Cable Selection Principle
When choosing wire and cable, attention should be paid to the selection of wire and cable types and specifications (conductor cross section).
_Selection of Wire and Cable Types
When choosing wires and cables, consideration should be given to their use, laying conditions and safety.
According to different uses, power cables, overhead insulated cables and control cables can be selected.
According to different laying conditions, general plastic insulated cables, rubber insulated cables, steel belt armoured cables, steel wire armoured cables, anti-corrosion cables can be selected.
According to the safety requirements, flame-retardant cables, halogen-free flame-retardant cables and fire-resistant cables can be selected.
_Selection of wire and cable specifications
When determining the specifications of wires and cables (conductor cross section), the selection conditions such as heating, voltage loss, economic current density and mechanical strength should generally be considered.
According to experience, low-voltage power line usually chooses section according to heating condition because of its large load current, and then checks its voltage loss and mechanical strength; low-voltage lighting line, because of its high requirement for voltage level, can choose section according to the allowable voltage loss condition first, then checks its heating condition and mechanical strength; and high-voltage power line, because of its high requirement for voltage level, can choose section according to the allowable voltage loss condition. First, the section is selected according to the economic current density, then the heating condition and the allowable voltage loss are checked, and the mechanical strength of the high voltage overhead line should also be checked. If the user has no experience, he should consult the relevant professional units or persons.