Mitsubishi Electric CAHV-P500YA-HPB User manual

Air-Cooled Heat Pump Unit CAHV
Instructions Manual
CONTENTS
Thoroughly read this manual prior to use.
Save this manual for future reference.
Some of the items in this manual may not apply to made-to-order units.
Safety Precautions................................................................... 2
1. External Appearance and Components ............................... 6
2. Operating the Unit................................................................ 7
[1] Initial Operation................................................................. 7
[2] Daily Operation ................................................................. 7
[3] Using the Unit in Sub-freezing or Snowy Conditions......... 8
3. Troubleshooting ................................................................... 9
[1] Diagnosing Problems Using Error Codes ......................... 9
[2] Calling for Service........................................................... 12
4. Safety and Maintenance Information ................................. 13
[1] Contact information............................................................ 13
[2] Refrigerant Information ................................................... 13
[3] Periodic Inspection.......................................................... 13
[4] Parts Inspection and Replacement Intervals................... 16
[5] Safety, Ventilation, and Fire-Extinguishing Devices........ 16
5. Warranty ............................................................................ 17
[1] Terms and Conditions..................................................... 17
[2] Exclusions....................................................................... 17
6. Main Specifications............................................................ 18
CAHV-P500YA-HPB

2/20
Safety Precautions
• Thoroughly read the following safety precautions prior to use.
• Observe these precautions carefully to ensure safety.
■General
WARNING
To reduce the risk of burns or electric shock,
do not touch exposed pipes and wires.
To reduce the risk of burns or frost bites, do
not touch the pipes or refrigerant circuit
components with bare hands during and
immediately after operation.
To reduce the risk of shorting, current leakage,
electric shock, malfunctions, smoke, or fire, do
not splash water on electric parts.
To reduce the risk of injury, keep children away
while installing, inspecting, or repairing the
unit.
To reduce the risk of electric shock,
malfunctions, smoke or fire, do not operate
the switches/buttons or touch other electrical
p
arts with wet hands.
To reduce the risk of fire or explosion, do not
use volatile or flammable substances as a heat
carrier.
To reduce the risk of electric shock and injury
from the fan or other rotating parts, stop the
operation and turn off the main power before
cleaning, maintaining, or inspecting the unit.
CAUTION
WARNING
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
frequently.
These substances can compromise the
performance of the unit or cause certain
components of the unit to corrode, which can
result in refrigerant leakage, water leakage,
injury, electric shock, malfunctions, 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
defeating the safety features of the devices
such as the pressure switch or the temperature
switch, making unauthorized changes to the
switch settings, or using accessories other
than the ones recommended by Mitsubishi
Electric may result in smoke, fire, or explosion. Keep the space well ventilated.
Refrigerant can displace air and cause oxygen
starvation. If leaked refrigerant comes in
contact with a heat source, toxic gas may be
generated.
IMPORTANT
Indicates a risk of injury or structural damage
Indicates a risk of death or serious injury
Indicates a risk of damage to the unit or other components in the system

3/20
If any abnormality (e.g., burning smell) is
noticed, stop the operation, turn off the
power switch, and consult your dealer.
Continuing the operation may result in electric
shock, malfunctions, or fire.
Always replace a fuse with one with the
correct current rating.
The use of improperly rated fuses or a
substitution of fuses with steel or copper wire
may result in fire or explosion.
Properly install all required covers and
panels on the terminal box and control box
to keep moisture and dust out.
Dust accumulation and water may result in
electric shock, smoke, or fire.
Consult an authorized agency for the
proper disposal of the unit.
Refrigerant oil and refrigerant that may be left
in the unit pose a risk of fire, explosion, or
environmental pollution.
CAUTION
To reduce the risk of fire or explosion, do not
place flammable materials or use flammable
sprays around the unit.
The model of heat pump unit described in this
manual is not intended for use to preserve
food, animals, plants, precision instruments, or
art work.
Do not operate the unit without panels and
safety guards properly installed.
To reduce the risk of injury, do not sit, stand,
or place objects on the unit.
To reduce the risk of adverse effects on plants
and animals, do not place them where they
are directly exposed to discharge air from the
unit.
To reduce the risk of injury, do not touch the
heat exchanger fins or sharp edges of
components with bare hands.
To reduce the risk of injury, do not insert
fingers 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, wear protective
gear when working on the unit.
Do not place a container filled with water
on the unit.
If water spills on the unit, it may result in
shorting, current leakage, electric shock,
malfunction
,
smoke
,
or fire.
Always wear protective gears when
touching electrical components on the
unit.
Several minutes after the power is switched
off, residual voltage may still cause electric
shock.
In areas where temperature drops to freezing,
use an anti-freeze circuit and leave the main
power turned on to prevent the water in the
water circuit from freezing and damaging the
unit or causing water leakage and resultant
damage to the furnishings.
Do not connect the makeup water pipe
directly to the potable water pipe. Use a
cistern tank between them.
Connecting these pipes directly may cause the
water in the unit to migrate into the potable
water and cause health problems.
Do not install the unit on or over things
that are vulnerable to water damage.
Condensation may drip from the unit.
Do not release refrigerant into the
atmosphere. Collect and reuse the
refrigerant, or have it properly disposed of
by an authorized agency.
Refrigerant poses environmental hazards if
released into the air.

4/20
■Installation
■Transportation and repairs
WARNING
WARNING
CAUTION
Periodically check the installation base for
damage.
To reduce the risk of shorting, electric shock,
fire, or malfunction, do not touch the circuit
board with tools or with your hands, and do
not allow dust to accumulate on the circuit
board.
Use clean tap water.
The use of acidic or alkaline water or water
high in chlorine may corrode the unit or the
pipes, causing water leakage and resultant
dama
g
e to the furnishin
g
s.
In areas where temperature can drop low
enough to cause the water in the pipes to
freeze, operate the unit often enough to
prevent the water from freezing.
Frozen water in the water circuit may cause
the water to freeze, resulting in burst pipes
and damage to the unit or the furnishings.
To prevent environmental pollution,
dispose of brine in the unit or cleaning
solutions according to the local
regulations.
It is punishable by law not to dispose of them
according to the applicable laws.
Periodically inspect and clean the water
circuit.
Dirty water circuit may compromise the unit's
performance or corrodes the unit or cause
water leakage and resultant damage to the
furnishings.
The water heated by the heat pump is not
suitable for use as drinking water or for
cooking.
It may cause health problems or degrade food.
In areas where temperature drops to
freezing during the periods of non-use,
blow the water out of the pipes or fill the
pipes with anti-freeze solution.
Not doing so may cause the water to freeze,
resulting in burst pipes and damage to the unit
or the furnishings.
The unit should be moved, disassembled,
or repaired only by qualified personnel. Do
not alter or modify the unit.
Improper repair or unauthorized modifications
may result in refrigerant leakage, water
leakage, injury, electric shock, or fire.
After disassembling the unit or making
repairs, replace all components as they
were.
Failing to replace all components may result in
injury, electric shock, or fire.
As an anti-freeze, use ethylene glycol or
propylene glycol diluted to the specified
concentration.
The use of other types of anti-freeze solution
may cause corrosion and resultant water
leakage. The use of flammable anti-freeze may
cause fire or explosion.

5/20
■General
IMPORTANT
To avoid damage to the unit, use appropriate
tools to install, inspect, or repair the unit.
To reduce the risk of malfunctions, use the unit
within its operating range.
To reduce the risk or malfunction, turn on the
power at least 12 hours before starting
operation, and leave the power turned on
throu
g
hout the o
p
eratin
g
season.
To maintain optimum performance and reduce
the risk of malfunction, keep the air pathway
clear.
Do not unnecessarily change the switch
settings or touch other parts in the
refrigerant circuit.
Doing so may change the operation mode or
damage the unit.
Recover all refrigerant from the unit.
It is punishable by law to release refrigerant into
the atmosphere.
Do not switch on or off the main power in a
cycle of shorter than 10 minutes.
Short-cycling the compressor may damage the
compressor.
Check the water system, using a relevant
manual as a reference.
Using the system that does not meet the
standards (including water quality and water
flow rate) may cause the water pipes to
corrode.
To ensure proper operation of the unit,
periodically check for proper concentration
of anti-freeze.
Inadequate concentration of anti-freeze may
compromise the performance of the unit or
cause the unit to abnormally stop.

6/20
1. External Appearance and Components
Discharge air outlet
Intake air inlet
Service panel
Hot water outlet
Control box
Hot water inlet
Service panel
Control box

7/20
2. Operating the Unit
[1] Initial Operation
1. Make sure the ON/OFF switch that controls the unit on the on-site control panel is switched off.
2. Switch on the main power.
3. Leave the main power switched on for at least 12 hours before turning on the ON/OFF switch that
controls the unit on the on-site control panel to warm up the compressor.
4. Switch on the ON/OFF switch that controls the unit on the on-site control panel.
[2] Daily Operation
To start an operation
Switch on the ON/OFF switch that controls the unit on the on-site control panel.
Note
The unit described in this manual features a circuit that protects the compressor from short-cycling. Once the
compressor stops, it will not start up again for up to 10 minutes. If the unit does not start when the ON/OFF
switch is turned on, leave the switch turned on for 10 minutes. The unit will automatically start up within 10
minutes.
To stop an operation
Switch off the ON/OFF switch that controls the unit on the on-site control panel.
IMPORTANT
・Keep the main power turned on throughout the operating season, in which the unit is stopped for three
days or shorter (e.g., during the night and on weekends).
・Unless in areas where the outside temperature drops to freezing, switch off the main power when the unit
will not be operated for four days or longer. (Switch off the water circulating pump if the pump is
connected to a separate circuit.)
・When resuming operation after the main power has been turned off for a full day or longer, follow the
steps under “Initial Operation” above.
・If the main power was turned off for six days or longer, make sure that the clock on the unit is correct.

8/20
[3] Using the Unit in Sub-freezing or Snowy Conditions
・Remove the snow off the unit before switching on the ON/OFF switch.
・In areas where the outside air drops below freezing, leave the main switch turned on even when the unit
will not be operated for four days or longer. Leave the switch on the water circulation pump turned on if
the pump is connected to a separate circuit.
・ If the unit is left turned off for a while (e.g., overnight) when the outside temperature drops below
freezing, the water in the water circuit will freeze and damage the pipes and the heat exchanger.
・ The recommended electric circuit has an anti-freeze circuit. For this circuit to function, the main
power must be turned on.
・ If the water circulation pump is connected differently from the recommended way, make sure the
circuit has some type of anti-freeze function*.
(* A function that automatically operates the water circulation pump to prevent the water in the circuit
from freezing when the water temperature drops.)
In areas where temperature drops to freezing,
use an anti-freeze circuit and leave the main
power turned on to prevent the water in the
water circuit from freezing and damaging the
unit or causing water leakage and resultant
damage to the furnishings.
In areas where temperature drops to
freezing during the periods of non-use,
blow the water out of the pipes or fill the
pipes with anti-freeze solution.
Not doing so may cause the water to freeze,
resulting in burst pipes and damage to the unit
or the furnishings.
In areas where temperature can drop low
enough to cause the water in the pipes to
freeze, operate the unit often enough to
prevent the water from freezing.
Frozen water in the water circuit may cause
the water to freeze, resulting in burst pipes and
damage to the unit or the furnishings.

9/20
3. Troubleshooting
If a problem occurs, please check the following before calling for service.
(1) Check the error code against the table below.
(2) Check for possible causes of problems listed in the "Cause" column that correspond to the error code.
(3) If the error codes that appear on the display are not listed in the table below, or no problems were found with the items
listed in the "Cause" column, please consult your maintenance provider.
[1] Diagnosing Problems Using Error Codes
Error
code *1
(PCB *2)
Error type Cause
(Installation/Setting error)
Cause
(Parts problems)
Error reset *3
Unit
side
(PCB)
Remote
SWS1
Operation
SW
A000 Unreset errors *4 Some of the errors have not been reset.
A-P0 Power failure *5 Power failure occurred when the operation
switch is switched on.
AFSA
Water supply cutoff
(Flow switch has been triggered.)
The water flow rate dropped below the flow
switch threshold.
Water supply cutoff
Open-circuited flow switch
Broken flow switch wiring
•
•
AHP1 High pressure fault No water
Water supply cutoff
Linear expansion valve fault
High-pressure sensor fault
•
•
AdSH
Compressor flooding Fan motor fault/broken fan motor wiring
Low-pressure sensor fault
Shell temperature thermistor fault
High-pressure sensor fault
Discharge refrigerant temperature
thermistor fault
Linear expansion valve fault
Hot gas solenoid valve fault
•
•
•
•
•
•
•
1303
Suction pressure fault The outside temperature was below the
operating range.
Sudden frosting or heavy snow clogged up
the air-refrigerant heat exchanger.
Low-pressure sensor fault
Air-refrigerant heat exchanger inlet
thermistor fault
Suction refrigerant temperature
thermistor fault
LEV bypass check valve fault
Linear expansion valve fault
Fan motor fault/broken fan motor wiring
Refrigerant deficiency (refrigerant gas leak)
•
•
•
•
•
•
•
1103
Shell temperature fault The outside temperature was above the
upper limit of the operating range.
Excessive oil flow
Shell temperature thermistor fault
Linear expansion valve fault
•
•
5109 Ther-
mistor
fault
Outside temperature (TH9) Broken or shorted thermistor wiring•
5110
5112
Inlet water temperature (TH10 MAIN Circuit)
Inlet water temperature (TH12 SUB Circuit)
Broken or shorted thermistor wiring•
5111
5113
Outlet water temperature (TH11 MAIN Circuit)
Outlet water temperature (TH13 SUB Circuit)
Broken or shorted thermistor wiring•
5103
5107
Shell temperature (TH3 MAIN Circuit)
Shell temperature (TH7 SUB Circuit)
Broken or shorted thermistor wiring•
5101
5105
Discharge temperature (TH1 MAIN Circuit)
Discharge temperature (TH5 SUB Circuit)
Broken or shorted thermistor wiring•
5102
5106
Inlet temperature (TH2 MAIN Circuit)
Inlet temperature (TH6 SUB Circuit)
Broken or shorted thermistor wiring•
5104
5108
Air-refrigerant heat exchanger inlet temperature
(TH4 MAIN Circuit)
Air-refrigerant heat exchanger inlet temperature
(TH8 SUB Circuit)
Broken or shorted thermistor wiring•
5114 Representative water temperature (TH14) Broken or shorted thermistor wiring•
5115 Representative water temperature (TH15) Broken or shorted thermistor wiring•
5117 High-pressure sensor fault/high-pressure fault
Broken or shorted pressure sensor wiring •
5118 Low-pressure sensor fault/low-pressure fault
Broken or shorted pressure sensor wiring •
7113 Model setting error 1 Dip switches on the PCB were set
incorrectly during maintenance.
7117 Model setting error 2 Resistor R21 fault (connected to the
Main control board)
•
4115 Power supply frequency fault Power supply frequency is a frequency
other than 50 Hz or 60 Hz.
A471 Open phase There is an open phase. Circuit board fault•
4106
(255)
Power supply fault Transmission power supply PCB
fault
•
4121 Active filter fault Active filter fault•
AC61
( Preliminary
AC71)
Discharge temperature fault
(A discharge refrigerant temperature of 120ºC or above is
detected for 30 seconds while the compressor is in operation.)
(A discharge refrigerant temperature of 125ºC or above is
detected momentarily while the compressor is in operation.)
No water
Abrupt change in water temperature
(5K/min. or greater)
Pump failure
High-pressure sensor fault
Linear expansion valve fault (Main
circuit LEV, injection LEV)
Injection solenoid valve fault
Refrigerant deficiency (refrigerant
gas leak)
•
•
•
•

10/20
Error
code *1
(PCB *2)
Error type Cause
(Installation/Setting error)
Cause
(Parts problems)
Error reset *3
Unit
side
(PCB)
Remote
SWS1
Operation
SW
1104
Heat exchanger freeze up *6 Drop in water flow or water supply cutoff
during the defrost cycle
Water temperature drop during defrost cycle
4-way valve switching failure•
4250
4255
(101)
Inverter
error
Electric
current
related
errors
during
opera-
tion
IPM error INV board fault
Ground fault of the compressor
Coil problem
IPM error (loose terminal screws,
cracked due to swelling)
Items listed under "Heatsink overheat
protection" below
•
•
•
•
•
4250
4255
(102)
ACCT overcurrent INV board fault
Ground fault of the compressor
Coil problem
IPM error (loose terminal screws,
cracked due to swelling)
•
•
•
•
4250
4255
(103)
DCCT overcurrent
4250
4255
(107)
Overcurrent relay trip (effective value)
(During operation)
4250
4255
(106)
Overcurrent relay trip (momentary value)
(During operation)
4250
4255
(104)
Short-circuited IPM/ground fault
(During operation)
Ground fault of the compressor
IPM error (loose terminal screws,
cracked due to swelling)
•
•
4250
4255
(105)
Overcurrent error due to a short-circuited
(During operation)
Inter-phase voltage drop
(Inter-phase voltage at or below 180 V)
Ground fault of the compressor
Shorted output wiring
•
•
4250
4255
(101)
Current-
related
pro-
blems
at start
up
IPM error
(At startup)
INV board fault
Ground fault of the compressor
Coil problem
IPM error (loose terminal screws,
cracked due to swelling)
Items listed under "Heatsink overheat
protection" below
•
•
•
•
•
4250
4255
(102)
ACCT overcurrent
(At startup)
INV board fault
Ground fault of the compressor
Coil problem
IPM error (loose terminal screws,
cracked due to swelling)
•
•
•
•
4250
4255
(103)
DCCT overcurrent
(At startup)
4250
4255
(107)
Overcurrent relay trip (effective value)
(At startup)
4250
4255
(106)
Overcurrent relay trip (momentary value)
(At startup)
4220
4225
(108)
Voltage-
related
pro-
blems
during
opera-
tion
Bus voltage drop protection Momentary power failure/power failure
Power supply voltage drop (Inter-phase
voltage is 180 V or below.)
Voltage drop
INV board CNDC2 wiring fault
INV board fault
72C fault
Diode stack failure
•
•
•
•
4220
4225
(109)
Bus voltage rise protection Incorrect power supply voltage INV board fault•
4220
4225
(111)
Logic error
Malfunction due to external noise interference
Faulty grounding
Improper transmission and external
wiring installation
(Shielded cable is not used.)
Low-voltage signal wire and high-voltage
wire are in contact.
(Placing the signal wire and power wire
in the same conduit)
•
•
•
INV board fault•
4220
4225
(131)
Voltage meter error at start up
(Bus voltage drop protection at start up (detected
by the Main unit side))
Power supply voltage drop PCB fault•
4230
4235
Heatsink fault
(Heatsink overheat protection)
Power supply voltage drop (Inter-phase
voltage is 180 V or below.)
Clogged heatsink cooling air passage
Fan motor fault
INV board fan output fault
THHS sensor fault
IPM error (loose terminal screws,
cracked due to swelling)
•
•
•
•
4240
4245
Overload protection Short-cycling of air (reduced air flow)
Clogged heatsink cooling air passage
Power supply voltage drop (Inter-phase
voltage is 180 V or below.)
THHS sensor fault
Current sensor fault
INV board fan output fault
INV circuit fault
Compressor fault
•
•
•
•
•
5301
5305
(115)
ACCT sensor fault INV board fault
Ground fault of the compressor and
IPM error
•
•

11/20
Error
code *1
(PCB *2)
Error type Cause
(Installation/Setting error)
Cause
(Parts problems)
Error reset *3
Unit
side
(PCB)
Remote
SWS1
Operation
SW
5301
5305
(116)
Inverter
error
DCCT sensor Poor contact at the INV board
connector CNCT
Poor contact at the INV board
connector DCCT
Ground fault of the compressor
and IPM error
•
•
•
5301
5305
(117)
ACCT sensor/circuit fault Poor contact at the INV board
connector CNCT2 (ACCT)
ACCT sensor fault
•
•
5301
5305
(118)
DCCT sensor/circuit fault Poor contact at the INV board
connector CNCT
Poor contact at the INV board
connector DCCT
DCCT sensor fault
INV board fault
•
•
•
•
5301
5305
(119)
Open-circuited IPM/loose ACCT sensor Disconnected ACCT sensor
(CNCT2)
ACCT sensor fault
Broken compressor wiring
INV circuit fault (IPM error etc.)
•
•
•
•
5301
5305
(120)
Faulty wiring ACCT sensor is connected in the
wrong phase.
ACCT sensor is connected in the
wrong orientation.
•
•
5110
(01) (05)
THHS sensor/circuit fault THHS sensor contact failure
THHS sensor fault
INV board fault
•
•
•
0403
(01) (05)
Serial communication error Communication error between
control board and INV board (noise
interference, broken wiring)
•
IPM system error INV board switch setting error Wiring or connector connection
between connectors on IPM-
driven power supply circuit
INV board fault
•
•
7105
Multiple
unit
system
error
Address setting error Address setting error (Non-consecutive
address)
7130 Incompatible combination of units Different types of units are connected to
the same system.
7102 No.-of-connected-unit setting is incorrect. No.-of-connected-unit setting is
incorrect (Main unit).
6500
Communication error between the main and sub
units
Communication error between the MAIN and SUB
circuits
6600 Transmission line power supply PCB fault
Communication error between the main and sub
units (Simple multiple unit control mode)
*7
Communication error due to external
noise interference
Broken wiring to the transmission
power supply circuit board
(between the main and sub units)
Transmission power supply PCB
communication circuit fault
•
•
6602
6603
6606
6607
6608
*1: The codes in the parentheses in the "Error code" column indicate error detail codes.
*2: If an error occurs, error codes shown above will appear in the 4-digit digital display on the PCB.
*3: Definition of symbols in the "Error reset" column.
: Errors that can be reset regardless of the switch settings
: Errors that cannot be reset if the remote reset setting on the unit is set to "Enable" (factory setting)
Errors that cannot be reset if the remote reset setting on the unit is set to "Disable"
: Errors that cannot be reset
: Errors that will be automatically cancelled once its cause is removed
*4: Power failure will be detected as an error only when the "Automatic recovery after power failure" setting on the unit is set to "Disable."
(The default setting for the "Automatic recovery after power failure" setting is "Enable.")
*5: Depending on the system configuration, if communication error lasts for 10 minutes or longer, units will make an abnormal stop.
This error can be reset by turning off and then back on the unit's power.
*6: This error code will appear when multiple errors occur that are reset in different ways and when one or more of these errors have not been reset. This error can
be reset by turning off and then back on the unit's power.
*7: Before resetting this error, remove its causes. Resuming operation without removing the causes of heat exchanger freeze up will cause heat exchanger damage.

12/20
[2] Calling for Service
If the problem cannot be solved by following the instructions provided in the table above, please contact
your maintenance provider (listed on the back cover) or the nearest Mitsubishi Electric dealer along with
the types of information listed below.
(1) Model name
The model name is a string that starts with “CAHV” and is found on the lower part of the left side of
the unit.
(2) Serial number
Example: 75W00001
(3) Error code
(4) Nature of the problem in detail
Example: The unit stops approximately one minute after it was started.

13/20
4. Safety and Maintenance Information
[1] Contact information
Manufacturer
Mitsubishi Electric Corporation AC&R Systems Works
Address:
Phone Number:
Installer
See the back cover.
Maintenance provider
See the back cover.
[2] Refrigerant Information
・See the nameplate for the refrigerant type, factory charged amount, and CO2equivalent.
・Charge or recover refrigerant through the service check joint.
・Refrigerant circuit must be serviced by a maintenance provider.
・Do not store spare refrigerant on site.
・It is illegal to release refrigerate containing chlorofluorocarbon into the atmosphere. Recover refrigerant
from the unit before disposing of it.
[3] Periodical Inspection
The table below summarizes the scheduled of periodical inspection to be performed by a maintenance
provider.
Periodical Inspection Schedule
Inspection
Item
(Inspection
Interval)
Check Point Check
Method
and tools
Note
Unit
(Biannual)
Check that the unit is not covered
with dust or dead leaves.
Visual
inspection
Check for loose or missing bolts and
nuts.
Visual
inspection
Check for rust. Visual
inspection
Touch up scratches with rust-proof paint as
necessary.
Check that the thermal and acoustic
insulations are not coming off.
Visual
inspection
Check for abnormal noises and
vibrations.
Auditory
inspection
Refrigerant
system
(Biannual)
Check for refrigerant leakage. Gas leak
detector
Check for sympathetic vibration
between pipes, capillary tubes, and
the compressor.
Visual
inspection
Check that all valves (expansion,
solenoid, and 4-way) are operating
properly.
Refer to the Parts Inspection and Replacement
Intervals table on page 16.
Check that the condensing
temperature is in the normal range.
While heating water, use the temperature
reading of the sensor on the water-side heat
exchanger outlet pipe in the liquid line (Approx.
300 mm from the water-side heat exchanger) as
the condensing temperature.
Water outlet temperature: 0 – +5 K

14/20
Cont’d Check that the evaporating
temperature is in the normal range.
While heating water, use the temperature
reading of the sensor on the air-side heat
exchanger inlet pipe as the evaporating
temperature.
Intake temperature: -3 – +8 K
Check that the operating current is
normal.
Compare the operating current against the
rated current.
Check for abnormal sounds and
vibrations.
Visual
inspection
Check that no foreign objects are caught in
the unit.
Compressor
Check that the compressors are
not short-cycling.
Check that the interval between the time
when the compressor starts up and the time
when it restarts is at least 10 minutes.
Check that the high-pressure
switch operates normally.
Protection
devices
(Biannual) Check that the pump interlock
circuit operates normally.
Check for loose terminal screws. Screwdriver
Check that all electrical contacts
are clean.
Visual
inspection
Check that the conductors and
relays are operating normally.
Check that the insulation resistance
of the operation circuit is normal.
500 V
ohmmeter
Min. 5 MΩ
Check that the insulation resistance
of the main circuit is normal.
500 V
ohmmeter
Min. 10 MΩ
Check that the ground wire is
properly connected.
Visual
inspection
Electrical
system
(Biannual)
Check that all wires are connected
properly.
Screwdriver
Check that the heating-water is
clean.
Check the strainer in the heating-water line.
Check that the water pressure is
normal.
Max. 1.0 MPa
Check for water leakage. Visual
inspection
Check that the water in the pump
does not drain back when the
pump stops.
Check that air is not trapped in the
water-side heat exchanger or
pipes.
Open the air vent valve to see if any air
comes out.
Check that the voltage and current
of the heating-water pump operates
normally.
Check that the heating-water
volume is normal.
Heating-
water
system
Check that the heating-water
quality meets the quality standards.
See the Quality Standards for Heating and
Makeup Water table below.
Air-side
heat
exchanger
(Biannual)
Check the fins and other parts for
corrosion.
Visual
inspection
Check that the fins are not dirty. Visual
inspection
Clean the fins if the high pressure has
dropped by 0.1 MPa or more compared to
the initial value. (To be measured under the
same conditions as at the time of
installation)

15/20
Quality Standards for Heating and Makeup Water
Properties Quality standards Corrosion and scaling
tendencies
Makeup water Circulating water
[Between 20ºC
(exclusive) and 60ºC
(inclusive)]
Circulating water
[Between 60ºC
(exclusive) and 90ºC
(inclusive)]
Corrosion Scaling
Ph (25ºC) 7.0–8.0 7.0–8.0 7.0–8.0 6.8 or below 8.0 or above
Electrical
conductivity
(mS/m)(25ºC)
30 or below 30 or below 30 or below
√√
Chloride ion
(mgCl-/l)
30 or below 50 or below 30 or below √
Sulphate ion
(mgSO4
2-/l)
30 or below 50 or below 30 or below √
Acid
consumption
(pH 4.8)
(mCaCO3/l)
50 or below 50 or below 50 or below
√
Total
hardness
(mgCaCO3/l)
70 or below 70 or below 70 or below
√
Calcium
hardness
(mgCaCO3/l)
50 or below 50 or below 50 or below
√
Ionized silica
(mgSiO2/l)
30 or below 30 or below 30 or below √
Iron (mgFe/l) 0.3 or below 1.0 or below 1.0 or below √√
Copper
(mgCu/l)
0.1 or below 1.0 or below 1.0 or below √
Sulphide ion
(mgS2-/l)
Not to be
detected
Not to be detected Not to be detected √
Ammonium
ion (mgNH4
+/l)
0.1 or below 0.3 or below 0.1 or below √
Residual
chlorine
(mgCl/l)
0.3 or below 0.25 or below 0.1 or below
√
Free carbon
dioxide
(mgCO2/l)
4.0 or below 0.4 or below 0.4 or below
√

16/20
[4] Parts Inspection and Replacement Intervals
The table below shows the recommended inspection and replacement intervals. Replacement interval is a
recommended replacement period and not the warranty period. Note that the replacement interval depends
on usage environment. Check the unit components periodically and replace them as necessary before
problems arise to prevent adverse effects on other parts.
Parts Inspection and Replacement Intervals
Parts Check item Inspection
interval (times
per year)
Replace-
ment
interval
Refrigerant
circuit
Compressor High and low pressures, vibrations,
abnormal noises, insulation
resistance, loose terminals
2 40,000
hours
Air-side HEX High and low pressures, dirty fins 2 10 years
Water-side HEX High and low pressures, water
pressure loss
2 10 years
Solenoid valves Operation, leakage, clogging 2 7 years
4-way valves Operation, leakage, clogging 2 7 years
Check valves Operation, leakage, clogging 1 10 years
Electric expansion
valves
Operation 2 7 years
Strainers Difference between the outlet and inlet
temperatures
1 When major
maintenance
is performed
Refrigerant tank Difference between the outlet and inlet
temperatures
1 10 years
Capillary tubes Contact abrasion, vibrations 1 10 years
Pipes Contact abrasion, vibrations 1 10 years
Electrical
circuit
Solenoid valves, 4-way
valve coils
Insulation resistance 2 7 years
Electric heater
(compressor case)
Insulation resistance 2 20,000
hours
Fuses External appearance 2 8 years
Electronic substrates External appearance 2 8 years
Pressure switches and
sensors
Contact resistance at the contact,
friction wear on the capillaries
2 7–10 years
Terminal blocks Loose terminals 2 8 years
Wires and connectors Breakage, looseness, deterioration,
friction
2 10 years
Smoothing capacitor Water leakage, deformation 2 10 years
Heatsink cooling fan Insulation resistance, abnormal
sounds
2 10 years
Ventilation
system
Fans Balance 2 10 years
Motors Insulation resistance, abnormal
sounds, vibrations
2 6–10 years
[5] Safety, Ventilation, and Fire-Extinguishing Devices
Read their respective manuals and understand how to use them correctly. Perform regular inspection and
maintenance to keep them in good conditions.

17/20
5. Warranty
[1] Terms and Conditions
The unit is covered by the warranty for a period of 1 year from the date of installation. Only the affected
parts or the parts authorized by Mitsubishi Electric on the compressor and the heating unit will be
replaced free of charge. Malfunctions resulting from the use of unit as listed below shall not be covered
even during the warranty period.
[2] Exclusions
(1) Damages resulting from incorrect selection of units or system design problem
Damages resulting from improper installation that deviates from the instructions and precautions
detailed in this manual.
Damages resulting from a selection of unit with a capacity that is obviously too large or too small
relative to the heating load of a given application.
(2) Damages resulting from making an unauthorized alteration, defeating the safety feature of the
protection device to stop the unit, or failing to interlock the operation of the pump with the unit.
(e.g., Damages inflicted to the heat exchanger caused by an operation of the unit without operating
the pump or continued operation of unit after a problem has occurred)
(3) Damages resulting from the use of unit outside of the specified outlet temperature, outside
temperature, or cold water flow rate ranges. Damages resulting from using the type of power source
other than the specified type (capacity shortage, voltage shortage, voltage imbalance).
(4) Damages resulting from inadequate operation, adjustment, and maintenance
a. Damages resulting from short-cycling of the compressor (cycle length shorter than 5 minutes)
b. Damages resulting from inadequate maintenance (e.g., shortage of water flow due to clogged
pipes, degradation of water quality, and salt damage)
c. Damages resulting from low-quality water (corrosion of heat exchanger)
(5) Act of God or fire
(6) Improper installation or improper selection of installation site
a. Damages resulting from chemicals and other corrosive substances on site
b. Damages resulting from careless handling during installation
c. Damages resulting from neglecting to address the installation problem that had been pointed out
by Mitsubishi personnel
d. Damages resulting from a poorly built foundation or frame
(7) Damages resulting from improper installation, misuse, improper adjustment, and lack of proper
maintenance shall not be covered by the warranty. Mitsubishi Electric shall not be held liable under
any circumstances for any secondary damage that may result from malfunctions of the heat pump,
such as loss of sales. Consult a Mitsubishi agent regarding purchasing coverage.
(8) The unit described in this manual is designed for use in Japan, and the contents of this manual are
applicable only in Japan.
Mitsubishi Electric does not provide maintenance/repair services for the units used outside of Japan.

18/20
6. Main Specifications
SPECIFICATIONS
Model CAHV-P500YA-HPB
Power source 3-phase 4-wire 380-400-415 V 50/60 Hz
kW 45
kcal/h 38700
Capacity *1 Btu/h 153540
Power input kW 12.9
Current input A 21.78-20.69-19.94
COP (kW/kW) 3.49
kW 45
kcal/h 38700
Capacity *2 Btu/h 145690
Power input kW 25.57
Current input A 43.17-41.01-39.53
COP (kW/kW) 1.76
Maximum current input *3 A 57.77-54.88-52.90
Water pressure drop *1 12.9 kPa (1.87 psi)
Outlet water temperature 35–65ºC (95–149ºF), 25–70ºC (77–158ºF)
Temperature range *4Outdoor temperature D.B. -20–+40ºC (-4–+104ºF), -10–+40ºC (14–104ºF)
Circulating water volume range 7.5 m3/h-15.0 m3/h
Sound pressure level (measured in an anechoic room) *1 dB (A) 59
Sound pressure level (measured in an anechoic room) *3 dB (A) 63
Inlet mm (in) 38.1 (Rc 1 1/2"), screw pipeWater pipe diameter and
type Outlet mm (in) 38.1 (Rc 1 1/2"), screw pipe
External finish Acrylic painted steel sheet
<Munsell 5Y 8/1 or similar>
External dimensions H x W x D mm
in
1710 (1650 not including legs) x 1977 x 758
67.3 (65.0 not including legs) x 77.8 x 29.8
Net weight kb (lb) 526 (1160)
Accessories Y-strainer Rc 1 1/2
R407C MPa 3.85
Design pressure Water MPa 1.0
Wiring kC94G268X01
Drawing number External appearance KC94G195X01
Water-side Copper brazed stainless steel sheet
Heat exchanger Air-side Plate fins and copper tubes
Type Inverter scroll hermetic compressor
Manufacturer MITSUBISHI ELECTRIC CORPORATION
Starting method Inverter
Motor output kW 7.5 x 2
Case heater kW 0.045 X 2
Compressor
Lubricant MEL 32
m3/min 185 x 2
L/s 3083 x 2
Air flow rate cfm 6532 x 2
External static pressure 0 Pa (0 mm H2O)
Type and quantity Propeller fan x 2
Control and driving mechanism Inverter control, direct driven by motor
Fan
Motor output kW 0.46 x 2
HIC (Heat inter-changer) circuit Copper pipe
High pressure High-pressure sensor and switch set at 3.85 MPa (643 psi)
Inverter circuit Overheat and overcurrent protection
Compressor Overheat protection
Protection devices
Fan motor Thermal switch
Defrosting method Auto-defrost mode (Reversed refrigerant cycle)
Type and factory charge kg R407C, 5.5 kg x 2
Refrigerant Flow and temperature control LEV and HIC circuit

19/20
*1 Under normal heating conditions at the outdoor temperature of 7ºCDB/6ºCWB (44.6ºFDB/42.8ºFWB)
and the outlet water temperature of 45ºC (113ºF)
*2 Under normal heating conditions at the outdoor temperature of 7ºCDB/6ºCWB (44.6ºFDB/42.8ºFWB)
and outlet water temperature of 70ºC (158ºF)
*3 Under normal heating conditions at the outdoor temperature of 7ºCDB/6ºCWB (44.6ºFDB/42.8ºFWB)
and the unit is set to the “Capacity Priority” mode through the no-voltage A-contact.
*4
・Due to continuing improvements, specifications may be subject to change without notice.
・Do not use steel pipes as water pipes.
・Keep the water circulated at all times. Blow the water out of the pipes if the unit will not be used for an
extended period of time.
・Do not use ground water or well water.
・Do not install the unit in an environment where the wet bulb temperature exceeds 32ºC.
・The water circuit must be a closed circuit.
Unit converter
Kcal = kW x 860
BTU/h = kW x 3.412
cfm = m3/min x 35.31
Lb = kg/0.4536

20/20
Installer’s Name, Address, and Phone Number
Maintenance Provider’s Name, Address, and Phone Number
AC&R Systems Works: 6-5-66 Tebira, Wakayama-shi, Wakayama, 640-8686, Japan WT06127X01