1, ambient temperature
The ambient temperature value used is the temperature of the surrounding medium when the cable or conductor is not loaded.
2, soil thermal resistivity
For cables laid in the ground, where the actual soil thermal resistivity is higher than 2.5 K.m / W, the carrying capacity must be appropriately reduced or the soil around the cable should be replaced with a suitable material.
3, multi-loop group
When installing more wires or cables in the same group, you must multiply the specified correction factor. The grouping correction coefficients are calculated on the basis of the assumption that the group's loop loads are the same
4, the number of stranded wire
The number of wires to be considered in a circuit is the number of wires that carry the load current. It is assumed that the neutral current is not required when the conductor carries a balanced current in the multiphase circuit. In the neutral line carrying current, while the phase line load is not reduced accordingly, the loop current rating should be determined to consider the neutral line.