Technical Catalogue-RUA-4AT3S to RUA10AT3S

HITACHI SELF-CONTAINED AIR CONDITIONERS

Technical Catalog ⅡⅡⅡⅡ

-Installation, Operation and Maintenance Instructions-

Models:

RUA-4AT3S

RUA-5AT3S

RUA-6AT3S

RUA-8AT3S

RUA-9AT3S

RUA-10AT3S

TU-TCⅡⅡⅡⅡ-11 (X4)

The standard utilization of the unit shall be explained

in these instructions. Therefore, the utilization of the

unit other than those indicated in these instructions is

not recommended. Please contact your local agent, as

the occasion arises.

HITACHI’s liability shall not cover defects arising from

the alternation performed by a customer without

HITACHI’s consent in a written form.

———— CONTENTS —

No. Item Page

Operation Instructions ............................................................... ⅠⅠⅠⅠ

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.............................................................. 4

3.1 Main Power Wiring Procedures................................................................... 4

3.2 Control Wiring ............................................................................................. 4

3.3 Printed Circuit Board (PCB) Layout ............................................................ 5

4. FAN SPEED ADJUSTMENT ..................................................... 7

5. REMOVING SHIPPING WASHERS .......................................... 8

6. TEST RUNNING ....................................................................... 9

6.1 Final Installation Check ............................................................................... 9

6.2 Preparation ................................................................................................. 9

6.3 Test Running............................................................................................... 9

6.4 Test Running Record ................................................................................ 10

6.5 Safety and Control Device Setting ............................................................ 13

7. MAINTENANCE .......................................................................14

8. WINTER SHUTDOWN .............................................................15

9. REPLACEMENT OF PARTS ...................................................15

10. TROUBLESHOOTING ...........................................................17

HITACHI SELF-CONTAINED AIR CONDITIONERS

OPERATION INSTRUCTIONS Models RUA-4AT3S, RUA-5AT3S, RUA-6AT3S, RUA-8AT3S, RUA-9AT3S and RUA-10AT3S

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

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?

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,

flow to the room thermostat?

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

Please contact your service shop if the

trouble is still not solved

PREPARATION

1

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 that

restrict condenser air flow 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 (see "Unit

General Data" in Technical Catalog I).

(mm)

Unit Dimensions Minimum Maintenance Space Minimum Air Intake Space

Maximum Height of

Wall Model

a b h A B C D E H

RUA-4AT3S 1,020 1,435 630 1,000 1,000 1,000 1,200 1,000 630

RUA-5AT3S 1,020 1,435 630 1,000 1,000 1,000 1,200 1,000 630

RUA-6AT3S 1,020 1,435 730 1,000 1,000 1,000 1,200 1,000 730

RUA-8AT3S 1,020 1,635 730 1,000 1,000 1,000 1,425 1,000 730

RUA-9AT3S 1,020 1,635 900 1,000 1,000 1,000 1,425 1,000 900

RUA-10AT3S 1,020 1,635 900 1,000 1,000 1,000 1,425 1,000 900

Fig. 1. Operation Space

PREPARATION

2

Fig. 2. Foundation Gradient

Model Dimensions A(mm)

RUA-4AT3S 1,460

RUA-5AT3S 1,460

RUA-6AT3S 1,460

RUA-8AT3S 1,660

RUA-9AT3S 1,660

RUA-10AT3S 1,660

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.

Dimensions

A B Model

deg. mm deg. mm

RUA-4AT3S 0.4 10 0.6 11

RUA-5AT3S 0.4 10 0.6 11

RUA-6AT3S 0.4 10 0.6 11

RUA-8AT3S 0.4 10 0.6 11

RUA-9AT3S 0.4 10 0.6 11

RUA-10AT3S 0.4 10 0.6 11

INSTALLATION

3

Dimensions(mm) Model

A B C D

Weight

(kg)

RUA-4AT3S 725 710 405 615 195

RUA-5AT3S 725 710 405 615 195

RUA-6AT3S 725 710 405 615 220

RUA-8AT3S 935 700 405 615 275

RUA-9AT3S 905 730 405 615 290

RUA-10AT3S 905 730 405 615 305

Fig. 4. Center of Gravity

2. INSTALLATION

2.1 Ducting Arrangement

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.

Fig. 5. Condensate Drain Connection

Unit

Larger than "L"

Larger than "1/2L"

Condensate Drain Connection

To Atmosphere

ELECTRICAL WIRING

4

3. ELECTRICAL WIRING

Tools and Instruments - One Set of Wiring

Tools, Electrical Tester (Clamp Meter)

Schedule Check - Confirm that the field

selected electrical components (main power

switch, fuses, wires, conduit connections, wire

terminals) are properly selected according to

"Electrical Data" in Technical Catalog Ⅰ , 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 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 earthling

wire through the connector to the screw

terminals for main power and earthing in the

magnetic switch box. The neutral wire to

380V and 415V 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) and

also Mp(N) for 380V and 415V power

supplies according to Fig. 6 or the wiring

label attached to the magnetic switch box.

A scroll compressor is equipped. Because that

the rotation direction of the orbiting scroll of the

HITACHI scroll type compressor is fixed,

therefore a reversal phase protection is

equipped in this unit. 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 reversal phase protection device.

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.

(2) Do not operate the compressor by depressing

the button of the magnetic switch for the

compressor.

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.

3.2 Control Wiring

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.

If a locally-supplied thermostat and switch are

installed, connect the wiring according

Technical Catalog Ⅰ .

Fig. 6. Field Wiring Connection

Power Source

R

Unit Side

S T Mp

ELECTRICAL WIRING

5

3.3 Printed Circuit Board (PCB) Layout

3.3.1 PCB Drawing

The PCB in the Unit is operating with 3 types of DIP Switches. The location is as follows

3.3.2 Different Main Power Supply

When the main power supply is 380V (nominal voltage), be sure to change the wiring connected terminal from L to M as shown figure below

3.3.3 Setting of Dip Switch (DSW)

All DSW were set correctly at factory, do not change settings of DSW. 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 to the setting are invalid. Mark of “ “ indicates the position of dip switch.

Mark Name of Parts Mark Name of Parts

CT1 Current Transformer for NO.1 Compressor DSW2 Dip Switch for Optional Function Setting (1)

CN6 Connector for Transformer Input DSW3 Dip Switch for Optional Function Setting (2)

CN7 Connector for Transformer Output L,M Terminal for Different Main Power Supply

DSW1 Dip Switch for Capacity Setting A,B,D,E,F Terminal for Room Thermostat

TSR MLN

17

FEDBA2 2119 2018

CT1

3213 41421 3 2IC1 / 7812

CN7

CN6

IC2 / 7805Flickers(Red Lamp)

0NDSW1

0N DIPDSW3 DSW2

DIP 0N DIP

Factory Setting Factory Setting 3

ON

1 2 3 4

ON

1 2

Dip Switch Setting

DSW2:Optional Function Settings (1)

Setting Position21 3

DSW1:Capacity Settings

Capacity 4HP

ON

Dip Switch Setting

10HP

DSW3:Optional Function Settings (2)

14 3 42 31 2 4

5HP

ON

6HP

ON

24321 1 43 321

9HP8HP

ON ON ON

4

ELECTRICAL WIRING

6

3.3.4 Alarm Detect Functions

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 10. 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 10. Troubleshooting)

3)Check the resistance of current transformer by tester.(Refer to Wiring nameplate)

5 Times Detect of Power Off 1)Check the main power supply.

6 Times Wrong Detect of CPU 1)The CPU of PCB self-checking.

(No need to check the item of unit)

7 Times No Capacity Setting of Unit 1)Check the setting of DSW1 switch.

(Refer to 3.3.3 Setting of Dip Switch)

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.

FAN SPEED ADJUSTMENT

7

4. FAN SPEED ADJUSTMENT RUA-4AT3S and RUA-5AT3S

Directly driven fan–The unit is equipped with a

directly driven fan motor. The fan speed can be

varied through wiring change of fan motor.

(refer to Table 1 and Fig. 7)

RUA-6AT3S, RUA-8AT3S, RUA-9AT3S and

RUA-10AT3S

Belt driven fan–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 2. Shows the setting speed and

the variable speed range. To change the speed,

adjust the motor pulley as follows (refer to Fig. 8).

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 setscrew in the movable pulley flange.

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 45 rpm.

4.Tighten the setscrew 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.

X: Regulation Space of Motor Pulley PD: Pitch Diameter of Motor Pulley (mm)

Factory Set point

x 0 1 2 3 4 5 6 7 Model

PD 112 109 106 103 99 96 93 90 x RPM PD

RPM /

Turn

RUA-6AT3S RPM 1,030 1,010 980 950 910 880 860 830 5 880 96 45

RUA-8AT3S RPM 1,120 1,090 1,060 1,025 995 960 930 900 7 900 90 45

RUA-9AT3S RPM 1,120 1,090 1,060 1,025 995 960 930 900 5.6 950 95 45

RUA-10AT3S RPM 1,120 1,090 1,060 1,025 995 960 930 900 4.1 990 99 45

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/Turn)

Table 2. Fan Speed Adjustment

Fig. 8. Adjustable Motor Pulley Fig. 7. Wiring for changeable of Fan Speed

Table 1. Fan Speed Adjustment

REMOVING SHIPPING WASHERS

8

5. REMOVING SHIPPING WASHERS

RUA-4AT3S, RUA-5AT3S and RUA-6AT3S-The compressors are mounted on rubber isolators, and are

held rigid during shipment by two sets of shipping washers (refer to Fig. 9-1). Before compressor starting,

remove the yellow-painted shipping washers, the compressor should float freely on the rubber isolators.

Fig. 9-1. For Models RUA-4AT3S, RUA-5AT3S and RUA-6AT3S

RUA-8AT3S , RUA-9AT3S and RUA-10AT3S-The compressors are mounted on rubber isolators, there are

not shipping washers (refer to Fig. 9-2).

Fig. 9-2. For Models RUA-8AT3S, RUA-9AT3S and RUA-10AT3S

Nut

(Yellow Painted)

Shipping Washer Stud Bolt

Compressor Frame

Rubber Isolator 1

Base

Rubber Isolator 2

Base

Rubber Isolator 1

Compressor Frame

Rubber Isolator 2

Stud Bolt

Nut

Washer

TEST RUNNING

9

6. TEST RUNNING 6.1 Final Installation Check

Inspect the installation work according to all documents and drawings. Table 3. Shows the minimum check points.

Table 3. Installation Check List

6.2 Preparation

Tools and Instruments - High and Low

Pressure Compound Gauge(s), An Electric

Tester, 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. 12.

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. 10).

3.After system operation has become stabilized,

check the suction and discharge pressures on the

compound gauges. Normal operating pressures

are shown in Fig. 11.

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 4).

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

TEST RUNNING

10

6.4 Test Running Record

Compile test running records according to Table 3. Utilize these records for periodic operation checks, as well as for troubleshooting.

Operational Sequence Chart �: ON �: OFF

*Main Power Switch OFF ON

FAN AUTO ON AUTO

COOL OFF ON

Operation

Equipments *Room Thermostat

TH ─ ─ ─ � � � �

Indoor Fan Motor MIF � � � � � � �

Outdoor Fan Motor MOF � � � � � � � Electric

Components Compressor MC � � � � � � �

Safety Devices Close Close Close Close Close Close Open

Fig. 10. Standard Operation Sequence

NOTES: 1. *: Field Supplied.

After 3 min.

TEST RUNNING

11

Fig. 11-1. Nominal Operation Pressures

for RUA-4AT3S


for RUA-6AT3S


for RUA-5AT3S


for RUA-8AT3S

TEST RUNNING

12

Fig. 11-5. Nominal Operation Pressures for RUA-9T3S

Fig. 11-6. Nominal Operation Pressures for RUA-10AT3S

TEST RUNNING

13

6.5 Safety and Control Device Setting

Table 4. Safety and Control Device Setting

Models RUA-4AT3S RUA-5AT3S RUA-6AT3S RUA-8AT3S RUA-9AT3S RUA-10AT3S

For Compressor 400DH 500DH 600DH 750EL 900EL 1000EL

High Pressure Switch Automatic Reset, Non-Adjustable

Cut-Out

Cut-In

kg/cm2G

kPa

kg/cm2G

kPa

30.0

2,940

24.0

2,350

30.0

2,940

24.0

2,350

30.0

2,940

24.0

2,350

30.0

2,940

24.0

2,350

30.0

2940

24.0

2350

30.0

2,940

24.0

2,350

Overcurrent Transformer Automatic Reset, Non-Adjustable

Cut-Out

A 13.2 16.8 19.8 24.2 28.5 31.5

For Compressor Motor

Automatic Reset, Non-Adjustable

Internal Thermostat

Cut-Out

Cut-In

°C

°C

135

113

135

113

135

113

135

113

135

113

135

113

CCP Timer for Compressor Non-Adjustable

(Building on PCB)

min. 3 3 3 3 3 3

Manual Reset, Adjustable For Evaporator Fan Motor

Overcurrent Relay

A 3.3 4.4 2.1 2.1 3.6 3.6

Automatic Reset, Non-Adjustable Internal Thermostat

Cut-Out

Cut-In

°C

°C

130

100

130

100

—

—

—

—

—

—

—

—

Automatic Reset, Non-Adjustable

For Condenser Fan Motor

Internal Thermostat

Cut-Out

Cut-In

°C

°C

160

130

160

130

160

130

160

130

160

130

160

130

For Control Circuit Fuse

Capacity

A

2.5

2.5

2.5

2.5

2.5

2.5

MAINTENANCE

14

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 air

flow, 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 4.

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 listed in "Component

Detailed Data" in Technical Catalog Ⅰ and the

compressor nameplate. It is not necessary to add

oil, if the cycle remains sealed.

Fan Motors and Bearings - All fan motors and

the evaporator fan shaft bearings are

pre-lubricated. Lubrication is not required.

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.12).

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.

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.

When Slight Leakage from the cycle Occurs –

Evacuation might not be required.

1.Connect a high-pressure compound gauge to

the high-pressure check joint.

2.Connect a charging cylinder and a low-pressure

compound gauge to the check joint illustrated in

the figure.

3.Operate the unit.

4.Slowly charge refrigerant vapor into the cycle,

until the pressure reach the points illustrated in

Fig. 12.

MAINTENANCE

15

Fig. 12. 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.

3.Remove the bolts fastened on the compressor frame.

4.Upward lift and pull out the compressor.

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 Ordering from the HITACHI Parts List should

perform replacement of parts. 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.

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.

▲▲▲▲DANGER ！！！！

Turn OFF all the switches before

servicing.

▲▲▲▲DANGER ！！！！

Capillary Tube

Unit Piping

Check Joint for Low Pressure Cylinder

Field Piping

Charging

Evaporator

Check Joint for

High Pressure

Low

Vacuum Pump

High

Pressure Gauge

Compressor

Condenser Strainer

Refrigerant R-22(kg)

Model Operating Charge

RUA-4AT3S 2.2

RUA-5AT3S 2.6

RUA-6AT3S 3.5

RUA-8AT3S 4.2

RUA-9AT3S 4.7

RUA-10AT3S 4.8

MAINTENANCE

16

Table 5. 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 ℃,WB ℃

Outlet: DB ℃,WB ℃

6. Check ambient Temperatures:

Inlet: DB ℃,WB ℃

Outlet: DB ℃,WB ℃

7. Check suction line Temperature and superheat:

Suction line Temperature: ℃,

Superheat: ℃,

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 ?

TROUBLESHOOTING

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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


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

TROUBLESHOOTING

18

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 Discharge Pressure or


Tripped


Single Phase or Phase Imbalance

Cycling ON

Faulty Switch

Condenser

Air Flow


Restricted

Clogged Condenser Coil

Low Fan Speed

Faulty Fan Motor

Circulating Air Flow

Overcharged Refrigerant

Non-Condensable Gas

Restricted Liquid Line


Condenser Air

Inlet Temperature

High

Condenser

Air Flow


Low Refrigerant Charge

Low Ambient Temperature

TROUBLESHOOTING

19


-----------------------------Reduce the Fresh Air Intake

-----------------------------Reinforce the Duct Insulation

-----------------------------Replace or Repair the Compressor

-----------------------------Charge Correct Refrigerant Quantity

-----------------------------See ”High Discharge Pressure”


-----------------------------Clean the Air Filter

-----------------------------Adjust the Belt Tension


-----------------------------Adjust the Fan Speed

-----------------------------Repair or Replace the Motor

-----------------------------Remove Obstacles to Air Circulation

-----------------------------Repair or Replace if Required


-----------------------------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 Excessive Fresh Air Intake

Insufficient Duct Insulation

Defective Compressor Valve



Evaporator

Air Flow


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


Noisy Compressor

Noisy Operation


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

Unremoved Shipping Bolt(s)


Shipping Bolt(s) Noisy

Strainer

Liquid Refrigerant

Backing up

Noisy

Specifications in this catalog are subject to change without notice, in order that HITACHI may bring the latest innovations to our customers.

Catalog No. TU-TCⅡ-11 Printed in Taiwan

Technical Catalogue-RUA-4AT3S to RUA10AT3S

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Transcript of Technical Catalogue-RUA-4AT3S to RUA10AT3S