24
General Service
Models 358 & 359
Evaporator Oil
If the unit refrigeration cycle runs longer than
normal, this indicates a possible oil-logged
evaporator coil. An oil-logged evaporator is usually
caused by a bent beater, worn or bent scraper
blades, a faulty expansion valve, or an overcharge
of refrigerant.
To remove oil from an evaporator, follow these
steps:
1.
Remove all mix and product from the freezer
and allow the freezing cylinder to warm slowly
to room temperature.
2.
With the freezing cylinder fully assembled (i.e.,
beater and scraper blades in place), fill the
hopper with hot water and place the machine in
the “AUTO” mode.
Figure 9
The hot water will cause the refrigerant in the
freezing cylinder walls to “boil” rapidly, removing the
oil and returning it to the compressor.
3.
Turn the automatic expansion valve clockwise
to approximately 10 PSI above its original
setting. This will increase the ability of the
refrigerant to flow across the evaporator.
4.
Periodically pull the draw valve and check the
water temperature. When the water becomes
cool, draw the remainder of the cool water from
the machine. This will allow more hot water to
flow into the freezing cylinder.
Figure 10
5.
Repeat the last step three times.
6.
Adjust the automatic expansion valve setting to
its original setting:
R404A = 20 - 22 psi (138 - 152 kPa)
Important: Do Not Leave the Unit Unattended
During This Procedure!
