JOHNSON CONTROLS
69
SECTION 5 – MAINTENANCE
FORM 160.81-NOM1
ISSUE DATE: 10/3/2020
5
In any operating system it is most important to pro-
vide a planned maintenance and inspection of its func-
tioning parts to keep it operating at its peak efficiency.
Therefore, the following maintenance should be per-
formed when prescribed.
Compressor
1.
Oil Filter – The oil filter must be changed when
the oil pressure drops 30% or semiannually if not
required earlier.
When the oil filter is changed, it should be in-
spected thoroughly for any metal particles which
would indicate possible bearing wear. If metal
particles are found this should be brought to the
attention of the nearest Johnson Controls Service
Office for their further investigation and recom-
mendations.
2. Oil Changing – The oil in the compressor must be
changed annually, or earlier if it becomes dark or
cloudy.
Pressure Testing
The unit should be pressure tested annually. 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 of the
water 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° greater than the difference recorded on a new
unit, it is a good indication that the condenser
tubes require cleaning. They should be cleaned as
instructed in the
of this manual,
.
2. The evaporator tubes under normal circumstances
will not require cleaning. If, however, the temper-
ature difference 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 water box requiring gasket replacement.
Oil Return System
1. Clean the strainer in the oil return system semian-
nually or earlier if the oil return system fails to
operate.
2. When the strainer is cleaned, 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.
