money paid on account of the contract. Such preliminary operation or the payment therefor, shall not be construed as an acceptance of any work of this contract. 16-19. TESTS: After the interior-wiring system installa- tion is completed, and at such time as the Engineer may di- rect, the Contractor shall conduct an operating test for &pproval, The equipment shall be demonstrated to operate in accordance with the requirements of this specification. Before any oil-filled transformer is energized an oil-flash test shall be performed. All 15 kv. cable shall be subject- ed to a "high-pot" or kynatron test. The test shall be per- formed in the presence of the Engineer or his authorized representative. The Contractor shall furnish all instruments and personnel required for the tests, and the Government will furnish the necessary electric power. 16-20, LOCATIONS: The locations as indicated on the draw- ings show the arrangements desired for the principal apparatus, fixtures, etc., and shall be followed as closely as possible. Proper judgment must be exercised in carrying on the work to secure the best possible head room and space conditions throughout, to secure a neat arrangement of the electrical systems and to overcome local difficulties and interferences of structural conditions wherever encountere¢é 16-21. GROUNDING: ‘16-22, WIRING: The conduit systems neutral conductor of wiring systems, lead cable sheaths, motor frames, switchgear and all metal enclosed equipment shall be securely grounded in accord with the Code. Branch circuit conductors shall not be smaller than No. 12 A.W.G. except that conductors for sig- nal and pilot control circuits may be No. 14, A.W.G., unles. otherwise specified on the drawings. Conductors shali be continuous from outlet to outlet, and no eplices shall be made except within outlet or junction boxes. Junction boi. may be utilized where required. Soldered joints insulated with tape shall be used unless otherwise approved. Rubber friction tape shall conform to the requirements of Federal Specifications HHt-llle and HH-T-1l0la, respectively. Viny!] plastic tape will be acceptable in lieu of rubber and fric tion tape. a. Conduit System: Conduit systems shall be installed in accordance with the applicable provisions of the National Electrical Code and shall have all of the characteristics specified in the standards of the Rigid Steel Conduit Industry. Rigid steel conduit shall be zinc-coated anc shall conform to the requirements of Federal Specification 16-5