11-15
CONTROL SYSTEM
SM YAZDCI 1-A.1 GB
11.5.7 Thermodynamic
Protections
11.5.7.1
Protection level definition
Five protection levels are defined:
Normal
– No protection status is ON.
Stop-Rise (SR
) –
System is in protection, first level
D1
- System is in protection, second level
D2
- System is in protection third level
Stop-Compressor (SC
)
– System is in protection fourth level
11.5.7.2
IDU Protection Level
The overall protection level of the indoor units will be the worst protection status among the
all indoor units
11.5.7.3
IDU Protections
11.5.7.3.1 Indoor Coil 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
11.5.7.3.2 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
11.5.7.4 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
