Daikin E Series, Service Manual

Page: 111 / 453

BP Unit Control SiAU18-715
98 Function
6.2.3 Full Closing of Electronic Expansion Valves
Purpose of the
Function 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 retightening
is completed.
6.2.4 Control Based on EV Opening Command from Outdoor Unit
Purpose of the
Function This function operates the electronic expansion valve based on EV opening command sent from
the outdoor unit.
Outline 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) Defrost operation
Power ON
P 1
P 1
0
0
P 1
0
P 1
0
EVA
EVB
EVC
EVH
(M1047)