AQ: How to select the right cable?
Before you select kind of cable for your consumer, you need to calculate expected operating current of cable which depends from rated power of your consumer. After that, before you select kind of cable for your consumer, you need to check size of cable which needs to satisfy next conditions:
1. you need to check cable if it satisfied limits in normal conditions without consequences in aspect of warming (normal work),
2. you need to check cable if he satisfied limits in abnormal conditions without consequences in aspect of warming (short circuit).
1. when you want to check cable if he satisfied limits in normal conditions, you need to choose installation place (trench, concrete channel etc.), you need to know heat resistance of land, you need to know appropriate temperature of land and you need to calculate number of cables in installation place.
Icalculate=number of cables*k1*k2*k3*k4*Irated cable>Irated (consumer)
k1 depends from installation place,
k2 depends from heat resistance of land,
k3 depends from appropriate temperature of land,
k4 depends from number of cables
2. when you want to check cable if he satisfied limits in abnormal conditions, you need to calculate expected current of short circuit and heat impulse in the place of installation.
If your cable satisfied these requirements, then you made the right choice.
