COOK HMD EN - Manual (Page 7)

7
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.
Motors are provided with a polyurea mineral oil NGLI #2
grease. All additions to the motor bearings are to be with
a compatible grease such as Exxon Mobil Polyrex EM and
Chevron SRI.
The above intervals should be reduced to half for vertical
shaft installations.
Relubrication Intervals
RPM Temp °F Greasing Interval
Up to 1000
-30 to 120 6 months
120 to 200 2 months
1000 to 3000
-30 to 120 3 months
120 to 200 1 month
Over 3000
-30 to 120 1 month
120 to 200 2 weeks
Any Speed < -30 Consult Factory
Any Speed > 200 1 week
Filter
Filter maintenance is generally limited to cleaning and
replacement.
If aluminum mesh filters are installed, they can be
washed in warm soapy water.
An adhesive spray can be added to aluminum mesh
filters to increase their efficiency.
If disposable filters are installed, they can be checked
by holding up to a light source. If light cannot pass through
the filter, it should be replaced.
When reinstalling filters, be sure to install them with the
airflow in the correct direction. An airflow direction arrow is
located on the side of the filters.
Replacement filters should be from the same
manufacturer and the same size as the original filters
provided with the unit.
Maintenance - Beginning of season
Start-Up
Repeat the Blower Start-Up Step #5 and Direct Gas
Start-Up Steps #1, #2 and #3. This will ensure that the gas
and air are set properly before the heating season begins
and should lead to trouble free operation all winter.
High Limit
The high limit switch may have tripped over the summer;
it should be checked and reset if necessary.
Burner
Inspect the burner for accumulation of scales on both the
upstream and downstream sides of the mixing plates. Any
scaling or foreign material should be removed with a wire
brush.
Visually check that all holes in the mixing plates are
clear. If any burner ports are plugged (even partially), clear
them with a piece of wire or another appropriate tool.
NOTICE! 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.
1. V-belt drives must be checked on a regular basis for
wear, tension, alignment, and dirt accumulation.
2. Check the tension by measuring the deflection in the
belt as shown here.
3. Check the alignment by using a straight edge across
both sheaves. The drawings below show where to
measure the allowable gap for the drive alignment
tolerance. All contact points (indicated by WXYZ)
are to have a gap less than the tolerance shown in
the table. When the pulleys are not the same width,
the allowable gap must be adjusted by half of the
difference in width.
Snow Accumulation
Clear snow away from roof mounted units. Keep the
snow clear of the intake and access doors.
Motors
Motor maintenance is generally limited to cleaning and
lubrication (where applicable). Cleaning should be limited
to exterior surfaces only. Removing dust and grease build-
up on the motor assures proper motor cooling.
Motors supplied with grease fittings should be greased
in accordance with the manufacturer’s recommendations.
Greasing motors is only intended when fittings are
provided. Many motors are permanently lubricated,
requiring no additional lubrication.
NOTICE! Do not allow water or solvents to enter
the motor or bearings. Motors and bearings should
never be sprayed with steam, water or solvents.
Relubrication Intervals
Service
Conditions
NEMA Frame Size
Up to and
including 184T
213T-365T 404T and larger
1800
RPM
and
less
Over
1800
RPM
1800
RPM
and
less
Over
1800
RPM
1800
RPM
and
less
Over
1800
RPM
Standard
3 yrs.
6
months
2 yrs.
6
months
1 yr.
3
months
Severe
1 yr.
3
months
1 yr.
3
months
6
months
1
months
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 are carefully selected to match the
maximum load and operating conditions of the specific fan