Figure. 5.3.23 - 119. Factors affecting the cooling and current-carrying capacity of a cable.
The current-carrying capacity of a cable mostly depends on the conductor's material and its diameter.
The second most important factor is the cable's insulating material and how much it can withstand
temperature. As can be seen in the image above, all factors (apart from the air temperature) are quite
stable, especially when the cable lies below the ground frost limit in places where the outside
temperature can dip well below 0 °C. The heat conduction from the cable into the surrounding ground
is the same, regardless whether the cable is heating or cooling. The composition of the soil defines
how well the ground conducts heat. However, these loading factors only affect the maximum current-
carrying capacity of the cable; they are not the cable's time constants. The only time constant to
consider is the heating time constant, which is equal to the cooling time constant for underground
cables.
Figure. 5.3.23 - 120. Simplified motor construction and time constants.
Any normal induction machine such as electric motors have the following major components:
A
AQ
Q-M255
-M255
Instruction manual
Version: 2.06
224
© Arcteq Relays Ltd
IM00020
Содержание AQ-M255
Страница 1: ...AQ M255 Motor protection IED Instruction manual...
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Страница 384: ...Figure 7 4 189 Example block scheme A AQ Q M255 M255 Instruction manual Version 2 06 382 Arcteq Relays Ltd IM00020...
Страница 405: ...Figure 8 14 211 Device installation A AQ Q M255 M255 Instruction manual Version 2 06 Arcteq Relays Ltd IM00020 403...