Midea M3OF-27HFN1-M - Heating Mode; Electronic Expansion Valve (EXV) Control

21
T 3
Increase fan speed increase
Keep current fan speed
Decrease fan speed
Fan stop
LowCoolT3_ON
LowCoolT3_Down
LowCoolT3_OFF
5.4.3.2 Heating Mode
Under normal operating conditions, the system
chooses a running fan speed according to
ambient temperature:
Outdoor temperature℃
21
B reeze fan speed
19
18
S upper low fan speed
16
15
L ow fan speed
13
12
M iddle fan speed
10
0
H igh fan speed
-2
S upper high fan speed
5.4.4 Electronic Expansion Valve (EXV)
Control
1. EXV remains fully closed while the device is
powering up. EXV then remains on standby with
350P open. It opens to the target angle after the
compressor starts.
2. EXV closes with -160P when the compressor
stops. Then it remains on standby with 350P
open. It opens to the target angle after the
compressor starts.
3. The action priority for the EXVs is A-B-C-D-E.
4. The compressor and outdoor fan commence
operation only after EXV initializes.
5.4.4.1 Cooling Mode
The initial open angle of the EXV depends on the
size of the indoor model. The adjustment range is
100-400p.
When the unit has been running for 3 minutes,
the outdoor receives indoor units' capacity
demand and T2B information and then calculates
their average. After comparing each indoor’s T2B
with the average, the outdoor gives the following
modification commands:
---- If the T2B＞average, the relevant valve needs
to open 16p more
---- If the T2B= average, the relevant valve’s open
range remains as is
---- If the T2B＜average, the relevant valve needs
to close 16p more
This modification is carried out every 2 minutes.
5.4.4.2 Heating Mode
The initial open angle of the EXV depends on the
size of the indoor model. The adjustment range is
150-350p.
When the unit has been running for 3 minutes,
the outdoor unit receives the indoor units' indoor
units' capacity demand and T2 information and
then calculates their average.
After comparing each indoor unit’s T2 with the
average, the outdoor gives the following
modification commands:
----If the T2 ＞ average+2, the relevant valve
needs to close 16p more
---- If average+2≥the T2≥ average-2, the relevant
valve’s open range remains as is
----If the T2＜average-2, the relevant valve needs
to open 16p more
This modification is carried out every 2 minutes.