TM 55-1930-209-14&P-16 Table C-1.  Preventive Maintenance Checks and Services for Ventilation, Heating and Air Conditioning System (Continued) B - Before D - Daily Q - Quarterly D - During W - Weekly S - Semiannually A - After M - Monthly A - Annually PROCEDURES INTERVAL CHECK FOR AND HAVE EQUIPMENT ITEM ITEM TO BE REPAIRED OR ADJUSTED IS NOT READY/ NO. B D A D W M Q S A INSPECTED AS NECESSARY AVAILABLE IF a    Make sure that air ducts are free of Air ducts are obstructions, dents, and other damage damaged or obstructed l l b  Check for rust, corrosion, and worn or chipped paint Remove by wire brushing, chipping, or scraping Immediately paint cleaned area in accordance with TB 43- 0144 Do not paint threads or labels l l c  Check for loose or missing fasteners and securements Tighten or replace as nec- essary 3 Fans and Motors WARNING Always make sure that electrical power is OFF before performing any maintenance on electrical systems.  Redtag appropri- ate switches and circuit breakers with: "WARNING - DO NOT ACTIVATE. REPAIRS BEING MADE." Observe all safety precautions listed at the beginning of this manual. l a Visually inspect fans and motors for dam-   Fans or age motors damaged l b Check fan blades for sufficient cleanli- Fan blades ness and clearance Clean as necessary do not have enough l c Check that electrical connections are clearance tight Tighten or repair as necessary using insulated tools l d Listen for and check any fan or motor which indicates a motor overload condi- ton or unusual vibration which could result in or be caused by bad bearings, broken Impeller blades, or housing shut- down and notify shift leader for repair or replacement l e Visually check deckhouse roof fans for corrosion or damage Repair as neces- sary l f     Check all fans and motors for rust and corrosion Remove with wire brush and paint as necessary in accordance with TB 43-0144 Do not paint threads or labels C-6