underground cable impedance data

[SphincterBoy]

Does anyone know of a source of positive and zero sequence impedance data for various sizes of high voltage underground cables? Ex: 4/o aluminum, 15kV, concentric neutral, 220-mil
EPR insulation

The websites for Okonite, Kerite, etc. have very minimal data for this, and do not list any of the impedance data.

 

[jghrist]

http://www.kerite.com/catalog/catalogfiles/impedance_data_power.htm

has tape shielded cable. The Cooper Power Distribution System Protection Manual has sequence impedances for concentric neutral cable and formulas for calculating zero-sequence impedance of concentric neutral cable not in the tables.

 

[SphincterBoy]

Thanks for the info!

 

[shaik1982]

can any body tell how to calculate voltage drop if there are more than one condutors per phase. if the connection is in between a transformer and low voltage switchgear. what are the considerations?

 

[fredpar]

You have to calculated this way 1/Rt=1/R1+1/R2, and same deal for the inductance.