high voltage means the classification of an electric component or circuit, if its working voltage is > 60 V and ≤ 1500 V DC or > 30 V and ≤ 1000 V AC root mean square (rms).
low voltage means the set of nominal voltage levels that are used for the distribution of electricity and whose upper limit is generally accepted to be an a.c. voltage of 1000V ( or a d.c. voltage of 1500 V). [SANS 1019]
Integrated Digital Loop Carrier means a subscriber loop carrier system that is twenty-four (24) local Loop transmission paths combined into a 1.544 Mbps digital signal which integrates within the switch at a DS1 level.
Low terrain means any area other than high terrain.