Mitsubishi Electric MS-A WA Quick start guide

MS-A•WA · MU-A•WA
MSZ-A•NA · MUZ-A•NA
· MUZ-A•NA -
MSY-A•NA · MUY-A•NA
· MXZ-A•NA
U
SERVICE TECHNICAL GUIDE
CONTENTS
1. MS MICROPROCESSOR CONTROL··················3
2. MSZ,MSY MICROPROCESSOR CONTROL·······6
3. MXZ MICROPROCESSOR CONTROL··············20
Wireless type Models
SPLIT-TYPE, AIR CONDITIONERS
SPLIT-TYPE, HEAT PUMPAIR CONDITIONERS
Inverter-controlled multi system type Models
No. OBT16
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1. MS MICROPROCESSOR CONTROL ···························································3
Indoor unit models Outdoor unit models
MS-A09WA MU-A09WA
MS-A12WA MU-A12WA
1-1. COOL OPERATION················································································3
1-2. DRY OPERATION ··················································································3
1-3. AUTO VANE OPERATION·····································································5
2. MSZ, MSY MICROPROCESSOR CONTROL ···············································6
Indoor unit models Outdoor unit models
MSZ-A09NA MUZ-A09NA
MSZ-A12NA MUZ-A12NA
MSZ-A15NA MUZ-A15NA
MSZ-A17NA MUZ-A17NA
MSZ-A24NA MUZ-A24NA
MSY-A15NA MUY-A15NA
MSY-A17NA MUY-A17NA
MSY-A24NA MUY-A24NA
2-1. COOL OPERATION···············································································6
2-2. DRY OPERATION ·················································································7
2-3. HEAT OPERATION ···············································································7
2-4. AUTO CHANGE OVER ··· AUTO MODE OPERATION························9
2-5. OUTDOOR FAN MOTOR CONTROL·················································10
2-6. AUTO VANE OPERATION··································································10
2-7 . INVERTER SYSTEM CONTROL························································12
2-8 . OPERATIONAL FREQUENCY CONTROL OF OUTDOOR UNIT······16
2-9 . EXPANSION VALVE CONTROL (LEV CONTROL)···························17
3. MXZ MICROPROCESSOR CONTROL·······················································20
Outdoor unit models
MXZ-2A20NA
MXZ-3A30NA
3-1. INVERTER SYSTEM CONTROL·························································20
3-2. EXPANSION VALVE CONTROL (LEV CONTROL) ····························22
3-3. OPERATIONAL FREQUENCY RANGE···············································27
3-4. HEAT DEFROSTING CONTROL········································· BACK PAGE
3-5. DISCHARGE TEMPERATURE PROTECTION CONTROL ·····BACK PAGE
3-6. OUTDOOR FAN CONTROL ················································ BACK PAGE
2
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3
MS MICROPROCESSOR CONTROL
1
1-1. COOL ( ) OPERATION
MS-A09WA MU-A09WA
MS-A12WA MU-A12WA
2. Indoor fan speed control
Indoor fan operates continuously at the set speed by FAN SPEED CONTROL button
regardless of the thermostat’s OFF-ON.
In AUTO the fan speed is as follows.
Room temperature minus set temperature : 3.1 degrees or more·······························High
Room temperature minus set temperature : Between 1.8 and 3.1 degrees
··················· Med.
Room temperature minus set temperature : less than 1.8 degrees ····························Low
Initial temperature difference
Difference between room
temperature and set temper-
ature during operation ( T)
Fan speed
3. Coil frost prevention
-1.8deg. -1.3deg.
1. Thermostat control
Thermostat is ON or OFF by difference between room temperature and set temperature
Initial temperature difference Thermostat
Room temperature minus set temperature : -1.8 degrees or more·····································ON
Room temperature minus set temperature : less than -1.8 degrees···································OFF
Set temperature
Difference between room
temperature and set temper-
ature during operation.
Set temperature is as shown on the right chart.
The system for dry operation uses the same refrigerant circuit as the
cooling circuit.
The compressor and the indoor fan are controlled by the room tem-
perature.
By such controls, indoor flow amounts will be reduced in order to
lower humidity without much room temperature decrease.
1-2. DRY ( ) OPERATION
95
86
77
68
59
50
ºF
50 59 68 77 86 95
Set temperature
Initial room temperature
Set temperature and
initial room temperature in dry mode
ºF
① Temperature control
When the indoor coil thermistor RT12 reads 37 ºF or below the coil frost prevention mode starts immediately.
However, the coil frost prevention doesn’t work for 5 minutes since the compressor has started.
The indoor fan operates at the set speed and the compressor stops for 5 minutes.
After that, if RT12 still reads below 37 ºF this mode prolonged until the RT12 reads over 37 ºF.
② Time control
When the three conditions as follows have been satisfied for 1 hour and 45 minutes, compressor stops for 3 minutes.
a. Compressor has been continuously operating.
b. Indoor fan speed is Low or Med.
c. Room temperature is below 79 ºF.
When compressor stops, the accumulated time is cancelled and when compressor restarts, time counting starts from the
beginning.
Time counting also stops temporarily when the indoor fan speed becomes High or the room temperature exceeds
79 ºF. However, when two of the above conditions (b.and c.) are satisfied again. Time accumulation is resumed.
Compressor
Outdoor fan OFF
ON
(continuously at set speed)
Indoor fan ON
ON
OFF
Operation chart
Example
5.4 deg.
3.1 deg.
1.8 deg.
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4
-1.8 deg. -1.3 deg.
1. Thermostat control
Thermostat is ON or OFF by difference between room temperature and set temperature.
Initial temperature difference Thermostat
Room temperature minus set temperature : -1.8 degrees or more·····································ON
Room temperature minus set temperature : less than -1.8 degrees···································OFF
Set temperature
Difference between room
temperature and set temper-
ature during operation
2. Indoor fan speed control
Indoor fan operates at the set speed by FAN SPEED CONTROL button.
When thermostat OFF (compressor OFF) fan speed becomes Very Low.
4. Coil frost prevention
Coil frost prevention is as same as COOL mode. (2-1.3.)
The indoor fan maintains the actual speed of the moment. However ,when coil frost prevention works while the compressor
is not operating it’s speed becomes the set speed.
In AUTO the fan speed is as follows.
Room temperature minus set temperature : 3.1 degrees or more·······························High
Room temperature minus set temperature : Between 1.8 degrees and 3.1 degrees
··· Med.
Room temperature minus set temperature : less than 1.8 degrees·····························Low 3.1 deg.4.5 deg.
1.8 deg.
Initial temperature difference Fan speed
Operation time chart
Example
Thermostat
Indoor fan
Outdoor fan
Compressor
ON ON
OFF
OFF
OFF
OFF
OFF
ON
ON
ON
ON
ON
ON
OFF
OFF
OFF
3. The operation of the compressor and indoor/ outdoor fan
Compressor operates by room temperature control and time control.
Set temperature is controlled to fall 4°F from initial room temperature.
Indoor fan and outdoor fan operate in the same cycle as the compressor.
•When the room temperature is 73°F or over:
When the thermostat is ON, the compressor repeats 8 minutes ON and 3 minutes OFF.
When the thermostat is OFF, the compressor repeats 4 minutes OFF and 1 minute ON.
•When the room temperature is under 73°F.
When the thermostat is ON, the compressor repeats 2 minutes ON and 3 minutes OFF.
When the thermostat is OFF, the compressor repeats 4 minutes OFF and 1 minute ON.
8 minutes 1 minute
4 minutes
3 minutes
Difference between room
temperature and set temper-
ature during operation ( T)
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1-3. AUTO VANE OPERATION
1. Horizontal vane
<SWING operation>
In swing operation of ECONO COOL operation mode, the initial air flow direction is adjusted to “Horizontal”.
According to the temperature of indoor coil thermistor RT12 at starting of this operation, next downward blow time is
decided. Then when the downward blow has been finished, next horizontal blow time is decided.
For initial 10 minutes the swing operation is performed in table G~H for quick cooling.
Also, after 10 minutes when the difference of set temperature and room temperature is more than 3.6 degrees, the
swing operation is performed in table D~H for more cooling.
The air conditioner repeats the swing operation in various cycle as follows.
ECONO COOL ( ) operation (ECONOmical operation)
When ECONO COOL button is pressed in COOL mode, set temperature is automatically set 3.6 degrees higher than
that in COOL mode.
Also the horizontal vane swings in various cycle according to the temperature of indoor heat exchanger (RT12).
SWING operation makes you feel cooler than set temperature. So, even though the set temperature is higher than that
in COOL mode, the air conditioner can keep comfort. As a result, energy can be saved.
ECONO COOL operation is cancelled when ECONO COOL button is pressed once again or VANE CONTROL
button is pressed or change to other operation mode.
Temperature of indoor
coil thermistor RT12
more than 75°F
5
2
Downward blow time
(second)
72°F to 75°F
70°F to 72°F
68°F to 70°F
64°F to 68°F
63°F to 64°F
59°F to 63°F
59°F or less
5
8
11
14
17
20
23
Horizontal blow time
(second)
20
17
14
11
8
2
23
A
H
G
F
E
D
C
B
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MSZ,MSY MICROPROCESSOR CONTROL
6
2
2-1. COOL ( ) OPERATION
MSZ-A09NA MSY-A15NA MUZ-A09NA MUY-A15NA
MSZ-A12NA MSY-A17NA MUZ-A12NA MUY-A17NA
MSZ-A15NA MSY-A24NA MUZ-A15NA MUY-A24NA
MSZ-A17NA MUZ-A17NA
MSZ-A24NA MUZ-A24NA
2. Indoor fan speed control
Indoor fan operates continuously at the set speed by FAN SPEED CONTROL button
regardless of the thermostat’s OFF-ON.
In AUTO the fan speed is as follows.
Room temperature minus set temperature : 3.1 degrees or more·······························High
Room temperature minus set temperature : Between 1.8 and 3.1 degrees
··················· Med.
Room temperature minus set temperature : less than 1.8 degrees ····························Low 3.1deg.5.4deg.
1.8deg.
Initial temperature difference
Difference between room
temperature and set temper-
ature during operation ( T)
Fan speed
Temperature of indoor coil thermistor
50°F or more
43°F to 46°F
37°F to 43°F
37°F or less
Operation frequency
Normal (variable)
46°F to 50°F Raise 6Hz
Fixed
Lower 3Hz
Lower 6Hz
Compressor is turned OFF for 5 minutes when temperature of
indoor coil thermistor continues 37°F or less for 5 minutes or more.
The indoor fan maintains the actual speed of the moment.
3. Coil frost prevention
Temperature control
When indoor coil thermistor detects following temperature for 90 seconds, operational frequency
of compressor is controlled according to the following table.
-1.8deg. -1.3deg.
1. Thermostat control
Thermostat is ON or OFF by difference between room temperature and set temperature
Initial temperature difference Thermostat
Room temperature minus set temperature : -1.8 degrees or more·····································ON
Room temperature minus set temperature : less than -1.8 degrees···································OFF
Set temperature
Difference between room
temperature and set temper-
ature during operation.
4. Low outside temperature operation
If the outside temperature falls to 64°F or less during operation in COOL mode, the unit enters the low outside temperature
operation mode.
<Operation>
(1) If the unit enters the low outside temperature operation mode, the outside fan rotation speed gets slow down.
(2) Even when the unit is in the "thermostat-off" status under the low outside temperature operation mode, the outside fan
rotation does not stop.
(3) In this mode to detect the exact outside temperature the compressor turns OFF with the outdoor fan ON for 3 minutes
once 1 hour; if the outside temperature rises over 64°F, the unit goes back to the normal COOL mode, and if the
outside temperature is still 64°F or less, the unit stays in the low outside temperature operation mode.
(4) Dew drop prevention
When the ambient temperature thermistor RT65 reads 10°F or less, as coil frost or dew drop from indoor unit may
occur, the compressor turns OFF with the outdoor fan ON for prevention of them.
WOther protections work as well as in the normal COOL mode.
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7
Set temperature is as shown on the right chart.
The system for dry operation uses the same refrigerant circuit as the
cooling circuit.
The compressor and the indoor fan are controlled by the room tem-
perature.
By such controls, indoor flow amounts will be reduced in order to
lower humidity without much room temperature decrease.
2-2. DRY ( ) OPERATION
95
86
77
68
59
50
ºF
50 59 68 77 86 95
Set temperature
Initial room temperature
Set temperature and
initial room temperature in dry mode
ºF
-1.8deg. -1.3deg.
1. Thermostat control
Thermostat is ON or OFF by difference between room temperature and set temperature.
Initial temperature difference Thermostat
Room temperature minus set temperature : -1.8 degrees or more·······································ON
Room temperature minus set temperature : less than -1.8 degrees······································OFF
Set temperature
Difference between room
temperature and set temper-
ature during operation
2. Indoor fan speed control
(1) Indoor fan operates at the set speed by FAN SPEED CONTROL button.
In Auto the fan speed is as follows.
Set temperature minus room temperature: 3.6 degrees or more ······································ High
Set temperature minus room temperature: Between 0.4 and 3.6 degrees ···················· Med.
Set temperature minus room temperature: less than 0.4 degrees···································· Low
0.4deg. 3deg.
3.6deg. 7.2deg.
Initial temperature difference Fan speed
Difference between room
temperature and set temper-
ature during operation
3deg. 3.6deg.
Set temperature
Difference between room
temperature and set temper-
ature during operation
1. Thermostat control
Thermostat is ON or OFF by difference between room temperature and set temperature.
Initial temperature difference Thermostat
Room temperature minus set temperature : less than 3.6 degrees····································ON
Room temperature minus set temperature : 3.6 degrees or more······································OFF
2. Indoor fan speed control
Indoor fan operates at the set speed by FAN SPEED CONTROL button.
When thermostat OFF (compressor OFF) fan speed becomes Very Low.
3. Coil frost prevention
Coil frost prevention is as same as COOL mode. (2-1.3.)
The indoor fan maintains the actual speed of the moment. However ,when coil frost prevention works while the compressor
is not operating it’s speed becomes the set speed.
4. Low outside temperature operation
Low outside temperature operation is as same as COOL mode. (2-1.4.)
2-3. HEAT ( ) OPERATION (MSZ)
In AUTO the fan speed is as follows.
Room temperature minus set temperature : 3.1 degrees or more·······························High
Room temperature minus set temperature : Between 1.8 and 3.1 degrees
··················· Med.
Room temperature minus set temperature : less than 1.8 degrees ····························Low 3.1deg.4.5deg.
1.8deg.
Initial temperature difference
Difference between room
temperature and set temper-
ature during operation ( T)
Fan speed
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8
(2) Cold air prevention control
MSZ-A09/12/15/17
1When the compressor is not operating,
(1) if the temperature of room temperature thermistor RT11 is less than 66°F, the fan stops.
(2) if the temperature of room temperature thermistor RT11 is 66°F or more and
(1) if the temperature of RT12 is less than 32°F, the fan stops.
(2) if the temperature of RT12 is 32°F or more, the fan operates at Very Low.
2When the compressor is operating,
(1) if the temperature of RT12 is 104°F or more, the fan operates at set speed.
(2) if the temperature of RT12 is less than 104°F and
(1) if heating operation starts after defrosting, the fan stops.
(2) if the temperature of room temperature thermistor RT11 is 66°F or less, the fan stops.
(3) if the temperature of room temperature thermistor RT11 is more than 66°F, the fan operates at Very Low.
NOTE : When 3 minutes have passed since the compressor started operation, this control is released regardless of the
temperature of RT11 and RT12.
MSZ-A24
1When the compressor is not operating,
(1) if the temperature of room temperature thermistor RT11 is 59°F or less, or RT12 is less than 64°F,
the fan stops.
(2) if the temperature of room temperature thermistor RT11 is more than 59°F, or RT12 is more than 64°F,
the fan operates at Very Low.
2When the compressor is operating,
(1) if the temperature of RT12 is 64°F or more, the fan operates at set speed.
(2) if the temperature of RT12 is less than 64°F and
(1) if heating operation starts after defrosting, the fan stops.
(2) if the temperature of room temperature thermistor RT11 is 59°F or less, the fan stops.
(3) if the temperature of room temperature thermistor RT11 is more than 59°F, the fan operates at Very Low.
NOTE : When 3 minutes have passed since the compressor started operation, this control is released regardless of the
temperature of RT11 and RT12.
3. Overload starting
When the room temperature thermistor RT11 reads 64°F or more, the compressor runs with its maximum frequency regulated
for 10 minutes after the start-up.
4. Defrosting
(1) Starting conditions of defrosting
When the following conditions a) ~ c) are satisfied, the defrosting starts.
a) The defrost thermistor reads 27°F or less.
b) The cumulative operation time of the compressor has reached any of the set valuesw(40, 45, 55, 65, 75, 85, 95, 105,
115, 125, 150 minutes(MUZ-A09/12/15/17))/(31,35,45,55,65,75,85,95,105,115,150minutes(MUZ-A24)).
c) More than 5 minutes have passed since the start-up of the compressor.
w Set value of compressor operation time (here in after referred to as defrost interval)
This is decided by the temperature of defrost thermistor and ambient temperature thermistor, the previous defrosting
time. For example, the first defrost interval is 40 minutes long, and the second is 45 minutes long. The third and subse-
quent intervals are set to be longer, and less frequent, depending on defrosting time.
The third and subsequent defrost intervals follow any of the three patterns …5 or 10 to 20 minutes longer, the same, or
5 or 10 to 20 minutes shorter compared with the previous defrost interval … with the longest 125 minutes and the
shortest 40 minutes.
(2) Releasing conditions of defrosting
Defrosting is released when any of the following conditions is satisfied:
a) The defrost thermistor continues to read 50°F or more (MUZ-A09/12) / 41°F or more (MUZ-A15/17) / 59°F or more
(MUZ-A24) for 30 seconds.
b) Defrosting time has exceeded 10 minutes.
c) Any other mode than HEAT mode is set during defrosting.
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Time chart of defrosting in HEAT mode (reverse type)
set position
set speed
set position
set speed
Indoor fan
Compressor normal
Outdoor fan
R.V. coil
(21S4) OFF (COOL)
OFF
Maximum frequency
horizontal
Horizontal vane
Very Low (temperature of indoor coil thermistor > 64°F)
30
seconds
30
seconds
30
seconds
40
seconds
5 seconds 5 seconds
40
seconds
OFF
OFF OFF
ON (HEAT)
ON ON
ON (HEAT)
<outdoor unit>
<indoor unit>
2-4. AUTO CHANGE OVER ··· AUTO MODE OPERATION (MSZ)
Once desired temperature is set, unit operation is switched automatically between COOL and HEAT operation.
1. Mode selection
(1) Initial mode
At first indoor unit operates only indoor fan with outdoor unit OFF for 3 minutes to detect present room temperature.
Following the conditions below, operation mode is selected.
1If the room temperature thermistor RT11 reads more than set temperature, COOL mode is selected.
2If the room temperature thermistor RT11 reads set temperature or less, HEAT mode is selected.
(2) Mode change
In case of the following conditions the operation mode is changed.
1COOL mode changes to HEAT mode when 15 minutes have passed with the room temperature 4 degrees below the
set temperature.
2HEAT mode changes to COOL mode when 15 minutes have passed with the room temperature 4 degrees above the
set temperature.
In the other cases than the above conditions, the present operation mode is continued.
NOTE1: Mode selection is performed when multi standby (refer to NOTE2) is released and the unit starts operation with
ON-timer.
NOTE2: If two or more indoor units are operating in multi system, there might be a case that the indoor unit, which is
operating in AUTO ( ), cannot change over the other operating mode (COOL HEAT) and becomes a
state of standby.
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10
(3) Indoor fan control/ Vane control
As the indoor fan speed and the horizontal vane position depend on the selected operation mode, when the operation
mode changes over, they change to the exclusive ones.
2-5. OUTDOOR FAN MOTOR CONTROL
Fan speed is switched according to the compressor frequency.
COOL
Fan speed
Up
Down
Up
Down
Mode
HEAT
(MUZ)
Compressor frequency (Hz)
MUZ-A09/12/15/17/24
MUY-A15/17/24
<Relation between compressor frequency and fan speed.>
44
33
44
33
Up
Down
Fan speed
High
Low Compressor frequencyMin. Max.
2-6. AUTO VANE OPERATION
1. Horizontal vane
(1) Cold air prevention in HEAT operation. (MUZ)
When any of the following conditions occurs in HEAT operation, the vane angle changes to Horizontal position automati-
cally to prevent cold air blowing on users.
① Compressor is not operating.
➁ Defrosting is performed.
➂ Indoor coil thermistor RT12 temperature does not exceed 102ºF within about 3 minutes after compressor starts.
NOTE: When 2 or more indoor units are operated with multi outdoor unit, even if any indoor unit turns thermostat off,
this control doesn’t work in the indoor unit.
(2) ECONO COOL ( ) operation (ECONOmical operation)
When ECONO COOL button is pressed in COOL mode, set temperature is automatically set 3.6 degrees higher than
that in COOL mode.
Also the horizontal vane swings in various cycle according to the temperature of indoor heat exchanger (RT12).
SWING operation makes you feel cooler than set temperature. So, even though the set temperature is higher than that
in COOL mode, the air conditioner can keep comfort. As a result, energy can be saved.
ECONO COOL operation is cancelled when ECONO COOL button is pressed once again or VANE CONTROL
button is pressed or change to other operation mode.
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