155
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.
Fig. 50 — Motor Plate Adjustment
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 mo-
mentarily 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. 51. 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 necessary, blower sheave can also be moved on the shaft.
Fig. 51 — 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 above.
7. Tighten setscrews.
8. Install belts and tension properly as described in Pulley
Alignment section above.
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. 52 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 if hub has no rubber hubcap.
5. Replace fan guard.
Содержание Weathermaster 48P2030-100
Страница 130: ...130 Fig 19 Typical Power Schematic Sizes 040 075 Shown ...
Страница 131: ...131 Fig 20 Main Base Board Input Output Connections ...
Страница 132: ...132 Fig 21 RXB EXB CEM SCB Input Output Connections ...
Страница 133: ...133 Fig 22 Typical Gas Heat Unit Control Wiring 48P030 100 Units Shown ...
Страница 134: ...134 Fig 23 Typical Electric Heat Wiring 50P030 100 Units Shown ...
Страница 135: ...135 Fig 24 Typical Power Wiring 115 V ...
Страница 136: ...136 Fig 25 Typical Gas Heat Section Size 030 050 Units Shown ...
Страница 138: ...138 Fig 27 Component Arrangement Size 030 035 Units ...
Страница 139: ...139 Fig 28 Component Arrangement Size 040 075 Units ...
Страница 140: ...140 Fig 29 Component Arrangement Size 090 100 Units ...