phase insulation
1.Three phase parallel connection heating cables are suitable forthethermal insulation of pipes with big diameters, pipe lines in nets and tanks.
2.This article introduces the application of phase change materails PCM in textiles with the concept of heat preservation and thermal insulation textiles, the heat preservation mechanism and the method of its producing and function evaluation as well as its application in textiles described.
3.Throngh thc phase-to-phasc impulsing test about 500kV substation buses system,we get the approximate relationship bctwccn livc-linc maintcnancc dischargc voltage and gaps,then get the smallest insulation gaps according to differcnt surge arrcstcrs.
4.After electric heating system is installed,check electrical insulation of all circuits.The insulation resistance between generatrix and shielding layer,core wires of series cable before connection at end not be less than 20 MΩ.And then check if DC resistance of circuit is normal and phase resistance is banlance.
5.In the light of new type tower and corresponding insulation coordination problem of Three-Gorges power transmission project,the live line replacement of middle-phase V-string insulators including the electrical clearance of tower head,combined gap,equal potential approach and operation method of replacement was discussed in detail.
6.The installation method of the Optical Fiber composition Phase Conductor(OPPC) is almost the same as that of OPGW cable,which is in compliance with the standard of IEEE Std 1138-1994 and IEEE Std 524-1992 for electric power enterprises with regard to the safety instruction and operation technique of the aerial wire installation. The connection of OPPC includes fiber splicing and optical-electric separation technique,which calls for strict requirement of the joint and high voltage insulation technique.
