Carrier AQUAZONE 50HQP072-120 Installation And Service Instructions Manual

Contents

29NOTE: There should be a 3 to 6 mm gap between themating part hub and the bushing flange. If the gap isclosed, the bushing is probably the wrong size.3. With taper-lock bushed hubs, be sure the bushing boltsare tightened evenly to prevent side-to-side pulley wob-ble. Check by rotating sheaves and rechecking sheavealignment. When substituting field-supplied sheaves forfactory-supplied sheaves, only the motor sheave shouldbe changed.Blower Fan Performance Adjustment — Theunit is supplied with variable sheave drive on the fan motor toadjust for differing airflows at various ESP conditions. Selectan airflow requirement on the left side of the table, then movehorizontally to right under the required ESP for the sheaveturns open, rpm and horsepower for that condition. Fullyclosed, the sheave will produce the highest static capability(higher rpm).To change fan speeds from factory settings:1. Shut off unit power supply.2. Remove belt from motor sheave.3. Lift motor assembly.4. Loosen the 5/16-in. hex nuts on the grommet motor adjust-ment bolts (2 per bolt). To increase the belt tension loosenthe top hex nut. To decrease the belt tension loosen thebottom hex nut.5. Turn the bolts by hand to the desired position then tightenthe 5/16-in. hex nuts ( 2 per bolt).6. Lower the motor assembly.7. Install the belt.8. Tension the belt per section below.9. Restore power to the unit.BELT TENSION ADJUSTMENT — Using a gage, apply4 lb of force to the center of the belt and adjust the tension untila deflection of 1/64-in. is achieved for every inch of shaft centerdistance. See Fig. 25.Ideal belt tension is the lowest value under which belt slipwill not occur at peak load conditions.Table 17 — Blower Sheave and Belt Specifications*Airflow configurations J, K, N, and P.†Airflow configurations Q, T, U, and V.**Airflow configurations W, X, Z, and 1.Fig. 24 — Sheave Alignmenta50-7135tfBELT SPANLB FORCEDEFLECTIONFig. 25 — Fan Belt Tensiona50-7136efUNIT SIZE50HQP COMPONENT DRIVE PACKAGEA* B† C**072BLOWER SHEAVE BK67 X 1 BK85 X 1 BK67 X 1MOTOR SHEAVE 1VP34 X 7/8 1VP34 X 7/8 1VP44 X 7/8MOTOR HP 1 1 1BELT B X 46 B X 50 B X 48096BLOWER SHEAVE BK67 X 1 BK77 X 1 BK62 X 1MOTOR SHEAVE 1VP40 X 7/8 1VP34 X 7/8 1VP44 X 7/8MOTOR HP 2 2 2BELT B X 46 B X 48 B X 46120BLOWER SHEAVE BK67 X 1 BK67 X 1 BK67 X 1MOTOR SHEAVE 1VP44 X 7/8 1VP34 X 7/8 1VP50 X 7/8MOTOR HP 3 3 3BELT B X 48 B X 46 B X 48