Leak Testing; Evaporator And Condenser - York R-134a Operation And Maintenance Manual

SECTION 7 - PREVENTIVE MAINTENANCE
We cannot approve use of any general purpose or "EP"
(extended pressure) greases, for the following reasons:
1. They are unlikely to contain all the properties re-
quired for the very demanding application of roll-
ing element bearings at 3600 RPM.
2. None of these have been approved by any major
motor manufacturer or electric motors up to 2000
HP.
3. Additives contained in "EP" greases have been
found to chemically attack the windings in elec-
tric motors.
"EP" greases are intended for very heavy, slow-moving
loads, such as earth-moving equipment. They are not a
proper grease for electric motors.
Unless specifically approved by the motor manufac-
turer, no synthetic greases are to be used. It is not best
practice to mix synthetic greases with mineral oil based
grease, which is the type of grease that is inside the
motor bearings as shipped from the YORK factory.
Mixing different greases is not
recommended.
Operating Temperature
Normal operating temperature for grease lubricated
bearings on YORK chillers is 40°C to 65°C (100°F to
150°F). It is normal to see the temperature elevate im-
mediately after re-lubrication, and then come down as
much as 20°F after a few hours of operation.
• If the temperature exceeds 65°C, at which point a
warning is issued, it is an indication that either the
bearings are in need of lubrication or that some-
thing is wrong, and operation should be checked.
• If temperature reaches 70°C, it generally indicates
some type of problem.
• Bearing RTDs are normally set to shut down the
motors at 90°C (194°F), although once this tem-
perature is reached, the bearings most likely have
already been compromised.
Procedure for WEG Motors
Provided it is not more than six months old (per its
nameplate), a WEG motor should be properly greased
from the factory and ready to operate directly out of its
crate, without the need for additional lubrication.
34
After the number of operational (run) hours listed on
the motor's nameplate (for each bearing), install the
specified quantity of the recommended grease into
each grease (zerk) fitting.
Follow the procedure below:
1. Remove the grease drain plugs from the drive-end
and non-drive-end
2. Wipe off the grease fillings with a clean cloth
3. Run the motor for at least 5 to 10 minutes (if the
motor is not already running)
4. While the motor is still running, add the specified
quantity of grease (listed on the motor's name-
plate) into each grease fitting
5. Run the motor for an additional 5 to 10 minutes
(to allow excess old grease to purge)
6. Replace the grease drain plugs
Continue normal operation until the next lubrication
interval.
If the motor is to be stored for more than
six months, the bearings must be re-
lubricated according to the WEG manual
before operation. In addition, at least one
time per month, the motor's shaft must be
rotated by hand at least five revolutions,
stopping the shaft at a different position
than the previous position. If the motor is
fitted with a shaft locking device, remove
it before rotating the shaft, and re-install
it afterwards.

LEAK TESTING

The unit should be leak tested monthly. Any leaks
found must be repaired immediately.

EVAPORATOR AND CONDENSER

The major portion of maintenance on the condenser
and evaporator will deal with maintaining the water
side of the condenser and evaporator in a clean condi-
tion.
The use of untreated water in cooling towers, closed
water systems, and so on, frequently results in one or
more of the following:
1. Scale Formation.
2. Corrosion or Rusting.
3. Slime and Algae Formation.
FORM 160.76-O1
ISSUE DATE: 05/22/2019
JOHNSON CONTROLS