Brief Introduction to Cables

Update:20-03-2020
Summary:

1.What are the requirements for the clamp that fixes th […]

1.What are the requirements for the clamp that fixes the AC single-core cable? Why?
A: The clamp must not have conductive objects to form a closed magnetic circuit to prevent electromagnetic interaction around the cable core when the current passes through it. The magnetic field lines are proportional to the current through the core. It can be known by magnetic induction that eddy currents will be generated in the iron parts to cause the cables to heat up and even burn the cables. Therefore, a conductive object cannot be used when it is used as a fixed function.
2.What are the biggest features and advantages of the following accessories for heat shrinkable cable heads?
Answer: The biggest feature of heat shrinkable accessories is to abandon the original stress cone and replace it with a stress tube, which simplifies the construction difficulty, reduces the terminal size of the joint, is easy to install, saves time and labor, has superior performance and saves metal. The heat shrinkable cable accessory is a combination of the characteristics of the pouring type and the dry package type, and enjoys the advantages of both.
3.What inspection work should be performed before the cable laying?
Answer: (1) The tools for installing fixed cables should be prepared.
(2) Check if the cable model, voltage, and specifications are consistent with the requirements.
(3) The cable is well insulated. When there is doubt about the sealing of the oil-paper cable, the moisture judgment should be made; the buried cable and the small bottom cable should pass the DC withstand voltage test, and the oil sample of the oil-filled cable should pass the test.
(4) The oil pressure of oil-filled cables should not be lower than 1.47MPa.

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