TM 55-1930-209-14&P-19 Table 16-4.  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 INTERVAL ITEM PROCEDURES EQUIPMENT ITEM TO BE CHECK FOR AND HAVE IS NOT READY/ NO. INSPECTED REPAIRED OR ADJUSTED AVAILABLE IF B   D   A   D  W  M   Q   S   A AS NECESSARY • • • b.     Check for rust, corrosion, and worn or chipped paint.  Remove by wire brushing, chipping, or scraping.  Immediately paint cleaned area with zinc chromate paint and finish to match surrounding area in accordance with TB 43-0144.  Do not paint threads or labels. • • 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. • • • a.      Visually inspect fans and motors for dam- Fans or motors age. damaged. • • • b.      Check fan blades for sufficient clearance Fan blades do not and cleanliness. have sufficient clearance. • • • c.   Check that electrical connections are tight.  Tighten or repair as necessary using insulated tools. • d.      Listen for and check any fan or motor which indicates a motor overload condi- tion or unusual vibration which could result in or be caused by loose mount- ings, bad bearings, broken impeller blades, or a broken housing.  Shutdown and notify shift leader for repair or replacement. • e.      Visually check deckhouse roof fans for corrosion or damage.  Repair as neces- sary. 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. 16-11