12-21
CONTROL SYSTEM
SM CKDDCI 2-A.3 GB
12.5.8
Compressor internal heating coil Operation
6HP and 4HP DCR units.
The crank case heater operates only when compressor is off and according to CTT and OAT.
12.5.9 Thermodynamic
Protections
12.5.9.1 Protection level definition
Five protection levels are defined:
Normal
– No protection status.
Stop-Rise (SR
) –
Compressor not allowed raise speed.
D1
- Compressor speed reduced.
D2
- Compressor speed reduced rapidly.
Stop-Compressor (SC
)
– Compressor stops.
12.5.9.2 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
Operation logic of all protections is the same. The controlled input (CTT, HST, ACC, DCC) 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:
Note
: The values hereby are for reference only. Each model may have its own values.
Protection
level
Compressor Overheat
(CTT)
Compressor AC
Over current (ACC)
Compressor DC
Over current (DCC)
Heat Sink
(HST)
SC
95
25.0
22.0
90
D2
92
24.6
21.4
87
D1
90
24.2
20.8
85
SR
87
23.6
20.0
83
Normal
78
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
12.5.9.3 Total Protection Level Definition
The total protection level is defined by the higher level of protection received.
