Freezer Evaporator (Model 690); Freezer Heat Exchanger (Model 690) - Sub-Zero 600 Series Technical & Service Manual

600 Series

Freezer Evaporator (Model 690)

NOTE: When replacing the evaporator, the filter-drier
must also be replaced.
After capturing the refrigerant from the sealed system,
remove the evaporator fan assembly and extract the
two evaporator retaining screws at top front of evapora-
tor bracket. Pull evaporator down and rotate it to the
right to gain access to the rear. Disconnect all electrical
leads at back of evaporator. Then, un-braze or cut the
evaporator inlet and outlet tubing, and pull evaporator
from compartment. (See Figure 7-75)

Freezer Heat Exchanger (Model 690)

One end of heat exchanger is connected to evapo-
rator. Evaporator fins are sharp. One end of heat
exchanger is connected to compressor and filter
drier. Compressor and tubing may be hot.
NOTE: When replacing a heat exchanger, the filter-drier
must also be replaced.
NOTE: It is not necessary to pull the unit from its instal-
lation in order to replace the heat exchanger. The heat
exchanger travels through the compartment ceiling to
the compressor area.
To remove the heat exchanger, the compressor area
and evaporator area will need to be accessed, and the
refrigerant captured from the sealed system. Now,
remove the evaporator fan assembly and extract the
two evaporator retaining screws at top front of evapora-
tor bracket. Pull evaporator down and rotate it to the
right to gain access to the rear. Disconnect all electrical
leads at back of evaporator. Then, un-braze or cut the
evaporator inlet and outlet tubing, and pull evaporator
from compartment. Now, un-braze or cut the suction
line from the compressor, and the capillary tube from
the drier. Clear any permagum from inside and outside
of the heat exchanger hole and pull the heat exchanger
out of the heat exchanger hole. (See Figures 7-71 and
7-75)
NOTE: When replacing the heat exchanger, it is recom-
mended to attach it at the evaporator end first, then
feed the heat exchanger up through the heat exchanger
hole.
(Prior to #1810000)
Defrost
Heater
Defrost
Terminator
Evaporator Outlet
Figure 7-75. Model 690 Freezer Evaporator (Rear View)
7-43
Component Access / Removal
#3756270 - Revision B - January, 2006
Evaporator
Inlet
Heat
Exchanger
Electricals