Pioneer YN018GMFI16M2D, Service Manual

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7.4.4 Electronic Expansion Valve (EXV)
Control
1.EXV will be fully closed when the power is first
turned on. Then EXV will stay at standby with
350P open and will open to target angle after
compressor starts.
2.EXV will close with -160P when compressor
stops. Then EXV will stay at standby with 350P
open and will open to target angle after
compressor starts.
3.The action priority of the EXVs is A-B-C-D.
4.Compressor and outdoor fan start operation
only after EXV is initialized.
7.4.4.1 Cooling mode
The initial open angle of EXV is 250P, adjustment
range is 100-350p. When the unit starts to work
for 3 minutes, the outdoor will receive indoor
units' (of capacity demand) T2B information and
calculate an average of them. After comparing
each indoor’s T2B with the average, the outdoor
gives the following modification commands:
If the T2B
＞ average, the relevant valve needs
16p more open;
If the T2B= average, the relevant valve’s open
range remains;
If the T2B
＜
average, the relevant valve needs
16p more close.
This modification will be carried out every 2
minutes.
7.4.4.2 Heating mode
The initial open angle of EXV is 250P, adjustment
range is 100-350p.. When the unit starts to work
for 3minutes, the outdoor will receive indoor units'
(of capacity demand) T2 information and
calculate the average of them. After comparing
each indoor’s T2 with the average, the outdoor
gives the following modification commands:
If the T2
＞
2, the relevant valve needs
16p more close;
If 2≥the T2≥ average-2, the relevant
valve’s open range remains;
If the T2
＜
average-2, the relevant valve needs
16p more open.
This modification will be carried out every 2
minutes.
7.4.5 Four-way valve control
In heating mode, four-way valve is activated. In
defrosting, four-way valve operates in according
to defrosting action. In other modes, four-way
valve is deactivated. When the heating mode to
other modes, the four-way valve goes off after
compressor is off for 2 minutes. Failure or
protection (not including discharge temperature
protection, high and low pressure protection),
four-way valve immediately turns off.