Air-Cooled Screw Chiller

Transcription

1 Airooled Screw Chiller Air Conditioning System R134a 75 to 350 RT

2 Introduction General Description LS air-cooled water chillers are complete, self-contained automatic refrigerating units that include the latest in engineering components arranged to provide a compact and efficient unit. Each unit is completely assembled; factory wired, evacuated, charged, tested and comes complete and ready for installation. Each unit consists of multiple air-cooled condensers with integral sub-cooler sections, one or more accessible semi-hermetic doublescrew compressors, star-delta starters, flooded type shell-and-tube evaporator, and complete refrigerant piping. Liquid line components included are manual liquid line shutoff valves, charging valves, filter-driers, liquid line solenoid valves, sight glass/moisture indicators, and electronic expansion valves. Nomenclature S A X X X C S A H - 3 Y F Evaporator type : F-flooded Start mode : Y-Δ Power : 3-380V 50Hz, 4-415V 50Hz, 5-440V 50Hz, 6-380V 60Hz H-high ambient, S-standard ambient Refrigerant : A-R134a Modules : S-single, D-double, T-triple Chiller type : C-cooled water chiller Capacity (RT) Cooling mode : Air cooled Compressor type : Semi-hermetic screw Inspection When the equipment is received, all items should be carefully checked against the bill of lading to ensure a complete shipment. All units should be carefully inspected for damage upon arrival. The unit s serial plate should be checked before unloading the unit to be sure that it agrees with the power supply available. Physical damage to unit after acceptance is not the responsibility of LS Company. 02 LS Airooled Screw Chillers

3 Specifications System Flow Chart Note: This is the flow chart of single refrigerant circuit type of air-cooled screw liquid chiller. For multi refrigerant circuit chillers each compressor has its own separate circuit as above. Compressor and windage losses. The nodular cast iron compressor casing encloses compressor, electric motor and oil separator in a single accessible housing ensuring the minimum levels of noise breakout and vibration. This rugged structure ensures stable and reliable operation in ambient temperatures ranging from -15 to +55 c. Cooler Type: The semi-hermetic twin screw compressor used in Model SA liquid chillers has the advantage of hermetically sealing the refrigerant and lubricating oil inside the compressor while allowing technicians access to service and repair internal moving parts. Capacity Control: Is achieved using a slide valve which automatically modulates compressor capacity in 4 steps 25%, 50%, 75% and 100% with equivalent reductions in energy consumption. Compressor Starting: The compressor starts fully unloaded using the star-delta (Y/Δ) method to minimize starting current inrush. Compressor Characteristics: Using the optimum screw rotor profile and precision machining of all components achieves minimum operating clearances to ensure the highest volumetric and compression efficiency and minimum friction All SA liquid chillers are fitted with a single cooler of the Flooded shell and tube type having refrigerant in the shell and chilled water inside the tubes. The shell is of welded alloy steel construction with steel tube sheets and copper heat exchange tubes. Removable steel water boxes at both ends of the cooler allow tube cleaning without disturbing the refrigerant circuit. Tubes are mechanically expanded into tube sheets with double grooves to ensure leak tight and trouble free operation. Multiple compressor/ circuit chillers have coolers with separate refrigeration circuits for each compressor. Each refrigeration circuit is provided with its own double safety LS Airooled Screw Chillers 03

4 Specifications (Continued) pressure relief valve. All chillers are fitted with drain valves on the removable heads and shell. All coolers are factory insulated with 25mm of closed cell expanded synthetic rubber with all joints vapor sealed. Coolers are designed in accordance with ASME guidelines and are rated according to the following pressures. REFRIGERANT SIDE WATER SIDE Kg/Sq. cm Lbs/Sq. cm Kg/Sq. Inch Lbs/Sq. Inch DESIGN PRESSURE TEST PRESSURE High efficiency heat transfer tubes are used in Model SA coolers having the external (refrigerant side) sur face expanded with saw tooth type fins. The inside surface has helical grooves to induce a swirling motion in the chilled water which improves heat transfer efficiency. Air Cooled Condenser Condenser coils are constructed from copper tubes with spiral grooves on their inside surface to maximize heat transfer efficiency. Aluminum condenser fins have a corrosion resistant and hydrophilic coating to minimize dust and moisture accumulation and ensure a long working life. The fins have rippled and louvered surfaces to improve heat dissipation efficiency. Each condenser section comprises 4 coils in a reversed M arrangement which ensures that at least 3 coils are always shaded from direct solar r a d i a t i o n a n d c a n t h e re f o re operate satisfactorily in ambient temperature up to 52 C (125 F). Condenser fans are axial type using high strength pressed and formed aluminum alloy fan blades mechanically attached to rustless steel fan hubs. Fan motors are waterproof rated to IP-54 with class F insulation suitable for operation in temperatures from -20 c to 65 c (-4 F to 150 F). control the refrigerant flow through the cooler. The very low pressure losses associated with electronic expansion v a l v e s e n s u r e s t h a t f u l l operating cost savings can be achieved during cooler seasons when ambient temperatures and condensing pressures are reduced. Economizer This is a standard feature of all Model SA liquid chillers. Economizers improve the efficiency of the compressor and refrigeration system and increase the capacity of the chiller. Control Center All SA liquid chillers are equipped with a factory fitted and wired control center mounted on one end of the chiller unit. The high voltage section incorporates compressor and fan contractors and safety controls and is protected by a door interlocked isolator. The low voltage control section is accessed by a separate lockable door and houses the microprocessor controller and LED screen displaying operating and historical date. For high ambient units a double panel (panel within a panel) arrangement is used with thermostatically controlled fans to ventilate the inter-panel space and prevent sunbaking in tropical areas causing excessively high temperatures inside the panel. Electronic Expansion Valve This is a standard feature on each refrigeration circuit on all Model SA liquid chillers, Electronic expansion valves ensure stable operation throughout their operating range and precisely 04 LS Airooled Screw Chillers

5 Factory Options Remote Monitoring System A remote monitoring system is available as an accessory for field installation. Vibration Isolators A feature of all Model SA chillers is their very low levels of noise and vibration. For most outdoor installations where chillers are positioned directly on a ground level concrete slab chillers can be quite satisfactorily mounted on the neoprene isolation pads that are supplied with the unit. For installation on building roofs or in sensitive noise areas (hospitals, studios and some residential areas) pre selected spring type isolators are available as a factory option shipped loose for field installation. High Static Condenser Fans These are available for certain models to provide increased airflow over condenser coils and increased cooling capacity or increased static pressure in installations where exhaust air has to be ducted away from the chiller. Specific performance data and costs can be provided for this option on application to LS Air Conditioning Co. Anti- Freeze Heaters For installations where ambient temperatures can fall to 0 c or below, factory installed and thermostatically controlled heater mats are available as an accessory to prevent freezing of water inside the cooler, tubes and waterboxes. Optimisation Main / Auxiliary Unit For multi chiller installations an optional Master Controller can be factory fitted to one of the chillers. This Master Controller will sequence up to four additional Slave chillers to optimize chiller running hours and energy consumption. ESD(Energy Saving Drive) Reduce Energy Use The energy saving drive (ESD) technology revolutionized the performance of air cooled chillers. ESD is a complete and high-quality device with a variable frequency drive inside. By modulating the frequency of the input power, it can always match chiller capacity to the building load and significantly lower energy consumption. And if an ESD is installed in the constant-speed chiller, almost 20% of the energy will be saved. KW/ton ESD Non-ESD Load (%) This graph shows typical energy savings when an ESD is installed on a constant speed chiller. Reduce electrical demand charges Along with lowering energy consumption, an ESD delivers other cost saving benefits, like the possible elimination of electrical demand charges. Electrical demand charges may be reduced because the motor will always start at low frequencies and maintain inrush current at or below full load amps. And the electronics and circuitry can be designed for Minimum Current Amps which reduces the size and cost of chiller wiring. Reduce Motor Stress Another important benefit of an ESD installation is that it reduces stress on your chiller s motor. Unlike conventional motor starters, an ESD avoids the sudden current surges that shock motors and drives during start-up. Starting the compressor slowly and then bringing it up to speed gradually reduces equipment stress. Multi-compressor Option Models SA125 and SA150 are also available with 2-compressor and refrigeration circuits. LS Airooled Screw Chillers 05

6 Physical Data - High Ambient Models MODEL SA Nominal cooling capacity(kw) Power supply 3PH 380/220V 50Hz Nominal total power(kw) Normal running current(a) Safety protection Type High/low pressure protection, water flow failier protection, low water temperature protection, motor overload, phase-failure and phase sequence protection. Rotary Screw Compressor Compressor Quantity Motor Kw Oil charge liters /23 23/23 23/28 28/28 28/28 28/28/28 28/28/28 28/28/28 Fan motor type Axial Air cooled condenser Quantity of fan motor /6 6/6 6/8 8/8 8/8 6/6/6 6/6/8 6/6/8 Motor Kw (each) Fan RPM Heat exchanger type Type High Efficiency Copper Tube with Aluminum Fins Shell and tube high efficiency heat exchanger Chilled water cooler Water side working pressure(kg/sq cm) Nominal flow(m³/h) Water resistance(kpa) Water pipe diameter(dn) Type R134a Refrigerant Charge / Circuit (kg) / / / / / /210/ /210/ /210/250 No. of Circuits Outline dimension length(mm) width(mm) 2200 height(mm) 2400 Net weight of unit(kg) Operating weight of unit(kg) Noise db(a) Note: 1. The nominal cooling capacities (stated above) are at chilled water temperatures of 12/7 c and ambient of 46 c. 2. Fouling Factor of evaporator is m2. k/kw. 3. Specification may be changed without further notification. 4. The unit conforms to standard ARI 550/ The cooling capacity and power supply is measured with the economizer at the nominal operating conditions defined in Note 1 above. 6. Noise db : Sound pressure level at 10 meters. 06 LS Airooled Screw Chillers

7 Physical Data - Standard Ambient Models MODEL SA Nominal cooling capacity(kw) Power supply 3PH 380/220V 50Hz Nominal total power(kw) Normal running current(a) Safety protection Type High/low pressure protection, water flow failier protection, low water temperature protection, motor overload, phase-failure and phase sequence protection. Rotary Screw Compressor Compressor Quantity Motor Kw Oil charge liters /18 23/23 23/23 23/23 28/28 23/23/23 23/23/23 23/23/28 Air cooled condenser Fan motor type Quantity of fan motor Axial /6 6/6 6/8 8/8 8/8 6/6/6 6/6/8 6/6/8 Motor Kw (each) Fan RPM Heat exchanger type Type High Efficiency Copper Tube with Aluminum Fins Shell and tube high efficiency heat exchanger Chilled water cooler Water side working pressure(kg/sq cm) Nominal flow(m³/h) Water resistance(kpa) Water pipe diameter(dn) Type R134a Refrigerant Charge / Circuit (kg) / / / / / /210/ /210/ /210/250 No. of Circuits Outline dimension length(mm) width(mm) 2200 height(mm) 2400 Net weight of unit(kg) Operating weight of unit(kg) Noise db(a) Note: 1. The nominal cooling capacities (stated above) are at chilled water temperatures of 12/7 c and ambient of 35 c. 2. Fouling Factor of evaporator is m2. k/kw. 3. Specification may be changed without further notification. 4. The unit conforms to standard ARI 550/ The cooling capacity and power supply is measured with the economizer at the nominal operating conditions defined in Note 1 above. 6. Noise db : Sound pressure level at 10 meters. LS Airooled Screw Chillers 07

8 Ratings - High Ambient Models MODEL SA075 SA100 SA125 SA150 SA170 SA210 Leaving Chilled Liquid C Condenser Air Entering Temperature C cool Power cool Power cool Power cool Power cool Power cool Power KW KW KW KW KW KW KW KW KW KW KW KW Note: 1. High ambient models are suitable for operation in ambient temperatures up to 52 c (125 F) 2. Fouling factor of evaporator is m2. k/kw. 3. Specification may be changed without further notification 4. The unit conforms to standard ARI 550/ The cooling capacity and power supply is measured with the economizer. 6. Power consumption values include compressors and fans. 08 LS Airooled Screw Chillers

9 Ratings - High Ambient Models (Continued) MODEL SA225 SA250 SA270 SA300 SA325 SA350 Leaving Chilled Liquid C Condenser Air Entering Temperature C cool Power cool Power cool Power cool Power cool Power cool Power KW KW KW KW KW KW KW KW KW KW KW KW Note: 1. High ambient models are suitable for operation in ambient temperatures up to 52 c (125 F) 2. Fouling Factor is m2. k/kw. 3.Specification may be changed without further notification 4. The unit conforms to standard ARI 550/ The cooling capacity and power supply is measured with the economizer. 6. Power consumption values include compressors and fans. LS Airooled Screw Chillers 09

10 Ratings - Standard Ambient Models MODEL Leaving Chilled Liquid C Condenser Air Entering Temperature C cool Power cool Power cool Power cool Power cool Power cool Power KW KW KW KW KW KW KW KW KW KW KW KW SA075 SA100 SA125 SA Note: 1. Standard models are designed for operation in ambient temperatures up to 46 c (115 F). When ambient temperatures rise above 46 c compressors will progressively unload to prevent trips on high pressure/temperature/current. 2. Fouling factor of evaporator is m2. k/kw. 3. Specification may be changed without further notification 4. The unit conforms to standard ARI 550/ The cooling capacity and power supply is measured with the economizer. 6. Power consumption values include compressors and fans. 10 LS Airooled Screw Chillers

11 Ratings - Standard Ambient Models (Continued) MODEL Leaving Chilled Liquid C Condenser Air Entering Temperature C cool Power cool Power cool Power cool Power cool Power cool Power KW KW KW KW KW KW KW KW KW KW KW KW SA170 SA210 SA270 SA Note: 1. Standard models are designed for operation in ambient temperatures up to 46 c (115 F). When ambient temperatures rise above 46 c compressors will progressively unload to prevent trips on high pressure/temperature/current. 2. Fouling factor of evaporator is m2. k/kw. 3. Specification may be changed without further notification 4. The unit conforms to standard ARI 550/ The cooling capacity and power supply is measured with the economizer. 6. Power consumption values include compressors and fans. LS Airooled Screw Chillers 11

12 Water Pressure Drop Water Pressure Drop Through Evaporator Pressure Drop (kpa) Water Flow Rate (l/s) Line A B C D E F Symbol SA075, SA100 SA125, SA150 SA170, SA210 SA250, SA270 SA300 SA325, SA LS Airooled Screw Chillers

13 Operating Limitations MODEL SA Min Max Min Max Min Max Min Max Min Max Min Max Water Leaving Temp C 4.5 to 15 Cooling Range (Entering Leaving) C 3 to 20 Evaporator Flow Rate m3/h Evaporator Pressure Drop kpa Maximum Water side Pressure bar 10 Air Entering Temperature C -10 to 52 Fan Available Static Pressure kpa 10 Maximum Refrigerant Side Pressure bar 16 Power Supply Voltage 3PH Hz 340 to 420 Max Running Current(A) High Ambient Model Standard Ambient Model MODEL SA Min Max Min Max Min Max Min Max Min Max Min Max Water Leaving Temp C 4.5 to 15 Cooling Range (Entering Leaving) C 3 to 20 Evaporator Flow Rate m3/h Evaporator Pressure Drop kpa Maximum Water side Pressure bar 10 Air Entering Temperature C -10 to 52 Fan Available Static Pressure kpa 10 Maximum Refrigerant Side Pressure bar 16 Power Supply Voltage 3PH Hz 340 to 420 Max Running Current(A) High Ambient Model Standard Ambient Model Max running Current values included compressors and fans. LS Airooled Screw Chillers 13

14 Electrical Data 1 Compressor Unit - Standard ambient model SA MODEL Volts(V) Freq.(Hz) Compressor Fans RLA MCC Start Amps Qty. RLA High ambient model SA MODEL Volts(V) Freq.(Hz) Compressor Fans RLA MCC Start Amps Qty. RLA Compressor Unit - Standard ambient model SA MODEL Volts(V) Freq.(Hz) System Compressor Fans RLA MCC Start Amps Qty. RLA l ll l ll l ll l ll l ll High ambient model SA MODEL Volts(V) Freq.(Hz) System Compressor Fans RLA MCC Start Amps Qty. RLA l ll l ll l ll l ll l ll LS Airooled Screw Chillers

15 Electrical Data (Continued) 3 Compressor Unit - Standard ambient model SA MODEL Volts(V) Freq.(Hz) System High ambient model SA MODEL Volts(V) Freq.(Hz) System Compressor Fans RLA MCC Start Amps Qty. RLA l ll lll l ll lll l ll lll Compressor Fans RLA MCC Start Amps Qty. RLA l ll lll l ll lll l ll lll Note: RLA: Rated Load Amps MCC: Maximum Continuous Current LS Airooled Screw Chillers 15

16 Electrical Data (Continued) High Ambient Model for 46 C Nominal Ambient Operation Electricity Supply 380/3/50 Model No. Chiller Total Power Input Nominal Kw Maximum Kw Nominal Running Amps Maximum Running Amps Maximum Start Amps SA SA SA SA SA SA SA SA SA SA SA SA Note: 1. Chiller total power includes all compressors and condenser fans running. 2. Nominal Kw and Amps (above) apply when chiller is operating in an ambient temperature of 46 c with leaving chilled water temperature of 7 c. 3. Max Kw and Amps (above) apply when chiller is operating at extreme limits beyond which safety controls will prevent higher values. 4. Max Start Amps occur when the last compressor starts while all other compressors and condenser fans are already running. 5. Max running Amps values include compressors and fans. Standard Model for 35 C Nominal Ambient Operation Electricity Supply 380/3/50 Model No. Chiller Total Power Input Nominal Kw Maximum Kw Nominal Running Amps Maximum Running Amps Maximum Start Amps SA SA SA SA SA SA SA SA SA SA SA SA Note: 1. Chiller total power includes all compressors and condenser fans running. 2. Nominal Kw and Amps (above) apply when chiller is operating in an ambient temperature of 35 c with a leaving chilled water temperature of 7 c. 3. Max Kw and Amps (above) apply when chiller is operating at extreme limits beyond which safety controls will prevent higher values. 4. Max Start Amps occur when the last compressor starts while all other compressors and condenser fans are already running 5. Max running Amps values include compressors and fans. 16 LS Airooled Screw Chillers

17 Chiller Control Automatic PLC Controller Model SA liquid chillers are equipped with PLC controllers which are housed in the low voltage section of the unit Control Center. The primary functions of the PLC are: Time Table Running Up to 3 start/stop programmes /day can be achieved. Soft Loading Function This ensures that the chiller will operate stably during system start up, when large fluctuations in cooling load can occur. To automatically start and stop the chiller in response to Cooling Demand signals. To start and stop individual compressors and associated condenser fans and to modulate the compressor capacity by unloading the compressor slide valve in response to unit cooling load. To activate and control peripheral equipment (i.e. chilled water pumps). To continuously monitor operating temperatures and safety controls and display readouts both locally and remotely. Optimization Main Auxiliary Unit For multi-compressor units an optimization function is available to equalize the running time of each compressor/ condenser assembly. For multi chiller installations one unit can be selected as the master and its controller will sequence up to 4 slave chillers. (option) Analogue data display function This function monitors and displays analog signals of refrigeration system temperatures and pressures. Network Control Function Model SA liquid chillers have interfaces for RS-232 & RS-485 and can work with MODBUS protocols. Each chiller can operate as a Master or Slave unit in a group control network. (option) Automatic and remote control of peripherals Remote start/stop function via cabled connection. On/Off of chiller and system peripherals together with functional monitoring can be achieved through remote BMS System. LS Airooled Screw Chillers 17

18 Typical Starter Diagram-1 Compressor MAIN POWER SUPPLY 3PH 380VAC 50/60HZ R0 S0 T0 NFB1 600V R1 S1 T1 CT 1M U V W P MOTOR X Y Z L1 L2 L3 VP IT C C AI3 G NFB2 10A R01 T01 TO CONTROL PANEL 380V 220V TR R02 700VA 2M S PB R11 S11 T11 L1 L2 L3 U11 V11 U12 V12 88 F1 W11 51 U21 F1 W12 U22 V21 V22 F2 88 W21 51 F2 W22 FM1 FM KM1 KM2 KM M S F1 F2 F M 2M F3 MP M1 M2 N 106 U31 V31 U32 V32 FM F F3 W31 51 F3 W32 U41 V41 U42 V42 FM4 88 F4 W41 51 F4 W42 STARTER PNL BODY WIRING R02 R02 CONTROL PNL R02 STOP SGL. EMERGERNCY ELECTRICAL PART LIST 1 1M,2M,S MAGNETIC CONTACTOR 2 NFB1 MOLDED CASED CIRCUIT BREAKER 3 NFB2 NO FUSE BREAKER 4 TR TRANSFORMER 700VA 5 PB EMERGERNCY STOP SWITCH 6 MP MOTOR PROTECT RELAY 7 VP POWER PROTECTOR 8 IT AMPERE TRANSDUCER 9 CT CURRENT TRANSFORMER MAGNETIC CONTACTOR 11 51F1-4 THERMAL RELAY 12 FM1-4 COOLING FAN 13 FAN COOLING FAN 14 KM1-3 AUX.RELAY CONTACT FROM CONTROL PNL Note 1. THESE PARTS ARE LOCATED IN CONTROL PANEL. 2. THESE PARTS ARE LOCATED ON CHILLER BODY. 3. FROM/TO CONTROL PANEL. AI3 G MP VP AI3 G CTRL. PANEL POWER AI3 G E MOTOR&POWER ABNORMAL SGL. CURRENT TRANSDUCER SGL. KM1 KM2 KM3 CONTACTOR SIGNAL COOLING FANS SIGAL TO CONTROL PANEL FROM CONTROL PANEL S L FAN 18 LS Airooled Screw Chillers

19 Typical Schematic Diagram-1 Compressor POWER 1PH 220VAC 50/60HZ MCCB 10A HQ KM2 FAN V0 N.F F.G 4 V1 V2 E E E V CH KM2 XC PU SW RS 103 CONTROL PNL R MP VP AI3 G AI3 G AI3 G FS PU SW RS HP OL MP VP EKD LP OP - + G 0 24 RS-485 TP04 DVPPS02 24V 0V 24V RS-485 0V S/S X0 X1 X2 X3 DVP-12SA OUT IN X4 X5 X6 X7 120 S/S X0 X1 X2 X3 X4 X5 X6 X7 IN DVP-16SP OUT DVP-08SN OUT N G + G C0 Y0 C1 200 Y1 C2 Y2 Y3 201 C0 Y0 Y1 Y2 Y3 Y4 Y5 Y6 Y C0 Y0 Y1 Y2 Y3 Y4 Y5 Y6 Y E E 1 1 F1/5A 2 CH XC KM1 KM2 KM3 EC PY SV1 SV3 SV2 TE01 TE02 TE05 EP + CP IT A 1B 1C 2A 2B 2C 5A 5B 5C AI1 AI2 AI3 G 24V 0V L+ L- I- FG L+ L- I- FG. 24V 0V L+ L- I- FG L+ L- I- FG. 24V 0V V+ I+ V+ I+ V+ I+ CH1 CH2 DVP-04PT CH3 CH4 CH1 CH2 DVP-04PT CH3 CH4 CH1 CH2 CH3 DVP-06XA CH4 CH5 CH6 G L+ L- I- FG L+ L- I- FG. 3A 3B 3C 4A 4B 4C G L+ L- I- FG L+ L- I- FG. G V+ I+ V+ I+ V+ I+ AO1 A 1 1 TR AC220/24V 20VA 3 3 F2/1A R33 TE03 TE04 TO ELEC.EXP.VALVE (ETS) VAC EKD ETS A AO1 120 CH TO EKD FROM PLC TO PLC KM1 KM2 KM CONTACTOR SIGNAL COOLING FANS RUN/STOP ELECTRICAL PART LIST 1 FS FLOW SWITCH 2 PU CHW PUMP INTERLOCK SGL FROM USER 3 SW REMOTE START/STOP SIGNAL FROM USER 4 RS REMOTE RESET SIGNAL FROM USER 5 VP POWER PROTECT RELAY 6 MP MOTOR PROTECT RELAY 7 HP HIGH PERSSURE SWITCH 8 LP LOW PRESSURE SWITCH 9 OL OIL LEVEL SWITCH 10 OP OIL DIFF. PRESSURE SWITCH 11 TE01 ECHW TEMPERATURE SENSOR PT TE02 LCHW TEMPERATURE SENSOR PT TE03 FIN TEMPERATURE SENSOR PT TE04 SUCTION TEMPREATURE SENSOR PT TE05 EXHAUST TEMPREATURE SENSOR PT EP EVAP PRESSURE TRANSMITTER 17 CP COND PRESSURE TRANSMITTER 18 IT CURRENT TRANSDUCER SIGNAL 19 KM1-3 AUX.RELAY (CONTACTOR) 20 CH AUX.RELAY (CHW PUMP) 21 XC AUX.RELAY (FAULT) 22 PY SPRAY LIQUID SOLENOID VALVE 23 ETS ELECTRONIC EXPANSION VALVE 24 SV1 SOLENOID VALVE 25% 25 SV2 SOLENOID VALVE 75% 26 SV3 SOLENOID VALVE 50% 27 HQ OIL HEATER 28 FAN COOLING FANS 29 MCCB MOLDED CASE CIRCUIT BREAKER 30 N.F. NOISE FILTER 31 F1-2 FUSE 32 V0-3 VARISTER 33 TR TRANSFORMER 34 EKD DRIVER MODULE -ETS 35 EC ECONOMIZER SOLENOID VALVE 36 PB EMERGERNCY STOP SWITCH L - E - E E - - E FOR CHW PUMP INTERLOCK FOR REMOTE START/STOP SGL FOR REMOTE RESTART SGL FOR CHW PUMP START/STOP SGL FOR PRESSOR RUN/STOP INDICATION FOR FAULT INDICATION BODY WIRING R02 STARTER PNL R02 EMERGERNCY STOP SGL PB CTRL. PANEL POWER MOTOR&POWER CURRENT ABNORMAL SGL TRANSDUCER SGL TO USER'S MCC FROM USER'S MCC FROM STARTER PANEL FANS RUN SGL TO STARTER PANEL NOTE SUPPLIED BY USERS LOCATED ON CHILLER BODY FROM/TO STARTER PANEL FROM/TO USER'S MCC LS Airooled Screw Chillers 19

20 Typical Starter Diagram-2 Compressor MAIN POWER SUPPLY 3PH 380VAC 50/60HZ AR0 AS0 AT0 STARTER PNL BODY WIRING R02 AI5 AIG MP VP R AI5 AIG MAIN POWER SUPPLY 3PH 380VAC 50/60HZ BR0 BS0 BT0 STARTER PNL 123 BODY WIRING MP VP 124 AI6 AI6 AIG AIG CONTROL PNL R02 EMERGERNCY STOP SGL. CTRL. PANEL POWER AI5 AIG E MOTOR&POWER ABNORMAL SGL CURRENT TRANSDUCER SGL. KM1 KM2 KM3 CONTACTOR SIGNAL COOLING FANS SIGAL AI6 AIG E CONTROL PNL KM1 KM2 KM3 MOTOR&POWER CURRENT ABNORMAL SGL TRANSDUCER SGL. CONTACTOR SIGNAL COOLING FANS SIGAL NFB1 600V AR1 AS1 AT1 TO CONTROL PANEL FROM CONTROL PANEL NFB1 600V BR1 BS1 BT1 TO CONTROL PANEL FROM CONTROL PANEL AU1 FM1 51F1 AV1 AW1 AU2 FM2 51F2 AV2 AW2 AU3 FM3 51F3 AV3 AW3 AU4 FM4 51F4 AV4 AW4 AU5 FM5 51F5 AV5 AW5 AU6 FM6 51F6 AV6 AW6 BU1 BV1 BW1 1 51F1 BU2 BV2 BW2 2 51F2 BU3 BV3 BW3 3 51F3 BU4 BV4 BW4 4 51F4 BU5 BV5 BW5 5 51F5 BU6 BV6 BW6 6 51F6 CT VP L1 L2 L NFB2 10A R01 T01 TR 380V 220V R02 PB KM1 KM2 KM M M 2M S KM1 KM2 KM M M 2M S 1M AU AX MP 1M AU L1 M1 AV L2 M2 106 BU BV BW AW L3 N AV AW 2M P MP MOTOR B P BU L1 M1 MOTOR A S BV L2 M2 123 BX BY BZ BW L3 AY AZ N S L L S FAN IT AC AC2 3 2 AI TO CONTROL PANEL G F1 51F2 51F F F5 51F F1 51F2 51F F4 51F5 51F CT VP L1 L2 L3 FM FM2 124 FM3 IT BC BC2 3 2 AI6 6 4 G FM4 FM5 FM6 ELECTRICAL PART LIST 1 1M,2M,S MAGNETIC CONTACTOR 2 NFB1 MOLDED CASED CIRCUIT BREAKER 3 NFB2 NO FUSE BREAKER 4 TR TRANSFORMER 700VA 5 PB EMERGERNCY STOP SWITCH 6 MP MOTOR PROTECT RELAY 7 VP POWER PROTECTOR 8 IT AMPERE TRANSDUCER 9 CT CURRENT TRANSFORMER MAGNETIC CONTACTOR 11 51F1-6 THERMAL RELAY 12 FM1-6 COOLING FAN 13 FAN COOLING FAN 14 KM1-3 AUX.RELAY CONTACT FROM CONTROL PNL 2M S Note 1. THESE PARTS ARE LOCATED IN CONTROL PANEL. 2. THESE PARTS ARE LOCATED ON CHILLER BODY. 3. FROM/TO CONTROL PANEL. 20 LS Airooled Screw Chillers

21 Typical Schematic Diagram-2 Compressor POWER 1PH 220VAC 50/60HZ MCCB 10A HQ KM2 KM2 341 HQ FAN FAN FAN V0 N.F. F.G V1 V2 E E E V3 1 1 CONTROL PNL BODY WIRING STARTER PNL R02 R02 R02 EMERGERNCY STOP SGL PB CTRL. PANEL POWER AI5 KM1 KM2 KM AI5 AIG E AI6 AIG MP VP MP VP AI5 AIG AI6 AIG MOTOR&POWER CURRENT CONTACTOR SIGNAL COOLING FANS RUN/STOP MOTOR&POWER CURRENT CONTACTOR SIGNAL COOLING FANS RUN/STOP ABNORMAL SGL TRANSDUCER SGL ABNORMAL SGL TRANSDUCER SGL FROM STARTER PANEL AIG TO STARTER PANEL KM1 KM2 KM AI6 AIG FROM STARTER PANEL TO STARTER PANEL - + G 0 24 RS-485 TP04 DVPPS02 24V 0V 24V RS-485 0V FS PU SW RS HP S/S X0 X1 X2 X3 DVP-12SA OUT IN OL LP OP X4 X5 X6 X7 MP VP EKD HP LP 121 OL OP MP VP S/S X0 X1 X2 X3 X4 X5 X6 X7 IN DVP-16SP OUT EKD 125 DVP-08SN OUT DVP-08SN OUT ELECTRICAL PART LIST 1 FS FLOW SWITCH 2 PU CHW PUMP INTERLOCK SGL FROM USER 3 SW REMOTE START/STOP SIGNAL FROM USER 4 RS REMOTE RESET SIGNAL FROM USER 5 VP POWER PROTECT RELAY 6 MP MOTOR PROTECT RELAY 7 HP HIGH PERSSURE SWITCH 8 LP LOW PRESSURE SWITCH N G + G C0 Y0 C1 Y1 C2 Y2 Y3 C0 Y0 Y1 Y2 Y3 Y4 Y5 Y6 Y7 C0 Y0 Y1 Y2 Y3 Y4 Y5 Y6 Y7 C0 Y0 Y1 Y2 Y3 Y4 Y5 Y6 Y7 9 OL OIL LEVEL SWITCH OP OIL DIFF. PRESSURE SWITCH E E 11 TE01 ECHW TEMPERATURE SENSOR PT TE02 LCHW TEMPERATURE SENSOR PT F1/5A 2 CH XC KM1 KM2 KM3 EC PY SV1 SV3 SV2 FANS RUN SGL KM1 KM2 KM3 EC PY SV1 SV3 SV2 FANS RUN SGL 13 TE03 FIN TEMPERATURE SENSOR A PT TE04 SUCTION TEMPREATURE SENSOR A PT TE05 EXHAUST TEMPREATURE SENSOR A PT TE06 FIN TEMPERATURE SENSOR B PT TE07 SUCTION TEMPREATURE SENSOR B PT TE08 EXHAUST TEMPREATURE SENSOR B PT100 TE01 TE02 TE05 TE06 EP - + CP - + IT IT 19 EP EVAP PRESSURE TRANSMITTER 20 CP COND PRESSURE TRANSMITTER V 1A 1B 1C 2A 2B 2C 0V L+ L- I- FG L+ L- I- FG. 24V CH1 CH2 DVP-04PT CH3 CH4 G L+ L- I- FG L+ L- I- FG. TR AC220/24V 20VA 3A 3B 3C 4A 4B 4C 0V 5A 5B 5C G L+ L- I- FG L+ L- I- FG. 6A 6B L+ L- I- FG L+ L- I- FG. CH1 CH2 DVP-04PT CH3 CH4 7A 7B 7C 8A 8B 8C TE03 TE04 TE07 TE F2/2A R33 TO ELEC.EXP.VALVE (ETS) TO ELEC.EXP.VALVE (ETS) VAC EKD ETS 24VAC EKD ETS A AO A AO2 125 CH CH 6C 24V G 0V AI1 AI2 V+ I+ FG V+ I+ FG. CH1 CH2 DVP-04AD CH3 CH4 V+ I+ FG V+ I+ FG AI3 AI4 + ĒP + - CP CH KM2 KM2 24V V V+ I+ AI5 AIG G V+ I+ XC V+ I+ AI6 AIG CH1 CH2 CH3 DVP-06XA CH4 CH5 CH6 PU AO1 A TO EXD V+ I+ V+ I+ V+ I+ SW RS 103 AO2 A TO EXD IT CURRENT TRANSDUCER SIGNAL 22 KM1-3 AUX.RELAY (CONTACTOR) 23 CH AUX.RELAY (CHW PUMP) 24 XC AUX.RELAY (FAULT) 25 PY SPRAY LIQUID SOLENOID VALVE 26 ETS ELECTRONIC EXPANSION VALVE 27 SV1 SOLENOID VALVE 25% 28 SV2 SOLENOID VALVE 75% 29 SV3 SOLENOID VALVE 50% 30 HQ OIL HEATER 31 FAN COOLING FANS 32 MCCB MOLDED CASE CIRCUIT BREAKER 33 N.F. NOISE FILTER 34 F1-2 FUSE 35 V0-3 VARISTER 36 TR TRANSFORMER 37 EKD DRIVER MODULE -ETS 38 EC ECONOMIZER SOLENOID VALVE 39 PB EMERGERNCY STOP SWITCH TO USER'S MCC FROM USER'S MCC FROM PLC TO PLC FROM PLC TO PLC E L - - E E. E E FOR CHW PUMP INTERLOCK FOR REMOTE START/STOP SGL FOR REMOTE RESTART SGL FOR CHW PUMP START/STOP SGL FOR PRESSOR A RUN/STOP INDICATION FOR PRESSOR B RUN/STOP INDICATION FOR FAULT INDICATION NOTE SUPPLIED BY USERS LOCATED ON CHILLER BODY FROM/TO STARTER PANEL FROM/TO USER'S MCC LS Airooled Screw Chillers 21

22 Typical Starter Diagram-3 Compressor MAIN POWER SUPPLY 3PH 380VAC 50/60HZ AR0 AS0 AT0 STARTER PNL BODY WIRING R02 AI7 AIG MP VP R AI7 AIG MAIN POWER SUPPLY 3PH 380VAC 50/60HZ BR0 BS0 BT0 STARTER PNL BODY WIRING 127 MP VP 130 AI8 AI8 AIG AIG PH 380VAC 50/60HZ STARTER PNL MAIN POWER SUPPLY BR0 BS0 BT0 BODY WIRING 134 MP VP 135 AI9 AI9 AIG3 AIG NFB1 CONTROL PNL R02 EMERGERNCY STOP SGL. CTRL. PANEL POWER AI7 AIG E MOTOR&POWER CURRENT ABNORMAL SGL TRANSDUCER SGL. TO CONTROL PANEL KM1 KM2 KM3 CONTACTOR SIGNAL COOLING FANS SIGAL AI8 AIG E CONTROL PNL KM2 KM1 KM3 MOTOR&POWER CURRENT ABNORMAL SGL TRANSDUCER SGL. CONTACTOR SIGNAL COOLING FANS SIGAL AI9 AIG E CONTROL PNL KM2 KM1 KM3 MOTOR&POWER CURRENT ACNORMAL SGL TRANSDUCER SGL. CONTACTOR SIGNAL COOLING FANS SIGAL FROM CONTROL PANEL NFB1 NFB1 TO CONTROL PANEL FROM CONTROL PANEL TO CONTROL PANEL FROM CONTROL PANEL AR1 AS1 AT1 BR1 BS1 BT1 CR1 CS1 CT AU1 FM1 51F1 AV1 AW1 AU2 FM2 51F2 AV2 AW2 AU3 FM3 51F3 AV3 AW3 AU4 FM4 51F4 AV4 AW4 AU5 FM5 51F5 AV5 AW5 AU6 FM6 51F6 AV6 AW6 AU7 FM7 51F7 AV7 AW7 AU8 AV8 FM8 51F8 AW8 BU1 1 51F1 BV1 BW1 BU2 2 51F2 BV2 BW2 BU3 3 51F3 BV3 BW3 BU4 4 51F4 BV4 BW4 BU5 5 51F5 BV5 BW5 BU6 6 51F6 BV6 BW6 CU1 CV1 CW1 1 51F1 CU2 CV2 CW2 2 51F2 CU3 CV3 CW3 3 51F3 CU4 CV4 CW4 4 51F4 CU5 CV5 CW5 5 51F5 CU6 CV6 CW6 6 51F6 NFB2 10A R01 T01 TR 380V 220V R02 PB FM1 FM2 FM3 FM4 FM5 FM6 FM1 FM2 FM3 FM4 FM5 FM6 AU AX CT VP L1 L2 L3 IT AC KM1 KM2 KM M M 2M S KM1 KM2 KM M M MP MP 1M AU L1 M1 BU L1 M1 1M AV L2 M2 122 BV L2 M2 127 BU BV BW AW L3 BW L3 AV AW 2M N N P MOTOR P MP B MOTOR A S CU L1 M1 BX BY BZ CV L2 M2 134 AY AZ CW L3 2M S S L S L FAN AC2 TO CONTROL PANEL F1 51F2 51F AI7 AIG F F5 51F6 51F F F1 51F2 51F F4 4 51F5 51F M 6 KM1 KM2 KM3 1M M 51F1 51F2 51F S N 3 51F4 4 51F5 51F CT Note VP L1 L2 L3 IT BC1 BC M 130 S AI8 AIG CT 1M CU CX CV P MOTOR CY C CW CZ IT CC1 CC2 VP L1 L2 L M 135 AI9 AIG S ELECTRICAL PART LIST 1 1M,2M,S MAGNETIC CONTACTOR 2 NFB1 MOLDED CASED CIRCUIT BREAKER 3 NFB2 NO FUSE BREAKER 4 TR TRANSFORMER 1000VA 5 PB EMERGERNCY STOP SWITCH 6 MP MOTOR PROTECT RELAY 7 VP POWER PROTECTOR 8 IT AMPERE TRANSDUCER 9 CT CURRENT TRANSFORMER MAGNETIC CONTACTOR 11 51F1-8 THERMAL RELAY 12 FM1-8 COOLING FAN 13 FAN COOLING FAN 14 KM1-3 AUX.RELAY CONTACT FROM CONTROL PNL 1. THESE PARTS ARE LOCATED IN CONTROL PANEL. 2. THESE PARTS ARE LOCATED ON CHILLER BODY. 3. FROM/TO CONTROL PANEL S L LS Airooled Screw Chillers

23 Typical Schematic Diagram-3 Compressor POWER 1PH 220VAC 50/60HZ MCCB 10A V0 N.F. V1 V2 V F.G 1 KM2 KM2 KM E E E HQ HQ HQ FAN FAN FAN CH KM2 KM2 PU SW RS 103 FS PU SW RS HP OL VP MP EKD HP OL MP VP EKD LP OP LP OP - + G 0 24 RS-485 TP04 DVPPS02 24V 0V AI1 AI S/S X0 X1 X2 X3 X4 X5 X6 X7 IN DVP-16SP OUT DVP-08SN OUT E E 1 1 F1/5A 2 CH XC KM1 KM2 KM3 EC PY SV1 SV3 SV2 FANS RUN SGL KM1 KM2 KM3 EC PY SV1 SV3 SV2 FANS RUN SGL TE01 TE02 TE05 TE06 EP - CP - IT 1A 1B 1C 2A 2B 2C 5A 5B 5C 6A 6B 6C AI3 AI4 AI9 AIG 24V 0V L+ L- FG L+ L- FG. 24V 0V L+ L- FG L+ L- FG. 24V 0V V+ I+ FG V+ I+ FG. 24V 0V V+ I+ V+ I+ V+ I+ G. L+ L- I- FG L+ L- I- FG G. L+ L- I- FG L+ L- I- FG V+ I+ FG V+ I+ FG G V+ I+ V+ I+ V+ I+ 3A 3B 3C 4A 4B 4C 7A 7B 7C 8A 8B 8C 11A 11B 11C AI5 AI6 AO2 A AO3 A TE03 TE04 TE07 TE08 + ĒP - + CP TO EXD TO EXD 1 TR AC220/24V 3 F2/2A R VA TO ELEC.EXP.VALVE (ETS) TO ELEC.EXP.VALVE (ETS) TO ELEC.EXP.VALVE (ETS) VAC ETS 24VAC EKD EKD ETS A AO A AO2 131 CH CH FROM PLC TO PLC FROM PLC TO PLC FROM PLC TO PLC R02 PB AI7 AIG 301 KM1 KM2 KM KM1 KM2 KM AI8 AIG R02 R02 CTRL. PANEL POWER AI7 AIG E AI8 AIG MP VP AI7 AIG CONTACTOR SIGNAL COOLING FANS RUN/STOP MP VP AI8 AIG CONTACTOR SIGNAL COOLING FANS RUN/STOP E L N I- G I- - + E I I- + E G E + +. E 8 7 FOR CHW PUMP INTERLOCK FOR REMOTE START/STOP SGL FOR REMOTE RESTART SGL FOR CHW PUMP START/STOP SGL FOR PRESSOR A RUN/STOP INDICATION FOR PRESSOR B RUN/STOP INDICATION XC TO USER'S MCC FROM USER'S MCC HP OL MP VP EKD EP - CP LP OP 24V RS-485 0V V0+ I0+ V1+ I1+ A/D DVP-10SX D/A S/S X0 X1 X2 X3 IN OUT S/S X0 X1 X2 X3 X4 X5 X6 X7 IN DVP-16SP OUT DVP-08SN OUT DVP-08SN OUT V0+ I0+ V1+ I1+ C0 Y0 Y1 C0 Y0 Y1 Y2 Y3 Y4 Y5 Y6 Y7 C0 Y0 Y1 Y2 Y3 Y4 Y5 Y6 Y7 C0 Y0 Y1 Y2 Y3 Y4 Y5 Y6 Y7 C0 Y0 Y1 Y2 Y3 Y4 Y5 Y6 Y7 C0 Y0 Y1 Y2 Y3 Y4 Y5 Y6 Y7 AO1 A TO EXD KM1 KM2 KM3 EC PY SV1 SV3 SV2 FANS RUN SGL TE09 TE10 IT IT 9A 9B 9C 10A 10B 10C AI7 AIG AI8 AIG 24V 0V L+ L- FG L+ L- FG. CH1 CH2 CH1 CH2 CH1 CH2 CH1 CH2 CH1 CH2 CH3 DVP-04PT DVP-04PT DVP-04PT DVP-04AD DVP-06XA CH5 CH3 CH4 CH3 CH4 CH3 CH4 CH3 CH4 CH4 CH6 G. L+ L- I- FG L+ L- I- FG TE VAC ETS EKD CH A AO3 136 CONTROL PNL BODY WIRING STARTER PNL EMERGERNCY STOP SGL MOTOR&POWER ABNORMAL SGL FROM STARTER PANEL CURRENT TRANSDUCER SGL TO STARTER PANEL MOTOR&POWER ABNORMAL SGL CURRENT TRANSDUCER SGL FROM STARTER PANEL TO STARTER PANEL + - G + +. E I- - + I FOR PRESSOR C RUN/STOP INDICATION FOR FAULT INDICATION KM AI9 AIG 307 KM1 KM2 KM MP VP MOTOR&POWER ABNORMAL SGL AI9 AIG AI9 AIG CURRENT TRANSDUCER SGL FROM STARTER PANEL CONTACTOR SIGNAL COOLING FANS RUN/STOP TO STARTER PANEL ELECTRICAL PART LIST 1 FS FLOW SWITCH 2 PU CHW PUMP INTERLOCK SGL FROM USER 3 SW REMOTE START/STOP SIGNAL FROM USER 4 RS REMOTE RESET SIGNAL FROM USER 5 VP POWER PROTECT RELAY 6 MP MOTOR PROTECT RELAY 7 HP HIGH PERSSURE SWITCH 8 LP LOW PRESSURE SWITCH 9 OL OIL LEVEL SWITCH 10 OP OIL DIFF. PRESSURE SWITCH 11 TE01 ECHW TEMPERATURE SENSOR PT TE02 LCHW TEMPERATURE SENSOR PT TE03 FIN TEMPERATURE SENSOR A PT TE04 SUCTION TEMPREATURE SENSOR A PT TE05 EXHAUST TEMPREATURE SENSOR A PT TE06 FIN TEMPERATURE SENSOR B PT TE07 SUCTION TEMPREATURE SENSOR B PT TE08 EXHAUST TEMPREATURE SENSOR B PT TE09 FIN TEMPERATURE SENSOR C PT TE10 SUCTION TEMPREATURE SENSOR C PT TE11 EXHAUST TEMPREATURE SENSOR C PT EP EVAP PRESSURE TRANSMITTER 23 CP COND PRESSURE TRANSMITTER 24 IT CURRENT TRANSDUCER SIGNAL 25 KM1-3 AUX.RELAY (CONTACTOR) 26 CH AUX.RELAY (CHW PUMP) 27 XC AUX.RELAY (FAULT) 28 PY SPRAY LIQUID SOLENOID VALVE 29 ETS ELECTRONIC EXPANSIONV ALVE 30 SV1 SOLENOID VALVE 25% 31 SV2 SOLENOID VALVE 75% 32 SV3 SOLENOID VALVE 50% 33 HQ OIL HEATER 34 FAN COOLING FANS 35 MCCB MOLDED CASE CIRCUIT BREAKER 36 N.F. NOISE FILTER 37 F1-2 FUSE 38 V0-3 VARISTER 39 TR TRANSFORMER 40 EKD DRIVER MODULE -ETS 41 EC ECONOMIZER SOLENOID VALVE 42 PB EMERGERNCY STOP SWITCH NOTE SUPPLIED BY USERS 1. LOCATED ON CHILLER BODY FROM/TO STARTER PANEL FROM/TO USER'S MCC E LS Airooled Screw Chillers 23

24 Interface Connection Diagram Connection between starter panel and motor, connection between control panel and starter, connection between starter panel and electrical actuator, connection between control panel and pressure/temperature transducer have been done in the factory. The dotted line box should be supplied by user. 1 Compressor LS'S WORKING SCOPE CHILLER CONTROL PANEL 101 USER'S WORK SCOPE USER'S AUX.EQUIP.CONTROL PANEL PU NOTE 3) NOTE 1) START/STOP SIGNAL FOR CHILLED WATER PUMP NOTE 2) FOR PRESSOR RUN/STOP INDICATION FOR FLAUT INDICATION REMOTE RUN/STOP SINGLE REMOTE RESET SINGLE SW RS NOTE 4) TERMINAL 2 Compressor LS'S WORKING SCOPE CHILLER CONTROL PANEL USER'S WORK SCOPE USER'S AUX.EQUIP.CONTROL PANEL 101 PU NOTE 3) NOTE 1) START/STOP SIGNAL FOR CHILLED WATER PUMP NOTE 2) FOR PRESSOR RUN/STOP INDICATION FOR PRESSOR RUN/STOP INDICATION FOR FLAUT INDICATION REMOTE RUN/STOP SINGLE REMOTE RESET SINGLE SW RS NOTE 4) TERMINAL 3 Compressor LS'S WORKING SCOPE CHILLER CONTROL PANEL NOTE 1) NOTE 2) START/STOP SIGNAL FOR CHILLED WATER PUMP FOR PRESSOR RUN/STOP INDICATION FOR PRESSOR RUN/STOP INDICATION FOR PRESSOR RUN/STOP INDICATION FOR FLAUT INDICATION REMOTE RUN/STOP SINGLE REMOTE RESET SINGLE TERMINAL USER'S WORK SCOPE USER'S AUX.EQUIP.CONTROL PANEL PU NOTE 3) SW NOTE 4) RS Note: 1. For start/stop peripheral equipment - Contact description: below 250vac,0.1a 2. Indication of chiller operation - Contact description: below 250vac,0.1a 3. Interlock contacts, supplied by user - Contact description: no-voltage contact (dry contact) - Allowable contact resistance: max. 100ohm 4. Remote running/restart conta ct, supplied by user - Contact description: no-votage contact (dry contact) - Allowable contact resistance: max. 100ohm 5. Symbol definition 52C : Interlock of chilled water pump SW : Remote run/stop switch RS : Remote restart switch 24 LS Airooled Screw Chillers