Carrier 50HCQA07 Installation Instructions Manual

Also see for 50HCQD07: Installation instructions

47Step 14 — Check Belt TensionMeasure the belt span length as shown in Fig. 54. Calculate therequired deflection by multiplying the belt span length by 1 /64.For example, if the belt span length is 32 inches: 32 x 1/64 =1/2 inch deflection.BELT FORCE — DEFLECTION METHODCheck the belt tension with a spring-force belt force deflectiongauge (available from drive belt manufacturer).1. Place a straightedge along the belt between the two pul-leys. Measure the distance between the motor shaft andthe blower shaft.2. Set the tension gauge to the desired tension (see Table 1 inFig. 54). Place the large O-ring at that point.3. Press the tension checker downward on the belt until thelarge O-ring is at the bottom of the straightedge.4. Adjust the belt tension as needed.Adjust belt tension by loosing the motor mounting plate frontbolts and rear bolt (see Fig. 55) and slide the plate towards thefan (to reduce tension) or away from the fan (to increase ten-sion). Ensure the blower shaft and motor shaft are parallel toeach other (pulleys aligned). Tighten all bolts securely whenfinished.BELT TENSION METHODRequires belt tension gauge that measures tension in belt inunits of lbs force.Fig. 54 — V-Belt Force LabelFig. 55 — Belt Drive Motor MountingPre-Start and Start-UpThis completes the mechanical installation of the unit. Refer tothe unit’s Service Manual for detailed Pre-Start and Start-Upinstructions. Download the latest versions from HVAC Part-ners (www.hvacpartners.com).Typical Unit PipingEach heat pump refrigeration system includes a compressor, ac-cumulator, reversing valve, dual-function outdoor coil with va-por header check valve, cooling liquid line with a filter drier anda check valve, dual-function indoor coil with a vapor headercheck valve, and heating liquid line with a check valve and astrainer. See Fig. 56 and Tables 21-23 for typical unit pipingschematic. Dual-function outdoor and indoor coils are designedto provide parallel coil circuits during evaporator-function oper-ation and converging coil circuits during the condenser-functionoperation.Table 1Table 2BELTCROSSSECTIONSMALLESTSHEAVEDIAMETERBELT DEFLECTION FORCE (LBS)UNNOTCHEDBELTS NOTCHED BELTSUSED NEW USED NEWA, AX3.0-3.6 3.7 5.5 4.1 6.13.8-4.8 4.5 6.8 5.0 7.45.0-7.0 5.4 8.0 5.7 8.4B, BX3.4-4.2 — — 4.9 7.24.4-5.6 5.3 7.9 7.1 10.55.8-8.6 6.3 9.4 8.5 12.6BELT CONDITION TENSION FORCE IN BELT (LBS)New 100Used 80BLOWER PULLEYV-BELTMOTORPULLEYMOTORMOTOR MOUNTINGPLATEMOUNTINGBOLTS (4)