Carrier 39MN14 Custom Air Handling Unit

Carrier Aero 39MN14 semi-custom indoor central station air handling unit, factory marked AHU-1, serial 2818U36618. The unit is a five-section, draw-through arrangement built on a galvanized frame with double-wall access-door panels: mixing box, flat filter section, chilled water / hot water coil section with plenum, blow-thru supply fan section, and a discharge plenum, as laid out on the unit nameplate (photo 7). The filter section takes pre-filters of (3) 16x20 and (3) 20x20 plus main filters of (3) 16x20 and (3) 20x20. The coil section carries a chilled water coil (28MCV828FAA059BRNA) and a hot water coil (28MHV228HAA059BRNA), both rated 300 PSIG maximum operating pressure at 200 F. The blow-thru supply fan section uses two 5 HP, 1800 RPM motors on 460V/3-phase/60 Hz power, 6.6 FLA / 8.3 MCA / 10 MOCP each, 15.4 maximum continuous amps for the unit; fan 39MBH9FVB28924FCCK, motor 93MS0725BA280X0XSB. Unit size 14 corresponds to a nominal coil face area of about 14 sq ft, roughly 7,000 nominal CFM at 500 FPM face velocity. Controls and components visible in the photos include a factory-mounted ABB ACH550 HVAC variable frequency drive with keypad and a fused disconnect switch, an Eaton 30A/600V heavy duty safety switch fed from panel 3PPH1 (circuits 1, 3, 5), a separate wall-mounted control panel with digital controller, and an Edwards GSA-SD photoelectric duct smoke detector mounted on the unit casing. The unit was photographed in place and in service: the ABB drive display is lit and running in AUTO at 90.0 Hz, 6.6 A, 2666 rpm (photos 3 and 4). It is currently ducted, hard-piped to chilled water and hot water supply/return lines and conduit-wired, so it will need to be disconnected by trades and rigged out. Overall dimensions approximately 216 in long x 72 in wide x 72 in high.