Panasonic OCU-CR1001VF User manual

Table of Contents
Cautions for Safety 2-6
Name of Each Part and Optional Accessories 7
Scope of Application 8
For Effectively Using the Refrigeration Unit 9-10
Selection of Installation Location 11
Carry-in/Installation 13
Installation Example 14
Refrigerant Piping Work 15-16
Piping Example 17
Refrigerant Circuit Diagram 18
Refrigerant Charging 19
Cautions for Electrical Wiring Work 20
Electrical Wiring Work 21
Electrical Circuit Diagram 22-23
What Needs to be Checked before Operation 24
Setting and Indication of the Control PCB 25-29
Control Functions 30-32
Adjustment during Operation 33-34
Oil Level Control Method 35-36
About Alarms 37-38
Maintenance and Inspection 39
Actions at the time of Failure 40-41
Failure Diagnosis 42-49
Warranty Condition of the Refrigeration Unit 50-51
Installation Instructions
Outdoor Type Refrigeration Unit
(Non-fluorocarbon Refrigeraton Unit with
CO2Refrigerant)
Model No.
OCU-CR1001VF
Thank you very much for purchasing
Panasonic products this time.
Please read this instruction booklet
and correctly comply with the
explanations.
In particular, please read "Cautions for
Safety" (Pages 2 to 6) for ensuring
safe operations.
Please retain this instruction booklet in
a safe place.
Caution labels are attached to the product.
This illustration represents OCU-CR1001VF

2
Cautions for Safety
For the purpose of avoiding harm to people and damage to properties, items to be complied with are
explained here.
Explanations are classified by degree of harm or damage caused by incorrect use.
Warning Indicates possibility of death or serious injury.
Caution Indicates possibility of minor injury or damage to properties.
Items to be observed are explained by the following pictograms.
Indicates what you should not do.
Indicates what you must do.
Warning
Installation Work
Request a specialty operator to perform
installation by conforming to the installation
instructions.
Incorrect installation work may lead to
malfunction such as abnormal vibration,
and generates refrigerant gas leak,
electrical shock, or fire.
Do not use other than the designated refrigerant
(for charging, adding or recharging)
Non-designated refrigerant may cause
equipment failure or burst, or injury.
Securely complete refrigerant piping before
carrying out airtight testing.
Refrigerant gas leak may cause
suffocation.
Installation should be made securely on a place
that can fully support the mass of the refrigeration
unit.
Insufficient foundation may cause falling or
dropping, and lead to refrigerant gas leak,
injury, electrical shock, or fire,
zRefrigeration unit should be secured on
a concrete base with a mass
approximately 3 times that of the unit
and fastened with anchor bolts.
Install the safety cover.
Touching the refrigeration unit by hand of
the people other than the designated
operators may cause injury.
zInstall a safety cover or protective fence.
Perform airtight test before charging refrigerant.
Refrigerant gas leak may cause insufficient
oxygen and lead to a death accident.
zCarry out airtight test and confirm no
leak of refrigerant.
Piping, equipment components and tools should
be exclusively for R744 (CO2refrigerant).
Use of components for HFC refrigerant
cay cause serious accidents such as
equipment failure and rupture of the
refrigerant cycle.
Be sure to comply with the following

3
Cautions for Safety
Electrical Work
Always use a dedicated circuit and install a ground
fault interrupter.
Incorrect electrical work may lead to
current leak and fire or electrical shock.
zWiring work should conform to the
installation instructions.
Grounding Work
Lack of grounding work may lead to
electrical shock caused by current leak.
zSecurely carry out grounding work by
qualified technicians.
Securely place the cover on the electrical box and
enclosure panel.
Incomplete attachment may lead to
penetration of water and living creatures,
thereby causing current leak and
fire/electrical shock.
zConfirm that covers are securely
installed.
Electrical wiring should use the specified cable
and to be properly secured.
When the specified cable is not used, or
connection or securing is incomplete,
electrical resistance becomes larger and
may cause abnormal heating or fire.
zUse the specified cable and properly
secure it on an appropriate location.
Cautions for Use
Do not change the set values of the safety device.
Using the refrigeration unit with changed
values may cause failure of the safety stop
function and lead to a burst or fire.
zDo not change the set values of the
safety device. If they are changed
unintentionally, shut off the power switch
and ground fault interrupter and consult
with the distributor.
Do not insert a finger, stick or foreign object into
the ventilation opening and fan guard of the
enclosure panel.
Such object may hit the fast rotating fan
and result in injury.
When water or other material gets into the
electrical box, turn off the power switch and shut
off the ground fault interrupter.
Continued use may cause short-circuit,
leading to fire or electrical shock.
zDo not splash water on electrical
components or wash them with water.
When the ground fault interrupter activates, report
to the specialty company.
Forced recovery of power may cause
current leak, leading to fire or electrical
shock.
For the purpose of controlling concentration of
refrigerant gas, install a leak detector and
mechanical ventilation equipment in the
refrigerant-handling facility (inside the room).
Refrigerant gas leak may cause suffocation.
Be sure to comply with the following

Cautions for Safety
Repairs
Disassembly or repairs should be performed by
a specialty operator.
Incorrect disassembly or repair may lead to
abnormal operation and causes injury, fire
or electrical shock.
zRequest a specialty operator to perform
disassembly or repair work.
Do not absolutely perform modification.
When abnormal operation was detected, or before
starting disassembly or repair, turn off the power
switch and shut off the ground fault interrupter.
Continued operation with abnormal
condition, or disassembly/repair without
shutting off the power would lead to current
leak or short-circuit and may cause fire or
electrical shock.
Stop the compressor before disconnecting the
refrigerant piping.
Disconnecting the piping while the
compressor is in operation would cause
abnormally high pressure with air intake,
and may lead to a burst or injury.
Specified components must be used for repair.
Use of non-specified components may
cause failure of the safety stop function and
lead to burst or fire.
zConsult with the distributor.
Moving or Change of Installation Location
Request a specialty operator for moving or
changing the location.
Incorrect installation or moving work may
lead to malfunction such as abnormal
vibration, and generates refrigerant gas
leak, electrical shock, or fire.
4
Use the piping, equipment components and tools
specifically designed for R744 (CO2refrigerant).
Using other materials for HFC refrigerant
may cause equipment failure and serious
accident such as rapture of the refrigeration
cycle components.
Be sure to comply with the following

5
Cautions for Safety
Caution
Installation Work
Do not install in a place with possible leak of
flammable gas.
Leaked flammable gas around the
refrigeration unit may catch fire from a
spark of a switch and lead to fire.
Produce a refrigeration cycle within the limits of
an operation standard (refer to “Scope of
Application”).
Non-standard refrigeration cycle may
generate abnormal high pressure and
abnormal heat generation, thereby causing
burst, smoke generation, fire and current
leak.
Apply heat insulation on the suction line and liquid
line.
Lack of heat insulation generates water
from condensation and mold and moss,
thus causing slipping on the floor.
Apply a drain work according to the need.
Without consideration of drain water
processing, moisture from rainwater and
defrosted water generates mold and moss,
and may cause slipping on the floor.
Request a specialty operator for moving
the refrigeration unit.
Incorrect moving may cause falling or
dropping of the refrigeration unit, and
cause injury.
zRefrigeration unit is a heavy item.
Always consult with a specialty operator.
Install in a place without air stagnation.
Leak of refrigerant gas may cause
insufficient oxygen and harm human health.
zInstall in a place with good ventilation.
Electrical Work
Always install a ground fault interrupter with the
specified capacity.
Incorrect capacity does not operate safety
stop function and may lead to fire or
electrical shock.
Do not include electrical wiring in the heat
insulation material.
Condensation of piping may cause current
leak and fire caused by overheating.
Be sure to comply with the following

6
Cautions for Safety
Cautions for Use
When the refrigerant bursts out, shut off the power
and fully close the service valve.
Blowout of refrigerant from the refrigeration
cycle by opening the service valve would
cause insufficient oxygen and harm human
health.
Do not use flammable spray near the refrigeration
unit. Do not place flammable materials nearby.
Flammable material may catch fire from
switch spark.
Before any inspection service, turn off the power
switch and shut down the ground fault interrupter.
Inspection work with power on may lead to
electrical shock, interference with the
moving mechanism, and heat generation,
thereby leading to injury and skin burn.
Do not touch electrical components by a wet hand.
Switching operation by a wet hand may
cause electrical shock and injury.
Periodically check operation of the ground fault
interrupter.
Failed interrupter does not operate safety
stop function and may lead to fire or
electrical shock.
When removing the fin guard of the gas cooler, do
not touch the fin.
Touching the fin and sliding along the fin
may cause skin cut by the fin edge.
Do not ride on the refrigeration unit.
Riding on the refrigeration unit or placing
an article on it may lead to falling or
dropping by vibration and cause injury.
Periodically check the installed base.
Damaged base after a long-time use may
cause the refrigeration unit to fall or drop
and lead to injury.
Request a specialty operator for disposing the
refrigeration unit.
Disposal with the refrigerant and oil inside
the refrigeration unit may cause fire or
explosion.
Do not operate with the service valves of each stage
around the compressor kept closed.
Operating the compressor with the
discharge service valve of each stage
closed, would generate abnormally high
pressure and may lead to rapture.
Disposal
Be sure to comply with the following

7
Name of Each Part and Optional Accessories
Name of Each Part
Optional Accessories
Note: The filter dryer (one is shipped with each refrigeration unit) is a standard component. When replacing the filter
dryer, use the same filter dryer (Model No. D-155T) shown above as the standard component.
Component Layout in the Electrical Box
Front of
refrigeration unit
Left side of
refrigeration unit
Left section of left side
of refrigeration unit
Name Model No. Applicable refrigeration unit Remarks
Suction filter S-008T
OCU-CR1001VF
Prevention of dust penetration
Filter Dryer D-155T
(Type: CO-085-S)
φ15.88
(Outer diameter welding)
Fin guard for gas cooler SPK-GA4014 Guard made from wire
Power terminal block
High voltage danger
indication light
INV-F PCB
Diode
Heatsink temperature sensor
Control terminal block
INV-M
PCB
Reactor FC3-
PCB
INV-H PCB CR2A-PCB
Operation
switch
From left 1X1, 1X2, 1X3
FM1
(Box back side)
From top F1, F2
F7
Compressor
Oil level switch
Oil separator
Low pressure
sensor
Electrical box
Low pressure
service valve
High pressure
service valve
Oil service valve
Ambient
temperature
sensor
Flash chamber
Intermediate
pressure sensor
Unit outlet
pressure sensor
Electronic expansion valve
for liquid return (MOV7)
High pressure
sensor
Electronic expansion
valve for pressure
reduction
(MOV5)
Balance pressure
solenoid valve
(EV2)
Electronic expansion
Valve for gas return
(MOV6)
Front of refrigeration unit Back of refrigeration unit

8
Scope of Application
This refrigeration unit operates with a rotary compressor.
Use the refrigeration unit within the range shown below.
Note ※: Operation may not be possible depending on the installed condition.
Counter measures in a cold weather operation
In order to prevent excessive reduction of high pressure in a cold weather location, surrounding around the refrigeration
unit should be made.
Item Standard Value Remarks
Refrigerant R744 The charge supply amount shall be adequate.
Evaporating temperature -45°Cto-5°CTemperature conversion of inlet pressure
Suction pressure 0.73MPa to 2.95MPa Unit inlet pressure
Inverter operation ※30 s-1 to 60 s-1 
Suction gas temperature 18°C or below Unit inlet (suction gas) pipe temperature
Superheat at suction 10 K or above Difference between evaporating temperature
and compressor inlet temperature
Discharge pressure 9.1MPa or below
(except transient) Compressor outlet pressure
Discharge gas temperature 97°C or below Compressor outlet temperature
Oil temperature 100°C or below
(Ambient temperature +10 K or above) 
Ambient temperature -15°Cto+43°CGas cooler intake air temperature
Applied electricity 3 phase 200 V ± 20 V Power source terminal voltage
on Refrigeration unit
Unbalance of phase voltage 2% or below 
Installation inclination angle 1° or below 
ON/OFF cycle period 10 minutes or longer
for ON/OFF cycle Oil return shall be ensured.
Installation Outdoor The foundation shall be rigid enough.

9
Cautions for Installation Work
This refrigeration unit has been designed exclusively for R744 (CO2refrigerant).
Refrigeration oil and each component including the compressor have been exclusively designed for
the refrigeration unit.
Please use sufficient caution for maintaining the reliability of the product.
(1) Since CO2refrigeration cycle becomes high pressure during operation, use the piping material and other components
particularly designed for CO2refrigerant with sufficient strength.
(2) As the refrigeration oil has high moisture absorption property, make the opening time as short as possible. Connection
of the piping to the refrigeration unit should be made at the last stage of piping installation work. Avoid outdoor work
on a rainy day.
(3) For piping work, use "phosphorous-deoxidized copper pipe" of refrigeration grade, clean, dehydrated and "phosphor-
copper brazing solder."
If "silver brazing solder" is to be used, do not use any flux containing chlorine.
(4) Do not use pipe joints made for HFC refrigerant, because they do not have the required strength. In addition,
absolutely do not use flared joints.
(5) For the purpose of protecting the refrigeration unit and refrigeration cycle, make sure to install the optional suction
filter and included filter dryer in the refrigeration unit.
(6) Gas leak detector used for airtight test should be foaming liquid or soap water. Do not use kitchen detergent. Kitchen
detergent may corrode metals.
For Effectively Using the Refrigeration Unit
For Economically Using the Refrigeration Unit
For the purpose of using the refrigeration unit economically, consider the following.
Cooling capacity largely vary by the method of use.
Reduction of evaporating temperature (unit inlet pressure converted to temperature) reduces cooling capacity by 2 to 4%,
and increase of discharge pressure decreases cooling capacity and increases power consumption.
In order to fully extract the unit performance, compressor suction pressure should be increased as high as possible, and
discharge pressure should be made as low as possible. For this reason, caution should be used in the following points.
(1) Make the piping resistance as small as possible.
Ref: Capacity change rate per 1°C pressure loss of suction line
(2) Select an evaporator of sufficient capacity for raising evaporating temperature as high as possible.
(3) Do not block the cold air outlet in a refrigerator, freezer, or display case with food items.
(4) Operate door opening of a refrigerator or freezer as quick as possible. (To avoid leak of cold air, reduce the time of
door opening)
(5) Periodically perform cleaning of the gas cooler to avoid clogging.
Evaporating temperature Capacity change rate per 1°C
-45°Cto-5°C2% to 4%

10
Caution for an Inverter-based Refrigeration Unit
(1) Even after turning the power OFF, voltage still remains in the charged part. Until the LED (red) of the inverter-PCB
turns off (until the capacitor discharges the potential), approximately 5 minutes are required. Do not touch the charged
part.
(2) Phase-advancing capacitor is prohibited
Do not attach a phase-advancing capacitor to an inverter compressor. It may cause inverter failure or capacitor
breakage.
(3) Inverter noise prevention
Take as much distance as possible from the wiring of a radio receiver or wired broadcasting.
Inverter noise may cause undesired noise sound.
(4) The two-stage compression mechanism prevents temperature rise of the second stage discharge gas of the
compressor.
During the operation with a small quantity of refrigerant in the refrigeration circuit, a protection device (the control
PCB) makes the compressor to stop.
Avoid refrigerant shortage operation.
(5) Rotary compressor consists of high precision components. Use caution during piping work to avoid contaminaion of
dust, metal powder, or oxide scale, etc.
For Effectively Using the Refrigeration Unit
Initial Oil Quantity
Oil are pre-charged in compressor and oil separator.
Model No. Compressor Oil separator
OCU-CR1001VF 1.8 L 5.0 L

11
Location not disturbing neighbors
Avoid air-blow from the gas cooler to the neighbor's
window or noise to disturb other people.
Selection of Installation Location
General Cautions
Each unit of the equipment should be placed by selecting the most convenient location such as
easy to install, operate or maintain.
(1) Each unit should be placed to make the piping and wiring length as short as possible and easy to install.
(2) Controller should be located within the reach of the user's hand for convenient daily operations (RUN, STOP, reset
warning, etc.). Do not locate the controller in a place easily accessed by the people other than the user.
(3) Install the refrigeration unit at a location easy to be serviced for daily maintenance and inspection.
Daily maintenance and inspection involves checking the operation pressure, compressor operation condition for
abnormal sound or vibration.
Location with a sturdy and level surface
Install the refrigeration unit on a firm foundation to avoid
an increase of noise and vibration.
Particularly at the boundary from the neighbor's lot,
comply with the regional laws and regulations.
Location away from a heat source
Installation should not be affected by reflection from the
floor.
Location with good ventilation
To ensure good ventilation, installed location should
ensure the intake air by the gas cooler is 43°C or below
with good airflow.
Location not affected by a wet floor
Refrigeration unit is often affected by rainwater and drain
water from defrosting. Apply drain water work as required.
Location not affected by snow accumulation
Installation in a cold weather location should avoid snow
accumulation and attachment of frost or freezing by
furnishing a roof.

Carry-in Operation
(1) Carry the refrigeration unit gently by keeping the
vertical position as much as possible.
(2) Absolutely avoid a lay-down position of the
refrigeration unit.
(3) When conveying the refrigeration unit with a forklift,
maintain the unit vertically by using the square holes
at the corners of the unit base.
12
Carry-in/Installation
Foundation/Platform Work
If a foundation meeting the requirement above cannot be secured, be sure to check that no abnormal vibration is
generated by resonation of the refrigeration unit and piping system.
(1) Basic foundation work when the pipe is extended horizontally.
Form a concrete foundation with a thickness of 150 mm or more on the floor surface, and place an anti-vibration pad
(thickness of 8 to 15 mm) on the entire unit base surface, and then secure it with anchor bolts.
(2) Basic foundation work when the pipe is extended downward.
Form an elevated foundation with vertical columns.
Place an anti-vibration pad (thickness of 8 to 15 mm) on the entire surface of the foundation and secure it with anchor
bolts.
Hoist Operation
When hoisting the refrigeration unit, use caution for the
following points.
(1) When hoisting the refrigeration unit, follow the
"Precautions for Hanging the Product" attached to the
refrigeration unit.
(2) When hoisting the refrigeration unit and conveying it,
keep it level without causing any impacts.
(3) Hoist rope, etc. must be strong enough to withstand
the weight of the refrigeration unit.
• As a reference, the foundation should be made from concrete having a mass about 3 times that of the refrigeration
unit. (Absorbing vibration by mass)
• Vibration should be reduced by a platform or anti-vibration pad for avoiding transmission of vibration to the floor and
wall.
• To avoid falling, secure the refrigeration unit by using anchor bolts. (Use all securing positions)
• The refrigeration unit must be installed with an inclination angle 1°or below.

13
External Dimensions
Carry-in/Installation
Service Piping [Optional Accessories]
The following service piping (optional) is required for the installation and service work of the refrigeration unit.
(1) Service piping for Evacuation, Airtight test, and Refrigerant charging (Model No. SPK-TU127)
(2) Service piping for Adding refrigeration oil (Model No. SPK-TU126)
295
(Piping hole
dimension)
106
(Piping hole
dimension)
Liquid line
(Unit outlet)
Suction line
(Unit inlet)
Details of piping hole on the bottom
of the refrigeration unit
851 (Installation pitch)
4-φ, 20-hole
for securing
the unit
Hole for
power cables
Monitor display
(Pressure,
Temperature,
Alarm code, etc.)
Hole for piping
Front of refrigeration unit Right side of refrigeration unit
Left side of refrigeration unit
700
(Installation pitch)
Suction line (Unit inlet)
(19.05 outer diameter
connection)
Liquid line (Unit outlet)
(15.88 outer diameter
connection)
Connected to the unit service valve
Nut (fastening torque 13 ± 1 N•m)
Nut (fastening torque 13 ± 1 N•m)
Connected to the unit service valve
CO2charging hose or 1/4”pipe
Connected to the CO2manifold gauge set
Joint (High pressure joint: Swagelok, etc.)
Connected to the service piping
Joint valve
(High pressure valve: Swagelok, etc.)
Locally procured components
Joint (High pressure joint: Swagelok, etc.)
Connected to the service piping
CO2charging hose or 1/4”pipe
Locally procured components
Joint valve
(High pressure valve: Swagelok, etc.)
Connected to the CO2manifold gauge set

14
Installation Example
When there's an obstacle in the upward
direction
When there's an obstacle in the
upward direction, the installation
should not cause a short cycle of
the gas cooler air exhaust.
When installing a roof, it should be
located at a distance of 1.5 m or
more with an upward slope, as
illustrated on the right.
Standard installation
The gas cooler is designed to take air from 3 directions,
including the front, left and right side, and blow out from
the top.
(1) Secure a service space of 500 mm or more on the
front and left sides.
(2) Secure a service space of 300 mm or more on the
back and right sides.
Protection in the snowfall areas
(1) Install a snow protection shed at the air outlet of the
gas cooler. (On-site installation)
(2) The entire refrigeration unit should not be surrounded
by accumulated snow.
Installation example
Back surface
suction space
Front surface
service space
Left side
service space
Right side
service space
500mm 300
mm
300mm
500mm
1.5 m or more
Continuous installation
When a wall exists on three sides
When a wall exists on four sides
When a wall exists on two sidesWhen a wall exists on one side
300 mm
or wider
500 mm
or wider
300 mm
or wider
500 mm
or wider
300 mm or wider
500 mm or
wider
500 mm or
wider
500 mm or
wider
Left side
service space
Left side
service space
Leftside s e r v i c e
space
Front surface
service space
Front surface
service space Front surface
service space
300 mm
or wider
500 mm
or wider
300 mm
or wider
500 mm
or wider
500 mm or
wider
Left side
service space
Front surface
service space
300 mm
or wider
500 mm
or wider
500 mm or
wider
Left side
service space
Front surface
service space
Left side
service space
500 mm or wider
500 mm or
wider Front surface
service space
500 mm
or wider
500 mm
or wider
Left side
service space
500 mm or
wider
Left side
service space
Front surface
service space
500 mm or
wider
Left side
service space
Front surface
service space
Notes: 1. Provide an air suction opening of 4 m2
or greater at the lower part.
2. The wall height must be up to the unit
height.
300 mm or wider
500 mm
or wider

15
Refrigerant Piping Work
Selection of Refrigerant Piping Size
The connection piping size for refrigeration unit is, in principle, as shown below, but each should be determined by
calculating pressure loss of the piping and refrigerant flow rate and making sure no problem occurs in the cooling
capacity and oil return.
As the refrigeration unit using CO2refrigerant incurs pressure higher than when using HFC refrigerant, it is necessary to
choose adequate materials.
(1) Piping material should be seamless phosphorous-deoxidized copper pipes (refrigeration grade.)
(2) The specified piping installation pressure is 8 MPa for both suction line and liquid line.
(3) When cutting pipes, use a pipe cutter and always apply deburring.
(4) When bending a pipe, the bending radius must be four times or greater of the pipe's outer diameter.
During bending, pay attention to distortion and scars.
Use sufficient caution for handling piping, and seal each pipe-end with tape or any other cover for
preventing the entry of contaminants and moisture in the pipe.
Caution
Design and installation of the refrigerant piping work largely affect the performance of the
refrigerating equipment as well as the product life and problem occurrence.
Installation work should comply with the following items.
Model No. Suction line (Unit inlet)
(Outer diameter welding)
Liquid line (Unit outlet)
(Outer diameter welding)
OCU-CR1001VF φ19.05 φ15.88
(Unit: mm)

16
Airtight Test
[Execute this test after completing piping
work but before starting heat insulation work]
Testing pressure should comply with the following.
Refrigerant Piping Work
Cautions for Heat Insulation Work
(1) Apply heat insulation on the suction line and liquid line for avoiding thermal effect from outside.
(2) Do not wrap together the suction line and liquid line with heat insulation material.
Refer to the right illustration.
(3) Apply heat insulation only after executing airtight test.
Piping Direction
The pipe can be connected from 2 directions (right side
or bottom of the condensing unit).
When connecting the refrigerant pipe, remove the right
side panel.
Prevent contamination of foreign objects such as dust, metal powder,
oxide scale, etc.
Since the compressor consists of high precision components, contaminants generate scratches on the sliding surfaces,
thereby increasing gas leak, deteriorating performance, and causing excessive wear and seizure.
(1) Flow nitrogen gas during welding.
(2) Piping inside and outside must be clean.
(3) Avoid mixing of debris during cutting
and deburring copper pipe.
Caution for Gas Leak
Gas leak may lead to excessive heat operation of
compressor and air-mixed operation, thus causing
compressor failure.
Note: Securely execute airtight test.
Filter Dryer
Be sure to attach the included filter dryer.
Model No. D-155T (Type: CO-085-S)
High pressure side Low pressure side
8MPa 8MPa
N2cylinder
Fill the gap with sealing material.
Open gap may cause air to be mixed.
Brazing position
Apply dry nitrogen gas flow
barely felt by the palm.
Suction Filter
Be sure to install the suction filter available as optional
accessory.
Model No. S-008T
Liquid line
Suction line
Correct Incorrect

17
Piping Example
When the evaporator is located lower
Height difference 20 m or below
To promote good oil return in the suction line, piping size and
trap need to be considered.
(1) The suction line should ideally slope gently towards the unit.
Recommendation slope is 1/200~1/250.
(2) Refrigerant pipe should be covered with heat insulation
material on both suction line and liquid line.
Since liquid line becomes approx. 0°C
during operation, apply heat insulation of
20 mm or more in thickness.
Suction line
Downward
slope
Oil trap
Step
Liquid line
6 m or below
20 m or below
Refrigeration unit
Downward
slope
Oil trap
Evaporator
Back-up
solenoid valve
Expansion valve
Note: Adjust refrigerant flow rate to 3.8 m/s or more
in the horizontal suction pipe.
Note: Adjust refrigerant flow rate to 7.6 m/s or more
in the vertical suction pipe.
Note: Oil traps should be installed every 6 meters.
Expansion valve
Back-up
solenoid
valve
Evaporator
5 m or below
Suction line
Liquid line
Liquid trap
(Make the bent higher
than the evaporator)
Downward
slope
Refrigeration unit
When the evaporator is located higher
Height difference 5 m or below
(1) The suction line should ideally slope gently towards the unit.
Recommendation slope is 1/200~1/250.
(2) Refrigerant pipe should be covered with heat insulation
material on both suction line and liquid line.
Since liquid line becomes approx. 0°C
during operation, apply heat insulation of
20 mm or more in thickness.

18
Refrigerant Circuit Diagram
Oil
separator
Compressor
Splitcycleheatexchanger
Gascooleroutlet
temperaturesensor
Suctionfilter
Intercooler
Gascooler
1ststage
discharge
2nd stage discharge
Unitoutlet
pressuresensor
MOV5
Electronicexpansion
valveforpressure
reduction
Ambient
temperaturesensor
Dischargegas
temperature
sensor
EV2
Balancepressure
solenoidvalve
Intermediate
pressuresensor
MOV1
Oilcontrol
electronic
expansionvalve
2ndstagesuction
1ststagesuction
Splitcycleoutlet
temperaturesensor
Unitoutlet
temperaturesensor
Unitoutlet
(Liquidline)
Filterdryer
Flash
chamber
MOV6
Electronicexpansion
valveforgasreturn
MOV7
Electronicexpansion
valveforliquidreturn
Highpressure
servicevalve
Oilcooler
Oilreturn
Oilservicevalve
2ndstage
suction
servicevalve
1ststage
discharge
servicevalve
Checkvalve
2ndstage
discharge
servicevalve
Highpressuresensor
Oillevelswitch
Lowpressure
sensor
1ststagesuction
servicevalve Suctiongas
temperature
sensor
Unitinlet
(Suctionline)
Lowpressure
servicevalve

19
Refrigerant Charging
(1) Execute refrigerant charging immediately after evacuation. (2) Charge refrigerant R744 (CO2refrigerant).
(3) Do not mix with other refrigerant.
Refrigerant Charging
Method of Charging
(1) Close the vacuum valve of the manifold gauge set exclusively for CO2refrigerant, and separate the vacuum pump.
(2) Place the refrigerant cylinder on the platform scale, and open the refrigerant cylinder valve and manifold gauge set
charging valve.
Notes: 1. Close the access ports of the low pressure and high pressure service valve.
2. Place the platform scale on a flat surface and perform zero-point adjustment.
(3) With the refrigeration unit being stopped, open the joint valve attached to the service piping and the access port of the
high pressure service valve, and charge liquid state refrigerant via the access port of the high pressure service valve.
Calculate the initial refrigerant charging quantity by using the formula below.
Initial refrigerant charging quantity = 0.25 (kg / ft) x Display case footage + 0.09 (kg / m) x Piping length (one-way: m)
Notes: 1. Do not absolutely charge liquid refrigerant from the low pressure side (low pressure access port).
2. If it is difficult to adjust refrigerant charging rate by operating the joint valve and manifold gauge set
charging valve, attach a capillary tube between the refrigerant cylinder and manifold gauge set.
3. Do not attach a capillary tube between the manifold gauge set and service piping.
4. For the method of charging refrigerant, refer to the Engineering Service Manual “Refrigerant Charging
Procedure."
(4) When the liquid refrigerant no longer goes into the refrigeration unit, close the access port of the high pressure service
valve and make the refrigeration unit in cooling operation condition to adjust refrigerant quantity.
Note: Refrigerant quantity adjustment should conform to the “Adjusting Refrigerant Quantity of the Refrigeration Unit"
in the section "Adjustment during Operation."
(5) After completing refrigerant quantity adjustment, close the refrigerant cylinder valve and check that the access ports of
the low pressure and high pressure service valve have been closed.
(6) Slowly open the purge valve of the manifold gauge set to emit the remaining refrigerant in the service piping and
manifold gauge set.
Note: Since refrigerant becomes cold when released, use caution when opening the valve for frost bite.
(7) After completing the operation, check gland nut loosening of the low pressure and high pressure service valves and
fasten them if any looseness exists. Fastening torque is 10 ±2 N・m.
Evacuation [Perform after completing electrical wiring.]
To avoid inclusion of air or moisture in the refrigerant circuit, be sure to execute vacuum drying of the entire circuit before
charging refrigerant by using a vacuum pump. Execute evacuation after securely carrying out airtight test by using the
following sequence.
Before starting evacuation, refer to the Engineering Service Manual “Vacuum Pump
Attachment and Evacuation Procedure.”
(1) Connect electrical wiring
Before starting evacuation, electronic expansion valve and solenoid valve
need to be opened.
(2) Before supplying power
• Turn ON the operation switch S1.
• Turn ON the DIP switch SW13－1 on the control PCB.
• Set the Slide switch SW15 (“Control/Check”) on the control PCB to “Check.”
(3) Supply power
Confirm that the digital display repeatedly alternates between “Low pressure Æ
High pressure ÆUnit outlet pressureÆuAcU.“
Electronic expansion valve and solenoid valve will open.
(4) Evacuation
• Connect a pressure gauge (vacuum pressure gauge) and vacuum pump to
the access ports of the low pressure and high pressure service valve, and
apply evacuation from the two ports.
• Evacuate down to 133 Pa (1 Torr), the target level for evacuation, and continue
for 1 to 3 hours.
(5) After evacuation
• Charge the refrigerant up to approximately 0.5MPa.
• Set the Slide switch SW15 (“Control/Check”) on the control PCB to “Control”.
• Turn OFF the DIP switch SW13－1 on the control PCB.
• Turn OFF the operation switch S1.
Front of refrigeration unit
Access port of low pressure
service valve
Access port of high pressure
service valve
Compressor
Electrical box

20
Always install a ground fault interrupter with the specified capacity
Incorrect capacity does not operate safety stop function and leads to fire or electrical shock.
Protection cannot be made by a current leak relay.
Electrical work must be carried out by a qualified electrical work specialist according to the
requirement.
Cautions for Electrical Wiring Work
Electrical Shock and Fire Prevention
(1) Apply grounding wiring.
(2) The circuit must not be shared with other circuits. (The wire should not be shared with other equipment)
(3) Electric wire should not touch high temperature components (compressor, gas cooler, discharge piping, etc.) and
any metal edge.
Allowable Power Voltage
Allowable power voltage of this refrigeration unit is shown below. Make sure to the requirement.
When a power failure is recovered, every equipment including the refrigeration unit normally start at once.
When sufficient margin is not given to the power supply capacity and wiring capacity, operating voltage tends to drop to
170 V and below, so that the motors cannot be started, and malfunction of a motor or electrical component may be
caused.
In such a case, sequential starting of each equipment should be adopted instead of starting all at once. (Delay timers are
necessary for such operation)
Selection of a Ground Fault Interrupter and Wiring Size
Notes: 1. The values in the table above indicate at wire ambient temperature 40°C or below, wire type 600 V vinyl
insulated wire 3 wires or less.
2. Wire thickness reflects the ambient temperature 32°C, evaporating temperature -10°C.
Model No.
Ground fault interrupter Power line thickness for wiring length
(mm2)Grounding
wire
thickness
(mm2)
Control
circuit
thickness
(mm2)
Rated
current
Detected
current 10 m 20 m 30 m 50 m
OCU-CR1001VF 50 A 100 mA 14 14 14 22 3.5 or
thicker 2.0
Voltage
Voltage during stop 190 V to 215 V [Recommended value]
Power supply voltage during operation 180 V to 220 V
Minimum voltage at starting 170 V or higher
Time
Measure voltage at the
power terminals of the
refrigeration unit.