11-15
CONTROL SYSTEM
SM TQDCI 1-A.1 GB
ON
OFF
OAT
0
2
Base
Heater
When OAT is faulty the base heater will be “ON” continuously in HEAT mode.
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 ODU receives the protection levels from each one of the IDU. The protection levels are
weighted according to the following table:
Protection Level
Weight
Normal 0
Stop-Rise 1
D1 2
D2 3
Stop-Compressor 0
The IDU protection level calculated weight according to the following average:
⎟
⎟
⎟
⎟
⎠
⎞
⎜
⎜
⎜
⎜
⎝
⎛
=
∑
=
n
weight
prtoction
IDU
up
round
level
protection
IDU
n
i
i
1
Where,
n- The number of active IDU units.
11.5.7.3 IDU Protections
11.5.7.3.1 Indoor Coil Defrost Protection
ICT Trend
ICT
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
CONTENTS