Mitsubishi PUHY-EP250 How to use

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Safety Precautions
Please read the following safety precautions carefully before installing the unit to ensure safety.
Make sure that this manual is passed on to the end user to retain for future reference.
Retain this manual for future reference. When the unit is reinstalled or repaired, have this manual available to those who pro-
vide these services. Make sure that this manual is passed on to any future users.
All electric work must be performed by qualified personnel.
Air tightness test must be performed by qualified personnel.
[1] General Precautions
Indicates a risk of death or serious injury.
Indicates a risk of serious injury or structural damage.
General Precautions
Do not use refrigerant other than the type in-
dicated in the manuals provided with the
unit and on the nameplate. Doing so may
cause the unit or pipes to burst, or result in
explosion or fire during use, during repair,
or at the time of disposal of the unit. It may
also be in violation of applicable laws. MIT-
SUBISHI ELECTRIC CORPORATION cannot
be held responsible for malfunctions or ac-
cidents resulting from the use of the wrong
type of refrigerant.
Do not install the unit in a place where large
amounts of oil, steam, organic solvents, or
corrosive gases, such as sulfuric gas, are
present or where acidic/alkaline solutions
or sprays containing sulfur are used fre-
quently. These substances can compro-
mise the performance of the unit or cause
certain components of the unit to corrode,
which can result in refrigerant leakage, wa-
ter leakage, injury, electric shock, malfunc-
tions, smoke, or fire.
Do not try to defeat the safety features of the
unit or make unauthorized setting changes.
Forcing the unit to operate the unit by de-
feating the safety features of the devices
such as the pressure switch or the tempera-
ture switch, making unauthorized changes
to the switch settings, or using accessories
other than the ones recommended by Mit-
subishi Electric may result in smoke, fire, or
explosion.
To reduce the risk of shorting, current leak-
age, electric shock, malfunctions, smoke, or
fire, do not splash water on electric parts.
To reduce the risk of electric shock, mal-
functions, smoke or fire, do not operate the
switches/buttons or touch other electrical
parts with wet hands.
To reduce the risk of pipe burst and explo-
sion, do not allow gas refrigerant and refrig-
erant oil to be trapped in the refrigerant
circuit.
To reduce the risk of burns or frost bites, do
not touch the refrigerant pipes or refrigerant
circuit components with bare hands during
and immediately after operation.
To reduce the risk of burns, do not touch
any electrical parts with bare hands during
or immediately after stopping operation.
To reduce the risk of injury from falling
tools, keep children away while installing,
inspecting, or repairing the unit.
Keep the space well ventilated. Refrigerant
can displace air and cause oxygen starva-
tion. If leaked refrigerant comes in contact
with a heat source, toxic gas may be gener-
ated.

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[2] Transportation a nd Installation
Always replace a fuse with one with the cor-
rect current rating. The use of improperly
rated fuses or a substitution of fuses with
steel or copper wire may result in bursting,
fire or explosion.
To reduce the risk of electric shock, smoke,
and fire due to infiltration of dust and water,
properly install all required covers and pan-
els on the terminal box and control box.
To reduce the risk of injury from units falling
or falling over, periodically check the instal-
lation base for damage.
Consult an authorized agency for the proper
disposal of the unit. Refrigerant oil and re-
frigerant that may be left in the unit pose a
risk of fire, explosion, or environmental pol-
lution.
To reduce the risk of being caught in rotat-
ing parts, electric shock, and burns, do not
operate the unit without all required panels
and guards being installed.
To reduce the risk of injury, do not sit,
stand, or place objects on the unit.
To reduce the risk of water leakage and mal-
functions, do not turn off the power immedi-
ately after stopping operation. Leave the
unit turned on for at least 5 minutes before
turning off the power.
Do not install the unit over things that are
vulnerable to water damage from condensa-
tion dripping.
To reduce the risk of injury, electric shock,
and malfunctions, do not touch or allow ca-
bles to come in contact with the edges of
components.
To reduce the risk of injury, do not touch the
heat exchanger fins or sharp edges of com-
ponents with bare hands.
Always wear protective gears when touch-
ing electrical components on the unit. Sev-
eral minutes after the power is switched off,
residual voltage may still cause electric
shock.
To reduce the risk of electric shock and
burns, always wear protective gear when
working on units.
To reduce the risk of injury, do not insert fin-
gers or foreign objects into air inlet/outlet
grills. If the unit is left on a damaged base, it
may fall and cause injury.
To reduce the risk of injury, always wear
protective gear when working on units.
Do not release refrigerant into the atmo-
sphere. Collect and reuse the refrigerant, or
have it properly disposed of by an autho-
rized agency. Refrigerant poses environ-
mental hazards if released into the air.
Transportation and Installation
Lift the unit by placing the slings at desig-
nated locations. Support the outdoor unit
securely at four points to keep it from slip-
ping and sliding. If the unit is not properly
supported, it may fall and cause personal
injury.
To reduce the risk of injury, do not carry the
product by the PP bands that are used on
some packages.
To reduce the risk of injury, products weigh-
ing 20 kg or more should be carried by two
or more people.

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[3] Installation
[4] Piping Work
Installation
Do not install the unit where there is a risk
of leaking flammable gas.
If flammable gas accumulates around the
unit, it may ignite and cause a fire or explo-
sion.
To reduce the risk of injury from coming in
contact with units, install units where they
are not accessible to people other than
maintenance personnel.
To reduce the risk of injury, properly dis-
pose of the packing materials so that chil-
dren will not play with them.
Properly dispose of the packing materials.
Plastic bags pose suffocation hazard to
children.
All drainage work should be performed by
the dealer or qualified personnel according
to the instructions detailed in the Installa-
tion Manual. Improper drainage work may
cause water leakage and resultant damage
to the furnishings.
Remove packing materials from the unit be-
fore operating the unit. Note that some ac-
cessories may be taped to the unit. Properly
install all accessories that are required. Fail-
ing to remove the packing materials or fail-
ing to install required accessories may
result in refrigerant leakage, oxygen depri-
vation, smoke, or fire.
Consult your dealer and take appropriate
measures to safeguard against refrigerant
leakage and resultant oxygen starvation. An
installation of a refrigerant gas detector is
recommended.
Any additional parts must be installed by
the dealer or qualified personnel. Only use
the parts specified by Mitsubishi Electric.
Installation by unauthorized personnel or
use of unauthorized parts or accessories
may result in water leakage, electric shock,
or fire.
Take appropriate safety measures against
wind gusts and earthquakes to prevent the
unit from toppling over and causing injury.
To reduce the risk of injury from units falling
or falling over, install the unit on a surface
that is strong enough to support its weight.
Do not install the unit over things that are
vulnerable to water damage. Provide an ad-
equate collective drainage system for the
drain water from unit as necessary.
To reduce the risk of damage to the unit and
resultant electric leak and electric shock,
keep small animals, snow, and rain water
from entering the unit by closing the gap in
the pipe and wire access holes.
To reduce the risk of rain water or drain wa-
ter from entering the room and damaging
the interior, drainage work must be per-
formed by your dealer or qualified person-
nel according to the instructions detailed in
the Installation Manual.
Piping Work
To reduce the risk of injury, including frost
bites, that may result from being blasted
with refrigerant, use caution when operat-
ing the refrigerant service valve. If refriger-
ant leaks out and comes in contact with an
open flame, toxic gases may be generated.
To reduce the risk of refrigerant catching
fire and causing burns, remove the refriger-
ant gas and the residual refrigerant oil in the
pipes before heating them.

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[5] Wiring Work
To reduce the risk of pipe damage, refriger-
ant leakage, and oxygen deprivation, use
pipes that meet the pipe thickness specifi-
cations, which vary by the type of refriger-
ant used, pipe diameter, and pipe material.
To reduce the risk of pipe burst or explo-
sion, evacuate the refrigerant circuit using a
vacuum pump, and do not purge the system
with refrigerant.
To reduce the risk of explosion and deterio-
ration of refrigerant oil caused by chloride,
do not use oxygen, flammable gas, or refrig-
erant that contains chloride as a pressuriz-
ing gas.
To prevent explosion, do not heat the unit
with refrigerant gas in the refrigerant circuit.
To reduce the risk of oxygen deprivation
and gas poisoning, check for gas leakage
and keep fire sources away.
Insulate pipe connections after completing
the air tightness test. Performing an air
tightness test with the pipe being insulated
may lead to failure to detect refrigerant leak-
age and cause oxygen deprivation.
To reduce the risk of pipe damage and re-
sultant refrigerant leakage and oxygen de-
privation, keep the field-installed pipes out
of contact with the edges of components.
To reduce the risk of pipe bursting and ex-
plosion due to abnormal pressure rise, do
not allow any substances other than R410A
(such as air) to enter the refrigerant circuit.
To keep the ceiling and floor from getting
wet due to condensation, properly insulate
the pipes.
Wiring Work
To reduce the risk of wire breakage, over-
heating, smoke, and fire, keep undue force
from being applied to the wires.
To reduce the risk of wire breakage, over-
heating, smoke, or fire, properly secure the
cables in place and provide adequate slack
in the cables so as not to stress the termi-
nals.
All electric work must be performed by a
qualified electrician according to the local
regulations, standards, and the instructions
detailed in the Installation Manual. Capacity
shortage to the power supply circuit or im-
proper installation may result in malfunc-
tion, electric shock, smoke, or fire.
To reduce the risk of electric shock, smoke,
or fire, install an inverter circuit breaker on
the power supply to each unit.
Use properly rated breakers and fuses (in-
verter circuit breaker, local switch <switch +
fuse>, no-fuse breaker). The use of a break-
er with a breaking capacity greater than the
specified capacity may cause electric
shock, malfunctions, smoke, or fire.
To reduce the risk of current leakage, over-
heating, smoke, or fire, use properly rated
cables with adequate current carrying ca-
pacity.
Proper grounding must be provided by a li-
censed electrician.
Do not connect the grounding wire to a gas
pipe, water pipe, lightning rod, or telephone
wire. Improper grounding may result in
electric shock, smoke, fire, or malfunction
due to electrical noise interference.
To reduce the risk of current leakage, wire
breakage, smoke, or fire, keep the wiring
out of contact with the refrigerant pipes and
other parts, especially sharp edges.

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[6] Relocation and Repairs
[7] Additional Precautions
Relocation and Repairs
To reduce the risk of refrigerant leakage,
water leakage, injury, electric shock, and
fire, units should only be moved or repaired
by your dealer or qualified personnel.
To reduce the risk of wire shorting, electric
leak, electric shock, smoke, or fire, do not
perform maintenance work in the rain.
To reduce the risk of injury, electric shock,
and fire, properly reinstall all removed com-
ponents after completing repair work.
To reduce the risk of wire shorting, electric
shock, malfunctions, or fire, keep circuit
boards dust free, and do not touch them
with your hands or tools.
To reduce the risk of refrigerant and water
leakage, check the pipe supports and insu-
lation for damage during inspection or re-
pair, and replace or repair the ones that are
found to be deteriorated.
Additional Precautions
To avoid damage to the unit, use appropri-
ate tools to install, inspect, or repair the
unit.
To reduce the risk or malfunction, turn on
the power at least 12 hours before starting
operation, and leave the power turned on
throughout the operating season.
Recover all refrigerant in the units, and dis-
pose of it properly according to any applica-
ble laws and regulations.
Provide a maintenance access to allow for
the inspection of pipes above the ceiling or
the buried pipes.
Take appropriate measures against electri-
cal noise interference when installing the air
conditioners in hospitals or facilities with
radio communication capabilities. Inverter,
high-frequency medical, or wireless com-
munication equipment as well as power
generators may cause the air conditioning
system to malfunction. Air conditioning
system may also adversely affect the opera-
tion of these types of equipment by creating
electrical noise.
To reduce the risk of damage to the unit,
leave the valves on the unit closed until re-
frigerant charging is completed.
Place a wet towel on the refrigerant service
valve before brazing the pipes to keep its
temperature from rising above 120ºC and
damaging the surrounding equipment.
Direct the blazing torch flame away from the
adjacent cables and sheet metal to keep
them from being overheated and damaged.
Prepare tools for exclusive use with R410A.
Do not use the following tools if they have
been used with the conventional refrigerant
(R22): gauge manifold, charging hose, re-
frigerant leak detector, check valve, refrig-
erant charge spout, vacuum gauge, and
refrigerant recovery equipment. R410A
does not contain chloride, so leak detectors
for use with older types of refrigerants will
not detect an R410A leak. Infiltration of the
residual refrigerant, refrigerant oil, or water
on these tools may cause the refrigerant oil
in the new system to deteriorate or damage
the compressor.
To reduce the risk of the vacuum pump oil
backflowing into the refrigerant cycle and
causing the refrigerant oil to deteriorate,
use a vacuum pump with a check valve.
Have a set of tools for exclusive use with
R410A. Consult your nearest Mitsubishi
Electric Dealer.
Keep dust, dirt, and water off charging hose
and flare tool. Infiltration of dust, dirt, or wa-
ter into the refrigerant circuit may cause the
refrigerant oil to deteriorate or damage the
compressor.

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Use refrigerant piping and couplings that
meet the applicable standards. For refriger-
ant pipes, use pipes made of phosphorus
deoxidized copper. Keep the inner and out-
er surfaces of pipes and couplings clean
and free of such contaminants as sulfur, ox-
ides, dust, dirt, shaving particles, oil, and
moisture. Failure to follow these directions
may result in the deterioration of refrigerant
oil or compressor damage.
Store the piping materials indoors, and
keep both ends of the pipes sealed until im-
mediately before brazing. Keep elbows and
other joints in plastic bags. Infiltration of
dust, dirt, or water into the refrigerant cir-
cuit may cause the refrigerant oil to deterio-
rate or damage the compressor.
Apply ester oil, ether oil, or a small amount
of alkyl benzene to flares and flanges. The
use and accidental infiltration of mineral oil
into the system may cause the refrigerant
oil to deteriorate or damage the compres-
sor.
To reduce the risk of oxidized film from en-
tering the refrigerant pipe and causing the
refrigerant oil to deteriorate or damaging
the compressor, braze pipes under nitrogen
purge.
Do not use the existing refrigerant piping. A
large amount of chloride that is contained in
the residual refrigerant and refrigerant oil in
the existing piping may cause the refriger-
ant oil in the new unit to deteriorate or dam-
age the compressor.
Charge refrigerant in the liquid state. If re-
frigerant is charged in the gas phase, the
composition of the refrigerant in the cylin-
der will change, compromising the unit's
performance.
Do not use a charging cylinder. The use of a
charging cylinder will change the composi-
tion of the refrigerant, compromising the
unit's performance.
Charge the system with an appropriate
amount of refrigerant in the liquid phase.
Refer to the relevant sections in the manu-
als to calculate the appropriate amount of
refrigerant to be charged. Refrigerant over-
charge or undercharge may result in perfor-
mance drop or abnormal stop of operation.
To reduce the risk of power capacity short-
age, always use a dedicated power supply
circuit.
To reduce the risk of both the breaker on the
product side and the upstream breaker from
tripping and causing problems, split the
power supply system or provide protection
coordination between the earth leakage
breaker and no-fuse breaker.
Have a backup system, if failure of the unit
has a potential for causing significant prob-
lems or damages.

CONTENTS
HWE12050 GB
Chapter 1 Piping Work
1-1 Preparation for Piping Work.................................................................................................................. 3
1-2 Handling and Characteristics of Piping Materials, Refrigerant, and Refrigerant Oil ....................... 5
1-3 Working with Refrigerant Piping......................................................................................................... 10
Chapter 2 Restrictions
2-1 System Configurations ........................................................................................................................ 17
2-2 Types and Maximum Allowable Length of Cables ............................................................................ 18
2-3 Switch Settings..................................................................................................................................... 19
2-4 M-NET Address Settings ..................................................................................................................... 20
2-5 Demand Control Overview .................................................................................................................. 26
2-6 System Connection Example .............................................................................................................. 28
2-7 Example System with an MA Remote Controller .............................................................................. 30
2-8 Example System with an ME Remote Controller............................................................................... 40
2-9 Example System with an MA and an ME Remote Controller............................................................ 42
2-10 Restrictions on Refrigerant Pipes ...................................................................................................... 44
Chapter 3 Major Components, Their Functions and Refrigerant Circuits
3-1 External Appearance and Refrigerant Circuit Components of Outdoor Unit ................................. 51
3-2 Outdoor Unit Refrigerant Circuit Diagrams ....................................................................................... 56
3-3 Functions of the Major Components of Outdoor Unit ...................................................................... 57
3-4 Functions of the Major Components of Indoor Unit ......................................................................... 60
Chapter 4 Electrical Components and Wiring Diagrams
4-1 Outdoor Unit Circuit Board Arrangement .......................................................................................... 63
4-2 Outdoor Unit Circuit Board Components .......................................................................................... 65
4-3 Outdoor Unit Electrical Wiring Diagrams........................................................................................... 71
4-4 Transmission Booster Electrical Wiring Diagrams........................................................................... 73
Chapter 5 Control
5-1 Dipswitch Functions and Factory Settings........................................................................................ 77
5-2 Outdoor Unit Control ........................................................................................................................... 83
5-3 Operation Flowcharts .......................................................................................................................... 96
Chapter 6 Test Run
6-1 Read before Test Run ........................................................................................................................ 103
6-2 MA and ME Remote Controller Functions and Specifications....................................................... 104
6-3 Making the Group and Interlock Settings from an ME Remote Controller ................................... 105
6-4 Selecting Remote Controller Functions from an ME Remote Controller...................................... 109
6-5 Making Interlock Settings from an MA Remote Controller............................................................. 111
6-6 Changing the Room Temperature Detection Position.................................................................... 117
6-7 Test Run Method ................................................................................................................................ 118
6-8 Operation Characteristics and Refrigerant Charge ........................................................................ 121
6-9 Evaluating and Adjusting Refrigerant Charge.................................................................................121
6-10 The Following Symptoms Are Normal ............................................................................................. 127
6-11 Standard Operation Data (Reference Data) ..................................................................................... 128
Chapter 7 Troubleshooting Using Error Codes
7-1 Error Code and Preliminary Error Code Lists ................................................................................. 145
7-2 Error Code Definitions and Solutions: Codes [0 - 999]................................................................... 148
7-3 Error Code Definitions and Solutions: Codes [1000 - 1999]........................................................... 149
7-4 Error Code Definitions and Solutions: Codes [2000 - 2999]........................................................... 153
7-5 Error Code Definitions and Solutions: Codes [3000 - 3999]........................................................... 159
7-6 Error Code Definitions and Solutions: Codes [4000 - 4999]........................................................... 160
7-7 Error Code Definitions and Solutions: Codes [5000 - 5999]........................................................... 173
7-8 Error Code Definitions and Solutions: Codes [6000 - 6999]........................................................... 180
7-9 Error Code Definitions and Solutions: Codes [7000 - 7999]........................................................... 196

CONTENTS
HWE12050 GB
Chapter 8 Troubleshooting Based on Observed Symptoms
8-1 MA Remote Controller Problems ...................................................................................................... 207
8-2 ME remote Controller Problems ....................................................................................................... 211
8-3 Refrigerant Control Problems ........................................................................................................... 215
8-4 Checking Transmission Waveform and for Electrical Noise Interference .................................... 220
8-5 Pressure Sensor Circuit Configuration and Troubleshooting Pressure Sensor Problems ........ 223
8-6 Troubleshooting Solenoid Valve Problems .....................................................................................225
8-7 Troubleshooting Outdoor Unit Fan Problems ................................................................................. 227
8-8 Troubleshooting LEV Problems........................................................................................................ 228
8-9 Troubleshooting Inverter Problems ................................................................................................. 234
8-10 Control Circuit .................................................................................................................................... 243
8-11 Measures for Refrigerant Leakage ................................................................................................... 246
8-12 Compressor Replacement Instructions ........................................................................................... 248
8-13 Troubleshooting Problems Using the LED Status Indicators on the Outdoor Unit..................... 250
Chapter 9 LED Status Indicators on the Outdoor Unit Circuit Board
9-1 LED Status Indicators ........................................................................................................................ 253
9-2 LED Status Indicators Table ............................................................................................................. 256

- 1 -
HWE12050 GB
Chapter 1 Piping Work
1-1 Preparation for Piping Work ................................................................................................................ 3
1-1-1 Read before Servicing ............................................................................................................................ 3
1-1-2 Tool Preparation ..................................................................................................................................... 4
1-2 Handling and Characteristics of Piping Materials, Refrigerant, and Refrigerant Oil...................... 5
1-2-1 Piping Materials ...................................................................................................................................... 5
1-2-2 Storage of Piping Materials..................................................................................................................... 7
1-2-3 Pipe Processing ...................................................................................................................................... 7
1-2-4 Characteristics of the New and Conventional Refrigerants .................................................................... 8
1-2-5 Refrigerant Oil......................................................................................................................................... 9
1-3 Working with Refrigerant Piping ....................................................................................................... 10
1-3-1 Pipe Brazing.......................................................................................................................................... 10
1-3-2 Air Tightness Test................................................................................................................................. 11
1-3-3 Vacuum Drying ..................................................................................................................................... 12
1-3-4 Refrigerant Charging............................................................................................................................. 13