-维护提示-
737NG 驾驶舱
驾驶舱很多红色开关上都有铜保险丝,以防止非故意操作;同时也方便辨别电门、电门保护罩未曾被动用过。紧急情况下,可以用力搬动电门或电门保护罩将其破除。
平时使用保险丝时,主要要注意粗细和材料要求。
驾驶舱的电门保护罩铜保险丝件号统一均为MS20995CY20(直径0.02英寸) 737NG 旅客氧气电门
而另一种件号MS20995CY15(直径0.015英寸)的铜保险,我目前只发现用在主轮舱APU灭火面板上的灭火瓶释放电门上。
APU远程灭火电门
特别注意这两种保险丝件号别用错了,细心的机组会发现粗细不一样的。
关于保险丝的互换性,波音有一个SL “
737-SL-20-057
Some operators have asked Boeing about acceptable usage of various materials of safety wire as it generally applies to the aircraft. Many of the referenced materials have no definitions describing interchangeability of Corrosion Resistant Steel (CRES), MONEL, and INCONEL materials. After the evaluation, see to following specification:
由于很多参考文件中都没有描述CRES,MONEL和INCONEL材料保险丝的互换性(目前AMM20-10-44已经有了),有用户向波音许询问不同材料(CRES, MONEL, INCONEL, Copper)的保险丝之间互换性问题。波音评估后说明如下:
Instruction and Requirement : 使用说明和要求:
The use of Monel, Inconel, and CRES safety wire in all areas, Other than the use of Copper, each of the above materials performs equally and is considered acceptable for use. For locations in maintenance documentation which specifically address the use of one material over the other, Boeing recommends if the particular material is available, to use it. 除了铜制保险丝外,其他材料(CRES不锈钢,MONEL铜镍合金,INCONEL铬镍铁合金)的保险丝性能相同,基本上是均可以互换的。如果在文件中有特别提出优先使用某种材料,在有货的情况下建议优先使用该材料的保险丝。
Copper wire, 0.020-inch diameter, is used when a wire seal is necessary. Wire sealing is a practice for the security of selected switches, levers, switch guards, etc., to deter inadvertent operation, to allow for physical breakout in an emergency, to identify to the Flight Crew and Engineers that, when present and intact, the relevant switches, levers, switch guards, etc., are in their correct configuration positions, to show that no person has used emergency equipment.Additionally, Copper safetywire is Cadmium plated and therefore should not be used in locations which are exposed to environmental effects particularly to runway de-icers. 0.02英寸直径的铜质保险丝仅用于固定电门、电门保护罩、推/拉杆等,以防止非故意操作。此类保险丝用于方便机组和工程师辨别电门、电门保护罩、推/拉杆和应急设备未曾被动用过,当紧急情况下可以用手将其破除。此外铜保险丝有铬基成分,因此不能用于裸露在自然环境中的位置,尤其是会接触到跑道防冰夜。
Clad 5056 Aluminum alloy wire should be used for safety wire which touches magnesium to prevent galvanic corrosion. 5056铝合金保险丝应该用于接触金属镁的位置,以防止电化学腐蚀(常见于液压系统油滤上)。
Boeing evaluated the requirements for safety wire and determined that CRES, MONEL, and INCONEL safety wire, are all acceptable and can be used interchangeably, when the same length and diameter are used. For all areas which exceed 700°F, INCONEL is the only acceptable option. 波音评估保险丝的要求如下:在正常情况下,同样直径和长度的CRES,MONEL和INCONEL保险丝是可以双向互换的。但在所有温度超过700°F(371℃)的区域,仅能使用INCONEL材料保险丝。
关于保险丝的更多知识,可进一步参考AMM TASK 20-10-44-400-801
保险丝的件号
保险丝规范NASM20995()
件号表示如下: MS20995XY
X=保险丝的材料标识符号
Y=以千分之一英寸为单位的保险丝的直径: 比如MS20995CY20,表示直径0.020英寸的铜保险丝
X=保险丝的材料标识符号
CRES(不锈钢)=C
MONEL(铜镍合金)=NC
INCONEL(铬镍铁合金)=N
Copper(铜,黄色)=CY
Carnon steel zinc coated(镀锌碳钢)=F
Aluminum Alloy(铝合金,蓝色)=AB
Y=以千分之一英寸为单位的保险丝的直径:
比如MS20995CY20,表示直径0.020英寸的铜保险丝
你用的保险丝对吗?
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