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4. Defrost
•
Actually a lot of our customers don’t use
defrost. They’ll run the unit for three to six
hours a day, and for the rest of the time it will
remain idle. The temperature in the unit
comes up above freezing and whatever ice is
on the evaporator coils will thaw and drain
from the unit before it gets used again.
•
If the performance of your blast chiller seems
to be diminishing, however, your evaporator
coil could be filling up with ice. Run the unit
through a defrost cycle.
•
To run defrost, after the unit has completed a
cycle, and you have removed the food cart,
push
F2
. You will be prompted to insert the
password, which is:
22
.
•
Push and hold the
F1
button until you see 20,
then push the left hand arrow button once to
reach 22.
•
After 22 is showing on the screen, hit
F2
again.
4.1 Defrost 1
During Defrost 1, heaters in the coils will turn on
and heat the coil. They will stay on even if the
door is opened.
The Defrost cycle ends one of
two ways: either by a 20 minute timer ending, or
by the Defrost Termination Switch (DTS).
4.2 Defrost 2
Once the defrost cycle ends, there is a
three minute time period where the refrigeration
is turned on but the fans are not. This allows any
water that is on the coil fins to freeze prior to the
fans turning on. During this time the countdown
to the end is shown.
Defrost Termination System
The DTS has a common wire that connects to one of
two other wires depending on temperature. Once the
switch senses temperature below 20°, it switches to the
“run” wire. It stays there until it senses temperature
above 60°, and then it switches to the “terminate” wire.
In your blast chiller, this “terminate” signal not only ends
the defrost cycle, but if you try to start the defrost cycle
while it is set to “terminate” (meaning the coil hasn’t
gone below 20° yet), it will prevent the defrost cycle
from starting.
