I'm looking into the specifications of Hitachi hydraulic excavator model EX8000E-6 with electric motor. The spec says the motors are of type HITACHI TFOA-KK and run off AC 6 000 – 6 600 V / 50 Hz, each of the two motors is rated at 124 amperes. In the picture (left bottom corner) there's a cable:
The cable looks as if it was a domestic vacuum cleaner cable – simply laying around.
Crafting such a cable looks like a major challenge – it has to be flexible and have enough insulation to withstand the 6 kilovolts in the wires. All the high voltage cable I've seen so far were designed for being buried underground and so were not really flexible. Even they have untrivial design.
How are such flexible cables for voltages around 6 kilovolts designed that they feature flexibility and capability to insulate the high voltage?
Best Answer
6kV is not actually so big deal.
Every cable production company (at least the bigger one) has such cables in their catalog.
Note, that such cables has multi layered insulation and probably the upper layer is made from abrasion resistant rubber. There are internal layers that provides the actual insulation.
A middle grounded braid layer provides the safety.
Here is an example with data sheets, found by simple search on my local cable distributor's site.