Lightning protection bushing (10~35kV/250~315A)
The transformer sleeve is the main insulating device outside the transformer box. The lead wire of the transformer winding must pass through the insulating sleeve to insulate the lead wire between the lead wire and the lead wire between the transformer shell, and to fix the lead wire at the same time.Due to different voltage levels, the insulation sleeve has pure porcelain sleeves, oil-filled sleeves and capacitive sleeves.Pure porcelain bushing is mostly used for transformers of 10kV and below. It is to wear a conductive copper rod in the porcelain bushing, and the inside of the porcelain bushing is air insulated.The oil-filled bushing is mainly used in the 35kV class transformer. It is oil-filled in the porcelain bushing. A conductive copper pole is worn in the porcelain bushing.Capacitive bushing is composed of main insulating capacitor core, outer insulating upper and lower porcelain parts, connecting sleeve, oil pillow, spring assembly, base, equalizing ball, measuring terminal, wiring terminal, rubber washer, insulating oil, etc.It is used in high voltage transformers above 100kV.
The lightning protection distance can be calculated as follow:
1. Standard lightning protection distance can be calculated by the lightning impulse withstand voltage as follow.
V一lightning impulse withstand voltage,unit kV.
C一Standard lightning protection distance,unit mm.
2. Modified lightning protection distance can be calculated by the altitude of the product installed as follow.
H一the altitude of the product installed, unit m.
CH一lightning protection distance at altiude, unit mm.
This method is only used as a preliminary calculation of lightning protection distance, if any standard can be found, please refer to the standard calculation.
Lightning protection bushing outline dimensions (10~35kV/250~315A)
|Sequence Number||Code||Model||Dimensions||Opening||Arcing distance||Creep distance||Shield|
|Page number||Serial number||H||d1||d4||E||C||d0||h1|
|1||AM.EDA.004||BJLB-10/315||49||4||305||115||48||115||50～70||65||122||320||3 single umbrella|
|2||AM.EFA.004||BJLB-20/315||51||4||365||115||48||115||50～120||65||182||380||3 single umbrella|
|3||AM.EFA.008||BJLB-20/315||51||8||375||115||48||115||50～120||65||192||430||4 single umbrella|
|4||AM.EFA.016||BJLBW-20/315||51||16||375||115||48||115||50～120||65||192||450||3 big 2 small|
|5||AM.EFA.020||BJLBW-20/315||53||12||375||135||48||115||50～120||65||192||510||3 big 2 small|
|6||AM.EFA.024||BJLB-20/315||53||4||505||115||48||115||120～210||70||322||530||4 single umbrella|
|7||AM.EFA.028||BJLB-20/315||53||18||505||135||48||115||120～210||70||322||810||7 single umbrella|
|8||AM.EHA.004||BJLB-35/315||55||4||550||175||48||200||170～220||105||328||930||7 single umbrella|
|9||AM.EHA.006||BJLB-35/250||55||8||756||175||71||200||170～300||105||447||1160||9 single umbrella|
Note: Other specifications can be customized according to customer needs.