Oil Return System; Electrical Controls - York R-134a Operation And Maintenance Manual

FORM 160.76-O1
ISSUE DATE: 05/22/2019
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 of the condenser and
the condenser liquid temperature is more than 5°-
6°F (3°-4°C) greater than the difference recorded
on a new unit, it is a good indication that the con-
denser tubes require cleaning. See 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 similar 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.
JOHNSON CONTROLS
SECTION 7 - PREVENTIVE MAINTENANCE
7
35