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5
REPLACING THE V-BELT
1. Use a belt with same section type or similar size. Do not
substitute a “FHP” or “notched” type V-belt.
2. Loosen (turn counterclockwise) the motor mounting plate
front bolts and rear bolts. See Fig. 4.
3. Loosen (turn counterclockwise) the jack bolt lock nuts.
Loosen (turn counterclockwise) the jack bolts relieving the
belt tension allowing easy removal of the belt by hand.
4. Remove the belt by gently lifting the old belt over one of
the pulleys.
5. Install the new belt by gently sliding the belt over both
pulleys, then tighten (turn clockwise) the jack bolts sliding
the motor plate away from the fan housing until proper
belt tension is achieved.
6. Check the alignment of the pulleys and adjust if necessary.
7. Tighten all bolts attaching the motor to the motor plate.
8. Tighten all jack bolt jam nuts by turning clockwise.
9. Check the tension after a few hours of runtime and re-
adjust as required. See Fig. 5.
ADJUSTABLE-PITCH PULLEY ON MOTOR
The motor pulley is an adjustable-pitch type that allows a ser-
vicer to implement changes in the fan wheel speed to match as-
installed ductwork systems. The pulley consists of a fixed
flange side that faces the motor (secured to the motor shaft)
and a movable flange side that can be rotated around the fixed
flange side that increases or reduces the pitch diameter of this
driver pulley. See Fig. 6.
As the pitch diameter is changed by adjusting the position of
the movable flange, the centerline on this pulley shifts laterally,
along the motor shaft. This creates a requirement for a realign-
ment of the pulleys after any adjustment of the movable flange.
Also reset the belt tension after each realignment. The factory
setting of the adjustable pulley is five turns open from full
closed.
Check the condition of the motor pulley for signs of wear.
Glazing of the belt contact surfaces and erosion on these sur-
faces are signs of improper belt tension and/or belt slippage.
Pulley replacement can be necessary.
CHANGING FAN SPEED:
1. Shut off unit power supply and apply approved lock-out/
tag-out procedures.
2. Loosen belt by loosening the motor adjustment bolts as
described in the Belt Adjustment section above. See
Fig. 4.
3. Loosen movable pulley flange setscrew. See Fig. 6.
4. Screw movable flange toward fixed flange to increase
speed and away from fixed flange to decrease speed.
Increasing fan speed increases load on motor. Do not
exceed maximum fan speed in the product data or motor
amperage as listed on the unit rating plate.
5. Set movable flange at nearest keyway or flat of pulley hub
and tighten setscrew to torque specifications. Torque pul-
ley set screw to 72 ± 5 in.-lb (8.14 ± 0.56 Nm).
ALIGNING THE FAN AND MOTOR PULLEYS:
1. Loosen fan pulley setscrews.
2. Slide fan pulley along fan shaft. Make angular alignment
by loosening motor from mounting. See Fig. 6.
3. Tighten fan pulley setscrews and motor mounting bolts to
torque specifications.
4. Recheck belt tension. See Fig. 5.
Fig. 6 — Supply-Fan Pulley Adjustment
BEARINGS
This fan system uses bearings featuring concentric split lock-
ing collars. The collars are tightened through a cap screw
bridging the split portion of the collar. The cap screw has a
Torx T25 socket head. To tighten the locking collar: Hold the
locking collar tightly against the inner race of the bearing and
torque the cap screw to 65 to 70 in.-lb (7.4-7.9 Nm). See Fig. 7.
Fig. 7 — Tightening Locking Collar
STAGED AIR VOLUME (SAV) CONTROL:
2-SPEED FAN WITH VARIABLE FREQUENCY
DRIVE (VFD)
Staged Air Volume (SAV) Indoor Fan Speed
System
NOTE: The SAV option is not available on units with Humidi-
MiZer
®
adaptive humidification system.
The SAV system utilizes a fan speed control board and Vari-
able Frequency Drive (VFD) to automatically adjust the indoor
fan motor speed in sequence with the unit’s ventilation, cooling
and heating operation. Conforming to ASHRAE 90.1 2010
Standard Section 6.4.3.10.b, during the first stage of cooling
operation the SAV system will adjust the fan motor to provide
two-thirds (
2
/
3
) of the design airflow rate for the unit. When the
CAUTION
EQUIPMENT DAMAGE HAZARD
Failure to follow this CAUTION can result in premature
wear and damage to equipment.
Do not use a screwdriver or a pry bar to place the new V-
belt in the pulley groove. This can cause stress on the V-belt
and the pulley resulting in premature wear on the V-belt
and damage to the pulley.
STRAIGHT EDGE
MUST BE PARALLEL
WITH BELT
SETSCREWS
MOTOR AND
FANSHAFTS
MUST BE
PARALLEL
FIXED FLANGE
MOVABLE
FLANGE
SINGLE - GROOVE
FAN PULLEY
MOTOR PULLEY
T --- 25 TORX SOCKET
HEAD CAP SCREW
LOCKING COLLAR
Summary of Contents for WeatherMaster Puron 48HC D17
Page 18: ...18 COOLING CHARGING CHARTS Fig 22 Cooling Charging Chart 15 Ton ...
Page 19: ...19 Fig 23 Cooling Charging Chart 17 5 Ton ...
Page 20: ...20 Fig 24 Cooling Charging Chart 20 Ton ...
Page 21: ...21 Fig 25 Cooling Charging Chart 25 Ton ...
Page 37: ...37 Fig 48 Unit Control Box IGC Location IGC Board IGC Board Side view Front view ...
Page 40: ...40 Fig 51 Typical IGC Wiring Diagram ...
Page 46: ...46 Fig 57 RTU Open Overlay for Economizer Wiring ...
Page 47: ...47 Fig 58 VFD Overlay for W2770 Controller Wiring ...
Page 84: ...84 Fig B 48HC D17 D28 Control Diagram 208 230 3 60 460 575 3 60 ...
Page 85: ...85 Fig C 48HC D17 D28 Power Diagram 208 230 3 60 ...
Page 86: ...86 Fig D 48HC D17 D28 Power Diagram 460 3 60 ...
Page 87: ...87 Fig E 48HC D17 D28 Power Diagram 575 3 60 ...
Page 88: ...88 Fig F 48HC D17 D28 Control Diagram with Humidi MiZer System ...
Page 89: ...89 Fig G 48HC D17 D28 Power Diagram 208 230 3 60 with Humidi MiZer System ...
Page 90: ...90 Fig H 48HC D17 D28 Power Diagram 460 3 60 with Humidi MiZer System ...
Page 91: ...91 Fig I 48HC D17 D28 Power Diagram 575 3 60 with Humidi MiZer System ...
Page 92: ...92 Fig J PremierLink System Control Wiring Diagram 50HE500891 F ...
Page 93: ...93 Fig K PremierLink System Control Wiring Diagram with Humidi MiZer System ...
Page 94: ...94 Fig L RTU OPEN Wiring Diagram ...
Page 95: ...95 Fig M RTU OPEN Wiring Diagram with Humidi MiZer System ...
Page 97: ......