Mitsubishi Electric SUZ-KA25VA2 Operating manual

TECHNICAL & SERVICE MANUAL
No.OCH472
REVISED EDITION-A
SPLIT-TYPE, HEAT PUMP AIR CONDITIONERS
R410A
Outdoor unit
[Model names] [Service Ref.]
SUZ-KA25VA2 SUZ-KA25VA2.TH
SUZ-KA35VA2 SUZ-KA35VA2.TH
SUZ-KA50VA2 SUZ-KA50VA2.TH
SUZ-KA60VA2 SUZ-KA60VA2.TH
SUZ-KA71VA2 SUZ-KA71VA2.TH
CONTENTS
1. COMBINATION OF INDOOR AND OUTDOOR UNITS
.......
2
2. TECHNICAL CHANGES
....................................
3
3. PART NAMES AND FUNCTIONS......................6
4. SPECIFICATION................................................. 7
5. NOISE CRITERIA CURVES...............................9
6. OUTLINES AND DIMENSIONS........................ 10
7. WIRING DIAGRAM...........................................13
8. REFRIGERANT SYSTEM DIAGRAM..............17
9. ACTUATOR CONTROL....................................21
10. SERVICE FUNCTIONS.....................................22
11. TROUBLESHOOTING......................................22
12. DISASSEMBLY INSTRUCTIONS.....................63
Indication of
model name
NOTE:
This service manual describes technical data of the
outdoor units.
RoHS compliant products have <G> mark on the spec
name plate.
For servicing of RoHS compliant products, refer to the
RoHS Parts List.
HFC
utilized
R410A
SUZ-KA25VA2.TH
SUZ-KA35VA2.TH
September 2011
PARTS CATALOG (OCB472)
Revision:
• Errors in "11.
TROUBLESHOOTING"
have been corrected in
REVISED EDITION-A.
• Some descriptions have
been modified.
• Please void OCH472.

2
1COMBINATION OF INDOOR AND OUTDOOR UNITS
Heat pump type
Outdoor unit
SUZ-
SLZ-KA25VA(L).TH
SLZ-KA35VA(L).TH
SLZ-KA50VA(L).TH
SLZ-KA25VAQ.TH
SLZ-KA35VAQ.TH
SLZ-KA50VAQ.TH
SEZ-KD25VA(L).TH
SEZ-KD35VA(L).TH
SEZ-KD50VA(L).TH
SEZ-KD60VA(L).TH
SEZ-KD71VA(L).TH
SEZ-KD25VAQ.TH
SEZ-KD35VAQ.TH
SEZ-KD50VAQ.TH
SEZ-KD60VAQ.TH
SEZ-KD71VAQ.TH
MFZ-KA25VA-E4
MFZ-KA35VA-E4
MFZ-KA50VA-E4
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
OC320
OCH493
OB409
Indoor unit
Service
Manual No.
Service Ref.
Heat pump without electric heater
KA25VA2.TH KA60VA2.TH KA71VA2.THKA50VA2.TH
HWE0711
HWE1008
KA35VA2.TH
(NOTE) Please refer to the service manual of indoor unit or the technical data book for the combination data.
1-1. INDOOR UNIT SERVICE MANUAL
OCH472A

3
2TECHNICAL CHANGES
Refrigerant
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
None
None
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
None
Refrigerant
Composition (Ratio)
Refrigerant handling
Chlorine
Safety group (ASHRAE)
Molecular weight
Boiling point ()
Steam pressure [25](Mpa)
Saturated steam density [25](Kg/*)
Combustibility
ODP +1
GWP +2
Refrigerant charge method
Additional charge on leakage
Kind
Color
Smell
+1: Ozone Depletion Potential : based on CFC-11
+2: Global Warming Potential : 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.
1 As 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/cm2[Gauge])
New Specification Current Specification
The incompatible refrigerant 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
refrigerant oil of the upper layer to flow back to the
compressor.
Since refrigerant and refrigerant oil are compatible with
each other, refrigerant oil backs to the compressor through
the lower position oil back hole.
Compressor
Suction muffler
Oil back hole
Refrigerant oil
Refrigerant
Compressor
Suction muffler
Oil back hole
Refrigerant oil /Refrigerant
Compressor
OCH472A

4
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.
-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/cm2[Gauge])
OCH472A

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 (mm)
R22
17
22
24
27
• 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.
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 refrigerant 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.
2. Refrigerant piping
1Specifications
Use the refrigerant pipes that meet the following specifications.
Wall thicknessOutside diameter
Pipe mm mm
For liquid
For gas
6.35
9.52
9.52
12.7
15.88
0.8
0.8
0.8
0.8
1.0
Heat resisting foam plastic
Specific gravity 0.045 Thickness
8 mm
Insulation material
OCH472A