McQuay Skyline IM 777-1, Installation And Maintenance Manual

20

McQuay IM 777-1

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.

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 

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.