Service manual

12-21
CONTROL SYSTEM
SM CINCO 1-A.1 GB
12.6.2 IDU Protections
ICT Value ICT Trend
Indoor Coil
Defrost
Protection
Indoor Coil
Over Heating
Protection
Fast
Increasing
Increasing No change Decreasing
Fast
Decreasing
ICT < -2 ICT > 62 SC SC SC SC SC
-2  ICT < 0 60 < ICT  62 D1 D1 D2 D2 D2
0  ICT < 2 55 < ICT  60 SR SR D1 D2 D2
2  ICT < 4 53 < ICT  55 SR SR SR D1 D2
4  ICT < 6 51 < ICT  53 Normal Normal SR SR D1
6  ICT < 8 49 < ICT  51 Normal Normal Normal SR SR
8  ICT ICT  49 Normal
12.6.3 ODU Protections
There are 5 ODU protections:
● Compressor overheating
● Heat sink overheating
● AC overcurrent
● DC Overcurrent
● Outdoor Coil Overheating
Operation logic of all protections is the same. The controlled input (CTT, HST, ACC, DCC,OMT) is controlled by
changing the protection level using the fuzzy logic algorithm according the input level and the change rate.
The following table summarizes the basic levels of each protection:
Protection
level
Compressor
Overheat
(CTTOH1-4)
Heat Sink
Overheat
(HSTOH1-5)
Compressor
AC
Overcurrent
(CCROC1-4)
Compressor
DC
Overcurrent
(DCCOC1-4)
Outdoor Coil
Overheating
(OMTOH1-5)
SC 95 80 19.0 12.6 66
D2 92 78 18.2 12.2 64
D1 90 75 17.6 12.8 62
SR 87 73 17.0 12.4 60
Normal 70 58
There are two sets of ACC values, the selection of the values are set according to the state of the Power-Shed
dry contact input.
Power-Shed input open  ACC
Power-Shed input short  PSOC
12.6.3.1 Total Protection Level Definition
The total protection level is defined by the higher level of protection received.
12.6.4 Deicing
12.6.4.1 Deicing Starting Conditions
Deicing operation will start when either one of the following conditions exist:
Case 1: OCT is 8 degree lower then the ambiant temp and the minimum time from the last deicer is passed.
Case 2: OCT is 12 degree lower then the ambiant temp and 30 minutes from the last deicer wa passed.
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.
In case one of the thermistors is bad the deicer will initiate in predefined intervals.
Deicer may accure also when the unit switch to stanby and the OCT is 8 degree lower then ambiant
temperature