58 of 124  Construction of Giresun Wastewater Treatment Plant  Tender Dossier Volume 3 Employer’s Requirements  Section 08: Electrical Works  Technical galleries and technical channels shall be reinforced concrete and shall be designed and constructed in  necessary locations within the plant by the Contractor considering the locations and requirements of the units. Their design shall be approved by the Engineer. Galleries shall be built for units where piping and cabling  systems are intense and intersect each others, and technical channels shall be installed for the remaining units.  Embedded inserts and plates for piping and cable tray supports shall be provided in the technical galleries.  Adequate ventilation shall be ensured and permanent lighting shall be provided through the galleries.  Technical galleries shall be rectangular sectioned underground structure and particularly shall be used for  following functions. Inner net height of galleries shall be taken as 2.10 m and inner width shall be taken as 1.60 m after considering  functions which are mentioned above.  The air of the technical galleries has to be H$_{2}$S and CH$_{4}$ monitored locally and warning system shall be  installed. Operation status of these sensors shall also be monitored and controlled by the SCADA.  Top of the technical channels shall be covered with concrete hinged lid with fully water tight to prevent water  infiltration from surface and underground.  Design of technical gallery and channels shall correspond with project requirements and technical  specifications. A drainage system shall be constructed in galleries and channels even though they are not  present in approved project of technical galleries and channels and water which may leak into galleries and  channels shall be discharged to suitable location. Slope floors of the galleries towards the drainage channel shall  be provided to minimize water on walking surfaces.  Heat isolation will be built accordingly with climate conditions for all pipes and any kind of equipment which  needs heat isolation and passes through technical gallery and technical canal. There will be fire detection,  vavienne LED illumination, CCTV system, gas detection, warning and ventilation.  Cables installed on trays, ladders and trunkings must be so arranged that there are no crossings or interlacing of  cables. The trays, ladders and trunkings must be sized for the cables' bending radius and weight. Cables shall be  secured to the tray and ladder by means of ultra-violet stabilised tie-wraps at the necessary intervals  commensurate with the cable size and weight. All cable tray, ladder and trunkings routes must be complete  before cables are installed.  Cables individually run and direct mounted on walls or ceilings must only be installed after building trades and  painters have finished their work. Cables may only be installed in vertical and horizontal planes and be  aesthetically acceptable taking the most unobtrusive routes possible. Single hole plastic fixing cleats only shall  be used.  All cables terminating at equipment are to employ screwed cable glands only - the use of epoxy putty is  expressly forbidden.  Cable runs shall be continuous throughout. Jointing shall not be carried out in conduits or at pulling points  under any circumstances.  Cables exposed to direct sunlight shall be able to withstand exposure.  8_Vol3_d4 3_Section 8 electrical works_en_GIR rev6.doc  8.16.5 Installation of cables  * Water distribution pipes (including fire water distribution)  * Heating distribution pipes  * Energy distribution cables  * Phone and fire alarm cables  * Chemical dosing pipe systems  * Other pipe systems of process units 