Introduction to the Structure of Fire-Resistant Power Cables

Fire-resistant power cable is usually used for special applications, it is different from common power cables, such as XLPE armored copper cable, aluminum xlpe power cable, and 36kv aluminum XLPE insulation cable.

Since the aluminum conductor is not resistant to high temperatures, the fire-resistant power cable is made of a copper conductor, and the conductor is a round conductor that is tightly twisted.

For small-section fire-resistant power cables, the following solutions are reasonable to meet the fire test requirements.

1 The conductor should be made of a round copper single wire. 

The soft structure beam line is easy to cause damage to the mica tape, so it is not easy to make a fire-resistant power cable conductor.

2 The refractory layer is covered by synthetic mica tape. 

When the mica tape is wrapped, when the design requires the number of layers to be even, 55% of the cover is wrapped.

When it is the base, the vertical package is added with 55% of the cover. 

When wrapping, focus on controlling the mica tape width, wrapping angle, and tension to ensure that the mica tape is over 50%. 

The wrapping equipment should adopt a wrapping machine with good stability and high processing precision. 

The traditional wrapping machine produces small-section fire-resistant power cables, and the quality stability is difficult to guarantee.

3 Insulation using polyethylene and cross-linked polyethylene is better than polyvinyl chloride. 

When extruding insulation, the selection of the inner membrane aperture should be properly enlarged to avoid damage to the insulation. 

The mica should be prevented from entering the water and damp. At the same time, the extrusion thickness should be strictly controlled to ensure the thin insulation effect.