198
START-UP
Checklist
Remove all construction debris from unit interior. Verify that all
drains are free of debris. Prime all condensate traps.
SINGLE POINT POWER OPTION
1. Follow all LOCKOUT-TAGOUT procedures.
2. Verify incoming power supply meets all electrical require
-
ments as shown on the Single Point Power Label found inside
the Single Point Power enclosure. (See Fig. 174
)
3. Verify incoming power supply enters the enclosure at a desig
-
nated ACCEPTABLE POWER ENTRANCE LOCATION.
(See Fig. 175.)
Fig. 174 —
Connection of Power to Single Point
Power Enclosure
Fig. 175 —
Acceptable Power Entrance Location
4. Verify incoming power supply wiring is correctly connected
per wiring schematic found inside the Single Point Power
enclosure.
FILTERS
Install unit filters in all filter sections.
AIRFOIL AND FORWARD-CURVED FANS
1. Release the holddown that fastens the fan sled to the sec
-
tion base.
2. Check lubrication of fan, motor bearings, and linkages.
Note that bearings are shipped completely full of grease
for corrosion protection and may run warm temporarily
on start-up until excess grease has discharged.
3. Check tightness of bearing setscrews (Fig. 176) or lock
-
ing collars (Fig. 177). Also, check tightness of setscrews
on fan wheels and sheaves.
4. Check tightness of fan-shaft bearing mounting. See
Fig. 177.
5. Recheck sheave alignment and belt tension. (Refer to
6. Hand turn fan to make certain fan wheel does not rub in
housing.
7. Check fan speed with a strobe-type tachometer or use the
following formula:
Obtain motor rpm from the fan motor nameplate and read
sheave pitch diameters marked on fan and motor pulleys, or
approximate the pitch diameters by using the pulley ODs.
Then:
Refer to Table 6 for maximum allowable fan speeds for
fan wheels. Excessive fan speed may result in condensate
carryover from cooling coil or fan motor overload and
wheel failure.
8. Check direction of rotation (see Table 34). Arrow on drive
side of fan housing indicates correct direction of rotation.
9. Check vibration. If excessive vibration occurs, check for
the following:
a. Variable sheave (if air balance of system has been
accomplished; replace sheave with fixed sheave for con
-
tinuous application).
b. Drive misalignment.
c. Mismatched, worn, or loose belts.
d. Wheel or sheaves loose on shaft.
e. Loose bearings.
f. Loose mounting bolts.
g. Motor out of balance.
h. Sheaves eccentric or out of balance.
i. Vibration isolators improperly adjusted.
j. Out-of-balance or corroded wheel (rebalance or replace
if necessary).
k. Accumulation of material on wheel (remove excess
material).
Fan RPM =
Motor Rpm x Motor Sheave
Pitch Diameter (in.)
Fan Sheave Pitch Diameter (in.)
EXAMPLE:
ACTUAL
APPROXIMATE
Nameplate Motor
RPM
=
1760
1760
Motor Sheave Pitch
Diameter
=
8.9
9.0 (OD)
Fan Sheave Pitch
Diameter
=
12.4
12.5 (OD)
Fan RPM
=
=
1760 x 8.9
12.4
1263 RPM
1760 x 9.0
12.5
= 1267 RPM
IMPORTANT: Drive ratios of 1:1 may cause excessive vibra
-
tion. Avoid if possible.
