1. When one or more core conductors of the telemetry cable are discontinuous and grounded through resistance, it is a broken wire and grounding fault.

2、當搖測電纜一芯或幾芯對地絕緣電阻，或芯與芯之間絕緣電阻低于100Ω時，為低電阻接地或短路故障。

2. When the insulation resistance of one or several cores of the cable to the ground is measured by shaking, or the insulation resistance between cores is less than 100 Ω, it is a low resistance grounding or short circuit fault.

3、閃絡性故障多發生于預防性耐壓試驗，發生部位大多在電纜終端和中間接頭。閃絡有時會連續多次發生，每次間隔幾秒至幾分鐘。

3. Flashover faults often occur in preventive voltage withstand tests, mostly at cable terminals and intermediate joints. Flashover sometimes occurs several times in a row, with an interval of a few seconds to a few minutes.

4、當搖測濟南橋架電纜一芯或幾芯對地絕緣電阻，或芯與芯之間絕緣電阻低于正常值很多，但高于100Ω時，為高電阻接地故障。

4. When the insulation resistance of one or several cores of Jinan Bridge cable to the ground is measured by shaking, or the insulation resistance between cores is much lower than the normal value but higher than 100 Ω, it is a high resistance grounding fault.

5、當搖測電纜一芯或幾芯對地絕緣電阻較高或正常，應進行導體連續性試驗，檢查濟南橋架是否有斷線，若有即為斷線故障。

5. When the insulation resistance of one or more cores of the telemetry cable to the ground is high or normal, a conductor continuity test shall be carried out to check whether there is a wire break in Jinan Bridge. If so, it is a wire break fault.

在使用橋架的過程中，還需要注意熱脹冷縮問題，由于環境溫度變化，鋼質電纜橋架會出現熱脹冷縮的現象。室外橋架受溫度影響較大例如環境高溫度為40℃，低溫度為-20℃，則電纜橋架的大收縮量按下式求得：Δt=11.2 ×10-6×60deg(度)×1000mm。

In the process of using the bridge, attention should also be paid to the problem of thermal expansion and cold contraction. Due to the change of ambient temperature, the steel cable bridge will have the phenomenon of thermal expansion and cold contraction. The outdoor cable tray is greatly affected by temperature. For example, if the ambient high temperature is 40 ℃ and the low temperature is - 20 ℃, the large shrinkage of the cable tray is calculated according to the following formula: Δ t=11.2  × 10-6 × 60Deg (degrees) × 1000mm。

由此得出結論：

It is concluded that:

溫差為60℃時 ，Δι =0.672mm/m。

When the temperature difference is 60 ℃, Δι = 0.672mm/m。

溫差為50℃時， Δι =0.560mm/m。

When the temperature difference is 50 ℃, Δι = 0.560mm/m。

溫差為40℃時， Δι =0.448mm/m。

When the temperature difference is 40 ℃, Δι = 0.448mm/m。

工程設計中直線段電纜橋架應考慮伸縮接頭，伸縮接頭的間距建議按以下取定：當溫差為40℃時為50m；當溫差為50℃時為40m。

In the engineering design, expansion joints shall be considered for the cable tray of straight section, and the spacing of expansion joints is recommended to be determined as follows: 50m when the temperature difference is 40 ℃; 40m when the temperature difference is 50 ℃.

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