It is a bit that, when rotated, drills a hole larger than its diameter.
It is including Matrix body and Steel body material .
The Bi-Center Bits provide cost-effective hole opening through installed casing or liner sections.
Engineered cutting structure designed .
High performance cutters from Great factory .
Gauge cutters designed Arc PDC cutters ,which is more abrasive then normal hard alloy gage pads .
Longer working life to save your drilling cost .
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Answer: The data line: the requirement is greater than 2.5mm2; when the length exceeds 0.5m, the requirement is greater than 4mm2. YD/T5098-1998.
Power line: when the cross-sectional area of ​​the phase is S≤16mm2, S is used for the ground wire; when the cross-sectional area of ​​the phase wire is 16mm2≤S≤35mm2, the ground wire is 16mm2; when the cross-sectional area of ​​the phase wire is S≥35mm2, the ground wire is required to be S/2; GB 50054 Article 2.2.9.
2. How to select the type of miniature circuit breaker that matches with SPD?
Answer: Asafe switch module is open circuit because of its damage, so you can not install miniature circuit breaker; the first stage module, such as AM1-40, need to use 63A of D-type miniature circuit breaker with breaking current capability of 10KA; The module, such as AM2-20, requires 32A C and D miniature circuit breakers with a breaking current capability of 6.5KA. Due to the difference in the In value of the operating curve, D-type is recommended; the third stage module, such as AM3-10 Requires the use of 16A breakers of C and D type with a breaking current capability of 4.5KA. Due to the difference in the In value of the operating curve, it is recommended to use the D type.
3, can use the fuse? Should pay attention to those problems?
Answer: You can use lightning fuses, but you can't use general fuses; the lightning fuses we use are VSP-100KA, 70KA, 40KA, and 20KA. Lightning protection fuses respond to lightning impulses. Generally, fuses respond to power frequency or DC current. The difference between the use of fuses and the use of miniature circuit breakers is: 1, over-current working curve of the fuse is affected by the ambient temperature, the disconnection of the over-current is not reliable miniature circuit breaker; 2, the fuse in the seat is under 8/ 20μs lightning overvoltage impact, will jump out from the base, so that the SPD can not work properly; 3, the welding of the fuse when the SPD degradation, can not be broken in less than 5s like a miniature circuit breaker, prone to short circuit And fire hazards, does not meet the requirements of GB 50054 and GB 50057 standards.
Three issues of lightning protection
1, SPD ground wire diameter?