Service manual

15-13
CONTROL SYSTEM > GC 24
SM HADDCI 1-A.2 GB
15.4.18.3 IDU Protections
15.4.18.3.1 Indoor Cooil Defrost Protection
ICT
ICT Trend
Fast Increasing Increasing No change Decreasing Fast Decreasing
ICT < -2 SC SC SC SC SC
-2 < ICT < 0 D1 D1 D2 D2 D2
0 < ICT < 2 SR SR D1 D2 D2
2 < ICT < 4 SR SR SR D1 D2
4 < ICT < 6 Norm Norm SR SR D1
6 < ICT < 8 Norm Norm Norm SR SR
8 < ICT Normal
15.4.18.3.2 Indoor Coil over Heating Protection
ICT
ICT Trend
Fast Decreasing Decreasing No Change Increasing Fast Increasing
ICT > 55 SC SC SC SC SC
53 < ICT < 55 D1 D1 D2 D2 D2
49 < ICT < 53 SR SR D1 D2 D2
47 < ICT < 49 SR SR SR D1 D2
45 < ICT < 47 Norm Norm SR SR D1
43 < ICT < 45 Norm Norm Norm SR SR
ICT < 43 Normal
15.4.18.4 ODU Protections
There are 3 ODU protections:
Compressor overheating•
Heat sink overheating•
System over power•
Operation logic of all protections is the same. The controlled input (CTT, HST, or PWR) is controlled by changing
the protection level using the fuzzy logic algorithm according the input level and the change rate.
There are two sets of POWER values, the selection of the values are set according to the state of the Power-
Shed dry contact input. Power-Shed input open -> Power1 Power-Shed input sort -> Power2
The following table summarizes the basic levels of each protection.
Protection level
Compressor
Overheat - cool
(CTT)
Compressor
Overheat - heat
(CTT)
Heat Sink
(HST)
Power1 Power2
Stop compressor 105 105 83 3600 2900
Down 2 100 100 81 3400 2750
Down 1 98 95 77 3200 2600
Stop rise 95 85 75 3100 2450
Normal 90 80 73 3050 2300
15.4.18.5 Total Protection Level Definition
The total protection level is defined by the higher level of protection received.
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