Chiller Air-cooled Screw R134a Operation & Maintenance Manual MODELS: RCAW - Compact (50Hz) IMPORTANT • Please read this Operation & Maintenance Manual completely before Operating & Maintenance the product. • Operating & Maintenance must be performed in accordance with the national wiring standards by authorized personnel only.
Air cooled Screw Operation & Maintenance Manual TABLE OF CONTENTS SAFETY CONSIDERATIONS Warning...........................3 Caution............................7 GENERAL Manipulation of HMI Unit.......................11 CONTROLS PLC and HMI Unit .........................21 Machine on/off control......................30 START-UP Pre Start-up ..........................31 Start-up Procedure........................32 Operation Limits ........................34 OPERATION Sequence of Operation ......................37 Sensors ..........................42 SERVICE Cycle Components........................43...
Safety Considerations SAFETY CONSIDERATIONS Installing, starting up, and servicing this equipment can be hazardous due to system pressures, electrical com- ponents, and equipment location (roof, elevated structures, etc). Only trained, qualified installers and service technicians should install, start up, and service this equipment. When working on this equipment, observe pre- cautions in the literature, and on tags, stickers, and labels attached to the equipment, and any other safety pre- cautions that apply.
Safety Considerations Always ground the product. Always intstall dedicated circuit and breaker. • There is risk of fire or electric shock. • Improper wiring or installation may cause fire or electric shock. For re-installation of the installed product, Do not install, remove, or re-install the unit by always contact a dealer or an Authorized yourself (customer).
Safety Considerations Do not damage or use an unspecified power Use a dedicated outlet for this appliance. cord. • There is risk of fire, electric shock, explosion, or • There is risk of fire or electrical shock. injury. Be cautious that water could not enter the Do not touch the power switch with wet product.
Safety Considerations Changing the set value is prohibited. Electric shock prevention. • Do not change the set value of the safety device. • When installing the freezer, always ground the wire. • If you operate the product with incorrectly set val- ues, it can cause defect, fire or explosion.
Safety Considerations Do not leave refrigerant system open to air any longer than necessary. • Seal circuits being serviced and charge with dry nitrogen to prevent oil contamination when timely repairs cannot be completed. Always check for gas (refrigerant) leakage Do not install the product where the noise or after installation or repair of product.
Safety Considerations Do not use the chiller in special Make the connections securely so that the environments. outside force of the cable may not be applied to the terminals. • Oil, steam, sulfuric smoke, etc. can significantly • Inadequate connection and fastening may gener- reduce the performance of the chiller or damage ate heat and cause a fire.
Safety Considerations Be careful of disposal. Be careful of high voltage. • When disposing the device, request to the spe- • Install separate wiring for the power and always install cialized expert. and use dedicated power supply and circuit breaker. •...
• LG assumes no responsibility for chiller or con- denser damage resulting from untreated or improperly treated water. Harsh chemical, household bleach or acid...
General GENERAL This manual is composed of information on control, operation, start-up, service and troubleshooting of RCAW Air Cooled Chiller. Manipulation of HMI(Human Machine Interface) Unit If it is strongly recommended that the user NOT change any programing without consulting LGE service personnel.
General Main Menu +17.9 °C CHW Out Temp Main Menu +17.2 °C System Setting Condensate Temp User Setting Status Message Closed-down Content Comp Running Hrs Hand/Auto Mode Auto Control Running Capacity Control Mode Local Control Start Interval Complete Modbus Date2009/03/03 13:05:00 +17.9 °C CHW In Temp...
General User Setting User Setting Week Modify I/O Display Main Menu Week Setting Content Week 5 °C ~12 °C Temp Setting Revision Code 7.0 °C Target Temp Oil Preheat Delay 5.0 °C Outage Temp 12.0 °C Restart Temp Hand Remote Mode Selection Mon Start 08:00:00...
General Compressor shutdown temperature means the temperature where the compressor must be shut downed by low temper- ature. Here, the default value is 5.0°C(41°F). Compressor restart temperature means the temperature where the com- pressor must restart after shutdown. Here the default value is 12°C(53.6°F). By difference between the shutdown tem- perature and the restart temperature, the compressor is protected from frequent starting.
General I/O Display DISCRETE INPUTS1 DISCRETE INPUTS5 DISCRETE OUTPUT3 I/O Display Fan4B5B Fan4A5A User Setting SV2 Magnet Valve Fan2B3B Alarm Display Fan4B5B Emergency Stop Content DISCRETE INPUTS2 DISCRETE INPUTS6 Remote Control Alarm Output System Oil M1 Contactor Main Contactor M2 Contactor Contactor M3 Contactor DISCRETE OUTPUT1...
General The liquid flow switch detects chilled water flow, and the water flow must build during running the chiller. The openness of the switch during starting up or running compressor is considered to be water flow alarm by the PLC. The DP switch means differential pressure switch input to the PLC.
General Alarm Display Alarm Display Delay Setting User Setting Content Alarm History 1/10 Alarm 2009/03/03 Date 12:53:50Time Clear ---- Alarm History 2/10 Alarm 2009/03/03 Date 12:53:50Time Clear Alarm History 10/10 Alarm 2009/03/03 Date 12:53:50Time Clear Fig. 5 Through the alarm display, recent 10 alarms are displayed with their invocation time. The alarm also can be cleared in this screen cut.
General System Setting System Setting Main Display Par. Setting Content Temp and Hours Correction +0.0 °C Chilled In +0.0 °C Chilled Out +0.0 °C Condensate Temp +0.0 °C Ambient Temp +0.0 °C Exhaust Temp Limit Comp Hrs 100000 Clear Comp Hrs ---- Fig.
General Parameter Setting 90.0 °C H Exhaust Temp Par. Setting 80.0~150.0 System Setting Delay Setting Content 35.0 °C Fan Start Temp3 34.0~37.9 30.0 °C Fan Start Temp2 29.0~33.9 26.0 °C Fan Start Temp1 25.0~28.9 29.0~200.0 Load Interval 15.0 °C Limit Temp 10.0~20.0 2.0 °C Low Temp...
General Delay Setting Delay Setting 0.3~1.5 Fan Feedback 2.0S Par. Setting 0.3~5.0 Contactor-feed 3.0S DP Delay 300.0S 90.0~350.0 Alarm Display Comp Protect 1.0S 0.5~1.5 Content Temp Alarm 3.0S 1.0~30.0 Fan Stop Delay 15.0~60.0 System Oil 30.0S 10.0~900.0 Water Flow 9.0S 1.0~20.0 System Pressure 3.0S...
Controls CONTROLS PLC and HMI Unit PLC and HMI Unit The HMI (Human Machine Interface) side of the PLC (Programmable Logic Controller) and HMI assembly is shown on the door side as shown in the below picture. The HMI is composed of wide full dot LCD with 4 line display and back light, 9 functional keys, and 15 indicating LEDs for rich user interface.
Controls Protected with Protected with Protected with Protected with User Code System Code System Code System Code Main Menu User Setting I/O Display Alarm Display Delay Setting System Setting Para. Setting Remote Chilled Water In Fan Control Hand/Auto Target Temp Current Alarms Start Interval Control Input...
Controls Indication Indicating Status Automatic Control: ON OUTPUT1 Auto/Manual Control Manual Control: OFF Remote Control: ON OUTPUT2 Local/Remote Control Local Control: OFF Run: ON OUTPUT3 Remote Start Input Stop: OFF Delaying: ON OUTPUT4 Start Interval Lapse Complete: OFF Recycle Stop: ON OUTPUT5 Compressor Recycle Running: OFF...
Controls On the top side of the PLC, DIP switches and indicating LEDs are installed. Normally, the D2 LED has to blink with 4 Hz frequency, and D3~D6 has to be off. The other LEDs blink according to communication status of the PLC. All switches of the 4-position DIP switch have to be positioned at off, and switches of the 8-position DIP switch have to indicate MODBUS slave device address.
Controls Fig. 13 MODBUS Fig. 14 Actual locations of the connectors are shown in the above pictures and detail descriptions of the connectors are shown in the below table. The power of discrete outputs is 220VAC and the power of the discrete inputs is 24VDC. Operation &...
Controls Connector Wire No. Description Remote Control System Oil Pressure M1 Contactor (Main Contactor) M2 Contactor ( Contactor) Low Water Temperature Switch System Pressure Switch Phase Protector Chilled Water Flow Switch Differential Pressure Switch (DI -1) Comp Overload (Internal Protector) Fan1A1B Fan2A3A Fan2B3B...
Controls Connector Description Wire No. RTD1+ Chilled Water In Temperature RTD1- RTD1- RTD2+ Chilled Water Out Temperature RTD2- RTD2- RTD3+ Compressor Exhaust Temperature RTD3- (RTDI) RTD3- RTD4+ Ambient Temperature RTD4- RTD4- RTD5+ Refrigerant Cond Out Temperature RTD5- RTD5- RX2/D2+ MODBUS on RS -485: D+ MODBUS TX2/D2 - MODBUS on RS - 485: D -...
Controls The MODBUS address map of registers is shown in the below table. MODBUS Address Meaning Indicating Unit Write 46101 Chilled Water Out Temp Actual Value x 10 [°C] 46102 Chilled Water In Temp Actual Value x 10 [°C] Actual Value x 10 [°C] 46103 Ref Cond Out Temp Actual Value x 10 [°C]...
Controls Machine On/off Control There are two modes to turn on/off the machine. One is the Hand Mode and the other is the Auto Mode. HAND MODE – Hand Mode is the default set mode from the factory, and the user can turn on/off the power of the product by pressing the Start/Stop button on the control box for 3 seconds.
Start-up START-UP Pre Start-Up Do not attempt to start the chiller until the following checks have been completed. • Check auxiliary facilities, such as the chilled water circulating pump, air-handling equipment, or other equip- ments to which the chiller supplies liquid are operational. Consult manufacturer’s instructions. If the unit has field-installed accessories, be sure all are properly installed and wired correctly.
Start-up Start-Up Procedure Do not manually operate contactors. Serious damage to the machine may result. The following procedure should be followed. • Be sure that water side load such as air-handling equipment, or other equipment to which the chiller supplies liquid are working.
Start-up Operation Limits Temperature Temperature Temperature limits during the operation of the unit are as follows. Maximum ambient temperature: 129.2°F(54°C) Minimum ambient temperature: 64.4°F(18°C) Maximum outlet water temperature: 59°F(15°C) Minimum outlet water temperature: 41°F(5°C) * Temperature of inlet water must not exceed 68°F(20°C) during continuous operation. Voltage Permitted maximum voltage and minimum voltage are displayed on PDB.
Start-up Flow Rate The basic flow rate of the chiller must follow the values of the table showing the maximum, minimum and designed flow rate. Higher or lower flow rates are permitted to make the lower or higher temperature rise. In order to assure appropriate heat exchange and turbulent flow inside the evaporator, the flow rate must exceed the Minimum flow rate.
50 RT 50 RT 40 RT 40 RT 40 RT Water flow rate (gpm) Note: For flow out of this range, consult LG. * : P – 380V, Q - 400V, R - 415V Fig. 15 36 Chiller Air-cooled Screw...
Operation OPERATION Sequence of Operation The sequence of the operation is depicted by the flow chart in the below. When the start is in effect, the condenser fan and water pump run concurrently. Additionally, for the minimum load position of the compressor, the MV1 is turned on. After condenser fan feedback delay, the feedback inputs from the contactors are checked.
Operation Delay control for the chiller is summarized in the below picture. There are two essential delays, stop to start delay and oil pre-heating delay in the picture. The stop to start delay is the duration between the stoppage of the compressor and the restart of the compressor.
Operation Fig. 19 100RT CONTROL POINT DEFAULT RANGE 30 ~ 34 35 ~ 39 40 ~ 45 Table 11 Operation & Maintenance Manual 41...
Operation Sensors RTD (Resistance Temperature Detect) To monitor the inlet water temperature, outlet water temperature, discharge temperature of the compressor, ambient temperature and discharge temperature of the condenser of the cooler during chiller operation, RTD (Resistance Temperature Detect) is used. Inlet water temperature sensor of Cooler Outlet water temperature sensor of Cooler Compressor discharge temperature sensor...
Service SERVICE Cycle Components The structure of the air-cooled cooling cycle is shown in the below. Fig. 20 PART PART PART PART Compressor Flow Control Device (13) Oil Level Switch (19) Relief Valve Condenser Flow Control Device (14) Oil Solenoid Valve (20) Temperature Sensor Reciever...
Service Number Description Number Description Compressor casing Discharge fixed ring Motor casing Disc spring Oil separator Bearing lock nut Motor rotor assembly Male rotor Motor stator assembly Suction bearings Motor rotor washer Suction bearings inner/outer spacer ring Motor rotor spacer ring Oil guiding ring Oil separator baffle Suction filter...
Service This means the displacement of refrigerant gas also increases, as a result the refrigeration capacity also increases. However, when any of the step solenoid valve is energized, the high pressure oil in the piston cylin- der bypasses to the suction port causing the piston and the slide valve to moved toward the left side, then some of the refrigerant gas by pass from the compression chamber back to the suction end.
Service The bearings used in the compressor required a small but steady quantity of oil for lubrication; the oil injection into the compression chamber creates an oil sealing film in the compression housing for increasing the efficien- cy and absorbing a part of heat of compression. In order to separate the oil from the mixed refrigerant gas, an oil separator is required to ensure the least amount of oil carried into the system.
Service SYMPTOMS CAUSE REMEDY Power line open Check main disconnect. Control fuse open Check control circuit for ground or short. Replace fuse. Use High-Pressure Switch (HPS) tripped Navigator to reset current alarms. Loose terminal connection Check connections from CCP to contactor. COMPRESSOR Improperly wired controls Check wiring and rewire.
Service Condenser Maintenance and cleaning of condenser coil Periodically cleaning the surface of the coil is essential in maintaining the normal operation of the unit. By removing any contaminant or hazardous substance on the coil, you can extend the life of the coil and the unit. The following mainte- nance and cleaning method is recommended as part of the periodical maintenance activity to extend the life of the coil.
Service Condenser fan The fan motor and the fan must be fixated firmly on the top plate of the condenser with the metallic bracket. Shroud pro- tects the parts from the fan rotating in high speed. Assembly of the condenser fan is as shown in the picture. as follows. Apply the grease on the exposed part of the motor to protect it from the rain.
Service Cooler Flow Switch Flow Switch is installed on the water outlet nozzle for all units as factory setting. The following pictures shows the Flow Switch in generally installed method. parts name cover insulation plate microswitch adjusting screw metal fitting for flow adjusting screw flow adjusting screw actuating plate...
Service Dual Pressure Switch Dual pressure switch has low pressure cutout switch and high pressure cutout switch inside. The cutoff points can be adjustable. The factory setting values are shown in the below. Low Pressure Cutout 3.2kgf/cm High Pressure Cutout 22kgf/cm Table 18 The low pressure switch and the high pressure switch are normally closed and tripped to opening when the detected...
Service Anti-freezing Switch The anti-freezing switch is used to detect too low water temperature. The switch is normally closed and tripped when the chilled water leaving temperature is under 35.6°F(2°C). The switch returns to the normal status when the tempera- ture increases over 41°F(5°C).
Service Refrigerant Cycle Leakage test As described in the installation manual, the unit is sufficiently charged with R134a refrigerant as factory setting. If the refrigerant pressure is lower than the factory setting, you must check for leakage. If the pressure inside the unit has dropped, use the Nitrogen to do a leakage test.
Service Refrigerant Cycle Oil Filter The oil filter is installed on the oil separator in oil return line to the compressor. Differential pressure between the inlet and outlet of the oil filter must be checked periodically. On the oil separator, the core valves for connection of the inlet/outlet with pressure gauge are installed.
Service Oil Heater The oil heater prevents poor lubrication due to too low viscosity. The oil heater is also installed on the oil sepa- rator. The 150W oil heater has 220VAC power input. Fig. 32 Solenoid Valve One of the Solenoid Valve is installed between the Flash Gas Tank where the oil separator is installed and the other is installed between the oil filter and Flash Gas Tank.
Service Control System The structures of the power panel and control panel are shown in the below. The power panel in the left is composed of the electrical components related to 400VAC main power, and the control in the right is composed of low-voltage com- ponents such as the PLC and the HMI unit.
Service Power Panel On the left side of the power panel, terminal blocks for main power connection are prepared. The field supplied 400VAC main power lines and neutral line for control power are connected to these terminal blocks. There are three magnetic contactors for the wye-delta starting of the compressor and OCR (Over Current Relay) for the compressor.
Service Wye Starting Delta Running 1M 2M 1M 2M Fig. 36 There is one magnetic contactor for each condenser fan. On the right bottom side of the power panel, voltage monitoring relay is installed to monitor proper power input. There are three fuses installed for the 400VAC power input to the voltage monitoring relay.
Service n Compressor OCR (Over Current Relay) The compressor OCR is thermal type and used to protect the compressor from overload condition. The OCR contact used for the control system is normally closed and the OCR contact switch is to be opened if it detects excessive cur- rent.
Service n Voltage Monitoring Relay (5E) The voltage monitoring relay is used for the verification of proper power supply of 400VAC. The voltage monitoring relay is shown in the below. Existing 3-phase voltage will be shown ordinally every 3 seconds as shown in the below. Fig.
Service UNBAL. AUTO REV. Reverse phase protected REV. Reverse phase unprotected Unbalance protected UNBAL. Unbalance unprotected Auto reset AUTO Manual reset Auto reset delay 5 sec 5S/1S Auto reset delay 1 sec Table 22 The voltage unbalance tripping is activated when the unbalance exceeds +5% more than 3 seconds. Similarly, phase loss tripping has 2 second delay and phase reverse tripping has 0.5 second delay.
Service Assist Relay Assist Relay is the relay to check power supply of 220V to the controller. Assist Relay is as follows. Fig. 40 Compressor Contactor Compressor Contactor controls the start, stop and static range of the compressor motor when the product is operating. Rated voltage of Compressor Contactor is 400V.
Service Fan Contactor Fan Contactor controls the start, stop and static range of the fan motor when the product is operating. Rated voltage of Fan Contactor is 400V. Fig. 42 Operation & Maintenance Manual 63...
Service Control Panel On the external door of the control panel there is emergency switch for the instant cutting out of control outputs from the PLC. By pushing the emergency switch, the 220VAC power supplied to the PLC relay outputs are cut out instantly. By turning the switch in clock-wise direction, the power to the output is recovered.
Service In the control panel, the PLC is installed as a central control station. The PLC is assembled with the HMI unit in a black case. The PLC is supplied 24VDC power from the SMPS (Switched Mode Power Supply) on the right side. Switched Mode Power Supply Control fuse...
Service Temp. Sensor in Control Box This is used to detecting the temperature within the Control Box when operating the product. The shapes and character- istics are as follows. Fig. 45 Ventilation Fan Ventilation Fan is attached on both sides of the Power Box and the Control Box. This fan responds to the temperature increase within both boxes while the product is operating and sends the air outside to prevent any issues from tempera- ture increase within each box.
Service Maintenance Maintenance Schedule Every Every Every Every Every Every Every Daily Monthly 2 months 3 months 6 months 1 year 2 years 3 years 6 years Check Point 500h 1000h 1500h 2500h 5000h 10000h 15000h 30000h Check 1. Cycle Status 2.
Trouble Shooting TROUBLE SHOOTING If a stoppage occurs more than once as a result of any of the safety devices, determine and correct the cause before attempting another restart. General Malfunction Before specific alarm trouble shooting, general troubles and their possible remedies are introduced. When the unit does not run at all, you have to check power supply to the chiller, refrigerant, configuration, and alarm invocation.
Trouble Shooting Symptom Possible Cause Possible Remedy Check for power to unit Check over current protection device Unit does not run Check no-fused disconnect (if equipped) Restore power to unit Low refrigerant charge Check for leak and add refrigerant Wrong or incorrect unit Check unit configuration configuration Active alarm...
Trouble Shooting Alarm Specific alarms, their recognition method, and their possible causes are listed here. To clear alarm and recover from the alarm, clear the alarm history after correction of the cause of the alarm. The emergency trouble means that the emergency switch installed on the right side of the control panel is pushed by operator.
Trouble Shooting Displayed Alarm Possible Remedy Possible Cause Recognition Message • Emergency switch • Turn the emergency switch • Trip of emergency Emergency Stop input(switch off) clockwise to return • Trip of differential pres- • Too high chilled CHW tempera- sure switch (switch off) •...
Trouble Shooting Displayed Alarm Possible Cause Possible Remedy Recognition Message • Charge additional refrigerant • Insufficient refrigerant • Test/Repair as necessary and • Refrigerant leakage charge additional refrigerant • Trip of low pressure • Low pressure switch setting too Pressure Alarm switch •...
Trouble Shooting Displayed Alarm Possible Cause Possible Remedy Recognition Message • Review voltage • Voltage error • Repair or replace controller • Trip of compressor • Controller DI or DO point error • Test or replace comp internal protector • Comp error (switch off) by high •...
Trouble Shooting Displayed Alarm Possible Cause Possible Remedy Recognition Message • Charge additional refrigerant or • Compressor discharge • Refrigerant flow rate insufficient review valve condition temperature is over Exhaust Temp • Comp error ≤194°F(90°C) after the Alarm • Repair comp •...
Trouble Shooting Displayed Alarm Possible Cause Possible Remedy Recognition Message • FAN2B3B magnetic contactor contact input • Replace FAN2B3B motor, check • Malfunction of FAN2B3B or overload relay con- FAN2B3B Alarm magnetic contactor or relay • Condenser FAN2B3B overload tact input (switch off) •...
Appendix n Cycle Diagram Liquid Injection Line Fig. 49 78 Chiller Air-cooled Screw...
Appendix n Check List Checklist for installation, and operation 1. Project information Contents Contents Description Description PJT name PJT name Address Address Installing contractor Installing contractor Sales office Sales office Start-up performer Start-up performer 2. Model information Contents Description Model: Unit Serial: Model:...
Appendix 3. PRELIMINARY EQUIPMENT CHECK Contents Check Is there any physical damage? If yes, where? Will this prevent start-up. All screws and bolts are tight. Power supply agrees with the unit nameplate. Electrical power wiring is installed properly. Unit is properly grounded. Electrical circuit protection has been sized and installed properly.
Appendix 5. START-UP & OPERATION Contents Check All refrigerant line service valves are open. (discharge, suction, economizer, oil line part … ) There is leakage of refrigerant. (Comp, Condenser, Economizer, Cooler … ) Voltage at terminal block is within 10% Voltage imbalance is within 2% There is no abnormal noise or vibration Alarm is not generated, and the unit operates normally.
P/No.: MFL63291701 Printed in Korea After reading this manual, keep it in a place easily accessible to the user for future reference.