Model IGX Make-Up Air
36
®
CAUTION
Lock-out the gas and the electrical power to the
unit before performing any maintenance or service
operations to this unit.
V-Belt Drives
(if applicable)
V-belt drives must be
checked on a regular basis
for wear, tension, alignment,
and dirt accumulation.
Check the tension by
measuring the deflection in
the belt as shown.
Check the alignment by using
a straight edge across both sheaves.
Differences in sheave width must be
accounted for.
Premature or frequent belt failures
can be caused by improper belt
tension, or misaligned sheaves.
• Abnormally high belt tension or drive misalignment
will cause excessive bearing loads and may result in
failure of the fan and/or motor bearings.
• Abnormally low belt tension will cause excessive
squealing on start-up, excessive belt flutter, slippage,
and overheated sheaves.
Do not pry belts on or off the sheave. Loosen belt
tension until belts can be removed by simply lifting the
belts off the sheaves.
When replacing V-belts on multiple groove drives,
all belts should be changed to provide uniform drive
loading.
Do not install new belts on worn sheaves. If the sheaves
have grooves worn in them, they must be replaced
before new belts are installed.
Snow Accumulation
Clear snow away from roof mounted units. Keep the
snow clear of the intake and access doors.
Supply Wheels
Supply wheels require little attention when moving
clean air. Occasionally oil and dust may accumulate on
the wheel causing imbalance. When this occurs, the
wheel and housing should be cleaned to assure proper
operation.
Recommended Bearing Lubrication Schedule
(in months*)
Fan
RPM
Bearing Bore Size (inches)
1
⁄
2
- 1
1
1
⁄
8
- 1
1
⁄
2
1
5
⁄
8
- 1
7
⁄
8
1
15
⁄
16
- 2
3
⁄
16
2
7
⁄
16
- 3
250
6
6
6
6
6
500
6
6
6
5
4
750
6
5
4
3
3
1000
5
3
2
1
1
1250
5
3
2
1
1
1500
5
2
1
1
0.5
2000
5
1
1
0.5
0.25
*Suggested initial greasing interval is based on 12 hour per day
operation and 150°F (48.9ºC) maximum housing temperature.
For continuous (24 hour) operation, decrease greasing interval
by 50%
• If extended grease lines are present, relubricate while in
operation, only without endangering personnel.
• For ball bearings (operating) relubricate until clean grease is
seen purging at the seals. Be sure not to unseat the seal by
over lubricating.
• For ball bearings (idle) add 1-2 shots of grease up to 2 inch
bore size, and 4-5 shots above 2 inch bore sizes with a
hand grease gun.
• For roller bearings add 4 shots of grease up to 2 inch bore
size, and 8 shots for 2-5 inch bore size with a hand grease
gun.
• Adjust relubrication frequency based on condition of purged
grease.
• A high quality lithium based grease conforming to NLGI
Grade 2 consistency, such as those listed here:
Mobil 532
Mobilux #2
Texaco Multifak #2
Texaco Premium #2
B Shell Alavania #2
Exxon Unirex #2
Bearings
(if applicable)
Fan bearings are carefully selected to match the
maximum load and operating conditions of the specific
class, arrangement and fan size. The instructions
provided in this manual and those provided by the
bearing manufacturer will minimize any bearing
problems.
Lubricate bearings prior to periods of extended
shutdowns or storage and rotate shaft monthly to aid in
corrosion prevention. If the fan is stored more than three
months, purge the bearings with new grease prior to
start-up.
Maintenance
General
Drive Alignment
Belt Span
Deflection =
Belt Span
64
Belt Tension
