Mitsubishi Electric Mr.SLIM PUZ-HA24NHA User manual

SERVICE MANUAL
CONTENTS
1. REFERENCE MANUAL····························· 2
2. SAFETY PRECAUTION····························· 2
3. FEATURES ············································· 6
4. SPECIFICATIONS ···································· 7
5. DATA······················································ 8
6. OUTLINES AND DIMENSIONS················· 10
7. WIRING DIAGRAM································· 11
8. WIRING SPECIFICATIONS ······················ 12
9. REFRIGERANT SYSTEM DIAGRAM ············ 16
10. TROUBLESHOOTING ····························· 17
11. EASY MAINTENANCE FUNCTION ············ 70
12. FUNCTION SETTING ······························ 72
13. MONITORING THE OPERATION DATA BY THE REMOTE CONTROLLER ··········77
14. DISASSEMBLY PROCEDURE ·················· 87
R410A
Notes:
• This manual describes service
data of the outdoor units only.
[Model Name]
PUZ-HA24NHA
[Service Ref.]
PUZ-HA24NHA
PARTS CATALOG (OCB721)
SPLIT-TYPE, HEAT PUMP AIR CONDITIONERS
No. OCH721
REVISED EDITION-A
October 2019
Revision:
• Some descriptions have
been modified
in REVISED EDITION-A.
OCH721 is void.

2
OCH721A
2SAFETY PRECAUTION
1REFERENCE MANUAL
Before obtaining access to terminal, all supply circuits must be disconnected.
Preparation before the repair service.
• Prepare the proper tools.
• Prepare the proper protectors.
• Provide adequate ventilation.
• After stopping the operation of the air conditioner, turn off the power-supply beaker.
• Discharge the condenser before the work involving the electric parts.
Precautions during the repair service.
• Do not perform the work involving the electric parts with wet hands.
• Do not pour water into the electric parts.
• Do not touch the refrigerant.
• Do not touch the hot or cold areas in the refrigerating cycle.
• When the repair or the inspection of the circuit needs to be done without turning off the power,
exercise great caution not to touch the live parts.
• When opening or closing the valve below freezing temperatures, refrigerant may spurt out
from the gap between the valve stem and the valve body, resulting in injuries.
2-1. ALWAYS OBSERVE FOR SAFETY
INDOOR UNIT
Model name Service Ref. Service manual No.
PLA-A24EA7 PLA-A24EA7 OCH640/OCB640
PKA-A24KA7 PKA-A24KA7.TH OCH639/OCB639
PCA-A24KA7 PCA-A24KA7.TH OCH638/OCB638
PEAD-A24AA7 PEAD-A24AA7 HWE1608A/BWE01629A
PVA-A24AA7 PVA-A24AA7 MD-1404-K011/MD-1404-K012

3
OCH721A
Cautions for units utilizing refrigerant R410A
2-2. CAUTIONS RELATED TO NEW REFRIGERANT
Use new refrigerant pipes.
Make sure that the inside and outside of refrige-
rant piping is clean and it has no contaminants
such as sulfur, oxides, dirt, shaving particles, etc.
which are hazard to refrigerant cycle.
In addition, use pipes with specified thickness.
Store the piping indoors, and both ends of the
piping sealed until just before brazing.
(Leave elbow joints, etc. in their packaging.)
The refrigerant oil applied to flare and flange
connections must be ester oil, ether oil or
alkylbenzene oil in a small amount.
In case of using the existing pipes for R22, be careful with
the following.
· Be sure to clean the pipes and make sure that the insides
of the pipes are clean.
· Change flare nut to the one provided with this product.
Use a newly flared pipe.
· Avoid using thin pipes.
Charge refrigerant from liquid phase of gas
cylinder.
If the refrigerant is charged from gas phase, composition
change may occur in refrigerant and the efficiency will be
lowered.
Contamination inside refrigerant piping can cause deterio-
ration of refrigerant oil, etc.
If dirt, dust or moisture enters into refrigerant cycle, that can
cause deterioration of refrigerant oil or malfunction of com-
pressor.
If large amount of mineral oil enters, that can cause deterio-
ration of refrigerant oil, etc.
Do not use refrigerant other than R410A.
If other refrigerant (R22, etc.) is used, chlorine in refrige-
rant can cause deterioration of refrigerant oil, etc.
Use a vacuum pump with a reverse flow check
valve.
Vacuum pump oil may flow back into refrigerant cycle and
that can cause deterioration of refrigerant oil, etc.
Use the following tools specifically designed for
use with R410A refrigerant.
The following tools are necessary to use R410A refrigerant.
Handle tools with care.
If dirt, dust or moisture enters into refrigerant cycle, that can
cause deterioration of refrigerant oil or malfunction of com-
pressor.
Do not use a charging cylinder.
If a charging cylinder is used, the composition of refrigera-
nt will change and the efficiency will be lowered.
Flare tool
Electronic refrigerant
charging scale
Vacuum pump adaptor
Size adjustment gauge
Gauge manifold
Torque wrench
Gas leak detector
Charge hose
Tools for R410A
Use the specified refrigerant only.
Never use any refrigerant other than that specified.
Doing so may cause a burst, an explosion, or fire when the
unit is being used, serviced, or disposed of.
Correct refrigerant is specified in the manuals and on the
spec labels provided with our products.
We will not be held responsible for mechanical failure,
system malfunction, unit breakdown or accidents caused
by failure to follow the instructions.
Ventilate the room if refrigerant leaks during
operation. If refrigerant comes into contact with
a flame, poisonous gases will be released.

4
OCH721A
Electric weighing scale
Unit
[3] Service tools
Use the below service tools as exclusive tools for R410A refrigerant.
[1] Cautions for service
(1) Perform service after recovering the refrigerant left in unit completely.
(2) Do not release refrigerant in the air.
(3) After completing service, charge the cycle with specified amount of refrigerant.
(4) When performing service, install a filter drier simultaneously.
Be sure to use a filter drier for new refrigerant.
[2] Additional refrigerant charge
When charging directly from cylinder
· Check that cylinder for R410A on the market is a syphon type.
· Charging should be performed with the cylinder of syphon stood vertically. (Refrigerant is charged from liquid phase.)
No. Tool name Specifications
1Gauge manifold · Only for R410A
· Use the existing fitting specifications.
· Use high-tension side pressure of 5.3MPa·G or over.
2Charge hose · Only for R410A
· Use pressure performance of 5.09MPa·G or over.
3Electronic weighing scale —
4Gas leak detector · Use the detector for R134a, R407C or R410A.
5Adaptor for reverse flow check · Attach on vacuum pump.
6Refrigerant charge base —
7Refrigerant cylinder · Only for R410A · Top of cylinder (Pink)
· Cylinder with syphon
8Refrigerant recovery equipment —

5
OCH721A
2-3. CAUTIONS FOR REFRIGERANT PIPING WORK
New refrigerant R410A is adopted for replacement inverter series. Although the refrigerant piping work for R410A is same as
for R22, exclusive tools are necessary so as not to mix with different kind of refrigerant. Furthermore as the working pressure
of R410A is 1.6 time higher than that of R22, their sizes of flared sections and flare nuts are different.
1Thickness of pipes
Because the working pressure of R410A is higher compared to R22, be sure to use refrigerant piping with thickness shown
below. (Never use pipes of 7/256 in [0.7 mm] or below.)
Nominal
dimensions (in)
Outside
diameter (mm)
Thickness: in (mm)
R410A R22
1/4 6.35 1/32 [0.8] 1/32 [0.8]
3/8 9.52 1/32 [0.8] 1/32 [0.8]
1/2 12.70 1/32 [0.8] 1/32 [0.8]
5/8 15.88 5/128 [1.0] 5/128 [1.0]
3/4 19.05 — 5/128 [1.0]
2Dimensions of flare cutting and flare nut
The component molecules in HFC refrigerant are smaller compared to conventional refrigerants. In addition to that, R410A
is a refrigerant, which has higher risk of leakage because its working pressure is higher than that of other refrigerants.
Therefore, to enhance air tightness and strength, flare cutting dimension of copper pipe for R410A has been specified sep-
arately from the dimensions for other refrigerants as shown below. The dimension B of flare nut for R410A also has partly
been changed to increase strength as shown below. Set copper pipe correctly referring to copper pipe flaring dimensions
for R410A below. For 1/2 and 5/8 inch pipes, the dimension B changes.
Use torque wrench corresponding to each dimension.
Dimension A
Dimension B
3Tools for R410A (The following table shows whether conventional tools can be used or not.)
Tools and materials Use R410A tools Can R22 tools be used?
Gauge manifold Air purge, refrigerant charge and
operation check
Tool exclusive for R410A
Charge hose Tool exclusive for R410A
Gas leak detector Gas leak check Tool for HFC refrigerant
Refrigerant recovery equipment Refrigerant recovery Tool exclusive for R410A
Refrigerant cylinder Refrigerant charge Tool exclusive for R410A
Applied oil Apply to ared section Ester oil and alkylbenzene oil
(minimum amount)
Safety charger Prevent compressor malfunction when
charging refrigerant by spraying liquid
refrigerant
Tool exclusive for R410A
Charge valve Prevent gas from blowing out when
detaching charge hose
Tool exclusive for R410A
Vacuum pump Vacuum drying and air purge Tools for other refrigerants can be
used if equipped with adopter for
reverse ow check
(Usable if equipped with adopter for
reverse ow)
Flare tool Flaring work of piping Tools for other refrigerants can be
used by adjusting aring dimension
(Usable by adjusting aring
dimension)
Bender Bend the pipes
Tools for other refrigerants can be used
Pipe cutter Cut the pipes Tools for other refrigerants can be used
Welder and nitrogen gas cylinder Weld the pipes Tools for other refrigerants can be used
Refrigerant charging scale Refrigerant charge Tools for other refrigerants can be used
Vacuum gauge or thermistor vacuum
gauge and vacuum valve
Check the degree of vacuum. (Vacuum
valve prevents back ow of oil and
refrigerant to thermistor vacuum gauge)
Tools for other refrigerants can be
used
Charging cylinder Refrigerant charge Tool exclusive for R410A
: Prepare a new tool. (Use the new tool as the tool exclusive for R410A.)
: Tools for other refrigerants can be used under certain conditions.
: Tools for other refrigerants can be used.
Flare cutting dimensions
Nominal
dimensions (in)
Outside
diameter (mm)
Dimension A ( + 0
-0.4 )
R410A (in[mm]) R22 (mm)
1/4 6.35 11/32-23/64 [ 9.1] 9.0
3/8 9.52 1/2-33/64 [13.2] 13.0
1/2 12.70 41/64-21/32 [16.6] 16.2
5/8 15.88 49/64-25/32 [19.7] 19.4
3/4 19.05 — 23.3
Flare nut dimensions
Nominal
dimensions (in)
Outside
diameter (mm)
Dimension B
R410A (in[mm]) R22 (mm)
1/4 6.35 43/64 [17.0] 17.0
3/8 9.52 7/8 [22.0] 22.0
1/2 12.70 1-3/64 [26.0] 24.0
5/8 15.88 1-9/64 [29.0] 27.0
3/4 19.05 — 36.0

6
OCH721A
3 FEATURES
HIGH HEATING CAPACITY
High capacity compressor is equipped, which enables to keep
the equal capacity to the rating even when outside temperature
is 5°F [−15°C].
WIDE HEATING RANGE
The heating range is expanded to −13°F [−25°C] compared to
PUZ-A type which is up to 10°F [−12°C].
CHARGELESS SYSTEM
PRE-CHARGED REFRIGERANT IS SUPPLIED FOR PIPING LENGTH AT SHIPMENT.
Maximum 70 ft, 21m
The refrigerant circuit with LEV (Linear Expansion Valve) and power receiver always control the optimal refrigerant level
regardless of the length (maximum: 70 ft [21 m] and minimum: 16 ft [5 m]) of piping. The additional refrigerant charg-
ing work during installation often causes problems. It is completely eliminated by chargeless system. This unique system
improves the quality and reliability of the work done. It also helps to speed up the installation time.
PUZ-HA24NHA
Outdoor W.B. temp.
Heating capacity
-13°F
[-25°C]
-4°F
[-20°C]
5°F
[-15°C]
14°F
[-10°C]
23°F
[-5°C]
32°F
[0°C]
A24
HA24
30,000
(Btu/h)
20,000
16,500Btu/h
26,000Btu/h
0
Performance
about 60%UP
Expanded
Up to -13
°F
Outdoor wet-bulb temperature
A24 type
HA24 type
-13°F
10°F
-13°F
[-25°C]
-4°F
[-20°C]
5°F
[-15°C]
14°F
[-10°C]
23°F
[-5°C]
32°F
[0°C]

7
OCH721A
4 SPECIFICATIONS
Service Ref. PUZ-HA24NHA
Power supply Phase Single
Cycle 60 Hz
Voltage 208/230 V
MCA A 19
MOCP A 26
Breaker size A 25
External nish Munsell 3Y 7.8/1.1
Heat exchanger Plate n coil
Defrost method Reverse cycle
Crankcase heater kW —
Compressor Hermetic
Model DNB28FBAMT
Motor output kW 4.7
R.L.A. 9
L.R.A. 18
Starter type Inverter
Fan Fan(drive) × No. Propeller fan x 1
Fan motor output kW 0.086
Fan motor F.L.A. 0.40
Airow m3/min 55
CFM 1940
Sound pressure level (SPL) Cooling dB 52
Heating dB 53
Protection devices HP switch
Comp. Surface thermistor
Dimensions W mm 950
D mm 330 + 30
H mm 943
W in 37 - 13/32
D in 13 + 1-3/16
H in 37 - 1/8
Weight kg 85
lb 188
Refrigerant R410A
Charged kg 3.5
lb 7 + 11/16
Control Linear expansion valve
Oil Charged Model FVC68D
L 1.0
oz 33
Refrigerant piping Pipe size O.D.
Liquid
mm 9.52
in 3/8
Pipe size O.D.
Gas
mm 15.88
in 5/8
Connection method Indoor Flared
Connection method Outdoor Flared
Height difference
IU-OU
m Maximum 30
ft Maximum 100
Piping length m Maximum 50
ft Maximum 165

8
OCH721A
5-1. REFILLING REFRIGERANT CHARGE (R410A: oz, kg)
Service Ref. Piping length (one way)
PUZ-HA24NHA 50 ft 60 ft 70 ft 80 ft 90 ft 100 ft 110 ft 120 ft 130 ft 140 ft 150 ft 160 ft 165 ft Factory
charged
15 m 18 m 21 m 24 m 27 m 30 m 34 m 37 m 40 m 43 m 46 m 49 m 50 m
123 oz 123 oz 123 oz 130 oz 137 oz 144 oz 151 oz 158 oz 165 oz 172 oz 179 oz 186 oz 190 oz 123 oz
3.5 kg 3.5 kg 3.5 kg 3.7 kg 3.9 kg 4.1 kg 4.3 kg 4.5 kg 4.7 kg 4.9 kg 5.1 kg 5.3 kg 5.4 kg 3.5 kg
5-2. COMPRESSOR TECHNICAL DATA
(Winding resistance at 68°F [20°C])
Service Ref. PUZ-HA24NHA
Compressor model DNB28FBAMT
Winding resistance
(Ω)
U-V 0.74
U-W 0.74
W-V 0.74
5DATA
5-3. NOISE CRITERION CURVES
PUZ-HA24NHA
10
20
30
40
50
60
70
80
90
63 125 250 500 1000 2000 4000 8000
COOLING
MODE
HEATING
52
SPL(dB)
53
LINE
OCTAVE BAND SOUND PRESSURE LEVEL, dB (0 dB = 0.0002 µbar)
BAND CENTER FREQUENCIES, Hz
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
5 ft
3.3 ft
MICROPHONE
UNIT
GROUND
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
Additional charge is required for pipes longer than 70 ft.

9
OCH721A
5-4. STANDARD OPERATION DATA
Representative matching PLA-A24EA7
Mode COOLING HEATING
Total Capacity Btu/h 24,000 26,000
Input W 1,710 1,700
Electrical circuit
Indoor unit model PLA-A24EA7
Phase Single
Cycle 60 Hz
Voltage 208/230 V
Current 0.49 A
Outdoor unit model PUZ-HA24NHA
Phase Single
Cycle 60 Hz
Voltage 208/230 V
Current 7.40 A
Refrigerant circuit
Discharge pressure PSIG 383 325
Suction pressure PSIG 145 101
Discharge temperature °F 146 141
Condensing temperature °F 114 98
Suction temperature °F 57 40
Ref. Pipe length ft 25 25
Discharge pressure Mpa 2.64 2.24
Suction pressure Mpa 1 0.7
Discharge temperature °C 63.5 60.5
Condensing temperature °C 45.3 36.7
Suction temperature °C 14 4.4
Ref. Pipe length m 7.6 7.6
Indoor
side
Intake air temperature D.B. °F 80 70
Intake air temperature W.B. °F 67 60
Discharge air temperature D.B. °F 58 100
Outoor
side
Intake air temperature D.B. °F 95 47
Intake air temperature W.B. °F 75 43
Indoor
side
Intake air temperature D.B. °C 26.7 21.1
Intake air temperature W.B. °C 19.4 15.6
Discharge air temperature D.B. °C 14.3 37.5
Outoor
side
Intake air temperature D.B. °C 35 8.3
Intake air temperature W.B. °C 23.9 6.1
SHF 0.86 ―
BF 0.05 ―

10
OCH721A
6OUTLINES AND DIMENSIONS
PUZ-HA24NHA Unit: mm<inch>