Mitsubishi Electric CITY MULTI PUHY-400YMF-C How to use

AIR CONDITIONERS CITY MULTI
Models PUHY-400YMF-C, 500YMF-C
PUHY-P400YMF-C, P500YMF-C
PUHY-600YSMF-C, 650YSMF-C, 700YSMF-C, 750YSMF-C
PUHY-P600YSMF-C, P650YSMF-C, P700YSMF-C, P750YSMF-C
Service Handbook
Service Handbook PUHY-400YMF-C, 500YMF-C
PUHY-P400YMF-C, P500YMF-C
PUHY-600YSMF-C, 650YSMF-C, 700YSMF-C, 750YSMF-C
PUHY-P600YSMF-C, P650YSMF-C, P700YSMF-C, P750YSMF-C
HEAD OFFICE MITSUBISHI DENKI BLDG. MARUNOUCHI TOKYO 100-0005 TELEX J24532 CABLE MELCO TOKYO
Issued in May 2003 MEE02K140
Printed in Japan
New publication effective Jan 2003
Specifications subject to change without notice.
Service Handbook PUHY-400·500YMF-C/PUHY-P400·P500YMF-C/PUHY-600·650·700·750YSMF-C/PUHY-P600·P650·P700·P750YSMF-C

Contents
1 PRECAUTIONS FOR DEVICES
THAT USE R407C REFRIGERANT ......................................... 1
[1] Storage of Piping Material ............................................. 2
[2] Piping Machining ........................................................... 3
[3] Brazing ........................................................................... 4
[4] Airtightness Test ............................................................. 5
[5] Vacuuming ..................................................................... 5
[6] Charging of Refrigerant ................................................. 6
[7] Dryer .............................................................................. 6
2 COMPONENT OF EQUIPMENT ............................................. 7
[1] Appearance of Components .......................................... 7
[2] Refrigerant Circuit Diagram and Thermal Sensor ........ 18
[3] Electrical Wiring Diagram ............................................. 22
[4] Standard Operation Data ............................................. 24
[5] Function of Dip SW and Rotary SW ............................ 36
3 TEST RUN ............................................................................. 42
[1] Before Test Run ........................................................... 42
[2] Test Run Method .......................................................... 48
4 GROUPING REGISTRATION OF INDOOR UNITS WITH
M-NETREMOTE CONTROLLER ........................................... 49
5 CONTROL.............................................................................. 55
[1] Control of Outdoor Unit ................................................ 55
[2] Operation Flow Chart ................................................. 106
[3] List of Major Component Functions ........................... 111
[4] Resistance of Temperature Sensor ............................ 115
6 REFRIGERANT AMOUNT ADJUSTMENT ......................... 116
[1] Operating Characteristics and Refrigerant Amount ... 116
[2] Adjustment and Judgement of Refrigerant Amount ... 116
[3] Refrigerant Volume Adjustment Mode Operation....... 119
7 TROUBLESHOOTING ......................................................... 125
[1] Principal Parts ............................................................ 125
[2] Self-diagnosis and Countermeasures Depending
on the Check Code Displayed ................................... 153
175
[3] LED Monitor Display ..................................................
8
.............................. 199
[1]
........................................................... 199
[2] ......... 200
[3]
.......................................................... 200
[4] .......... 201
9 ...... 202
PREPARATION, REPAIRS AND REFRIGERANT
REFILLING WHEN REPAIRING LEAKS
Location of leaks: Extension piping or indoor units
(when cooling)
Location of leaks: Outdoor unit (Cooling mode)
Location of leaks: Extension piping or indoor units
(Heating mode)
Location of leaks: Outdoor unit (when heating)
CHECK THE COMPOSITION OF THE REFRIGERANT

Safety precautions
This equipment may not be applicable to
EN61000-3-2: 1995 and EN61000-3-3: 1995.
Please report to or take consent by the supply
authority before connection to the system.
Symbols used in the text
Warning:
Describes precautions thatshould be observed to
prevent danger of injury or death to the user.
Caution:
Describes precautionsthat should be observed to
preventdamage to the unit.
Symbols used in the illustrations
: Indicates an action that must be avoided.
: Indicates important instructions must be followed.
: Indicates a part which must be grounded.
: Beware of electric shock (This symbol is displayed on the
main unit label.) <Color: Yellow>
Warning:
Carefully read the labels affixed to the main unit.
Warning:
•Use the specified cables for wiring.Make the connections
securely so that the outside force of the cable is not
applied to the terminals.
- Inadequate connection and fastening may generate heat and
cause a fire.
•Have all electric work done by a licensedelectrician
according to “Electric Facility Engineering Standard”and
“Interior Wire Regulations”and the instructions given in
this manual and always use a dedicated circuit.
- If the power source capacity is inadequate or electric work is
performed improperly, electric shock and fire may result.
•Securely install the cover of control box and the panel.
- If the cover and panel are not installed properly, dust or water
may enter the outdoor unit and fire or electric shock may
result.
•After completing service work, make sure that refrigerant
gas is not leaking.
- If the refrigerant gas leaks and is exposed to a fan heater,
stove, oven, or other heat source, it may generate noxious
gases.
•Do not reconstruct or change the settings of the protection
devices.
- If the pressure switch, thermal switch, or other protection
device is shorted and operated forcibly, or parts other than
those specified by Mitsubishi Electric are used, fire or
explosion may result.
Before installing the unit, make sure you read all
the “Safety precautions”.
The “Saftey precautions” provide very important
points regarding safety. Make sure you follow
them.
This equipment may have an adverse effect on
equipment on the same electrical supply system.
Before installation and electric work

-1-
¡PRECAUTIONS FOR DEVICES THAT USE R407C REFRIGERANT
Caution
Do not use the existing refrigerant piping.
•The old refrigerant and refrigerator oil in the existing
piping contains a large amount of chlorine which may
cause the refrigerator oil of the new unit to deterio-
rate.
Use refrigerant piping made of phosphorus deoxi-
dized copper and copper alloy seamless pipes and
tubes”. In addition, be sure that the inner and outer
surfaces of the pipes are clean and free of hazardous
sulphur, oxides, dust/dirt, shaving particles, oils,
moisture, or any other contaminant.
•Contaminants on the inside of the refrigerant piping
may cause the refrigerant residual oil to deteriorate.
Store the piping to be used during installation indoors
and keep both ends of the piping sealed until just
before brazing. (Store elbows and other joints in a
plastic bag.)
•If dust, dirt, or water enters the refrigerant cycle,
deterioration of the oil and compressor trouble may
result.
Use ester oil, ether oil or alkylbenzene (small
amount) as the refrigerator oil to coat flares and
flange connections.
•The refrigerator oil will degrade if it is mixed with a
large amount of mineral oil.
Use liquid refrigerant to seal the system.
•If gas refrigerant is used to seal the system, the com-
position of the refrigerant in the cylinder will change
and performance may drop.
Do not use a refrigerant other than that specified.
•If another refrigerant is used, the chlorine in the
refrigerant may cause the refrigerator oil to
Use a vacuum pump with a reverse flow check valve.
•The vacuum pump oil may flow back into the refriger-
ant cycle and cause the refrigerator oil to deteriorate.
Do not use the following tools that have been used
with conventional refrigerants.
(Gauge manifold, charge hose, gas leak detector, re-
verse flow check valve, refrigerant charge base,
vacuum gauge, refrigerant recovery equipment)
•If the conventional refrigerant and refrigerator oil are
mixed in the R407C, the refrigerant may deterio-
rated.
•If water is mixed in the R407C, the refrigerator oil
may deteriorate.
•Since R407C does not contain any chlorine, gas
leak detectors for conventional refrigerants will not
react to it.
Do not use a charging cylinder.
•Using a charging cylinder may cause the refrigerant
to deteriorate.
Be especially careful when managing tools.
•If dust, dirt, or water that gets in the refrigerant cycle,
may cause the refrigerant to deteriorate.
If the refrigerant leaks, recover the refrigerant in the
refrigerant cycle, then recharge the cycle with the
specified amount of the liquid refrigerant indicated
on the air conditioner.
•Since R407C is a nonazeotropic refrigerant, if addi-
tionally charged when the refrigerant leaked, the com-
position of the refrigerant in the refrigerant cycle will
change and result in a drop in performance or abnor-
mal stopping.
deteriorate.

-2-
[1] Storage of Piping Material
(1) Storage location
Store the pipes to be used indoors. (Warehouse at site or owner’s warehouse)
Storing them outdoors may cause dirt, waste, or water to infiltrate.
(2) Pipe sealing before storage
Both ends of the pipes should be sealed until immediately before brazing.
Wrap elbows and T’s in plastic bags for storage.
* The new refrigerator oil is 10 times more hygroscopic than the conventional refrigerator oil (such as Suniso). Water
infiltration in the refrigerant circuit may deteriorate the oil or cause a compressor failure. Piping materials must be
stored with more care than with the conventional refrigerant pipes.