Trane TVR Pro CO Series - 4.5 Electronic Expansion Valve Control

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Figure 3-4.1: Compressor priority and rotation – one outdoor unit
Figure 3-4.2: Compressor priority and rotation – two outdoor units
Figure 3-4.3: Compressor priority and rotation – three outdoor units
4.5 Electronic Expansion Valve Control
EXVA control
The position of electronic expansion valve EXVA is controlled in steps from 0 (fully closed) to 3000 (fully open).
In cooling mode:
 When all outdoor units are in standby:
 All EXVAs are at position 352×6(steps).
 When some outdoor units are running and some outdoor units are in standby:
 EXVAs on running outdoor units are controlled according to discharge temperature. EXVAs of units in standby are
BP
No. 1
BP1
No. 1 No. 2
BP2
BP
BP
No. 1
No. 2
No.
2 No. 1
BP1
No. 1 No. 2 No. 3
No. 2 No. 3 No. 1
BP2 BP
BP1 BP1
No. 1
No. 2 No. 3 No. 4
BP2
No. 3 No. 4 No. 1 No. 2
BP2
BP BP
No. 1 No. 2 No. 3
No. 3 No. 1 No. 2
BP
No. 2 No. 3 No. 1
BP
No. 1 No. 2 No. 3 No. 4
No. 3 No. 4 No. 1 No. 2
BP
No. 2 No. 3 No. 4 No. 1
BP1 BP2
BP1 BP2
No. 1 No. 2 No. 3 No. 4 No. 5
BP
No. 4 No. 5 No. 1 No. 2 No. 3
No. 2 No. 3 No. 4 No. 5 No. 1
BP1 BP2 BP1 BP2 BP1 BP2
No. 3 No. 4 No. 5 No. 6 No. 1 No. 2
No. 1 No. 2 No. 3 No. 4 No. 5 No. 6
No. 5 No. 6 No. 1 No. 2 No. 3 No. 4
BP1 BP2
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②
①
②
①
②
①
②
③
①
②
③
①
②
③
①
②
③