Mitsubishi Electric MXZ-SM72TAM-U1 Service Manual page 91

Bit Function
7 While the outdoor unit
is in HEAT operation,
additionally increase by
50 to 70 pulses of the
LEV opening on the
indoor unit which is in
FAN, STOP, COOL or
thermo-OFF.
*1
8 While the outdoor unit
is in HEAT operation,
fully close the LEV on
the indoor unit which is
in FAN or COOL.
*1. SW5-7 Opens the indoor-linear expansion valve as a countermeasure against the indoor unit in FAN, COOL, STOP,
or thermo-OFF operation with refrigerant-shortage status due to an accumulation of liquid refrigerant in the indoor
unit.
*2. SW5-8 Countermeasure against room temperature rise for indoor unit in FAN and COOL mode.
■ SW6: Function switch
Initial setting
ON
OFF
1 2 3 4 5 6 7 8
The black square (■) indicates a switch position.
SW6-6
Target Pdm (kg/cm²)
SW6-7
SW6-8
Target ETm (°F [°C])
Bit Function
1 -
2 -
3 Preventing the com-
pressor from operating
for a defined period of
time when the breaker
turns on for the first
time under low ambient
temperature
4 Change of defrosting
control
5 External static pressure
mode
6 Switching the target
discharge pressure
(Pdm)
7 Switching (1) the target
evaporation tempera-
ture (ETm)
8 Switching (2) the target
evaporation tempera-
ture (ETm)
■ SW7: Function switch
Initial setting
ON
OFF
1 2 3 4 5 6
The black square (■) indicates a switch position.
Bit Function
1 Ignore current sensor
abnormality and
rotational frequency
abnormality of
outdoor fan motor
2 Setting to energize
the freeze stat heater
(optional part) only
during heating
OCH800A_91
Operation in each switch setting
ON OFF When to set
Activated Deactivated Any time
Activated Deactivated Any time
*2
OFF ON
29.5 31.5
OFF ON OFF ON
OFF OFF ON ON
48 [9] 52 [11] 43 [6] 57 [14]
Operation in each switch setting
ON OFF When to set
- -
- -
Deactivated Activated Any time
(Nomal)
Activated Deactivated Any time
(For high
humidity)
Activated Deactivated Any time
Activated Deactivated Any time
Activated Deactivated Any time
Activated Deactivated Any time
Operation in each switch setting
ON OFF When to set
Activated Deactivated OFF to ON under
suspension after
the power is
turned on.*
Activated* Deactivated Any time
4
*
5
Purpose
To additionally increase by about 50 to 70
pulses of the LEV opening for units other
than in HEAT operation.
To avoid a refrigerant shortage (less
capacity) due to refrigerant liquid accumu-
lation in the units which is not in operation.
To reduce the room temperature increase
by setting the LEV opening lower for the
indoor units in FAN or COOL.
Purpose
- -
- -
To prevent the compressor from break down
This function does not allow the compressor to
operate until any of (1) to (3) is satisfied.
(1) 7.3 hours has passed after the breaker turns on.
(2) Ambient temperature (TH7) > 14°F (-10°C)
(3) Compressor temperature (TH4) > 41°F (5°C)
Turn the switch on when you want the compressor
to operate in the event of an unexpected breaker off
such as a power failure.
To shorten the defrosting prohibition time in high
humidity (or heavy snow) region, in order to reduce
malfunctions caused by frost.
To raise the fan rotation to raise the performance
when an external static pressure is applied.
To raise the performance by setting the PDm higher
during HEAT operation.
To raise/lower the temperature by changing the
target ETm during COOL operation.
Switch to lower the temperature:
raises the performance
Switch to raise the temperature: prevents conden-
sation
Purpose
To perform a test run for electrical parts
alone without running the compressor.
Also, to perform the troubleshooting of
electrical parts without operating the
3
outdoor unit's fan.
To reduce snow on the base, even it blows
inside the unit, by setting the base heater
ON while the HEAT operation is stopped.
Additional information
A refrigerant flow noise might be generat-
ed in units other than the one in opera-
tion.
The refrigerant is more likely to collect in
the indoor units in FAN or COOL, which
can cause refrigerant shortage of units,
resulting in less capacity and increase in
discharge temperature.
Additional information
-
-
Using this function may cause a
breakdown of the compressor,
so ask your dealer if this function
can be used or not.
It is not recommended to keep
the switch on all the time.
The performance of HEAT
operation is somewhat reduced
since the defrosting operation is
frequently performed.
It can support the external static
pressure up to 0.12 in. WG (30
Pa). The power input and the
sound level become larger due
to increasing the outdoor unit's
fan rotation.
Power consumption increases
due to a higher frequency. (The
performance would not increase
at the maximum operating
frequency.)
Switching it to lower the tem-
perature, it raises the power
consumption, and produces
more condensation. Switching it
to raise the temperature, it
makes the performance insuffi-
cient.
Additional information
Make sure to connect the connectors
to the compressor after checking the
electrical parts. Be careful not to get
electrical shock while working on
electrical parts.
Power consumption raises while the
operation is stopped.