Cable insulation damp and aging how to do?

Update:29 Jan 2018
Summary:

Insulation will cause damp cable pressure drop caused b […]

Insulation will cause damp cable pressure drop caused by failure. Cable damp main reasons are:
(1) Water inflow due to improper sealing of the connector box or terminal box structure or poor installation.
(2) poor cable manufacturing, metal jacket with holes or cracks.
(3) metal sheath stabbed or corroded by foreign objects perforation.

Insulation aging deterioration
Insulation aging can cause cable breakdown and failure. The main reasons for cable aging are:
(1) Inside the cable media, the slag or air gap creates dissociation and hydrolysis under the action of an electric field.
(2) The cable overload or poor ventilation of the cable, resulting in local overheating.
(3) Insulation loss of oil-soaked paper insulated cable.
(4) use of power cable time-out.

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