scope:

This publication presents calculated ampacities for single-conductor solid-dielectric 15 through 35 kV power cables with multiple bonded and grounded shields, copper or aluminum conductors, single or three phase operation, spaced or trefoil configurations, single or double circuits, directly buried or in buried ducts. Ampacities are given for three or four different shield resistances for each conductor size.

The ampacity calculations provided in this guide have been performed with the software program CYMCAP Ver. 5.3 Rev 2 from CYME International. The methodology used in the calculations is based on Neher-McGrath [6] and the international standard IEC 60287 [9]. Recognizing that both this IEC standard and the CYMCAP modeling program will undergo changes over time, the user may not get repeatable results with CYMCAP in the future from those shown in this guide. To minimize these potential differences, the values shown have been rounded to the nearest 5 amps and should not be considered as exact since it is generally accepted that there are many variables that influence the actual ampacity of an installation even beyond those of the calculation method.