Mitsubishi Electric MXZ-A14WV User manual

SERVICE MANUAL
CONTENTS
1. TECHNICAL CHANGES ····································2
2. PART NAMES AND FUNCTIONS······················6
3. INDOOR/OUTDOOR
CORRESPONDENCE TABLE ···························6
4. INDOOR UNITS COMBINATION·······················9
5. SPECIFICATION···············································21
6. NOISE CRITERIA CURVES·····························23
7. OUTLINES AND DIMENSIONS ·······················24
8. WIRING DIAGRAM ··········································27
9. REFRIGERANT SYSTEM DIAGRAM··············30
10. PERFORMANCE CURVES······························33
11. MICROPROCESSOR CONTROL·····················47
12. TROUBLESHOOTING······································52
13. DISASSEMBLY INSTRUCTIONS·····················71
14. PARTS LIST······················································78
15. OPTIONAL PARTS···········································83
Inverter-controlled multi system type
Models
MXZ-A14WV -
MXZ-A18WV -
MXZ-A26WV -
MXZ-A32WV - E1
E1
E1
E1
No. OB319
REVISED EDITION-A
HFC
utilized
R410A
SPLIT-TYPE, HEAT PUMPAIR CONDITIONERS
MXZ-A18WV - E1
Indication of model name
NOTE:
•This service manual describes technical data of outdoor units.
As for indoor units, refer to the service manual OB307 REVISED EDITION-C, OB321, OB327, OB329,
OB336 REVISED EDITION-A, OB345, OC302 or OC303.
Please void OB319.
Revision A:
●MXZ-A14WV -has been added.
E1
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TECHNICAL CHANGES
2
1
MXZ-14WV -
New model
MXZ-18TV - ➔MXZ-A18WV -
1. Outdoor model has been changed.
2. Refrigerant has been changed. (R22➔R410A)
MXZ-24UV - ➔MXZ-A26WV -
1. Cooling capacity has been made larger. (7.1kW➔7.2kW)
2. Combinations of connectable indoor units have been increased.
3. Capacity class of connectable indoor units have been made larger.
4. Compressor has been changed. (THV247FBA➔TNB220FMCH)
5. Outdoor fan motor has been changed. (RA6V60-BA➔PM8H60-UA)
6. Refrigerant has been changed. (R22➔R410A)
7. Refrigerant system diagram has been changed.
• 1 of 2 high pressure switch has been removed.
• Accumulator has been removed.
• Receiver has been added.
MXZ-32SV - ➔MXZ-A32WV -
1. Combinations of connectable indoor units have been increased.
2. Capacity class of connectable indoor units have been made larger.
3. Compressor has been changed. (THV247FBA➔TNB220FMCH)
4. Outdoor fan motor has been changed. (RA6V60-BA➔PM8H60-UA)
5. Refrigerant has been changed. (R22➔R410A)
6. Refrigerant system diagram has been changed.
• 1 of 2 high pressure switch has been removed.
• Accumulator has been removed.
• Receiver has been added.
E1E2
E1E2
E1E2
E1
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3
Refrigerating
oil
Refrigerant
New refrigerant
R410A
HFC-32: HFC-125 (50%:50%)
Pseudo-azeotropic refrigerant
Not included
A1/A1
72.6
-51.4
1.557
64
Non combustible
0
1730
From liquid phase in cylinder
Possible
Incompatible oil
Non
Non
Previous refrigerant
R22
R22 (100%)
Single refrigerant
Included
A1
86.5
-40.8
0.94
44.4
Non combustible
0.055
1700
Gas phase
Possible
Compatible oil
Light yellow
Non
Refrigerant
Composition (Ratio)
Refrigerant handling
Chlorine
Safety group (ASHRAE)
Molecular weight
Boiling point (:)
Steam pressure [25:](Mpa)
Saturated steam density [25:](Kg/K)
Combustibility
ODP w1
GWP w2
Refrigerant charge method
Additional charge on leakage
Kind
Color
Smell
w1:Ozone Destruction Parameter : based on CFC-11
w2 :Global Warmth Parameter : based on CO2
INFORMATION FOR THE AIR CONDITIONER WITH R410A REFRIGERANT
• This room air conditioner adopts an HFC refrigerant (R410A) which never destroys the ozone layer.
• Pay particular attention to the following points, though the basic installation procedure is same as that for R22 conditioners.
1As R410A has working pressure approximate 1.6 times as high as that of R22, some special tools and piping parts/
materials are required. Refer to the table below.
2Take sufficient care not to allow water and other contaminations to enter the R410A refrigerant during storage and
installation, since it is more susceptible to contaminations than R22.
3For refrigerant piping, use clean, pressure-proof parts/materials specifically designed for R410A. (Refer to 2. Refrigerant
piping.)
4Composition change may occur in R410A since it is a mixed refrigerant. When charging, charge liquid refrigerant to prevent
composition change.
NOTE : The unit of pressure has been changed to MPa on the international system of units(SI unit system).
The conversion factor is: 1(MPa [Gauge]) =10.2(kgf/ff[Gauge])
New Specification Current Specification
The incompatible refrigerating oil easily separates from
refrigerant and is in the upper layer inside the suction muffler.
Raising position of the oil back hole enables to back the
refrigerating oil of the upper layer to flow back to the
compressor.
Since refrigerant and refrigerating oil are compatible each,
refrigerating oil backs to the compressor through the lower
position oil back hole.
Compressor
Suction muffler
Oil back hole
Refrigerating oil
Refrigerant
Compressor
Suction muffler
Oil back hole
Refrigerating oil /Refrigerant
Compressor
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4
-30 -20 -10 0 10 20 30 40 50 60
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
(MPa [Gauge])
R410A
R22
Conversion chart of refrigerant temperature and pressure
Saturated liquid pressure
(:)
NOTE : The unit of pressure has been changed to MPa on the
international system of units(SI unit system).
The conversion factor is: 1(MPa [Gauge]) =10.2(kgf/ff[Gauge])
R410A tools Can R22 tools be used?
Gas leak detector
R410A has high pressures beyond the measurement range of existing
gauges. Port diameters have been changed to prevent any other refrigerant
from being charged into the unit.
Hose material and cap size have been changed to improve the pressure
resistance.
Dedicated for HFC refrigerant.
6.35 mm and 9.52 mm
Description
Clamp bar hole has been enlarged to reinforce the spring strength in the tool.
Provided for flaring work (to be used with R22 flare tool).
Provided to prevent the back flow of oil. This adapter enables you to use
vacuum pumps.
It is difficult to measure R410Awith a charging cylinder because the
refrigerant bubbles due to high pressure and high-speed vaporization
No
No
No
Yes
Yes
New
New
New
Gauge manifold
Charge hose
Torque wrench
Flare tool
Flare gauge
Vacuum pump
adapter
Electronic scale for
refrigerant charging
No : Not Substitutable for R410A Yes : Substitutable for R410A
No 12.7 mm and 15.88 mm
1.Tools dedicated for the air conditioner with R410A refrigerant
The following tools are required for R410A refrigerant. Some R22 tools can be substituted for R410A tools.
The diameter of the service port on the stop valve in outdoor unit has been changed to prevent any other refrigerant being
charged into the unit. Cap size has been changed from 7/16 UNF with 20 threads to 1/2 UNF with 20 threads.
2.Refrigerant piping
1Specifications
Use the refrigerant pipes that meet the following specifications.
• Use a copper pipe or a copper-alloy seamless pipe with a thickness of 0.8 mm. Never use any pipe with a thickness less
than 0.8mm, as the pressure resistance is insufficient.
Wall thickness
Outside diameter
Pipe mm
For liquid
For gas
6.35/9.52
9.52
12.7
15.88
0.8 mm/0.8 mm
0.8 mm
0.8 mm
1.0 mm
Heat resisting foam plastic
Specific gravity 0.045 Thickness 8 mm
Insulation material
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5
Electronic scale for refrigerant charging
Outdoor unit
Refrigerant gas
cylinder
operating valve
Refrigerant gas cylinder
for R410A with siphon
Refrigerant (liquid)
Service port
Gauge manifold
valve (for R410A)
Union
Liquid pipe
Gas pipe
Stop valve
Indoor unit
Charge hose (for R410A)
R410A
Pipe diameter
mm
6.35
9.52
12.7
15.88
17
22
26
29
Dimension of flare nut
R22
17
22
24
27
2Flaring work and flare nut
Flaring work for R410A pipe differs from that for R22 pipe.
For details of flaring work, refer to Installation manual “FLARING WORK”.
3.Refrigerant oil
Apply the special refrigeration oil (accessories: packed with indoor unit) to the flare and the union seat surfaces.
4.Air purge
• Do not discharge the refrigerant into the atmosphere.
Take care not to discharge refrigerant into the atmosphere during installation, reinstallation, or repairs to the refrigerant
circuit.
• Use the vacuum pump for air purging for the purpose of environmental protection.
5.Additional charge
For additional charging, charge the refrigerant from liquid phase of the gas cylinder.
If the refrigerant is charged from the gas phase, composition change may occur in the refrigerant inside the cylinder and the
outdoor unit. In this case, ability of the refrigerating cycle decreases or normal operation can be impossible. However,
charging the liquid refrigerant all at once may cause the compressor to be locked. Thus, charge the refrigerant slowly.
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