11-8
CONTROL SYSTEM
SM DUO38I 1-A.2 GB
11.17.5
Heat Sink Over Heating Protection (NA for DCI 25 and 35)
HST
HST Trend
Decreasing
No Change
Increasing
HST > 90
SC
SC
SC
85 < HST
≤
90
D1
D2
D2
82 < HST
≤
85
SR
D1
D2
80 < HST
≤
82
SR
SR
D1
78 < HST
≤
80
Norm
Norm
SR
HST
≤
78
Normal
11.17.6 Outdoor Coil Deicing Protection
11.17.6.1 Deicing Starting 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
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.
