Figure 6-43.An ice cube machine refrigeration cycle during the freezing process.
the system to form corrosion products. A strong acid
combined with high discharge and compressor
temperature can cause decomposition of lubricating
oil and produce a sludge of breakdown products.
Either the corrosion or the oil breakdown products can
plug valves, strainers, and dryers and cause a serious
NOTE: The formation of ice from a minute
quantity of moisture in expansion valves and capillary
tubes can occur when operating below 32°F.
LOCATION OF EQUIPMENT
Adequate space should always be left around
major portions of equipment for servicing purposes;
otherwise, the equipment must be moved after
installation so serviceable parts are accessible (figs.
6-45 and 6-46). Compressors require overhead
clearance for removal of the head, discharge valve
plate, and pistons with side clearance to permit
removal of the flywheel and crankshaft where
Water-cooled condensers require a free
area equal to the length of the condenser at one end to
provide room for cleaning tubes, installing new tubes,
or removal of the condenser tube assembly.
needed for servicing valves and accessory equipment.
Service openings and inspection panels on unitary
equipment require generally at least 18 inches of
clearance for removal of the panel.
condensing units should be placed in a location that
permits unrestricted flow of air for condensing,
whether the condenser is in a unitary piece of
equipment or separate. Inadequate ventilation around
air-cooled condensers can cause overloading of the
motor and loss of capacity.
Certain general precautions for the installation of
refrigerant lines should be followed.
receiver is above the cooling coil, the liquid line should
be turned up before going down to the evaporator.
This inverted loop prevents siphoning of the liquid
from the receiver over into the cooling coil through an
open or leaking expansion valve during compressor