 95 60 85 53 75
125
102 145 100 140 94 134 88 125 85 121 81 115 74 105 67 95
160
130 185 123 176 118 168 112 160 108 155 105 150 96 137 91 130
200
161 230 154 220 147 210 140 200 136 194 133 190 123 175 112 160
225
188 269 179 255 168 241 158 225 152 218 146 208 133 190 119 170
250
200 285 193 275 183 262 175 250 169 242 168 240 161 230 154 220