Service Manual

Branch Provider (BP) Unit Control SiUS181631EA
70 Functions and Control
6.2.3 Full Closing of Electronic Expansion Valves
Outline The electronic expansion valves are initialized when the power is turned on.
Details The following processes are conducted.
1. Conducts P1 pulses close when power is turned on, and sets current opening to 0 pulse (fully
closing process).
2. Sends electronic expansion valve initialization signal to outdoor unit.
3. Closes the electronic expansion valve of each chamber (sets the electronic expansion valve
pulse to 0).
4. Stops transmission of electronic expansion valve initialization signal when EVH (bypass
electronic expansion valve) retightening is completed.
6.2.4 Control Based on EV Opening Command from Outdoor Unit
Outline This function operates the electronic expansion valve based on EV opening command sent from
the outdoor unit.
Details The electronic expansion valve operation based on EV opening command provides the following
functions.
1) Pressure equalization prior to startup
2) Startup control
3) Restart standby
4) Pump-down residual operation
5) Oil return operation
6) Defrosting operation
P 1
P 1
0
0
P 1
0
P 1
0
EVA
EVB
EVC
EVH
(M1047)
Power ON