FORM 160.75-O1 (211)
JOHNSON CONTROLS
36
SECTION 7 - PREVENTIVE MAINTENANCE
Additional information on motor lubrica-
tion and other service issues can be found
in the A-C Motors Instruction Manual.
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 the maintaining the wa-
ter side of the condenser and evaporator in a clean
condition.
The use of untreated water in cooling towers, closed
water systems, etc. frequently results in one or more of
the following:
1. Scale Formation.
2. Corrosion or Rusting.
3. Slime and Algae Formation.
It is therefore to the benefit of the user to provide for
proper water treatment to provide for a longer and
more economical life of the equipment. The following
recommendation should be followed in determining
the condition of the water side of the condenser and
evaporator tubes.
1. The condenser tubes should be cleaned annually
or earlier if conditions warrant. If the temperature
difference between the water off the condenser
and the condenser liquid temperature is more than
4°F (2°C) greater than the difference recorded on
a new unit, it is a good indication that the con-
denser tubes require cleaning. Refer to SECTION
6 - MAINTENANCE of this manual for condenser
tube cleaning instructions.
2. The evaporator tubes under normal circumstances
will not require cleaning. If the temperature dif-
ference between the refrigerant and the chilled
water increases slowly over the operating season,
it is an indication that the evaporator tubes may be
fouling or that there may be a water bypass in the
waterbox requiring gasket replacement or refrig-
erant may have leaked from the chiller.
3. Heat recovery condenser tubes should be evalu-
ated similiar to evaporator tubes when the heating
circuit is a treated, closed loop. Fouling could be
detected as ability to meet heat load requirements
decreases.
OIL RETURN SYSTEM
1. Change the dehydrator in the oil return system
semi-annually or earlier if the oil return system
fails to operate.
2. When the dehydrator is changed, the nozzle of the
eductor should be checked for any foreign par-
ticles that may be obstructing the jet.
ELECTRICAL CONTROLS
1. All electrical controls should be inspected for ob-
vious malfunctions.
2. It is important that the factory settings of controls
(operation and safety) not be changed. If the set-
tings are changed without Johnson Controls ap-
proval, the warranty will be jeopardized.
To Next Page
Loading...
Need help?
General
