5.2.2 Insulating Barrier
1.Basic Structure And Function of Insulating Barrier
(1)Basic structure
①The insulating separator is generally made of epoxy resin FRP material,as shown in Fig.5-18.
②The insulating separator is mainly composed of impregnated paper,cotton cloth,alkali-free glass-fiber cloth,impregnated phenolic aldehyde,epoxy resin and other materials,and which are impregnated,pressurized,dried,polished and solidified into the hard plate-like insulating material.
(2)Basic function
①The insulating barrier shall have high insulation property,corrosion resistance and high heat resistance,and play the role in temporary insulation and isolation of electrified parts,limiting the motion range of live working personnel and improving the insulation level of adjacent phases.
②In live working,the insulating barrier can also be placed between the moving and static contacts of the pull-apart disconnector,so as to prevent the disconnector from dropping by itself and delivering power by mistake.
③Epoxy resin has good mechanical property and stable withstand voltage,and has the functions of blocking electric arc,voltage and partial current.
Fig.5-18 Sample Drawing of Insulating Barrier
(a)Vertical insulating barrier;(b)Transverse insulating barrier
2.Classification and Technical Specifications of Insulating Barrier
(1)Classification
The insulating barrier is mainly divided into the insulating barrier with handle and the insulating barrier with tether.
(2)Technical specifications
①The appearance and surface of the epoxy resin insulating board shall be smooth and flat,and the whole board shall be used for production,with uniform color.Impurities and other obvious defects are not allowed,while slight bruises are allowed,but the edges shall be cut neatly,and there are no delamination and cracks on the cross section.
②The epoxy resin insulating separator has high temperature resistance of 180～200°C,high mechanical and dielectric properties,good heat resistance and moisture resistance,and good machining property.
③The color of epoxy resin insulating separator is beige,with good oil resistance and corrosion resistance.(https://www.daowen.com)
3.Inspection Contents of Insulating Barrier
In order to ensure the integrity of the electrical and mechanical properties of the insulating barrier,careful inspection shall be carried out before each use.Its appearance and surface shall be flat and smooth,uniform in color,free from impurities and other obvious defects,with neat edges and no delamination or cracks on the cross section;the insulating barrier surface shall be clean and dry;the components of the insulating barrier shall be complete and intact;the insulating barrier shall be operated correctly,and the locking function shall be correct.
4.Usage of Insulating Barrier
(1)It is only for live working of power equipment 10kV or below.The insulating barrier shall be used as shown in Fig.5-19.
Fig.5-19 Use of Insulating Barrier
(2)The insulating barrier does not play the role in main insulation,and shall be used in conjunction with the human body safety protection appliances.
(3)The isolation scope of each insulating barrier shall not exceed the protection of the barrier.
(4)The installation shall be firm and reliable,and it is easy to disassemble it after installation.
5.Precautions for Storage of Insulating Barrier
(1)The insulating barrier cannot be squeezed and shall be placed flat.
(2)It is prohibited to contact the insulating barrier with oil,acid,alkali or other harmful substances,and it shall be kept more than 1m away from the heat source.The storage environment temperature should be 10-21°C.
(3)The damp insulating barrier shall be thoroughly dried,but the drying temperature shall not exceed 65°C.
6.Test Contents of Insulating Barrier
The test contents of the insulating barrier are as follows.
(1)Mechanical test.The mechanical property of the shield cover shall include simulated assembly test and low-temperature impulse resistance test.
(2)Electrical test.Including:power frequency withstand voltage and leakage current test,certification test,etc.
(3)The preventive test of the insulating barrier shall be conducted one by one once every six months.