Service Manual

SEQUENCE OF OPERATION
PAGE 26
ENGLISH
The suction line temperature sensor provides the tempera-
ture sensed at the incoming suction line pipe.
The compressor discharge sensor provides the temperature
sensed at the discharge pipe of the compressor.
To stop dry mode, press the power button to turn the system
o, or change to another mode.
Defrost Operation
Defrosting Program Entry Conditions
Condition 1: For the rst time to power on the unit , the
compressor should run for 30 min accumulatively and run
continuously for 1 min . When meeting the frosting condition,
the defrosting is allowed.
Condition 2: After the rst defrosting , the compressor with
heating mode should run for 30 min accumulatively and run
continuously for 1 min. and the time interval between de-
frosting cycle is more than 45 min. When meeting the frosting
condition, the defrosting is allowed.
Conditions Used to Determination if Frost has Formed
Under the running state of the compressor , by detecting
defrost sensor Te and outdoor ambient temperature sen-
sor Tao, it can satisfy any of the following conditions for 2
minutes continuously and is considered to meet the frosting
conditions
Condition 1: Let Tes(condensation temperature) =
C×Tao－α, When Tao < 0 32
O
F then C=0.8 , when Tao≥32
O
F
then C=0.6 , α is set to a constant = 5.
Condition 2: Meet condition 1, and ΔT1-T1≥35.6
O
F, T1 is
dened as Δ T1’s minimum value, Δ T1 = T(outdoor ambient
temperature )-T (outdoor coil temperature).
Defrost Actions
• When C×Tao－α≥23
O
F, then Te≤23
O
F and the defrost
cycle is 45min(Benchmark defrost cycle).
• When 14
O
F ≤C×Tao－α<23
O
F , then Te≤Tes and defrost
cycle is 45min(Benchmark defrost cycle).
• When 8.6
O
F < C×Tao－α ≤14
O
F , then Te≤Tes and defrost
cycle is 65min (Def1 =65min-Benchmark defrost cycle ).
• When 5
O
F ≤C×Tao－α ≤ 8.6
O
F, then Te≤Tes and defrost
cycle is 65min (Def1 =65min-Benchmark defrost cycle ).
• When C×Tao－α<5
O
F, then Te≤ 5
O
F and defrost cycle is
75min (Def2 =75min-Benchmark defrost cycle ).
• When defrosting begins, the compressor stops for 1min
rst and outdoor fan runs at a high speed, after 50s, the
4-way o and then after 55s , the outdoor fan stops.
• The compressor start after 1min, the compressor run-
ning for 60s at defrosting frequency 38Hz and then running
for 60s defrosting frequency 58Hz and running for 60s at
defrosting frequency 88Hz , the nal run is 88Hz.
• During the defrosting period, the mechanical and electrical
current of the compressor and the air vent of the com-
pressor are eectively protected.
• After entering defrosting, the minimum running time must
be guaranteed 2 minutes before exiting defrosting.
Defrosting Exit Conditions
When any of the following conditions are met, the defrosting
operation returns to the heating operation
• The temperature of the outdoor coil exceeds 44.6
O
F for 60
seconds continuously
• The temperature of the outdoor coil exceeds 53.6
O
F for 20
seconds continuously
• Continuous 11 minutes for defrosting operation
• During defrosting, valve opening remains unchanged at
200, and the opening of defrosting starting valve is con-
trolled according to starting oil return
Protection Functions
TTC High Temperature Protection
The compressor discharge pipe sensor (exhaust temp)
senses the temperature of the refrigerant exiting the com-
pressor. The sensed temperature received from the sensor
by the control circuitry will cause the compressor frequency
to increase or decrease. (see chart below). If a temperature
of >= 230°F is sensed for 20 seconds, an exhaust overheating
protection error code will be indicated at the outdoor unit.
Abnormal stop
Decreasing the frequency rapidly (1HZ/1second)
TTC (°F)
230
°F
212°F
209°F
199°F
194°F
Decreasing the frequency slowly (1HZ/10 seconds)
The frequency doesn’t change
Increasing the frequency (1HZ/10 seconds)
Increasing the frequency (1HZ/1second)