22
McQuay IM 777-2
Service and Maintenance
Service and Maintenance
Periodic Service and Maintenance
1
Check all moving parts for wear every six months.
2
Check bearing collar, sheave, and wheel hub setscrews,
sheave capscrews, and bearing hold-down bolts for
tightness every six months.
3
Annually check and snug all electrical connections. Inspect
for signs of water damage such as corrosion and repair if
necessary. Check ground conductor and connection
integrity. Service if needed.
Ball Bearing Lubrication
1
Motor bearings—All ball bearings are prelubricated and do
not require additional grease at time of installation.
However, periodic cleaning out and renewal of grease is
necessary. Exercise extreme care to prevent foreign matter
from entering the bearing. It also is important to avoid over
greasing. Use a high grade, clean mineral grease with the
following characteristics:
•
Melting point over 302°F (150°C)
•
Free from oil and soap separation under operating and
storage conditions
•
Free of abrasive matter, acid, alkali and moisture
Specific greasing instructions are located on a label
attached to the fan section door.
2
Fan shaft bearings—All ball bearings are prelubricated and
do not require addition of grease at time of installation.
However, periodic renewal of grease is necessary. Bearings
are accessible through access door in fan section. Grease
fittings are located in front of door opening on drive end of
blower section. Apply grease slowly until a very slight
bleeding of grease from the seals is noted. Tie hinged
door(s) open.
Do not over lubricate.
Wipe off any excess
grease to prevent overheating.
The lubrication interval varies with the period of operation
and temperature of the ambient air. Use the guidelines in
the table below.
Note
: Temperature ranges over 225°F are shown for lubricants only. High
temperature applications are not suitable for standard air handler
components.
Fan Drive Adjustments
Upon completion of the air balance, replace the variable
pitched motor sheave with a properly sized, fixed sheave. A
matching fixed sheave provides longer belt and bearing life
and minimizes vibration. Initially, it is best to have a variable
pitched motor sheave for the purpose of air balancing. Once
the balance is achieved, fixed sheaves maintain balancing and
alignment more effectively. Replace the adjustable sheaves
with fixed sheaves.
With the electrical power disconnected, locked and tagged out,
measure the diameter of the V-belt outer surface where it
passes around the sheave (pitch diameter). Calculate fan speed
from the motor nameplate rpm.
Table 12: Lubrication Guidelines
Bearing operating temp range
Temperature
to 130°F
(54°C)
to 150°F
(66°C)
over 150°F
(66°C)
Continuous operation
6 months
4 months
2 months
12-hr. day operation
12 months
12 months
6 months
Table 13: Lubricants Recommended for Fan Shaft Ball
Bearings
Manufacturer
Product name
Temp. range
°F
°C
Texaco Lubricants Company
Premium RB
–30 to 300 –34 to 149
Keystone Ind. Lubricants
81EP-2
0 to 250
–
18 to 121
Mobil Oil Corporation
Mobilith SCH100
–
40 to 350
–
40 to 177
Chevron U.S.A. Inc.
SRI-2
–
20 to 325
–
29 to 163
Exxon Company, U.S.A.
Ronex MP
–
40 to 300
–
40 to 149
Shell Oil Company
Alvania No. 2
–
20 to 240
–
29 to 116
WARNING
Before servicing fans, lock out and tag out all power to the
unit.
Fans or belts can cause severe personal injury or death.
AVERTISSEMENT
Avant de faire le service sur les ventilateurs,couper et
indiquer que le courant est coupé.
Les ventilateurs ou les
courroies peuvent causer des blessures personnelles graves
ou entraîner la mort.
WARNING
Do not open the hinged access door and screw-fastened
access panels while the unit is operating.
Moving parts and
strong suction forces can cause severe personal injury or death.
AVERTISSEMENT
Ne pas ouvrir les portes d’accès à charnières et les
panneaux à vis lorsque l’unité fonctionne.
Les pièces
mobiles et le niveau de succion peuvent causer des blessures
personnelles graves ou même entraîner la mort.
Fan rpm = motor rpm ×
Measured diameter at motor sheave
Measured diameter at fan sheave
