Hitachi RUA-NP20ATS User manual

IMPORTANT:
READ AND UNDERSTAND THIS
INSTRUCTION MANUAL BEFORE
USING THIS AIR CONDITIONER.
KEEP THIS MANUAL FOR FUTURE
REFERENCE.
INSTRUCTIONS MANUAL
Installation, Operation and Maintenance
65MP3208
REFRIGERANT:R410A
Models:
AIR CONDITIONERS
RUA-NP30ATS
RUA-NP20ATS
SELF-CONTAINED

Model
M
a
x
i
m
u
m
Min
i
m
u
m
M
a
x
i
m
u
m
M
in
i
m
u
m
All
Models
43°C
109°F
21°C
70°F
32°C /
22.5°C
90°F /
72.5°F
21°C /
15.5°C
70°F /
60°F
IMPORTANT NOTICE
 HITACHI pursues a policy of continuing improvement in design and performance of products.
The
right is therefore reserved to vary specification without
notice.
 HITACHI cannot anticipate every possible circumstance that might involve a potential hazard.
 No part of this manual may be reproduced without written
permission.
 Signal words (DANGER, WARNING and CAUTION) are used to identify levels of
hazard
seriousness. Definitions for identifying hazard levels are provided below with their respective
signal
words.
:
:
:
NOTE :
Immediate hazards which WILL result in severe personal injury
or
death.
Hazards or unsafe practices which COULD result in severs
personal
injury or
death.
Hazards or unsafe practices which COULD result in minor
personal
injury or product or property
damage.
Useful information for this operation and/or
maintenance.
 If you have any questions, contact your contractor or dealer of HITACHI
.
 This manual gives a common description and information for this air conditioner which you
operate as well as for other models.
 This air conditioner has been designed for the following temperatures. Operate the air conditioner
within this range
.
Condenser Air Inlet Temperature and Evaporator Air Inlet
Temperature
This manual should be considered as a permanent part of the air conditioning equipment and should
remain with the air conditioning equipment
Hitachi’s air conditioners are designed and manufactured based on using the specified refrigerants. The applicable
refrigerants are specified to each unit models. However, in the global sites, it is revealed that charging different type
of refrigerants instead of the specified refrigerants. This action may cause mechanical troubles, malfunction and
failure, and in the worst case, it endangers
safety
seriously and may cause a fire or an explosion.
Therefore, do not charge the non-specified refrigerants or others in the refrigerant cycle of the unit as follows:
 Hydrocarbon Refrigerants such as Propane or etc.
 Oxygen, Flammable Gases such as Acetylene or etc.
 Poisonous Gases.
The types of charging refrigerants are indicated in the Installation and Maintenance Manuals, Technical Catalogs,
Service Manuals and the
specification
label in the each unit. Be aware that Hitachi does not take any
responsibility
for unit failure, troubles of malfunction, and any accidents caused by charging the
non-specified refrigerants or others such as above.
Condenser Air Inlet Temperature
-Dry Bulb-
Evaporator Air Inlet Temperature
-Dry/Wet Bulb-

— CONTENTS —
No. Item .................................................................................................. Page
Operation Instructions.......................................................................... Ⅰ
1. PREPARATION ................................................................................... 1
1.1 Initial Check........................................................................................................... 1
1.2 Transportation ....................................................................................................... 1
1.3 Placing the Unit ..................................................................................................... 2
2. INSTALLATION .................................................................................. 3
2.1 Ducting Arrangement ............................................................................................ 3
2.2 Condensate Drain Piping ...................................................................................... 3
3. ELECTRICAL WIRING ....................................................................... 3
3.1 Main Power W iring P rocedures ............................................................................. 3
4. FAN SPEED ADJUSTMENT ............................................................... 6
5. REMOVING SHIPPING WASHERS ................................................... 6
6. TEST RUNNING ................................................................................. 7
6.1 Final Installation Check ......................................................................................... 7
6.2 Preparation............................................................................................................ 7
6.5 Safety and Control Device Setting......................................................................... 9
7. MAINTENANCE................................................................................... 10
8. WINTER SHUTDOWN......................................................................... 11
9. REPLACEMENT OF PARTS ............................................................... 11
......................................................................................................... 7
10. TROUBLESHOOTING......................................................................... 13
6.3 Test Running
6.4 Test Running Record ............................................................................................ 8
3.2 Control W iring ....................................................................................................... 4
3.3 Printed Circuit Board (PCB) Layout .......................................................................... 4

Starting Procedures
1. Switch ON the main power source to the unit. 2. Set the operation switch of the room thermostat
to the desired operation position. FAN –Ventilation Operation COOL –Cooling Operation
3. Set the thermostat knob of the room thermostat
to the desired temperature.
4. Set the system switch of the room thermostat to
the ON positions.
Stopping Procedures
1. Set the system switch to the OFF position. 2. Switch OFF the main power source to the unit.
Troubleshooting Poor Cooling Operation
1. Are there any obstacles, which hamper
sufficient air to the condenser?
2. Check to ensure that the thermostat is set at the
desired position.
3. Check the air filter for clogging. 4. Are there any obstacles, which hamper free air
Please contact your service shop if the trouble is still not solved.
Maintenance
1. Clean or replace the filter. 2. Clean the cabinet with cleaner. 3. Clean the condensate drain pan and the drain
piping.
4. Clean the condenser. It is recommended that a
specialist be contacted for this type of work.
5. Check for abnormal sounds and vibration. Stop
the unit and contact your service shop, if observed.
Ⅰ
HITACHI SELF-CONTAINED AIR CONDITIONERS
Unit Does Not Start
1. Is the main power source switch to the unit ON? 2. Is the main fuse normal? 3. Is the phase of main power source right?
OPERATION INSTRUCTIONS Models：RUA-NP20ATS RUA-NP30ATS
flow to the room thermostat.

1
PREPARATION
1. PREPARATION
1.1 Initial Check
Required Materials –Measure, Architectural
Information Regarding Installation Location.
Installation Location –Confirm that the final
Installation location is provided with convenient
piping and wiring work. Strong water runoff should
be avoided.
Installation Space –Check for obstacles, which
restrict condenser airflow or hamper maintenance
work in the space specified in Fig. 1.
Foundation –Check to ensure that the
foundation is flat, level, and sufficiently strong,
taking into account the maximum foundation
gradient (Fig. 2) and the unit weight balance.
Confirm elevation provision for the unit on a solid
base with an iron frame or concrete curbs shown
in Fig. 3, in order to obtain proper clearance
beneath the unit for either rooftop or
on-the-ground installation. Additionally, for
on-the-ground installation, provide a gravel or
concrete space around the condenser air intake,
in order to avoid airflow obstruction due to grass
or other vegetation.
Unit –Check to ensure that the unit has been
transported without damage. File a damage claim
with the transportation companies if mishandling
due to transportation company negligence is
suspected.
1.2 Transportation
Secure the route to the final installation location
by confirming the packing dimensions.
(mm)
Minimum
Maintenance Space
Minimum Air
Intake Space
Maximum
Height of
Wall
ab h A B C D E H
Unit Dimensions
Model
When the unit is installed at a location, which is encircled with walls and obstruction to free air
circulation is suspected, consult HITACHI regarding the operation space.
Fig. 1. Operation Space
NOTE:
RUA-NP30ATS 2,000 2,450 1,910 1,000 1,000 1,000 1,000 1,400 1,910
RUA-NP20ATS 1,600 2,120 1,560 1,000 1,000 1,000 1,000 1,400 1,910

2
PREPARATION
Model
Dimensions
A
B
deg.
mm
deg.
mm
Fig. 3. Recommended Concrete Curbs
1.3 Placing the Unit
Tools and Instruments –Pincers, Wrenches,
Facilities to Transport and Place the Unit.
Transportation –Transport the unit as close to
the final installation location as practical before
unpacking is performed. Keep the unit upright.
When transporting the unit after unpacking has
been performed, take note of the following.
Rolling –Place three equal - sized rollers under
the base frames. Each roller must carry both of
the outer frames, and must be situated to balance
the unit (refer to the center of gravity in Fig. 4).
Lifting by Forklift –Insert the forks under the base
frames from the indicated direction in Fig.4. Lift the
unit, exercising care to catch both of the outer frames.
Rigging –Apply spreader bars to the top of the unit,
in order to prevent damage to the unit due to cable
scratches.
Unpacking –Follow the instructions marked on the
packing.
NOTES:
1. Keep the unit covered with a vinyl cover during installation work for peripheral equipment.
2. Do not expose the unit under the direct sunshine.
Dimensions (mm)
Fig. 2. Foundation Gradient
0.4 21 0.6 21
RUA-NP30ATS
RUA-NP20ATS 0.4 140.6 17
For Model RUA-NP30ATS
For Model RUA-NP20ATS
2,308 2,068
RUA-NP30ATS
A B
RUA-NP20ATS 1,970 1,540
Model

3
INSTALLATION
2. INSTALLATION
Tools and Instruments –General tools for
ducting.
Connection –Pre-drilled duct flanges are
provided at the supply and return air duct
connections. A field-supplied or optional filter box
with filter must be installed at a proper location in
the return air duct. It is recommended that flexible
duct connections be installed to minimize sound
and vibration transmission. All ducts running
outside must be sufficiently insulated and
weatherproofed.
2.2 Condensate Drain Piping
Tools and Instruments –General piping tools.
Drain Trap –A female piping thread screw
connection is provided at side of the unit.
Dimension "L" in Fig. 5 should be sufficiently
longer than the negative fan pressure at the drain
connection (50mm to 100mm, depending on the
return air duct design). Always fill the trap with
water.
For Models RUA-13AT3S and RUA-15AT3S
Fig. 5. Condensate Drain Connection
Fig. 4. Rolling,Lifitng and Rigging
2.1 Ducting Arrangement
3. ELECTRICAL WIRING
Tools and Instruments –One set of wiring tools,
electrical tester (Clamp meter).
Confirm that electrical power is not being supplied
to the installation location prior to any electrical
installation work.
1. Install the field-supplied main switch box at the
properly selected location.
2. Install conduit connectors in the hole for power
wiring (knockout holes).
3. Lead the main power wires and the earthing
wire through the connector to the screw
terminals for main power and earthing in the
magnetic switch box. The neutral wire to 220V
power supplies should also be led through the
connector. Firmly connect the wires with wire
terminals to the unit screw terminals R(L1),
S(L2) and T(L3) for 220V power supplies
according to Fig. 6 or the wiring label attached
to the magnetic switch box.
Schedule Check –Confirm that the field selected
electrical components (main power switch, fuses,
wires, conduit connections, wire terminals) are
properly selected and ensure that they comply
with national and local codes. It is recommended
that the main power switch be locked at the OFF
position, to prevent against accidental supply of
the power during unit servicing.
Service Panel –Access to the magnetic switch
box is provided from the service panel, which is
fixed with screws (see the panel location in the
Operation Instructions.)
3.1 Main Power Wiring Procedures
A scroll compressor is equipped. Because that
the rotation direction of the orbiting scroll of the
HITACHI scroll type compressor is fixed,
therefore a reverse & single phase sequence
protection relay is equipped in this unit.
ELECTRICAL WIRING

ELECTRICAL WIRING
All DSW were set correctly at factory, do not change settings of DSW. The following figures are only for
reference in installation. After installation, make sure all DSW were set as factory setting.
3.3.1 PCB Drawing
3.3.2 Factory Setting of Dip Switch (DSW)
DSW1: Capacity Settings
DSW2: Optional Function Settings (1)
Setting
Position
ON
1 2
3
Setting
Position
ON
1 2
34
Setting
Position
ON
1 2
34
DSW3: Optional Function Settings (2)
The PCB in the Unit is operating with 3 types of DIP switches. The location is as follows:
R S T Mp
Unit Side
If each phase R, S or T of the power source is
incorrectly connected, the compressor does not
start due to the activation of the reverse & single
phase sequence protection relay. Therefore, in
order to check the correct wiring connection, the
utilization of a phase sequence indicator is
recommended when the unit is started after
installation of the unit.
(1) If the phase is wrong, exchange two of the
three wires connected from the main power
source to the main terminals of the unit as
indicated with dotted lines, and then check the
rotation direction of the phase sequence
indicator once again. Do not exchange the
wires in the unit in order to protect the
compressor against the reversal rotation.
3.2 Control Wiring
(2) Do not operate the compressor by depressing
the button of the magnetic switch for the
compressor.
Install the optional room thermostat at a suitable
location in the space to be air-conditioned.
Connect the control wires between the unit
terminals and the thermostat terminals according
to Fig. 6 or the wiring label.
A three-phase condenser fan motor is equipped;
therefore, the fan motor rotation should be
checked. Interchange two of the three main power
source wires, if incorrect rotation is detected
during initial start-up.
Power Source Fig. 6. Field Wiring Connection
4
3.3 Printed Circuit Board (PCB) Layout

3.3.3 Optional Function Settings of Dip Switch (DSW2,3)
Before setting DSW, firstly turn off power source and set the position of the DSW. If the switches are set
without turning off the power source, the contents of the setting are invalid. Mark of “■”indicates the
position of dip switch.
DSW2: Optional Function Settings (1)
Dip Switch
Setting
Force No.1 Compressor Stop
Force No.2 Compressor Stop
Force No.3 Compressor Stop
3.3.4 Alarm Detect Function
If the system is operated under abnormal conditions, during the test running or in normal operate, the
red lamp of the PCB flickers. The states of red lamp flickers are indicated in following Table.
State of
Red Lamp Flickers
Description
Check Item
Continue Light
Normal
—
Once
Reverse or Single Phase of
Main Power Source
1)Check the connection of main power supply.
(Refer to 3.1 Main Power Wiring Procedures)
Twice
Incorrect Wiring Connection
of Room Thermostat
1)Check wiring and connections between unit and
thermostat. (Refer to 3. 2 Control Wiring)
3 Times
Trip Detected of Safety Device
1)Check the current for indoor fan motor.
2)Check the current for outdoor fan motor.
3)Check the pressure of discharge and suction line.
(Refer to 16. Troubleshooting)
4)Check the internal thermostat of compressor.
4 Times
Overcurrent of Compressor
1)Check the current for compressor motor.
2)Check the pressure of discharge and suction line.
(Refer to 16. Troubleshooting)
3)Check the resistance of current transformer by
tester.(Refer to Wiring Nameplate)
Notes:
1) The Red Lamp Flickers cycle will continue showing at intervals of 3 seconds until the Indication
problem be solved.
2) If unit still under abnormal conditions, please contact your distributor.
ON
123
ON
123
ON
123
5 Times Detect of Power Off 1)Check the main power supply.
(No need to check the item of unit)
2)Check the Current for Compressor Motor.
Abnormal Current Detection
1)Check the setting of DSW1 switch.
7 Times No Capacity Setting of Unit
1)The CPU of PCB self-checking.
6 Times Wrong Detect of CPU
Low Current of Compressor or
8 Times
(Refer to 3.3.2 Factory Setting of Dip Switch)
1)Check the main power supply.
5
ELECTRICAL WIRING

The unit is equipped with an adjustable motor
pulley. The fan speed can be varied through a
given range by adjustment of the pulley. Table 1.
shows the setting speed and the variable speed
range. To change the speed, adjust the motor
pulley as follows (refer to Fig. 7).
1. Loosen the two bolts on the adjusting bracket
for the fan belt tension and loosen the belt by
pushing the motor upward.
2. Loosen the set screw in the movable pulley
flange.
4. Tighten the set screw in the movable pulley,
which is positioned over the flat surfaces of the
fixed pulley.
5. Adjust the belt tension (approximately 20 mm
deflection with one finger) by pushing the motor
downward and tightening the bolts on the
adjusting bracket.
3. Turn the movable pulley flange toward the fixed
flange to increase the speed, and turn it away
from the fixed flange to decrease the speed.
Each turn of the movable flange will increase or
decrease the fan speed by 32 rpm.
Fig. 7. Adjustable Motor Pulley
Table 1. Fan Speed Adjustment
RPM: Fan Speed (RPM)
PD* : Pitch Diameter of Motor Pulley (mm)
RPM/Turn**: Fan Speed Change per One Turn of Movable Motor Pulley Flange (RPM per Turn)
5. REMOVING SHIPPING WASHERS
Fig.8-1. Removing Shipping Washers
Compressor is mounted on rubber isolators, and is held rigid during shipment by two sets of shipping
washers (refer to Fig. 8-1). Before starting the compressor, remove the yellow-painted shipping washers, the
compressor should float freely on the rubber isolators.
6
REMOVING SHIPPING WASHERS
4. FAN SPEED ADJUSTMENT
FAN SPEED ADJUSTMENT

TEST RUNNING
6. TEST RUNNING
6.1 Final Installation Check
Inspect the installation work according to all documents and drawings. Table 2 shows the minimum
checkpoints. Table 2. Installation Check List
INSTALLATION WORK CHECK LIST
1.Is the unit solidly mounted and leveled?
2.Is the installation location adequate?
Space for Condenser Air Flow
Space for Maintenance Work
Noise and Vibration
Sunshine and Rainfall
Appearance
3.Is the ducting work adequate?
Filter Soundproofing
Size and Length Insulation
4.Are the condensate drain lines properly arranged?
Trap Drain Ditch
5.Is the electrical wiring system adequate?
Wire Size Tightened Connections
Switch Size Operation Control Devices
Fuse Size Safety Devices
Voltage Hz
6. Have the shipping washers been removed from the rubber-mounted compressor?
6.2 Preparation
Tools and Instruments –High and Low
Pressure Compound Gauge(s), An Electric Tester,
and General Tools.
Preparation –Confirm that the system switch on
the room thermostat is at the OFF position.
Pressure Gauges –Equip high and low pressure
compound gauges according to Fig. 11.
Thermostat –Set the thermostat at a lower
temperature than the room temperature.
6.3 Test Running
Test running should be performed as follows,
when the unit is wired according to the HITACHI
standard wiring label.
1. Set the operation switch to the FAN position
and the system switch to the ON position, and
the evaporator fan will start immediately.
Check the rotation direction, fan speed and air
flow quantity through the evaporator.
2. Set the operation switch to the COOL position,
and the compressor and condenser fans will
start 3 minutes after this operation (refer to Fig.
9).
3. After system operation has become stabilized,
check the suction and discharge pressures on
the compound gauges
4. Check the operating voltage, phase balance
and operating current.
5. Check to ensure that the thermostat functions
properly.
6. Check to ensure that the control and
protective devices function properly (refer to
Table 3).
7

TEST RUNNING
Compile test running records according to Table 4. Utilize these records for periodic operation checks, as
well as for troubleshooting.
Operational Sequence Chart : ON : OFF
Operation
Equipments
*Main Power Switch
OFF
ON
*Room Thermostat
FAN
AUTO
ON
AUTO
COOL
OFF
ON
TH
(Stage)
COOLING CALL
1st …
ON
ON
ON
ON
OFF
ON
2nd …
ON
ON
ON
OFF
OFF
ON
Electric
Components
Indoor Fan Motor
MIF









Outdoor Fan Motor 1,2
MOF1,2 














After 3 min. and
After 3 min.30 sec.
After 4 min. (4)
Start Delay Time
Safety Devices
Close
Close
Close
Close
Close
Close
Close
Close
Open




After 3 min. and
After 3 min.30 sec.
After 4 min. (4)
Compressor 1,2 MC1,2 
Compressor 3,4 MC3,4  
Start Delay Time
RUA-
NP30ATS

RUA-
NP20ATS
Compressor 3 MC3  
Compressor 1,2 MC1,2 
Fig. 9-1. Standard Operation Sequence
NOTES:
1. *：Field Supplied.
6.4 Test Running Record
8

Table 3. Safety and Control Device Setting
Model RUA-NP20ATS RUA-NP30ATS
For Compressor E505DH/E855DH E855DH
High Pressure Switch Automatic Reset, Non-Adjustable
Cut-Out MPa 4.15 4.15
kg/cm
2
G 42.3 42.3
Cut-In MPa 3.2 3.2
kg/cm
2
G 32.6 32.6
Overcurrent Relay Automatic Reset, Non-Adjustable
230V, 60Hz
380V, 60Hz
A
A
40
---
41
21
Discharge Gas Thermostat
Cut-Out °C 120 120
Cut-In °C 98 98
CCP Timer for Compressor Non-Adjustable
(built-in PCB)
No. 1 min 3 3
No. 2 min 3.5 3.5
No. 3 min 4 4
For Evaporator Fan Motor
230V, 60Hz
380V, 60Hz
A
A
14
---
21
11
For Condenser Fan Motor Automatic Reset, Non-Adjustable
Internal Thermostat
Cut-Out °C 160 160
Cut-In °C 125 125
For Control Circuit Fuse
Capacity A 5 5
6.5 Safety and Control Device Setting
9
TEST RUNNING

MAINTENANCE
7. MAINTENANCE
The unit should be periodically inspected
according to the same items as those described in
the paragraph entitled "Test Running". In order to
ensure dependable operation and long life, the
following additional items should be given
particular attention.
Components
Compressor –No maintenance work is required
for hermetic compressors, if the cycle remains
sealed.
Air-Cooled Condenser –Inspect the condenser
and remove any accumulated dirt from the coil at
regular intervals. Other obstacles such as growing
grass and pieces of paper, which might restrict
airflow, should also be removed.
Electrical Equipment –Always pay careful
attention to working voltage, amperage and phase
balance. Check for faulty contact caused by
loosened terminal connections, oxidized contacts,
foreign matter, and others.
Control and Protective Devices –Do not
readjust the setting in the field unless the setting is
maintained at a point other than the point listed in
Table 3.
Field-Supplied Filter –Inspect for accumulated
dirt on the filter. Exchange or clean the filter if
required. The inspection interval may be
determined by the operating conditions for each
installation site.
Condensate Drain Pan and Drain Line –Inspect
and/or clean the condensate drain line at least
twice a year.
Evaporator Fan –Check for a loosened fan belt
and abnormal sounds.
Lubrication
Compressor –The compressors are charged at
the factory with the correct oil and the compressor
nameplate. It is not necessary to add oil, if the
cycle remains sealed.
Refrigerant Cycle
Strainer –Check for clogging after the time when
the cycle is opened.
Refrigerant Re-Charge –When the cycle requires
re-charging due to leakage or replacement of parts,
follow the procedures given below for two cases
(refer to Fig.11).
1. Connect a vacuum pump and a low-pressure
compound gauge to the high-pressure check
joint at the compressor discharge side, and
completely evacuate the cycle.
● R410A is non-azeotrope refrigerant.
Therefore, when the refrigerant leaks,
its component’s weight percentage will
change. Instead of recharging
refrigerant, we should process the
system all over again.
● When charging R410A refrigerant, be
sure the refrigerant being charged is in
its liquid state.
● Too much or insufficient charging of
refrigerant will lead to compressor
failure.
● Keep the refrigerant charging error at
about ± 0.1 kg.
▲
▲▲
▲CAUTION
！
！！
！
2. Connect a charging cylinder to the check joint
illustrated in the figure, and charge refrigerant
in the cycle by weighing the charging cylinder.
Proper refrigerant charge is specified on the
unit nameplate or given in the figure.
3. Be sure to conduct the leakage
detection work.
Fan Motors and Bearings –All fan motors and
the evaporator fan shaft bearings are
pre-lubricated. Lubrication is not required.
10

▲DANGER
！
▲DANGER
！
MAINTENANCE
Compressor
Model
Operating
Charge
Fig. 11. Refrigerant Re-Charge
Compressor Removal
When removing the compressor,
1. Shut OFF the power supply to the unit.
2. Remove all wiring connections and piping
connections to the compressor.
4. Pull out the compressor seat and remove
compressor fastened bolts.
Turn OFF all the switches before
servicing.
Do not charge OXYGEN,
ACETYLENE or other flammable
and poisonous gases into the
refrigeration cycle when
performing a leakage test or an
airtight test. These types of
gases are extremely dangerous,
because explosion can occur. It
is recommended that
compressed air, nitrogen or
refrigerant be charged for these
types of tests.
8. WINTER SHUTDOWN
Winter shutdown
When shutting down the unit for winter, clean the
inside and the outside of the cabinet and dry the
unit, especially the drain pan and the drain lines.
This unit shall be preferably covered during
shutdown, in order to protect it from dust and
environmental conditions.
Spring Start-Up
After any extended shutdown period, prepare the
unit for operation as follows.
1. Thoroughly inspect and clean the unit.
2. Clean or replace the air filters.
3. Clean the condensate drain lines.
4. Remove any accumulated dirt from the
condenser and the evaporator coil.
5. Check the fan balance and attempt to operate
the fan.
6. Check the fan belt tension.
7. Tighten all wiring connections and access
panels.
9. REPLACEMENT OF PARTS
Replacement of parts should be performed by
ordering from the HITACHI Parts List. The Form A
HITACHI Recommended Spare Parts List is
advisable. When replacement of parts becomes
necessary, prepare the parts shown in the Form A
Parts List.
Refrigerant R410A (kg)
Model
3. Remove the bolts on the compressor seat
fastened on the base.
RUA-NP30ATS E855DH 4 x 4.5
RUA-NP20ATS
E855DH 2 x 4.2
E505DH 3.5
11

MAINTENANCE
Table 4. Test Running and Maintenance Record
MODEL: RUA-_____________ MFG. NO._________________COMPRESSOR MFG. NO.:____________
CUSTOMER'S NAME AND ADDRESS:___________________________________DATE: ____________
1. Is the rotation direction of the evaporator fan correct?
2. Is the rotation direction of the condenser fan correct?
3. Are there any abnormal sounds?
4. Has the unit been operated at least twenty (20) minutes?
5. Check Room Temperatures:
Inlet: DB °C, WB °C
Outlet: DB °C, WB °C
6. Check ambient Temperatures:
Inlet: DB °C, WB °C
Outlet: DB °C, WB °C
7. Check suction line Temperature and superheat:
Suction line Temperature: °C
Superheat: °C
8. Check Pressures:
Discharge Pressure: kg/cm2G
Suction Pressure: kg/cm2G
9. Check Voltage:
Rated Voltage: V
Operation Voltage:R-S V, S-T V, T-R V
Starting Voltage: V
Phase Imbalance: 1 –V/Vm=
10. Check Compressor input and running current:
Input: kW
Running Current: A
11. Do the control devices function properly?
12. Do the protective devices function correctly?
13. Is the refrigerant charge adequate?
14. Are the drain lines draining freely?
15. Are the air filters clean?
16. Are the evaporator coil and condenser tubes clean?
17. Are all cabinet panels fixed?
18. Are all cabinet panels free from rattling?
19. Has the unit been checked for refrigerant leakage?
20. Is the unit clean inside and outside?
12

TROUBLESHOOTING
10.TROUBLESHOOTING
Troubleshooting Charts
The following charts show efficient checking procedures for trouble.
：Fault ：Check ：Cause No Brackets：Remedy
No Cooling
----------------------------------Obtain the Correct Voltage
----------------------------------Repair the Power Line
----------------------------------Repair or Replace the
Components
----------------------------------Tighten the Connections
----------------------------------Obtain the Correct Voltage
----------------------------------Check the Power Supply
to the Motor：
Repair When Required
----------------------------------Replace the Bearing
----------------------------------Adjust Belt Tension
----------------------------------Check Fan Speed and the
Ducting System
----------------------------------Replace the Contactor
----------------------------------Repair the Contacts
----------------------------------Repair or Replace the Switch
----------------------------------Obtain Correct Voltage
----------------------------------Check the Power Supply
to the Motor：
Repair When Required
----------------------------------Repair or Replace if Required
----------------------------------Replace the Contactor
----------------------------------Repair the Contacts
----------------------------------Replace the Compressor
----------------------------------Correct the Wiring
No Voltage or Low Voltage
Single-Phase
Shorted Components
Loose Connections
High Voltage or Low Voltage
Single-Phase or Phase Imbalance
Faulty Fan Bearing
Excessive Fan Belt Tension
Excessive Fan Load
Burned Coil
Faulty Contact
Defective Operation Switch
High Voltage or Low Voltage
Single-Phase or Phase Imbalance
Burned Coil
Faulty Contact
Other Faulty Electrical Components
Open Compressor Windings
Incorrect Wiring
Faulty
Unit Power Supply
Blown
Fuses for Operation
Circuit
Tripped
Overcurrent Relay
for Evaporator Fan
Tripped
Evaporator Fan
Motor Contactor
Faulty
Internal Thermostat
for Condenser Fan
Compressor
Contactor
Evaporator
Fan Motor
Stopped
Operating
Condenser
Fan Motor
Stopped
Operating
No Cooling (Compressor Does Not Start)
Faulty
13

TROUBLESHOOTING
Insufficient Cooling
----------------------------See ”High Discharge Pressure”or
”Low Suction Pressure”
----------------------------Repair the Clogging and
Replace the Switch if Required
----------------------------Repair or Replace if required
----------------------------Obtain Correct Voltage
----------------------------Check the Power Line to the
Compressor: Repair when Required
----------------------------See ”High Discharge Pressure”and
”High Suction Pressure”
----------------------------Tighten the Connections
----------------------------See ”High Suction Pressure”
----------------------------See ”High Discharge Pressure” or
”Low Suction Pressure”
High Discharge Pressure
-----------------------------Clean the Condenser
-----------------------------Check the Voltage and Obtain Correct Voltage
-----------------------------Repair or Replace the Motor
-----------------------------Secure Space for the Required Air Flow
-----------------------------Charge the Correct Refrigerant Quantity
-----------------------------Purge the Gas
-----------------------------Remove the Restriction
-----------------------------See ”High Suction Pressure”
Low Discharge Pressure
-----------------------------Add Refrigerant
-----------------------------See ”Unit Working Range”
Operating
High Discharge Pressure or
Low Suction Pressure
Clogged Capillary of Pressure Switch
High or Low
Pressure Switch
Tripped
Overcurrent Relay
for Compressor
Compressor
Cycling
Insufficient Cooling
High Discharge Pressure and
High Suction Pressure
Loose Connections
High Suction Pressure
High Discharge Pressure or
Low Suction Pressure
Tripped
High Voltage or Low Voltage
Single Phase or Phase Imbalance
Cycling ON
Faulty Switch
Condenser
Air Flow
High Discharge Pressure
Restricted
Clogged Condenser Coil
Low Fan Speed
Faulty Fan Motor
Circulating Air Flow
Overcharged Refrigerant
Non-Condensable Gas
Restricted Liquid Line
High Suction Pressure
Condenser Air
Inlet Temperature
High
Condenser
Air Flow
Low Discharge Pressure
Low Refrigerant Charge
Low Ambient Temperature
14

TROUBLESHOOTING
High Suction Pressure
-----------------------------Reduce the Fresh Air Intake
-----------------------------Reinforce the Duct Insulation
-----------------------------Replace or Repair the Compressor
-----------------------------Charge Correct Refrigerant Quantity
-----------------------------See ”High Discharge Pressure”
Low Suction Pressure
-----------------------------Clean the Air Filter
-----------------------------Adjust the Belt Tension
-----------------------------Remove the Restriction
-----------------------------Adjust the Fan Speed
-----------------------------Repair or Replace the Motor
-----------------------------Remove Obstacles to Air Circulation
-----------------------------Repair or Replace if Required
-----------------------------Remove the Restriction
-----------------------------Add Refrigerant
-----------------------------See ”Low Discharge Pressure”
Noisy Operation
----------Remove the Bolt(s)
----------Charge the Correct Refrigerant Quantity
----------See ”Low Suction Pressure”
----------Replace or Repair the Compressor
----------Fix the Runner or Casing Properly
----------Replace the Bearing
----------Adjust Fan Belt Tension
----------Clean the Strainer
----------Add Refrigerant
----------Tighten All Fixed Screws
----------See the Installation Guide
----------Clean the Flexible Ducts
Evaporator Air
Inlet Temperature
High Suction Pressure
High
Excessive Fresh Air Intake
Insufficient Duct Insulation
Defective Compressor Valve
Overcharged Refrigerant
High Discharge Pressure
Evaporator
Air Flow
Low Suction Pressure
Restricted
Clogged Air Filter
Slipping Fan Belt
Restricted Duct
Low Fan Speed
Faulty Fan Motor
Short Cycling
Faulty Thermostat
Restricted Liquid Line and Suction Line
Low Refrigerant Charge
Evaporator Air
Inlet Temperature
Low
Low Discharge Pressure
Compressor
Noisy Operation
Low Suction Pressure
Worn Compressor Parts
Knocking Runner
Worn Bearing
Loose Fan Belt
Partially Clogged
Refrigerant Short Charge
Loose Fixed Screw
Weak Foundation Installation
Liquid Line
Whistling
Inadequate Duct Work
Evaporator Fan
Noisy
Unremoved Shipping Bolt(s)
Overcharged Refrigerant
Shipping Bolt(s)
Noisy
Strainer
Liquid Refrigerant
Backing Up
15

65MP3208 Printed in the Philippines