MXZ-SM48NAM Service Manual
6
OCH789
When the set temperature ranges overlap, the previously set pattern (1, 2 or 3) has a priority.
The stage 1 has the highest priority, 2 the second and then 3.
b) Based on above chart listed the sequence of operation on "On ambient decrease"
Stage 1: (TH7 = > 50°F [10
:
]): the outdoor unit runs in HP mode.
Stage 2: (TH7 = 50 to −13°F [10
to −25
:
]): the outdoor unit runs in HP mode with auxiliary heating.
Stage 3: (TH7 = < −13°F [−25
:
]): Auxiliary heating only (Outdoor unit is OFF).
c) Based on above chart listed the sequence of operation on "On ambient increase"
Stage 3: (TH7 = < 32°F [0
:
]): Auxiliary heating only (Outdoor unit is OFF).
Stage 2: (TH7 = > 32 to 68°F [0 to 20
:
]): Auxiliary heating with outdoor unit in HP mode.
Stage 1: (TH7 = > 68°F [20
:
]): Outdoor unit in HP mode only.
(4) Determine fan speed setting during indoor thermo-OFF conditions:
a) These settings are done within Indoor DIPSW1-7 and DIPSW1-8, see chart below for options.
b) Recommended SW1-7 OFF and SW1-8 ON will determine airflow based on "Setting on the remote controller".
Fan speed
setting
Fan speed
setting
OFF ON
SW1-7 SW1-8
OFF OFF Very low
ON OFF Low
OFF ON
Setting on
remote
controller
ON
ON
Stopped
Auxiliary heating
signal
Thermo condition
(5) Setting outdoor unit and auxiliary heat switch over temperatures
When the DIPSW 5-4 is set to "ON", the outdoor unit and the contact output operates as shown below.
a) Outdoor default setting and operations are shown below:
Stage 1
A
mb. decreasing - Outdoor unit HP operation
Amb. increasing - Defrost : Heater contact ON signal
- Other than defrost : Contact OFF
Stage 2
- Outdoor unit HP operation
- Heater contact ON signal
Stage 3
- Outdoor unit OFF (Standby)
- Heater contact ON signal
TH7 = Outdoor temperature
a
−25
-C
[
−
13-F]
b
0
-C
[32-F]
c
10
-C
[50-F]
d
20
-C
[68-F]
Setting on
remote
controller