Explain the following terms as applied to industrial installation. (i) Duct. (ii) Trunking. – NABTEB QUESTION

(i) Duct:

A closed passage – way formed underground or in a structure and intended to receive one or more cables which may be drawn in space factor is 35%.

(ii) Trunking:

A fabricated casing for cables normally of rectangular cross section of which one side is removable or hinged to allow cables to be laid there in. Spare factor is 4.5%.