Greenheck DG / DGX with Direct Spark (470652) - Manual (Page 33)

Direct Spark Ignition Make-Up Air 33
®
Maintenance - Routine
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
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 below.
Check the alignment by using a straight edge across
both sheaves as shown below.
Belt Tension
Belt Span
Deflection =
Belt Span
64
Drive Alignment
IMPORTANT
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 squealing
on start-up, excessive belt flutter, slippage, and
overheated sheaves.
IMPORTANT
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.
IMPORTANT
When replacing V-belts on multiple groove drives,
all belts should be changed to provide uniform drive
loading.
IMPORTANT
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.
IMPORTANT
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.
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 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
Snow Accumulation
Clear snow away from roof mounted units. Keep the
snow clear of the intake and access doors.
Wheels
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.
Bearings
The bearings for our fans 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.