Avish said:
Can someone please describe to me the various factors affecting cable
sizing, and the step-by-step procedures how to do it, with examples if
possible. This has to do with one-size up cabling in a textile manufacturing plant, and to analuse what effect this will have on the cost, and also about the payback.
Thanks.
Dear Avish ;
I answered many time about the section of cables calculation and how should be done, noting that the last one was before about one week where the name of Topic is ” Cable Size ” with an example about it.
In all case, the factors that affect the cable's size accordignly to ” IEC… ” are :
– The type of cable :
– Single Core or Multi Cores
– Cu or Alu
– PVC or XLPE
– The number of cables per phase
– The Method of Installation ” Unburied or Buried ” with the relevant ways for each one
– The numer of layers
– The ambient temperature
– The number of cables have been laid together.
– The Harmonics
After doing the necessary calculation and definingthe section of cable according to the above factors, we should take into consideration the following points :
– Calculate the percentage of ” Total Voltage Drop ” from the Source to the Load that should be compliance with the standard percentages, if not, the cable's section should be over sized.
– At the 1sf and the 2nd levels of the networks where the short circuit currents values are important, we should calculate the Thermal Stress to know if that cable can withstand it during the tripping time of the protection device, if not, the cable's section should be over sized.
Regards