Sakura SRT-30RA User manual

ROOFTOP PACKAGE AIR CONDITIONER
INSTALLATION MANUAL
This manual provides the procedures of installation to ensure a safe and good standard of
operation for the air conditioner unit.
Special adjustment may be necessary to suit local requirements.
Before using your air conditioner, please read this instruction manual carefully and keep it for
future reference.
SRT-30RA

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FEATURES
Electro Galvanized Steel Panels
Corrosion Resistant Cabinet - The weather proof characteristics of the panels have been significantly
reinforced by the adoption of electro galvanized steel panel which have been coated with polyester powder
coated paint to resist corrosion.
Protection System
Compressor Protection - The compressor is protected with high pressure switch, an over current relay,
an internal overload protector.
Fan motor - The evaporator fan motor and outdoor fan motor are protected with internal overload
protector.
Condenser and Evaporator Coil - The coil have seamless Inner groove copper tubing mechanically
bonded to high efficiency. Each coil is factory tested at 600 psig. And easily accessible for service.
SAFETY PRECAUTIONS
Before installing the air conditioner unit, please read the following safety precautions carefully.
Warning
•Installation and maintenance should be preformed by qualified persons who are familiar
with local code and regulation, and experienced with this type of appliance.
•All field wiring must be installed in accordance with the national wiring regulation.
•Ensure that the rated voltage of the unit corresponds to that of the name plate before
commencing wiring work according to the wiring diagram.
•The unit must be GROUNDED to prevent possible hazard due to insulation failure.
•All electrical wiring must not touch the refrigerant piping, compressor or any moving parts
of the fan motors.
•Confirm that the unit has been switched OFF before installing or servicing the unit.
•Do not touch the compressor or refrigerant piping without wearing gloves.
Caution
Please take note of the following important points when installing.
-Do not install the unit where leakage of flammable gas may occur.
If gas leaks and accumulates at the surrounding of the unit, it may cause fire ignition.
-Ensure that the drainage piping is connected properly.
If the drainage piping is not connected properly, it may cause water leakage.
-Do not overcharge the unit.
This unit is factory full charged. Overcharge will cause over-current or damage to the
compressor.
-Ensure that the unit panel is closed after service or installation.
Unsecured panels will cause the unit to operate noisily.

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OUTLINE AND DIMENSIONAL DATA
SRT-30RA
NOTE: “Standard marking on the cover applicable to specific models; check with label data on the unit.”

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INSTALLATION OF THE UNIT
Location For Installation
Install the unit in such way that air distributed by the unit cannot be drawn in again (as in the case of
short circuit of discharge air). Allow sufficient space for maintenance around the unit.
Ensure that there are no obstructions of air flow into or out of the unit. Remove obstacles which blocks
air intake or discharge.
When two or more outdoor units are installed in a location, they must be positioned such that one unit
will not be taking the discharge air from another.
The location must be well ventilated, so that the unit can draw and distribute plenty of air.
A place capable of bearing the weight of the outdoor unit and isolating noise and vibration.
A place protected from direct sunlight. Otherwise use an awning for protection, if necessary.
A place where smooth drainage of rain water and water formed by defrosting is acceptable.
A place where the unit will not be buried in snow.
A place where air outlet port is not exposed to strong wind.
A place where the air discharge and operating sound level will not annoy the neighbors.
The location must not be susceptible to dust or oil mist.
Caution
If the condensing unit is operated in an atmosphere containing oils (including machine oils), salt
(coastal area), sulfide gas (near hot spring, oil refinery plant), such substances may lead to failure of
the unit.

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INSTALLATION OF THE UNIT
Unit Support
1. The figure shows the use of the roof curb available for mounting these units.
2. The curb should be sealed and fixed to the roof by weather stripping. A suggested means of sealing
the unit and roof curb as shown in the left.
Duct construction
-These units are equipped with supply and return air openings. Duct connection to the unit
should be made with duct flanges and secured directly to the air opening with flexible duct
connectors to avoid normal noise transmission.
-To prevent air leakage, all duct seams should be sealed.
-Ducts in the spaces that not air-conditioned, must be insulated.
-Ducts exposed to the outside must be weather proofed.
-Ducts that entering building through the roof, the entering should be sealed with weather
stripping to prevent the rain, sand, dust etc. from entering the building.
-Correct size of filter must be installed at the return air duct.
Refrigerant Charge
The units are full charged in Factory, no additional charge is necessary. The table below shows the
amount charged pre unit.
Refrigerant R-410A
Model Charge in circuit (kg)
SRT-30RA 1.35
INSTALLATION OF THE UNIT
Drain piping
-A 1 MPT condensate drain fitting is provided. The drain pipe can be led out at the front side.
-The drain pipe must be provided with a trap on the outside of the unit and also installed at an
incline for proper drainage, as shown in the right.
-To prevent condensate formation and leakage, provide the drain pipe with insulation to
safeguard against sweating.
-Upon completion of the piping work, check that there is no leakage and that the water drains
off properly.

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Control System & Electrical Wiring
Function and Specification
1. Major component
-. Main unit
-. Display unit
-. Display cable 2 cores, length 4 metres between Main unit and Display unit
-. Flush-mounted box
Main Unit Display Unit
Flush-mounted box

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2. User’s Features
2.1 Power on/off
Push button to on or off unit
2.2 Fan speed
Push button FAN to change fan motor speed. (High, medium, low or auto) In AUTO FAN operation mode,
fan motor speed will be change automatic according to the difference temperature gap between Troom &
Tset. (ΔT)
2.3 Operation mode
Push button MODE, system will operate as below
? 2 Operating modes (fan, cool) In case of COOL version
? 3 operation modes (fan, heat, cool) In case of Heat/Cool version
Note : In case of remote control utilization, it can be set mode in 5 mode (Fan, Cool, Dry, Heat,
Auto)
FAN : Air conditioner will operate as fan only. (Compressor will not work) And in this mode, it can’t use
SLEEP mode and it can’t set temperature while there is no temperature display on remote control.
COOL : Air conditioner will operate as cooling by room temperature higher than setting temperature and
compressor operation stop working more than 3 minute, compressor will operate again to decrease
room temperature.
∆T Speed
> 3°C high
= 2°C medium
< 1°C low

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
Dry : Air conditioner will operate to reduce
room humidity. The operation in DRY
MODE will be separate in to each
ZONE which are ZONE A, B, C, and D
as below.
Zone A : Room temperature range is
higher than setting temperature for 2°C.
Zone B : It will be operated in room
temperature range equal to setting
temperature or temperature gap is
lower than 1°C.
Zone C : Room temperature range is
lower than setting temperature for 1-2°C
Zone D : Room temperature range is
higher than setting temperature for 3°C.
Exclude temperature
range which are in range
of Zone A & Zone B,
Zone B & Zone C and
Zone C & Zone D, these
call DEAD BAND. These
Zones have stability
which is no changing
Zone in these
temperature ranges.

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Zone calculation will be determined in every 12 minutes which is one operating cycle in DRY MODE and
the operation of compressor and fan motor while in each ZONE has show in the picture. By fan motor will operate
before compressor starting for 30 seconds and fan motor will stop operation after compressor stop for 30 seconds.
In DRY MODE, we can’t use SLEEP function or change speed of fan motor by there is no show fan motor
speed on remote control
HEAT : Air Conditioner will operate as heater which call HEAT PUMP
When system operated as HEAT PUMP, controlling system will reverse refrigerant cycle by open
REVERSING VALVE to make air conditioner work as heater. When room temperature is lower than setting
temperature and compressor has stopped working more than 3 minute, compressor will operate to increase room
temperature.
AUTO : Air conditioner operate by controlling system will choose operating system to be COOL or HEAT
automatically. It depend on setting temperature and room temperature at that time.
While operating as COOL MODE, setting temperature will simply increase 1°C from setting temperature on
remote control. It will use this value as setting temperature to calculate other value.
Tset working in Cool (TSC) = Tset actual + 1°C
While operating as HEAT MODE, setting temperature will simply decrease 1°C from setting temperature on
remote control. It will use this value as setting temperature to calculate other value.
Tset working in Heat (TSH) = Tset actual - 1°C
While operating as COOL MODE, it will change to HEAT MODE when room temperature at that time is
lower than Tset working in Cool (TSC) from 3°C below. And while operating in HEAT MODE, it will change to COOL
MODE when room temperature at that time is higher than set working in Heat (TSH) from 3°C upper.

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2.4 Temperature setting
Push button or to change Setting temperature from 18-30°C
2.5 Dim
Push button or by holding for 3 seconds to reduce the intense of LED light. When turn off air
conditioner, the intense of light will change to be normal
2.6 Remote Handset
Can use function in remote control as usual such as SLEEP, TIMER
3. SYSEM FEATURES
3.1 Watchdog : In controlling system, when system error according to computerized system which may come
from unstable of electrical voltage or from noise, system will set computer to reset immediately.
3.2 Compressor delay protection : In case of compressor stop operation, it always delay time before restart
again for 3 minute. And in case of electric shut off from system and resupply again, it will delay operating of
compressor for 3-4 minute by randomly.
3.3 Compressor minimum on time : compressor always have to operate at least 24 seconds before stop
operation.
3.4 Auto restart : In case of electric shut down, when electricity restart as normally, system will operate
according to last setting program except SLEEP and TIMER that will be cancelled by value will keep record
in MEMORY after changing in value at least 5 seconds. So if the changing in value does not reach 5
seconds before electric shutdown, when system restart, it will operate according to memory value before
changing.
3.5 Freeze protection : In Cool or Dry mode, if T indoor coil ≤ 0°C and compressor has been operating at least 10
minutes continuously. Freeze will occur. System will stop compressor operation and fan speed will operate
in low.
System will return to operate as normally when T indoor coil ≥ 7°C or turn off product.
3.6 Defrost function : In Heat mode, if T outdoor coil has low value compressor will operate as in effective way.
Defrost function will help to protect compressor from damaging.

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Defrost approaching
Immediately that T outdoor coil <3°C, Defrost timer will be counted. If T outdoor coil is more than 3°C over 2
minutes, Defrost timer will be reset and Defrost function will be operate when
a) Compressor continue operate in heat mode over than 5 minutes and
b) Defrost timer are in below condition.
? T outdoor coil decease from +3 to -8°C (line AB) within 30-60 minutes and still ≤-8°C over than 5
minute
? T outdoor coil decease from +3 to -4°C (line AC) within 60-120 minutes and still ≤-4°C over than 5
minute
? T outdoor coil decease from +3 to -2°C (line AD) after 120 minutes and still ≤-2°C over than 5 minute
While Defrost function
Indoor and outdoor fan motor will stop operation but compressor will operate similar to Cool mode
After Defrost function finish
When T outdoor coil over than 14°C or operating in defrost function more than 10 minutes, system will turn
back to operate in Hat mode automatically.
3.7 Pre heat & Post heat functions
Pre heat function help to protect indoor fan motor to blow cool air in Heat mode while compressor operate.
? When T indoor coil is lower than 30°C, fan motor will stop operation.
? When T indoor coil is in between 30-37°C, fan motor will operate at low speed.
? When T indoor coil is more than 37°C, fan motor will operate at setting speed.
Post heat function help to protect indoor fan motor to blow cool air in Heat mode while compressor operate.
? When T indoor coil is more than 30°C, fan motor will operate at setting speed.
? When T indoor coil is in between 18-30°C, fan motor will operate at low speed.
? When T indoor coil is lower than 18°C, fan motor will stop operation.
In case of model that doesn’t have indoor coil sensor, function Post heat will operate as below.
? Fan motor operate at low speed when compressor start operation for 30 seconds. After that fan
motor will operate at setting speed.
? Fan motor will stop operation after compressor stop operation for 30 seconds.

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3.8 Compressor overload protection
When compressor operate in heat mode and T indoor coil has high value , compressor will stop operation and
alarm. (Section 3.14)
System will restart to operate normally when Tindoor coil is lower than 42°C
3.9 Reversing valve change protection
Reversing valve can change stage after compressor stop operation more than 1 minute
3.10 Anti overheat (Outdoor coil) protection
In COOL or DRY mode, if T outdoor coil has high value, compressor will stop operate and alarm. (Section 3.14)
System will restart to operate normally when T outdoor coil is lower than 50°C or change Mode.
3.11 Low ambient protection
When system operate in COOL or DRY mode and compressor operate at least 30 seconds but T outdoor coil
is lower than 30°C, outdoor fan motor will stop operation and alarm. (Section 3.14) System will restart to
operate normally when T outdoor coil is higher than 38°C or operating mode change to FAN or HEAT MODE
or Turn OFF/ON product again.
3.12 Cooling Fail
When system operate in COOL or DRY mode and compressor operate at least 3 minute but T indoor coil is
higher than 25°C, it will alarm. (Section 3.14)
System will restart to operate normally when turn off product or change mode.

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3.13 Heating Fail
When system operate in HEAT MODE, defrost function doesn’t activate and compressor operate at least 3
minute but T indoor coil is lower than 25°C, it will alarm. (Section 3.14)
System will restart to operate normally when turn off product or change mode.
3.14 Error display
When Error, Display will be show as below.
Error code Description
E1 Freeze protection
E2 Defrost protection
E3 Compressor overload protection
E4 Anti overheat protection
E5 Low ambient protection
E6 Cooling fail
E7 Heating fail
E8 Sensor error
3.15 Sensor Error
When abnormal occur to room sensor, controlling system will operate by turn ON/OFF compressor in every
5 minute. And when abnormal occur in indoor coil or outdoor coil sensor, controlling system will operate
without concerning of temperature at indoor coil or outdoor coil sensor

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Electrical Wiring Diagram
SRT-30RA
MAINTENANCE
Warning
- Disconnect from the main power supply before servicing the air conditioner unit.
- Do Not pull out the power cord when the power is ON. This may cause serious electrical shocks which
may result in fire hazards.
Caution
Before turning off the power supply, set the remote controller’s ON/OFF switch to the “OFF” position to
prevent the nuisance tripping of the unit.
If this is not done, the unit’s fans will start turning automatically when power resumes, posing a hazard to
service personnel or the user.

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TROUBLESHOOTING
If any malfunction of the air conditioner unit is noted, check the following fault conditions and causes for
some simple troubleshooting tips.
Symptoms Probably Causes Remedy
Power Failure. Press the (ON/OFF) after power
restore.
Fuse blown or circuit breaker
tripped.
Replace fuse or reset circuit breaker.
Unit does not run.
Power supply wiring phase
incorrect.
Modify the wiring phase.
Power line open. Reset Circuit breaker.
Control circuit breaker trip. Check control circuit for ground or
short ; repair and reset breaker.
Safety device tripped Reset control circuit.
Contactor stuck open Replace contactor.
Loose terminal connection Check connections.
Improperly wired controls Check wiring and rewire.
Low line voltage Check line voltage—determine
location of voltage drop and remedy
deficiency.
Compressor motor defective Check motor winding for open or
short. Replace compressor, if
necessary.
Compressor does not
run.
Seized compressor Replace compressor.
Low pressure control erratic in
action
Raise differential setting. Check
capillary for pinches. Replace
control.
Compressor suction shutoff valve
partially closed
Open valve.
Compressor stop on low
pressure control
Low refrigerant charge Add refrigerant.
High pressure control erratic in
action
Check capillary tube for pinches. Set
control is required.
Compressor discharge valve
partially closed
Open valve, or replace if defective.
Air in system Purge.
Compressor cycles on
high pressure control
Condenser fan not operating Reset condenser fan overload.
Check motor and wiring, Repair or
replace if defective.
Low refrigerant charge Add refrigerant.
Control contacts fused Replace control.
Air in system Purge.
Unit operates long or
continuously
Defective insulation Replace or repair.
Compressor loses oil Leak in system Repair leak.

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Symptoms Probably Causes Remedy
Piping vibration Support piping as required. Check
for loose pipe connections.
System noise
Compressor noisy Check valve plates for valve noise.
Replace compressor (worn bearing).
Check for loose compressor hold-
down bolts.
Frosted or swearing
suction line
Capillary tube clogged. Check capillary tube.
Hot liquid line Shortage of refrigerant due to leak Repair leak and recharge.
Frosted liquid line Restricted filter dryer Remove restriction or replace filter
dryer.
Burned out coil Replace coil.
Leaky bypass piston Replace.
Compressor will not
unload
Weak bypass piston spring Replace.
Filter is filled with dust and dirt. Clean the filter. Airflow is low.
There are some obstacles at the air
inlet or outlet of the units.
Remove obstacles.
Dirty air filter. Clean the air filter.
Temperature setting too low (for
cooling).
Reset the temperature.
Compressor operates
continuously.
Temperature setting too high (for
heating).
Temperature setting too high (for
cooling)
Set the temperature lower. No cool air come out
during cooling cycle, or
no hot air come out
during heating cycle. Temperature setting too low (for
heating).
Set the temperature higher.
If the fault persists, please call your authorized local dealer/serviceman.