Routine maintenance, Variable frequency drive operation, Motors – Greenheck Centrifugal (CSW, BIDW, AFDW), Industrial (IPA, IPO, IPW) and Filtered Supply (LSF) (463687) User Manual
Page 8: Shaft bearings
8
Centrifugal, Industrial and Filtered Supply
Routine Maintenance
Once the unit has been put into operation, a routine
maintenance schedule should be set up to accomplish
the following:
1. Lubrication of bearings and motor (see below).
2. Variable inlet vanes should be checked for
freedom of operation and wear.
3. Wheel, housing, bolts and set screws on the entire
fan should be checked for tightness.
4. Any dirt accumulation on the wheel or in the
housing should be removed to prevent unbalance
and possible damage.
5. Isolation bases should be checked for freedom
of movement and the bolts for tightness. Springs
should be checked for breaks and fatigue. Rubber
isolators should be checked for deterioration.
6. Inspect fan impeller and housing looking for
fatigue, corrosion, or wear.
When performing any service to the fan, disconnect
the electrical supply and secure fan impeller.
Motors
Motor maintenance is generally limited to cleaning
and lubrication. Cleaning should be limited to exterior
surfaces only. Removing dust and grease build up
on the motor housing assists proper motor cooling.
Never wash-down motor with high pressure spray.
Many fractional motors are permanently lubricated for
life and require no further lubrication. Motors supplied
with grease fittings should be greased in accordance
with the manufacturer’s recommendations.
CAUTION
When operating conditions of the fan are to be
changed (speed, pressure, temperature, etc.),
consult Greenheck to determine if the unit can
operate safely at the new conditions.
Shaft Bearings
The bearings for Greenheck 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. Bearings are the
most critical moving part of the fan, therefore special
care is required when mounting them on the unit and
maintaining them.
Refer to the following chart and the manufacturers
instructions for grease types and intervals for various
operating conditions. Never mix greases made with
different bases. This will cause a breakdown of the
grease and possible failure of the bearing.
Recommended Bearing Lubrication Schedule
Relubrication Schedule in Months*
Fan
RPM
Bearing Bore (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
3
3
⁄
16
-
3
1
⁄
2
3
15
⁄
16
-
4
1
⁄
2
4
15
⁄
16
-
5
1
⁄
2
To 250
12
12
12
12
12
12
10
8
500
12
12
11
10
8
7
5
4
750
12
9
8
7
6
4
3
2
1000
12
7
6
5
4
3
2
1
1250
12
6
5
4
3
2
1
.5
1500
12
5
4
3
2
1
.75
2000
12
3
3
2
1
.5
.25
2500
12
2
2
1
.5
.25
3000
12
2
1
.5
.25
3500
12
1
.5
.25
4000
12
.5
.25
5000
12
.25
Number
of shots**
4
8
8
10
16
25
41
57
* Lubrication interval is based on 12 hour day operation and
maximum 160˚F housing temperature.
For 24 hour per day operation, the interval should be cut
in half.
** Lubricant should be added with the shaft rotating and
until clean grease is seen purging from the bearing.
The lubrication interval may be modified based on the
condition of the purged grease. If bearing is not visible to
observe purged grease, lubricate with number of shots
indicated for bore size.
• For conditions including high temperatures, moisture, dirt
or excessive vibration, consult the factory for a specific
lubrication interval for your application.
• Lubricant should be a high quality lithium complex grease
conforming to NLGI Grade 2. Factory recommends
Mobilux EP-2 or synthetic Mobilith SHC100.
• The use of synthetic lubricants will increase lubrication
intervals by approximately three times.
• Storage periods of three months or longer require monthly
rotation of the shaft and purging grease prior to storage
and start-up.
Variable Frequency Drive Operation
WARNING
For operation with Variable Frequency Drive (VFD),
always check motor amps when adjusting the
operating frequency. Motor may be sized for the
original selected operating speed under 60 Hz.
Bypassing the VFD or increasing the speed from this
original selection, even if less than 60 Hz, may cause
motor overload or failure. Consult factory with fan
serial number before increasing the upper limiting
frequency.
Always check the fan rpm when adjusting the
operating frequency. Do not exceed maximum
class fan rpm of the wheel as stated on the unit
identification nameplate.