JOHNSON CONTROLS
95
SECTION 4 – MAINTENANCE
FORM 145.05-NOM7
ISSUE DATE: 10/31/2019
4
4. Fasten the bearing housing to the unit mounting
support with hex head cap screws, washers, new
lock washers and hex nuts before securing the
bearing to the shaft. This permits the bearing to
align itself in position along the shaft and elimi-
nates any possibility of cramping loads.
5. Rotate the shaft to make certain it turns freely.
6. Bearings may employ one of several different
methods to lock the bearing to the shaft.
There are various degrees of self-alignment in bear-
ings of the same manufacturer. The force required for
the self-alignment of the bearings used in Johnson
Controls manufactured units has been specified and is
closely monitored at the factory. If it is necessary to
purchase a bearing locally, be sure it can be worked
around in the housing with a short shaft made of wood
or other soft material placed in the bearing.
Prior to installing the bearing on the shaft, it should be
worked around in the housing to make sure that self-
alignment is obtained where the bearing is installed.
After the shaft journal has been inspected for clean-
liness, metal chips or burrs, the bearing is slipped,
not forced, onto the shaft. Forcing the bearing onto
the shaft by the use of flange, pillow block, or outer
ring damages the bearing internally. Force applied in
this way transmits the load to the inner race through
the balls in the bearing. Since the bearings are not de-
signed for axial loading, the sides of the races in which
the balls turn can be damaged.
If the bearing cannot be made to slip onto the shaft
by pressing on the inner ring of the bearing, check the
shaft for burrs. Install the bearing so the part of the in-
ner race, which receives the locking collar or contains
setscrews, is toward the outside of the unit.
If the grease fitting must be changed on bearings that
utilize a locking pin under the fitting, it is important
to properly replace it. If an adapter or grease fitting of
improper size and length is used, the locking pin may
be either too tight or loose and can affect the alignment
and re-lubrication of the bearing.
Shaft should be free from burrs. If old
shaft is used, be sure a ball bearing is
not seated on worn section and shaft is
not bent.
Bearing Locking Devices
Various types of locking devices are used to secure
bearing(s) to the fan shaft.
Refer to the instructions
packed with bearings for special information.
The
various locking devices can be classified under basic
types:
• Setscrew-type locking type
• Eccentric locking type
• Concentric locking type
• Skwezloc type.
Condenser Coil Cleaning
The condenser water pressure drop tables can be used
to determine proper water flow during unit start up. In
addition, they can be used as one of several factors, re-
frigerant pressures, compressor amps, etc in determin-
ing if the unit has a buildup of scale and sludge in the
condenser. The following procedure should be used to
clean the waterside of the condenser section if required.
1. Shut down the unit.
2. Utilize the appropriate lock out tag out procedure.
3. Open the low point external drain to remove water
from the condenser.
4. Remove the condenser access panel from the con-
trol compartment side of the unit.
5. Remove the lower drain plug from the cover of
the condenser to drain any remaining water from
the condenser.
6. Remove the bolts from the condenser shell cover
and remove the cover.
7. Clean the condenser tubes with a cable type tube
cleaner. The tubes are 5/8" OD.
Refer to the Renewal Parts Manual (
Form 145.05-
RP2, -RP3 or -RP4
) for the correct part number
for the gasket.
8. Replace the cover and use a crossing pattern in
replacing the bolts. The bolts should be torqued
to 60 FT/LBS.
9.
Refill the waterside of the condenser and purge
the air.
10. Open the shut off isolation valves.
11. Inspect the condenser cover and gasket for leaks.