II) PLS CAD Method: Following values shall be considered for the purpose of sag- tension calculation:-
i) Final values of modulus of elasticity of Aluminium Alloy/ Core strands, Coefficient of Linear Expansion of Aluminium Alloy/ Core strands, Stress-Strain coefficients & Creep coefficients of Aluminium alloy / core strands in the cable data (.wir file) used for calculation of sag in PLSCAD shall be based on either of the following :-
Existing standard files on PLS website
A file derived from existing standard file on PLS website for conductor of equivalent/near equivalent stranding and size.
However, value of Final values of modulus of elasticity of Aluminium Alloy/ Core strands, Coefficient of Linear Expansion of Aluminium Alloy/ Core strands shall be within the limits defined under I) above
In each of the above cases, proper justification in the form of test reports/ calculations/ print out of ‘.wir’ file as available on PLS website, etc. shall be required to be submitted by the bidder along with the bid.
ii) PLSCAD Sagging criteria/conditions shall be based on the sag tension limits specified above at Clause 1.4.1 and shall be carried out in a manner that the above mentioned sag- tension limits are met in “After Creep” as well as in “After Load” condition.
The newly designed conductor without standard published .wir file will not be accepted.
b) In case of composite core conductor: Sag-Tension calculations for composite core conductor can be carried by using PLSCAD. Following values shall be considered for the purpose of sag-tension calculation: -
i) Final values of modulus of elasticity of Aluminium/ composite core, Coefficient of Linear Expansion of Aluminium/ composite core, Stress-Strain coefficients & Creep coefficients of Aluminium/ composite core in the cable data (.wir file) used for calculation of sag in PLSCAD shall be based on either of the following
Existing standard files on PLS website
A file derived from existing standard file on PLS website for conductor of equivalent/ near equivalent stranding and size.
In each of the above cases, proper justification in the form of test reports/ calculations/ print out of ‘.wir’ file as available on PLS website, etc. shall be required to be submitted by the bidder along with the bid.
ii) PLSCAD Sagging criteria/conditions shall be based on the sag tension limits specified above at Clause 1.4.1and shall be carried out in a manner that the above mentioned sag- tension limits are met in “After Creep” as well as in “After Load” condition.
The newly designed conductor without standard published .wir file will not be accepted.
1.4.2 Various conductor parameters (viz. modulus of elasticity, coefficient of linear expansion, stress- engineering based on type tests conducted.