(a) Lighting.

1. (1) Lighting shall be electric, with all interior wiring in conduit and installed in accordance with the National Electric Code, NFPA No. 70. Conduit if exposed shall preferably be located on the ceiling; where it is carried through the wall of the vault the hole shall be made as small as possible and the space around the conduit shall be completely filled with cement grouting. Floors and roofs shall not be pierced for conduit.
2. (2) The wiring shall provide as many fixed lamps as needed for adequate illumination, and may provide a reasonable number of convenience outlets. There shall be no pendant or extension cord within the vault.
3. (3) Wiring shall be so arranged that both wires of the circuit are disconnected when the lights are out. Main switches shall be outside the vault and provided with a pilot light.

(c) Ventilation. Ventilation of the interior should preferably be through door openings. Where it is imperative that a ventilating system be provided, it should be recognized that the presence of this system adds to the possibility of entrance of fire or damaging heat from outside. To minimize this possibility, the system shall be installed in accordance with the Standard for Air Conditioning Systems, NFPA No. 90A, and the following safeguards shall be taken:

1. (1) All air conditioning apparatus, fans, filters, etc., shall be located outside the vault.
2. (2) Each duct shall be provided with an adjustable fire damper equipped with approved automatic means for closing it and shutting down fans in the event of fire outside or inside the vault.
3. (3) Ducts shall be located so as to avoid the possibility of records coming in contact with them.
4. (4) Where a duct is carried through the wall, its installation shall be such that it will not impair the ability of the vault to protect its contents. The floors and roofs of vaults shall not be pierced for ducts.