Table of Contents
Advertisement
SUPPLY FAN AND POWER EXHAUST MOTOR PLATE
Adjust using a 15/16 in. wrench on the adjusting bolts.
1.
Loosen holddown bolts. (See Fig. 51.)
2.
Turn the adjusting bolts to move the motor mounting plate
toward or away from the fan to loosen or tighten the belts.
Make the same number of turns to each bolt.
3.
Re-tighten holddown bolts.
Fig. 51 — Motor Plate Adjustment
BELT INSTALLATION AND TENSIONING
IMPORTANT: When installing or replacing belts, always use a
complete set of new, matched belts to prevent potential vibration
problems. Mixing belts often results in premature breakage of
the new belts.
1.
Turn off unit power.
2.
Adjust motor plate so belts can be installed without
stretching over the grooves of the pulley. Forcing the belts
can result in uneven belt stretching and a mismatched set
of belts.
3.
Before tensioning the belts, equalize belt slack so that it is
on the same side of the belt for all belts. Failure to do so
may result in uneven belt stretching.
4.
Tighten belts using the motor plate adjusting bolts.
5.
Adjust until proper belt tension (1/2 in. [13 mm] deflection
with one finger centered between pulleys) is obtained. Be
sure to adjust both adjusting bolts the same number of turns.
NOTE: Check the tension at least twice during the first day of op-
eration, as there is normally a rapid decrease in tension until the
belts have run in. Check tension periodically thereafter and keep it
at the recommended tension.
With the correct belt tension, belts may slip and squeal momentar-
ily on start-up. This slippage is normal and disappears after wheel
reaches operating speed. Excessive belt tension shortens belt life
and may cause bearing and shaft damage.
PULLEY ALIGNMENT
For proper belt life, the motor and fan pulleys must be properly
aligned. To check, first turn off unit power. Place a straightedge
against the motor and fan pulleys. See Fig. 52. If the pulleys are
properly aligned, the straightedge should be parallel to the belts.
If they are not parallel, check that the motor shaft and fan shaft are
parallel. If they are not, adjust the motor plate adjusting bolts until
they are.
After verifying that the shafts are parallel, loosen the setscrews on
the motor pulley. Move pulley on the shaft until the pulleys are
parallel. To move the sheave on the shaft, loosen the belts. If nec-
essary, blower sheave can also be moved on the shaft.
Fig. 52 — Pulley Alignment
INSTALLING REPLACEMENT MOTOR PULLEY (SUP-
PLY FAN ONLY)
To install a field-supplied replacement pulley:
1.
Turn off unit power.
2.
Loosen belts using motor adjusting bolts until belts can be
removed without stretching them over the grooves of the
pulley.
3.
Remove belts.
4.
Loosen setscrews on motor pulley.
5.
Slide pulley off motor shaft. Make sure setscrews on new
pulley are loose.
6.
Slide new pulley onto fan shaft and align it with the fan
pulley as described in Pulley Alignment section.
7.
Tighten setscrews.
8.
Install belts and tension properly as described in Pulley
Alignment section.
CONDENSER FAN ADJUSTMENT (ALL UNITS EXCEPT
SIZE 035)
1.
Turn off unit power.
2.
Remove fan guard and loosen fan hub setscrew.
3.
See Fig. 53 and adjust fan height using a straight edge laid
across the fan deck.
4.
Tighten setscrew to 12.5 to 13.75 ft-lb and replace rubber
hubcap to prevent hub from rusting to the motor shaft. Fill
hub recess with Permagum
5.
Replace fan guard.
1. Third-party trademarks and logos are property of their respective
owners.
161
1
if hub has no rubber hubcap.
Advertisement
Table of Contents
Troubleshooting
