Cables

Cables

 

The select cable must be specified the following:-

 

1- Operation Voltage

A-   Low voltage cable up to 1 kv

B-   Medium voltage cable from 3 kv to 30 kv

C-    Over head conductor from 66 kv to 500 kv

D-   Control Cables

2- Operation frequency

E-    50 Hz        

F-     60 Hz

3- Insulation level

A-      PVC

·       Standard normal temperature about 70° C

·       Withstand max temperature at short circuit about 160° C If C.S.A < 300 m² , and 140° C If C.S.A > 300 m²

 

B-       XLPE

·       Standard normal temperature about 90° C

·       Withstand max temperature at short circuit about 250° c

 

Note

·       XLPE withstand short circuit current higher than PVC at the same duration and same C.S.A

·       PVC used as sheath and withstand temp about 200° C

C-          S.T.A  (Steel Tap Armored)

·       Not Flexible

·       Used in Cable if cable put underground to Withstand stress.

 

D-         S.W.A   (Steel Wire Armored)

·       Used in Cable if cable put underground to Withstand stress.

 

4- Type of conductor

 

A-              Copper

The same C.S.A  Copper can carry high current than aluminum

B-     Aluminum

aluminum is approximately 70 percent lighter in weight than copper