Bundled Conductors in Tranmission Lines

Bundled Conductors are used in transmission lines where the voltage exceeds 230 kV.  At such high voltages, ordinary conductors will result in excessive corona and noise which may affect communication lines.  The increased corona will result in significant power loss.  Bundle conductors consist of three or four conductors for each phase.  The conductors are separated from each other by means of spacers at regular intervals.  Thus, they do not touch each other. 

Bundled conductors have higher ampacity (current carrying capacity see Article) as compared to ordinary conductors for a given weight.  This is due to the reduced influence of the skin effect (see Article). 

The reactance of bundled conductors is also lesser than single conductors.  However, bundled conductors experience greater wind loading than single conductors.