Service manual

13-7
CONTROL SYSTEM > GC 18/GC 21
SM HADDCI 1-A.2 GB
13.7.4 Compressor over Current Protection
13.7.5 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
13.7.6 Outdoor Coil Deicing Protection
13.7.6.1 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
 Case 6: OCT < 19 AND TLD > 60 minutes.
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.
Normal
Stop-Rise
HzDown1
HzDown2
Stop-Compresor
CCROC1
CCROC2
CCROC3
CCROC4
CCR
CONTENTS