Carrier 42HVM109303 Service Manual page 38

The units run with T3＜3
minutes.
℃
----T4＜0 ,
st
If the 1 condition and 2
℃
more than 5 .When T2 has decreased more than 5 , enter the defrosting mode.
----No matter what value of the T4 is and whether the T2 drops more than 5
℃
runs with T3＜3 for more than 120 minutes and T3 keeps lower than
minutes, the machine will enter defrosting mode.
Condition of ending defrosting:
If any one of the following items is satisfied, the defrosting will finish and the machine will turn to
normal heating mode.
----T3 rises to be higher than TCDE1 .
----T3 keeps to be higher than TCDE2 ℃ for 80 seconds.
----The machine has run for 10 minutes in defrosting mode.
Defrosting action：
For 9k,12k models:
Compressor
4-way valve
Outdoor fan
Indoor fan
Indoor fan breeze(10s)
XX=60.
℃
for 80 minutes and T3 keeps
nd
condition items are satisfied, then the program judges if T2 has decreased
℃
Frequency F2
on
off
on
off
on
off
on
off
lower than TCDI+2
℃
FrequencyF8
10s
xx
10s
no longer than 10m
38
℃ or more than 3
f
℃
or not , if the machine
℃
TCDI+4 for more than 3
30s