Service manual

12-11
CONTROL SYSTEM
SM SX DCI 1-A.3 GB
► Deicing Operation Procedure
COMP
RV
OFAN
EEV
ON
HEAT
COOL
ON
OFF
EEVDeicerOpen
Any
T1 T2
T3 T3
T1
12
0
Threshold
DT
max. 12 minutes
OCT
DeiceFreqChRV
T1=60 secondes;T2=36 secondes;T3=6 secondes
12.7.7.2 Outdoor coil Deicing Protection For DCI72/80
► Entering Deicing Conditions
Deicing operation will start when either one of the following conditions exist:
Case 1: OCT < OAT – 8 AND TLD > DI
Case 2: OCT < OAT – 12 AND TLD > 30 minutes.
Case 3: OCT is Invalid AND TLD > DI
Case 4: Unit is just switched to STBY AND OCT < OAT – 8
Case 5: NLOAD = 0 AND OCT < OAT - 8
Case 6: OAT is invalid AND OCT< 8 AND TLD > DI AND Compressor ON Time > 15 minutes
All this condition will exist during 400 seconds
OCT – Outdoor Coil Temperature
OAT – Outdoor Air Temperature
TLD – Time from Last Deicing
DI – Deicing Interval (Time Interval between Two Deicing)
Deicing interval time when compressor is first started in heat mode, is 10 minutes if OCT < -2, and
is 40 minutes in other cases.
Deicing interval time is changed (increased/ decreased in 10 minutes steps) as a function of deicing
time. If deicing time is shorter then former deicing time, the deicing interval time will be increased. If
deicing time is longer then former deicing time, the deicing interval time will be decreased.
CONTENT