Cable

[Hanisoal]

I have a question about “NON-BURSTING CURRENT” in: 

“No cable shall carry a current in excess of 70% of its maximum designated non-bursting current”

Is it possible to tell me what “NON-BURSTING CURRENT” is?

[s]

Hi 

 

The electrical current has 2 main effects : thermal effect and electromagnetic effect.

 

The non-bursting current is the maximum current that the cable can carry without causing the bursting of the sheath ( cable isolator) caused by electromagnetic forces,

Commonly those forces are neglected and only the thermal effect of the current is considered,

But for larger currents the electromagnetic forces are considerable and taking them into consideration during the calculation sometimes causes a lower cable's short circuit current rating .

 

Please note that many respected cable manufacturers provide the maximum non-bursting current value.

 

Hope that those info are useful for you,

 

Take care

 

Nael Samman 

[Spir Georges GHALI]

Dear ;

 

Adding to that said by Mr. Samman, be sure that the cables can carry their nominal currents defined by ” IEC 364-5-52 ” but with one condition that the selection of cable's section have been correctly done by taking into consideration :

– All correction factors accordingly to the working & installation conditions.

– The cables can withstand the short circuit currents specially at the 1st  &  2nd levels of electric networks, or when we should use a small section of cables installed to the MDB.

 

Regards.

[Author]

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