MOTIVAIR COOLING SOLUTIONS AIR COOLED CHILLERS MODELS: MLC-SC-FC 0200 MLC-SC-FC 1100 INSTALLATION, OPERATION, AND MAINTENANCE MANUAL

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1 MOTIVAIR COOLING SOLUTIONS AIR COOLED CHILLERS MODELS: MLC-SC-FC 0200 MLC-SC-FC 1100 INSTALLATION, OPERATION, AND MAINTENANCE MANUAL This chiller has been factory run tested to the specified water pressure *****DO NOT OVER PRESSURIZE CHILLER WHEN LEAK CHECKING PIPING OR FILLING HYDRAULIC SYSTEM***** *Isolate chiller from piping if higher test pressure is required for leak checking* *Chiller damaged caused by over pressurization is NOT covered by warranty* 85 Woodridge Dr. Amherst, NY Phone# Fax#

2 LEGAL PROVISIONS & SAFETY INSTRUCTIONS WARNING Operation of these systems involves potentially Iethal dangers (high voltage and high pressures). Therefore, all safety precautions and warnings described in this manual must be precisely observed. Otherwise, severe or fatal injury may be caused. Operator's Responsibility This chiller MUST be installed, maintained and operated by a person(s) qualified for this equipment. This chillercontains refrigeration, water circulation and electrical components. The person(s) most suited for this equipment is a qualified licenced refrigeration technician. Intervention by unauthorized or unqualified parties may void the warranty. SAFETY INSTRUCTIONS The installation, start-up and maintenance of the chillers are dangerous, Due to: High pressures is generated in the equipment Electrical parts are energized The equipment contains hot pipes (Refrigeration system) Rotating parts (fans and or pumps) can cause injury the chillers themselves may be installed in a dangerous position (roof, high built frame etc.) For these reasons, the chiller must be installed and connected to the electricity/water installations by qualified companies only. Startup and maintenance must be conducted by a qualified refrigeration company only. Simple maintenance operations on the equipment without opening them may be performed by the operator. All other work must be performed by specially qualified personnel.

3 TRANSPORT AND HANDLING LIFTING - UNLOADING POSITIONING Notices (symbols) on device packing must be observed. Check the center of gravity of the chiller. Use appropriate unloading equipment. Remove protective film from chiller and cardboard. behind condenser before use. MANUFACTURER'S NOTE The machine may be damaged by: Dropping or tipping it on the ground. Pulling the chiller by cords, straps, etc. Lifting the chiller by its piping system. Excessive shaking by cranes. Damage of this type is not covered by warranty. ECA ECA MAX 45 ECA ECA

4 LIFTING - UNLOADING POSITIONING Notices (symbols) on device packing must be observed. Check the center of gravity of the chiller. Use appropriate unloading equipment. Remove protective film from metal panels before use. MANUFACTURER'S NOTE The machine may be damaged by: Dropping it or tipping it on the ground. Pulling the chiller by cords, straps etc. Lifting the chiller by its piping system. Excessive shaking by crane. Damage of this type is not covered by warranty. Installing with a fork lift truck Use the forks to lift with: they must be as long as the chiller. Use of fork extensions if required, OR SERIOUS DAMAGE MAY RESULT. LIFTING WITH A CRANE Use the holes in the bottom framework for lifting. To distribute the weight evenly place a strong L-shaped section between the belts and structure work. INSERT SPREADER BARS TO PREVENT CRUSHING HOOKING TO THE STRUCTURE Hook only to the points indicated by the lifting labels. Make sure there is no possibility that the hooks can slip out due to swinging or movements from the crane

5 CHILLER INSTALLATION Foundation Site Installation All chillers must be mounted on a solid, horizontal surface, suitable for the weight of the chiller.* Note the chiller weight is incresed by filling with glycol/water mixture. Observe all local regulations. Installation Compliance with the following basic rules for the erection of devices with radial fans will ensure problem-free operation and the rated refrigeration capacity. Basic rules: 1. The condenser air is blown out vertically or horizontally. 2. Do not install the device close to heat sources. Heated air intake must be avoided. 3. The condenser fans are rated for ZERO external static pressure. The fan do not have the capacity to push air through ducting, which means that NO DUCTS OR MUFFLERS may be used on the inlet ot outlet of the chillers. 4. No air short-circuit is permitted, i.e. the heated discharge air from the condenser fans must never be drawn back into the condenser inlet. This will occur if the chiller is too close to a wall, or a low ceiling or other obstructions. 5. In the case of shaft or trench mounting, contact the manufacturer for advice on the installation site. Structure-borne noise It is possible that noise or vibration may be transmitted through the ground, or building structure. If this occurs, it may be necessary to install a vibration elimination device. The construction specifications of the customer/engineering contractor regarding structure transmitted noise or vibration must be observed. Vibrations May be transmitted through the chilled water piping. This can be avoided by the use of flexible piping connections. Clearances Must be maintained for servicing and ventilation purposes. All removable side panels must be available service. *See CLEARANCE REQUIREMENTS section under MOTIVAIR INSTALLATION ENGINEERING BULLETIN

6 Motivair Installation Engineering Bulletin Service Access: Compressors, filter-driers, and manual liquid line shutoff valves are accessible on the front end and both sides of the chiller. Each compressor (two) has its own contactors and overloads mounted in the control box located in the front of the chiller. The main control box contains the chiller PLC (Programmable Logic Controller). The solid state compressor starter, fan control and other power equipment are located in the main control box. Condenser fan VFD s and overloads are located in an independent box on the side of the chiller. The side clearance required for airflow provides sufficient service clearance. On all MLC/MLC-FC condenser fan assemblies can be removed from the top of the unit for service if necessary. CAUTION Disconnect all power to the chiller while servicing condenser fan motors or compressors. Failure to do so can cause bodily injury or death. Do not obstruct access to the sides or ends of the chiller with piping or conduit. These areas must be open for service access. Do not obstruct any access to the control panels with field mounted disconnect switches. Make sure that the power conduit to each panel does not restrict access to the filter-driers located between the compressors under the main control box. Motivair Installation Guide Page 1

7 Clearance Requirements: Figure 1 Notes: 1. Minimum side clearance between units is 12 feet (3.7 meters). 2. Unit must not be installed in a pit or enclosure that is deeper or taller than the height of the unit unless extra clearance is provided per note Minimum clearance on each side is 8 feet (2.4 meters) when installed in a pit no deeper than the unit height. 4. Minimum side clearance to a side wall or building taller than the unit height is 7 (2.1 meters) feet provided no solid wall above 7 (2.1 meters) feet is closer than 12 (3.7 meters) feet to the opposite side of the unit. 5. Do not mount electrical conduits where they can block service access to compressor controls, refrigerant driers or valves. 6. There must be no obstruction of the fan discharge. 7. Field installed switches must not interfere with service access or airflow. 8. MLC/MLC-FC chillers use axial fans and are not suitable for ducted applications. 9. See the following pages if the airflow clearance cannot be met. Restricted Airflow: General The clearances required for design operation of MLC/MLC-FC air-cooled condensers are described in the previous section. Occasionally, these clearances cannot be maintained due to Motivair Installation Guide Page 2

8 site restrictions such as units being too close together or a fence or wall restricting airflow, or both. The Motivair MLC/MLC-FC chillers have several features that can mitigate the problems attributable to restricted airflow. Figure 2 The W shape of the condenser section allows inlet air for these coils to come in from both sides and the bottom. Facing the control cabinet, the right-side V condenser serves the compressor on the right and vice versa for the left. Every compressor always has its own independent refrigerant circuit. The PLC control is proactive in response to off-design conditions. In the case of single or compounded influences restricting airflow to the unit, the PLC will act to keep the compressor(s) running (at reduced capacity) as long as possible, rather than allowing a shut-off on high discharge pressure. The following sections discuss the most common situations of condenser air restriction and give capacity adjustment factors for each. Note that in unusually severe conditions, the PLC controller would adjust the unit operation to remain online until a less severe condition is reached. CAUTION The unit capacity adjustment charts in this engineering bulletin serve only as a guide, and DO NOT take into account prevailing site conditions. Motivair Installation Guide Page 3

9 Case 1, Building or Wall on One side of One Unit: The presence of a screening wall or the wall of a building, in close proximity to an air-cooled chiller is common in both rooftop and ground level applications. Hot air recirculation on the coils adjoining the wall increases compressor discharge pressure, decreasing capacity and increasing power consumption. When close to a wall, it is desirable to place chillers on the north or east side of them (to minimize solar effect). It is also desirable to have prevailing winds blowing parallel to the unit s long axis. The worst scenario is having wind blowing hot discharge air into the wall. Figure 3 Figure 4, Adjustment Factor Motivair Installation Guide Page 4

10 Case 2, Two Units Side By Side: Two or more chillers positioned side by side are common. If spaced closer than 12 feet it is necessary to adjust the performance of each unit; circuits adjoining each other are affected. If one of the two units also has a wall adjoining it, see Case 1. Add the two adjustment factors together (Figure 4 and Figure 6) and apply to the unit between the wall and the other unit. Mounting units end to end will not require adjusting performance. Depending on the actual arrangement, sufficient space must be left between the units for access to the control panel door opening and/or evaporator tube removal. See Clearance section of this guide for requirements for specific units. Pit or solid wall surrounds should not be used where the ambient air temperature exceeds 105 F. Figure 5, Two Chillers Side by Side Figure 6, Adjustment Factor Motivair Installation Guide Page 5

11 Case 3, Three or More Units Side By Side: When three or more units are side by side, the outside units (chillers 1 and 3 in this case) are influenced by the middle chiller only on their inside circuits. Their adjustment factors will be the same as Case 2. All inside units (only chiller 2 in this case) are influenced on both sides and must be adjusted by the factors shown below. Figure 7, Three or more Chillers Chiller 1 Chiller 2 Chiller 3 Figure 8, Adjustment Factor Motivair Installation Guide Page 6

12 Case 4, Open Screening Walls: Decorative screening walls are common to help conceal a chiller either on grade or on a rooftop. These walls should be designed such that the combination of their open area and distance from the chiller do not require performance adjustment. It is assumed that the wall height is equal to, or less than the chiller height when mounted on its base support. This is usually acceptable for concealment. If the wall height is greater than the unit height, see Case 5 (Pit Installation). The distance from the sides of the unit to the side walls should be sufficient for service and opening control panel doors. If each side wall is a different distance from the unit, the distances can be averaged, providing either wall is not less than 8 feet from the unit. For example, do not average 4 feet and 20 feet to equal 12 feet. Figure 9, Open Screening Walls Figure 10 Motivair Installation Guide Page 7

13 Case 5, Pit/Solid Wall Installation: Pit installations can cause operating problems and great care should be exercised if they are to be used on any installation. Recirculation and restriction are probable. A solid wall surrounding a unit is effectively the same as a pit and the data given in Case 5 should be used. Steel grating is sometimes used to cover a pit to prevent accidental falls or trips into the pit. The grating material and installation design must be strong enough to prevent such accidents, yet provide abundant open area or serious recirculation problems will occur. Have any pit installation reviewed by Motivair application engineers prior to installation to discuss whether it has sufficient airflow characteristics. The installation design engineer must approve the work and is responsible for design criteria. Figure 11, Pit Installation Figure 12, Adjustment Factor Motivair Installation Guide Page 8

14 System Volume Requirements: Customer is responsible for insuring there is an adequate amount of system volume. Motivair requires 3 to 5 times the amount of flow through the chiller at a minimum. (Example: 5 min X 292 GPM At design conditions = 1,460 Gallons.) Motivair Installation Guide Page 9

15 PIPING INSTALLATION/RECOMMENDATIONS This section is intended as a guide for the correct installation of the chilled water piping system, including this chiller. However, the chiller manufacturer accepts no responsibility what so ever for the installation of the chiller or the associated piping. All piping must be installed only by a licensed plumbing contractor, and in compliance with local codes. DO NOT USE GALVANIZED PIPING IF GLYCOL IS TO BE USED IN THE CHILLED WATER SYSTEM. Chemical reaction between the glycol and the galvanized piping can be detrimental to the cooling system, the glycol and chiller. Piping material may be copper, plastic, carbon or stainless steel depending on the requirements of each installation. It is the responsibility of the engineer and/or the piping contractor to insure that the piping is correctly sized in relation to the installation, and the available dynamic head of the pump installed inside the chiller. The chilled water pipe connections on the chiller are not necessarily the appropriate size for the system piping. As a general guide, the chiller pipe connections should be considered as the minimum pipe size required for the installation. Drastic reduction in pipe sizing (small hoses, etc.) will reduce the chilled water flow and may cause a low flow alarm, or freezing damage to the evaporator. Note: Installation with low water flow/high water temperature rise should always have a full-ported by-pass installed between the chiller inlet and outlet connections, with a manually adjustable gate valve in the by-pass line. Correctly adjusted, this blended return water will maintain an adequate flow through the chiller, at an acceptable return temperature. Always install a pressure gauge in the return piping close to the chiller. This is essential for monitoring system pressure and pump performance. It is recommended and also good piping practice, especially on systems with short piping runs and/or low system pressure loss, to install a gate valve or balancing valve (i.e. triple duty valve or circuit setter) in the DISCHARGE line from the chiller for throttling purposes. This allows the operator to maintain optimum pump performance by adding resistance to the system. During system balancing NEVER throttle the water flow on the return line to the chiller. This will cause cavitations and overheating of the pump. CAUTION ALWAYS INSTALL A FILTER/STRAINER ON THE INLET OF THE CHILLER, IN ORDER PREVENT PARTICULATES (RUST, DIRT, INSTALLATION DEBRIS) FROM BLOCKING THE EVAPORATOR. Blockage will severely impair chiller performance and is NOT covered by warranty.

16 AUTOMATIC WATER MAKE-UP If the chilled water cooling system is expected to lose water during normal operation an automatic water make-up system should be installed, or can be supplied as a factory option. The auto make-up system must include a water pressure regulator and pressure gauge. CAUTION: The tank inside the chiller has a maximum pressure rating of 45PSIG. Do not discharge city water (which can be 60-80psig) directly into the chiller. Instantaneous pressurization can cause the tank to rupture before the pressure relief valve opens. NOTE: Do not use an automatic water make-up system if glycol is installed for anti-freeze protection. The glycol will become diluted and the freeze protection point will be higher (less protection from freezing). Some critical applications require the installation of emergency city water and drain solenoid valves, in the event of a chiller failure. In this case, the chiller MUST be isolated from the city water pressure to avoid damage. After operation of the emergency city water system, the glycol concentration must be carefully checked using a spectrometer. Add glycol to maintain the correct antifreeze concentration if required. EXPANSION TANK There is a small air space provided inside the top of the insulated reservoir of the chiller. This is designed to act as a compression chamber, in order to absorb moderate hydraulic expansion of the water, during operation. For systems with extensive piping, or large system chilled water volumes it is recommended to install a closed diaphragm expansion tank in the return chilled water line, close to the chiller. The tank should be sized using the appropriate calculations for the volume of water in the system, and the maximum expected temperature fluctuation of the water in the piping system, under any conditions. The purpose of the expansion tank is to absorb hydraulic expansion of the water in the system, which can cause damage to the chiller, piping and/or equipment to be cooled. The expansion tank should be connected to the side of a vertical pipe or the bottom of the horizontal return piping so that trapped air circulating in the chilled water does not become trapped in the expansion tank. Expansion tanks are typically factory pre-charged with compressed air to approximately psig. After installation, filling & venting of the entire system, the pressure of the expansion tank should be set to provide a pressure of 5-10 PSIG on the return side of the chiller, with the chiller in operation. Air pressure can be added or removed from the diaphragm tank via the Schraeder valve. NOTE: Vertical piping immediately connected to and from the chiller will impose a static (or standing) head pressure, which can be read on the pump discharge gauge of the chiller, and the gauge installed onthe return line to the chiller, when the system is not operating. For example, if the supply and/or return piping from the chiller rises 15 feet before running above a ceiling, etc. this will show a gauge static pressure of approximately 6-7psig on the gauges (feet x.424 = psig). This is simply the weight of water in the vertical piping at that location, and does not indicate an overall system pressure. SYSTEM VENTING The single most common problem in chiller piping installations is lack of chilled water flow caused by poor piping practices and/or inadequate venting of the system. The symptom is a repeated flow alarm, when the flow switch installed in the return line inside the chiller contacts open which in turns triggers the flow alarm on the control panel. This chiller is a CLOSED CIRCUIT system and is not open to atmosphere. This means that air will remain in all local high points of the system when it is initially filled with water. NOTE: A local high point is any point in the piping, which can be described as an inverted U section. More clearly defined, if the piping rises vertically ANYWHERE, AND AT ANY ELEVATION IN THE SYSTEM, travels horizontally, then drops again vertically, this inverted U section of piping IS A PERMANENT AIR LOCK AND MUST BE VENTED. Venting is required AT ALL LOCAL HIGH POINTS, and is required on both the supply and return pipes. Vents can be either manual, or automatic. Automatic vents should always be installed with an isolation valve for future service access, repair or replacement. Automatic vents are particularly susceptible to drawing air into the return chilled water piping if this line is allowed to fall into a vacuum.

17 POSITIVE PRESSURIZATION OF THE SYSTEM There are (2) reasons for positive pressure in a closed loop, pump piping system: 1. Prevention of air being drawn into the system at vent locations close to the chiller, caused by the pump drawing a vacuum in the return line. 2. Optimizing pump performance by providing a net positive suction head (N.P.S.H.) to the pump. Positive system pressure can be imposed by carefully and slowly introducing city water pressure, via a hose connection anywhere in the system. After the system has been completely filled and vented, note the gauge pressure at the supply and return lines of the chiller. If there is no significant vertical piping connected directly to the chiller, the gauges should be at zero. If a pre-pressurized expansion tank is installed in the system, the initial system pressure should be approximately that of the expansion tank. Start the chiller and observe the operating pressure on both the return and discharge water pressure gauges. The return line to the chiller (while operating) should be enough to supply a N.P.S.H. The discharge gauge on the chiller will be higher, depending on the pump, piping and system pressure losses of each installation. The return (or suction) pressure can be raised or lowered by carefully using city water pressure via a hose connection, or by adjusting the diaphragm pressure of the expansion tank, or combination of both. NOTE: The expansion tank should not normally be pressurized to more than 20psig, measured when the system is not operating. The final discharge pump pressure should NEVER be allowed to exceed the maximum pump rating pressure. CAUTION: Supercharging the pump with city water pressure higher than nominal rating of the pump, can damage the mechanical pump seal(s), or cause damage to the chiller, piping system or customer equipment. This damage is not covered by the chiller warranty.

18 WATER/GLYCOL FILLING If glycol is required for antifreeze protection, ALWAYS use an industrial inhibited ethylene glycol, or propylene (food grade) glycol. DO NOT use automobile antifreeze. Suitable glycols are manufactured by the Dow Chemical Company for this purpose, and available nationwide. There are other glycol suppliers available, but always exercise great caution in the selection of a glycol supplier, and always confirm the freeze protection after installation, using a spectrometer. Damage caused by freezing is not covered under warranty. Glycol can be pre-mixed with water to the correct concentration, then pumped into the system, or pumped in separately from the water, provided the system capacity is calculated accurately. The most common method for filling the system is to pump the water glycol into the fill or drain connection of the chiller, with all system vents open. There is a manual vent located at the back of the chiller for initial filling/venting purposes, in addition to the high point piping vents. NOTE: The system should be filled slowly and carefully, allowing all the air to escape. The system can only be filled as fast as the air can escape. Be patient, and do not over-pressurize the system. After initial operation, check all air is vented from the system. GLYCOL CHART Ethylene Glycol Propylene Glycol % of Glycol Freeze Point % of Glycol Freeze Point 0% 32F 0% 32F 10% 26F 10% 26F 20% 16F 20% 19F 30% 4F 30% 8F 40% -12F 40% -7F 50% -34F 50% -28F 60% -60F 60% -60F

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20 WATER/GLYCOL INSTRUCTIONS MANUFACTURER'S SPECIFICATIONS The chiller circuit must be 100% filled with water/glycol for operation. If the cooling process causes a loss of water/glycol in the circuit a automatic water make-up vavle must be installed. Insufficient fluid in the water/glycol circuit wiil lead to malfunction of: 1. Safety devices 2. Controls,due to compressor fluctuations/ hunting (frequent switching). And compressor starts. 3. Cooling Capacity These can be avoided by adding a reservoir on the inlet side of the chiller. OnIy operate the chiller with a flow switch (supplied) that switches off the chiller in the event of insufficient water or a faulty pump. If this condition is not satisfied: ALL WARRANTY CLAIMS SHALL BE VOIDED Flow meter and a automatic water make-up system can be purchased from the factory. COLD WATER PIPING Water piping and connection to the chiller must conform with all generally accepted piping practices and local codes. All piping should be performed by a qaulified person(s) or company. The following specifications are intended to prevent damage to the chiller. 1. Avoid unnecessary pressure drop by ensuring correct pipe sizes and routing. 2. Connect the chiller with vibration eliminators to avoid transmission of noise and vibrations. 3. Shut-off valves should be installed at the inlet and outlet of the chiller so that maintenance and repair work can be performed without draining the piping system. 4. Y-Strainer (40 mesh) should be installed on the inlet piping to the chiller to ensure no foreign particles enter the evaporator and or pump.*without a Y-Strainer installed blockage of the evaporator will occur 5. Automatic vents should be installed at all local high points of the piping system to eliminate air locks. See chilled water system diagram for location(s). COLD WATER PIPING CONT. 6. Ensure that the water circuit is maintained at the correct pressure by installing an appropriate sized diaphragm expansion tank close to the inlet of the chiller. The return side of the chiller must be 5-10psig when the pump is running. 7. Install temperature and pressure gauges at the inlet and outlet of the chiller and the heat load to ensure easy inspection and maintenance. 8. All chilled water lines should be insulated. Only insulate pipes AFTER the circuit was tested for leaks. GLYCOL IN CIRCUIT Glycol mixture The following basic rules must be followed: 1. The freezing point of the mixture must be lower than the minimum evaporation temperature. Or the lowest outside piping temperature, whichever is the lower of the two. 2. See correction factors for glycol concentration on back page of the MPCA chiller brochure. 3. Use only an industrial grade inhibited ethylene glycol or food grade propylene glycol solution. DO NOT use automotive antifreeze. 4. Check the ph-value of the solution. lt should be about 9 and must never be less than Check the ph-value regularly (maintenance). 6. DO NOT use galvanized piping or fittings Operating the devices with a glycol mixture Check the extemal cold water network and pumps: sufficient pressure for increased water volume pumps suitable for glycol operation bleed valves (rapid bleeder unsuitable) IMPORTANT: NEVER change the antifreeze alarm parameter on chiller without written authorization from factory. If parameter is changed withour factory consent WARRANTY WILL BE VOIDED.!!!WARNING!!! The glycol/water mixture must not be discharged into the normal water drainage system. lt must be collected in suitable containers and disposed of in accordance with legal regulations.

21 The manufacturer of the supplied chiller accepts NO LIABILITY for the work supplied by the customer or civil engineering contractor. MAIN ELECTRICAL INSTALLATION WIRING DIAGRAM INSPECTION Check that the wiring diagram supplied with the chiller is correct and complete: MAIN ELECTRICAL CONNECTION The connection of the device to the main electrical power supply must only be carried out by an licensed electrician, and in strict accordance with local electrical codes and safety standards. ELECTRICAL COMPONENTS FuIIy wired electrical panel The electrical panel is mounted in the chiller and contains all necessary controls for the chiller. Additional wiring in the electrical panel Additional wiring is permitted but must not modify the original condition of the factory-installed wiring. All changes must be recorded in the original wiring diagram and must be available to the manufacturer. MODEL INFORMATION: REFER TO DATA ON SERIAL STICKER FOR EACH MODEL WARNING MANUFACTURER S NOTICE The main disconnect switch on the chiller must be switched off before carrying out any wiring work. Do not switch on the microprocessor until startup and commissioning has been successfully completed. MAIN VOLTAGE SUPPLY 460V/60Hz/3~ The permissible voltage tolerance is ±5%. These values are BINDING and COMPULSORY. INFORMATION ON EXTERNAL WIRING Main power feed Note: If for local code or other reasons the cable size of the power supply line is larger than the terminal size on the main disconnect or power block: 1. A junction box must be fitted to the chiller in compliance with local codes in order to reduce the cable size Or 2. The main disconnect switch or power block of the chiller must be replaced (prior approval of the manufacturer is required).

22 Description of Free-Cooling Free-cooling control exploits the temperature of the outside air to provide free-cooling of the chiller water. This function uses a heat exchanger, through which a special valve diverts the return chilled water from the system. The favorable outside air temperature cools the water prior to its return, and the operation of the compressor is therefore delayed. TFC (B3) = Free-Cooling coil inlet temperature B5 = Outside temperature VFC = Free-Cooling valve T IN = Evaporator water inlet temperature T OUT = Evaporator water outlet temperature pco2 = control board F1, F2, = Condenser fans Activation of the Free-Cooling Function The Free-Cooling function is based on the relationship that compares the temperature measured by the outside temperature probe, the temperature measured by the temperature probe located al the Free-Cooling coil inlet, and the set Free-Cooling delta. Outside Temp. < Free-Cooling In Temp. Minimum Free-cooling Delta If this condition is true, the Free-Cooling function will be enabled, by activating/deactivating the dedicated devices.

23 Set-point plan for Compressors Compressor ON 50.0 F 25% 50% 75% 100% Compressors OFF PROP. BAND = 7.2 F water in. Temp. SUMMER SET POINT =46.4 F SET+PROP.BAND 53.6 F Proportional band is divided in 8 equal parts to activate 8 step when inlet water temperature increases (so, when the required power increases). Set-point plan for Free-Cooling When there are free cooling conditions, the regulation of free cooling occurs at water outlet F 50.0 F 53.6 F 1 CP 2 CP F (100% free cooling valve) (0% fans) OFFSET = 2.7 F water in. Temp. water out. Temp F (0% free cooling valve) (0% fans) Free cooling band = 5.04 F F (100% free cooling valve) (100% fans) REGULATION FREE COOLING SET POINT = SET POINT OFFSET = 11.7 F Main parameters to regulate the free cooling are the OFFSET and the FREE COOLING BAND. Taking away at the set point the value of the offset you have the set point of free cooling regulation (that it is the centre/middle of free cooling proportional.

24 Valve and Fan Modulation Min. inverter speed threshold for free cooling = 25% of free cooling band (= F) = F FANS: MAX. SPEED water out Temp. VALVE: 100% Free Cooling FANS: MIN SPEED VALVE: 0% Free Cooling Max. valve opening threshold for free cooling valve = 25% of free cooling band (= F) = F Free cooling band = 5.04 F Parameters Pf establishes how 3-way valve and fans work inside the free-cooling band. For example, if Max. valve opening threshold for free cooling valve = 25%, 3-way valve regulates in this way: - Starting from the minimum threshold of F the port for the evaporator is completely opened and the port for the free cooling coil completely closed; - Reaching 25% of free cooling band (41.18 F + 25% of 5.04 F = F+1.26 F = F) the port for evaporator is completely closed and the port for free cooling coil is completely opened; - Between F and F the valve modulates from 0 to 100% opening in the direction of free cooling. With Min. inverter speed threshold for free cooling = 25%, fans work this way: - Between F and F fans don t work (0 rpm); - Starting from 25% of the band (42.44 F) the fans work at the minimum speed; - reaching 100% of the free cooling band (46.22 F) fans are at maximum speed; - between F and F fan speed control modulates from minimum to maximum speed. Conditions for Free-Cooling Working (External Air): The free cooling works as above only if the difference between free cooling valve inlet water probe and external air temperature is higher than Minimum freecooling delta. If the difference is higher than Maximum freecooling delta the capacity of free cooling guarantees 100% of cooling capacity required, consequently compressors are stopped. Outside temp. < Free-cooling In temp. Maximum Free-cooling Delta For example: Parameter Maximum freecooling delta = 28.8 F If inlet water temperature is 55.4 F and air temperature is 24.8 F, compressors will be switched off.

25 Other NOTES on Free-Cooling with Carel Controller: With electronic control there are 4 temperature probes: - 3 ways valve inlet; - evaporator inlet (outlet free cooling coil) - evaporator outlet (anti freeze) - external air (suction side of free cooling coil) 3 way valves can be choosen or modulating kind (0-100% of opening) or ON-OFF (all open or all closed in free cooling). Fans in free cooling can be regulated between the minimum and maximum speed. One circuit (chillers with 2 refrigeration circuits) can operate on free-cooling (fans at maximum speed, controlled by leaving glycol temperature) while the other circuit can operate at full or partial compressor capacity (fans at variable speed, sensing refrigerant head pressure).

26 SEQUENCE OF OPERATION: Free-Cooling Chillers Mechanical cooling inlet control On a call for cooling set point = 50*F + diff = 7*F entering temperature = 57*F glycol pump running flow switch closed the first stage compressor(s) start. (NOTE: A STAGE COULD = 2 COMPRESSORS BASED ON CHILLER SIZE) The control reads the Inlet temperature if the temperature is within SP + ½ diff (53.5*F) the compressor holds at the present stage. If the inlet temperature rises over 53.5*F (SP + ½ diff) and the delay staging timer has expired the next compressor(s) will stage on. If the inlet temp is < SP the compressors will stage off. As the loop temp falls, the first compressor on will turn off at intervals = ½ the differential setting to maintain set point. With the compressor rotation FOFO (first on first off) the next compressor to start will be the second stage. Partial free cooling (pre-cooling) Cooling set point = 50*F Ambient = 49*F LWT = 48*F EWT = 58*F At these conditions the chiller is running in 100% mechanical cooling as the ambient temperature falls to a point = to 9*F below the EWT (i.e. 58*F - 9*F = 49*F) the free cooling valve cycles to the free cooling position diverting the 58*F return water to the free cooling coils. At this point the 49*F ambient temperature is passed across the 58*F return water and pre-cools the EWT dropping the temperature of the return water before entering the evaporator thus reducing the load on the compressors which will stage on and off to maintain set point reducing the energy consumption of the chiller. Total 100% free cooling Cooling set point = 50*F Ambient = 29*F LWT = 48*F EWT = 58*F At these conditions the chiller is operating in partial free-cooling as described above with the compressor(s) online and available for added mechanical cooling to meet set point. As the ambient continues to fall to a point = to or > 29*F below the EWT (i.e. 58*F 29*F = 29*F) the mechanical cooling is locked off as the chillers full tonnage capacity is available by design at this ambient temperature. The condenser/free-cooling fans VFD will modulate on the outlet temperature to maintain an outlet temperature set point within SP - 5.4*F (44.6*F). The compressors will stay locked out until the ambient rises to a point where free cooling cannot be maintained. The advantage to this chiller system is that the integration of the free cooling, the mechanical cooling, and the single control system that operates both in one unit. This integration takes all the errors out of trying to control a built-up system and provides the maximum available free cooling at any and all ambient temperatures that make free cooling efficient.

27 PLC CONTROL SYSTEM A PLC controls all unit functions and allows any adjustments to be made. By means of the microprocessor the set-point values and functioning parameters can be entered directly. This type of PLC can control up to four compressors. It is equipped with an acoustic and visual alarm, push buttons for the various functions, continuous control of the system and a data saving system in the case of a power cut. The set-point values can be set and shown on the display. Main Functions - Indication of the inlet and outlet water temperatures; - Identification and display of alarms; - The control of up to two pumps (stand-by function) with automatic change-over in the case of a failure; - Continuous modulation of the Free-cooling 3-way valve; - Delay of the flow switch at start up; - Operation hour counter for the compressor(s); - Compressor rotation; - The non simultaneous turning on of the compressors; - Pump-down functioning; - Electronic antifreeze thermostat; - Remote On-Off; - Functioning signal; - Manual operation; - Manual reset; - Alarms: high and low pressure, oil and thermal overload cut-out for each compressor; fan thermal overload cut-out; antifreeze; flow switch; Eeprom error. Accessories: - Electronic card for connection to monitoring or remote support facility services; - Remote display up to a maximum of 1000 yards [3000 ft].

28 VERSIONS WITH TANKS AND PUMPS GENERAL FEATURES MLC-FC, MLC-SC-FC, and MPC-FC Version with tank The version has an integrated tank. Completely insulated, with the relevant connections for water inlet and outlet. The tank is fitted with a drain for water and there is also the possibility of installing a heating element (4000 BTU/h) as accessory. A thermostat turns the element no and off, working according to the temperature set. The thermostat is supplied with the heating element and is wired and fitted to the unit. MLC-FC, MLC-SC-FC, and MPC-FC Version with pump The version is supplied with a pump wired and piped. A second pump (stand by) is available as an accessory. As an alternative to the standard pump, a high head pump can big supplied. Maximum working pressure is 87 PSI MLC-FC, MLC-SC-FC, and MPC-FC Version with tank and pump This is the combination of the chiller with tank and the chiller with pump. All the technical information given for the tank with pump versions are applicable. WATER CIRCUIT DIAGRAM- with tank and pump The components with a dotted line are to be considered accessories or options LEGEND MBP= low pressure gauge MW = water pressure MP= electric pump EAT= air temperature sensor EC= electric control FL= flow switch FLT= refrigerant filter LIQ= humidity indicator MC= compressor MAR= muffler MW= fan PAP= high pressure switch BP= low pressure switch RLQ= liquid receiver RL= liquid line cock RV= fan speed regulator SCA= water exchanger SCE= air exchanger SCR= fill-up valve SER= tank SFA= manual air valve SFC= air water exchanger SV= solenoid valve TA= evaporator outlet temperature sensor TFC= free cooling water temperature sensor TRS=pressure transducer VFC= 3 ways valve VS= safety valve VSA= shut off valve VSC= water discharge valve V RA= non return valve VSW= safety water valve VTS=thermal expansion valve

29 Motivair MLC-SC-FC BMS points list 3.7v Type Direction BMS ModBus ModBus Description Address Register TCP/IP A R 1 Condenser Inlet Temperature (Water-cooled units Only) A R 2 Condenser Outlet Temperature Water-cooled units Only) A R 3 Outside Temperature (F.C. Only) A R 4 Water Inlet Temperature A R 5 Water Outlet Temperature A R 6 Freecooling Temperature A R 7 High Pressure Circuit A R 8 High Pressure Circuit A R 9 Freecooling Valve A R/W 11 Cooling Set Point A R/W 13 Condenser Set Point (Air Cooled Only) A R 14 Current Set Point A R/W 15 Temperature Control Band A R/W 16 Minimum Freecooling Delta A R/W 17 Freecooling Differential A R/W 20 Cooling Set Point Lower Limit A R/W 21 Cooling Set Point Upper Limit A R 26 Status of Freecooling Valve A R/W 28 Condenser Control Differential (Air Cooled Only) I R 12 Unit Status0 = unit active 1 = off from alarm 2 = off from supervisor 3 = off from time bands 4 = off from digital input (DIN3) 5 = off from local control (terminal keypad) I R 20 Main Pump Operating Hrs (high byte) I R 21 Main Pump Operating Hrs (low byte) I R 22 Compressor 1 Operating Hrs (high byte) I R 23 Compressor 1 Operating Hrs (low byte) I R 24 Compressor 2 Operating Hrs (high byte) I R 25 Compressor 2 Operating Hrs (low byte) I R 26 Compressor 3 Operating Hrs (high byte) I R 27 Compressor 3 Operating Hrs (low byte) I R 28 Compressor 4 Operating Hrs (high byte) I R 29 Compressor 4 Operating Hrs (low byte) I R 37 Condenser Fan Inverter Speed I R 39 Opening of Freecooling Valve I R 40 Status of Freecooling Valve I R 46 plan Address I R/W 66 Set Minutes I R/W 67 Set Hours I R 68 Current Minutes I R 69 Current Hours

30 D R 1 Unit ON OFF D R 10 Compressor 1 Status D R 11 Compressor 2 Status D R 12 Liquid Solenoid Valve Circuit D R 13 Compressor 3 Status D R 14 Compressor 4 Status D R 15 Liquid Solenoid Valve Circuit D R 16 Main Pump Status D R 17 General Alarm D R 18 Condenser Fan Status D R 19 Freecooling Valve Status D R 20 Antifreeze Heater Status D R/W 42 ON OFF From Supervisor D R/W 57 Reset the alarms D R 65 Unit 1 Online D R 70 General Alarm D R 71 Antifreeze Alarm D R 72 Compressor 1 Thermal Cutout D R 73 Compressor 2 Thermal Cutout D R 74 Compressor 3 Thermal Cutout D R 75 Compressor 4 Thermal Cutout D R 77 Flow Switch Alarm D R 78 High Pressure Switch Circuit 1 Alarm D R 79 High Pressure Switch Circuit 2 Alarm D R 82 Low Pressure Switch Circuit 1 Alarm D R 83 Low Pressure Switch Circuit 2 Alarm D R 84 High Pressure Transducer Circuit 1 Alarm D R 85 High Pressure Transducer Circuit 2 Alarm D R 86 Serious Alarm From Digital Input D R 87 Condenser Fan Thermal Cutout Alarm D R 92 Main Pump Thermal Cutout Alarm D R 97 Condenser Inlet Temperture Probe Disconnected or Broken D R 98 Condenser Outlet Temperture Probe Disconnected or Broken D R 99 Ambient Temperture Probe Disconnected or Broken D R 100 Inlet Temperture Probe Disconnected or Broken D R 101 Outlet Temperture Probe Disconnected or Broken D R 102 Freecooling Temperture Probe Disconnected or Broken D R 103 High Pressure Circuit 1 Switch Disconnected or Broken D R 104 High Pressure Circuit 2 Switch Disconnected or Broken D R 105 Main Pump Maintenance Alarm D R 106 Compressor 1 Maintenance Alarm D R 107 Compressor 2 Maintenance Alarm D R 108 Compressor 3 Maintenance Alarm D R 109 Compressor 4 Maintenance Alarm

31 MLC-SC-FC pco Point List ANALOGUE VARIABLES OBJECT DESCRIPTION OBJECT A001 Condenser Inlet Temperature (MPCW Only) D001 A002 Condenser Outlet Temperature (MPCW Only) D010 A003 Outside Temperature (F.C. Only) D011 A004 Water Inlet Temperature D012 A005 Water Outlet Temperature D013 A006 Freecooling Temperature D014 A007 High Pressure Circuit 1 D015 A008 High Pressure Circuit 2 D016 A009 Freecooling Valve D017 A011 Cooling Set Point D018 A013 Condenser Set Point (Air Cooled Only) D019 A014 Current Set Point D020 A015 Temperature Control Band D042 A016 Minimum Freecooling Delta D057 A017 Freecooling Differential D065 A020 Cooling Set Point Lower Limit D070 A021 Cooling Set Point Upper Limit D071 A026 Status of Freecooling Valve D072 A028 Condenser Control Differential (Air Cooled Only) INTERGER VARIABLES D073 D074 D075 OBJECT DESCRIPTION D077 I012 Unit Status D078 I020 Main Pump Operating Hrs (high byte) D079 I021 Main Pump Operating Hrs (low byte) D082 I022 Compressor 1 Operating Hrs (high byte) D083 I023 Compressor 1 Operating Hrs (low byte) D084 I024 Compressor 2 Operating Hrs (high byte) D085 I025 Compressor 2 Operating Hrs (low byte) D086 I026 Compressor 3 Operating Hrs (high byte) D087 I027 Compressor 3 Operating Hrs (low byte) D092 I028 Compressor 4 Operating Hrs (high byte) D097 I029 Compressor 4 Operating Hrs (low byte) D098 I037 Condenser Fan Inverter Speed D099 I039 Opening of Freecooling Valve D100 I040 Status of Freecooling Valve D101 I046 plan Address D102 I066 Set Minutes D103 I067 Set Hours D104 I068 Current Minutes D105 I069 Current Hours D106 D107 D108 D109 D132 DIGITAL VARIABLES DESCRIPTION Unit ON-OFF Compressor 1 Status Compressor 2 Status Liquid Solenoid Valve Circuit 1 Compressor 3 Status Compressor 4 Status Liquid Solenoid Valve Circuit 2 Main Pump Status General Alarm Condenser Fan Status Freecooling Valve Status Antifreeze Heater Status ON - OFF From Supervisor Reset the alarms Unit 1 Online General Alarm Antifreeze Alarm Compressor 1 Thermal Cutout Compressor 2 Thermal Cutout Compressor 3 Thermal Cutout Compressor 4 Thermal Cutout Flow Switch Alarm High Pressure Switch Circuit 1 Alarm High Pressure Switch Circuit 2 Alarm Low Pressure Switch Circuit 1 Alarm Low Pressure Switch Circuit 2 Alarm High Pressure Transducer Circuit 1 Alarm High Pressure Transducer Circuit 2 Alarm Serious Alarm From Digital Input Condenser Fan Thermal Cutout Alarm Main Pump Thermal Cutout Alarm Condenser Inlet Temperture Probe Disconnected or Broken Condenser Outlet Temperture Probe Disconnected or Broken Ambient Temperture Probe Disconnected or Broken Inlet Temperture Probe Disconnected or Broken Outlet Temperture Probe Disconnected or Broken Freecooling Temperture Probe Disconnected or Broken High Pressure Circuit 1 Switch Disconnected or Broken High Pressure Circuit 2 Switch Disconnected or Broken Main Pump Maintenance Alarm Compressor 1 Maintenance Alarm Compressor 2 Maintenance Alarm Compressor 3 Maintenance Alarm Compressor 4 Maintenance Alarm Unit OFF

32 6.2 Chiller unit with freecooling, configuration 1 AIR/WATER units with maximum 8 tandem hermetic compressors. Standard modular Chiller HP 1 / 8 compressors with CAREL driver DIGITAL INPUTS No. pco 2 /pco 3 MEDIUM pco 1 MEDIUM pco C MEDIUM Master (address 1) Slave (address 2) Master (address 1) Slave (address 2) Master (address 1) Slave (address 2) ID 1 Serious alarm Serious alarm (can be enabled) Serious alarm Serious alarm (can be enabled) Serious alarm Serious alarm (can be enabled) ID 2 Evaporator flow switch Evap. flow switch (can be enabled) Evaporator flow switch Evap. flow switch (can be enabled) Evaporator flow switch Evap. flow switch (can be enabled) ID 3 Remote ON/OFF Remote ON/OFF Remote ON/OFF ID 4 Pump 1 thermal overload Pump 2 thermal overload Pump thermal overload Pump 2 thermal overload Pump thermal overload ID 5 Low press. switch 1 Low press. switch 3 Low press. switch 1 Low press. switch 3 Low press. switch 1 Low press. switch 3 ID 6 Comp. 1 thermal overload Comp. 5 thermal overload Comp. 1 thermal overload Comp. 5 thermal overload Comp. 1 thermal overload Comp. 5 thermal overload ID 7 Comp. 2 thermal overload Comp. 6 thermal overload Comp. 2 thermal overload Comp. 6 thermal overload Comp. 2 thermal overload Comp. 6 thermal overload ID 8 Low press. switch 2 Low press. switch 4 Low press. switch 2 Low press. switch 4 Low press. switch 2 Low press. switch 4 ID 9 Comp. 3 thermal overload Comp. 7 thermal overload Comp. 3 thermal overload Comp. 7 thermal overload Comp. 3 thermal overload Comp. 7 thermal overload ID10 Comp. 4 thermal overload Comp. 8 thermal overload Comp. 4 thermal overload Comp. 8 thermal overload Comp. 4 thermal overload Comp. 8 thermal overload ID11 High press. switch 1 High press. switch 3 ID12 High press. switch 2 High press. switch 4 ID13 High press. switch 1 High press. switch 3 High press. switch 1 High press. switch 3 ID14 High press. switch 2 High press. switch 4 High press. switch 2 High press. switch 4 ANALOGUE INPUTS No. pco 2 /pco 3 MEDIUM pco 1 MEDIUM pco C MEDIUM Master (address 1) Slave (address 2) Master (address 1) Slave (address 2) Master (address 1) Slave (address 2) B1 Cond. temp. circuit 1 Cond. temp. circuit 3 Outside temperature Water inlet temp. B2 Cond. temp. circuit 2 Cond. temp. circuit 4 Freecooling temperature Water outlet temp. 1 Water outlet temp. 2 B3 Outside temperature High pressure circuit 1 High pressure circuit 3 Cond. temp. circuit 1 Cond. temp. circuit 3 B4 Water inlet temp. High pressure circuit 2 High pressure circuit 4 Cond. temp. circuit 2 Cond. temp. circuit 4 B5 Water outlet temp. 1 Water outlet temp. 2 Water inlet temp. Outside temperature B6 Freecooling temperature Water outlet temp. 1 Water outlet temp. 2 Freecooling temperature B7 High pressure circuit 1 High pressure circuit 3 Cond. temp. circuit 1 Cond. temp. circuit 3 High pressure circuit 1 High pressure circuit 3 B8 High pressure circuit 2 High pressure circuit 4 Cond. temp. circuit 2 Cond. temp. circuit 4 High pressure circuit 2 High pressure circuit 4 DIGITAL OUTPUTS No. pco 2 MEDIUM pco 1 MEDIUM pco C MEDIUM Master (address 1) Slave (address 2) Master (address 1) Slave (address 2) Master (address 1) Slave (address 2) NO1 Compressor 1 Compressor 5 Compressor 1 Compressor 5 Evap. pump 1 NO2 Compressor 2 Compressor 6 Compressor 2 Compressor 6 Compressor 1 Compressor 5 NO3 Liq. solenoid circuit 1 Liq. solenoid circuit 3 Liq. solenoid circuit 1 Liq. solenoid circuit 3 Compressor 2 Compressor 6 NO 4 Compressor 3 Compressor 7 Compressor 3 Compressor 7 Liq. solenoid circuit 1 Liq. solenoid circuit 3 NO 5 Compressor 4 Compressor 8 Compressor 4 Compressor 8 NO 6 Liq. solenoid circuit 2 Liq. solenoid circuit 4 Liq. solenoid circuit 2 Liq. solenoid circuit 4 Compressor 3 Compressor 7 NO 7 Evap. pump 1 Evap. pump 2. / Disable fan coil Evap. pump 1 Evap. pump 2. / Disable fan coil Compressor 4 Compressor 8 NO 8 General alarm General alarm General alarm General alarm Liq. solenoid circuit 2 Liq. solenoid circuit 4 NO 9 Cond. fan 1 circuit 1 Cond. fan 1 circuit 3 Cond. fan 1 circuit 1 Cond. fan 1 circuit 3 Cond. fan 1 circuit 2 or Cond. fan Cond. fan 1 circuit 4 or Cond. fan 2 circuit 1 2 circuit 3 Antifreeze heater 1 Antifreeze heater 2 NO10 ON/OFF freecooling valve Cond. fan 1 circuit 4 or Cond. ON/OFF freecooling valve Cond. fan 1 circuit 4 or Cond. fan fan 2 circuit 3 2 circuit 3 NO11 Antifreeze heater 1 Antifreeze heater 2 Antifreeze heater 1 Antifreeze heater 2 General alarm General alarm NO12 Cond. fan 1 circuit 1 Cond. fan 1 circuit 3 NO13 Cond. fan 1 circuit 2 or Cond. fan Cond. fan 1 circuit 4 or Cond. Cond. fan 1 circuit 2 or Cond. fan Cond. fan 1 circuit 4 or Cond. fan ON/OFF freecooling valve Cond. fan 1 circuit 4 or Cond. fan 2 circuit 1 fan 2 circuit 3 2 circuit 1 2 circuit 3 2 circuit 3 ANALOGUE OUTPUTS No. pco 2 /pco 3 MEDIUM pco 1 MEDIUM pco C MEDIUM Master (address 1) Slave (address 2) Master (address 1) Slave (address 2) Master (address 1) Slave (address 2) Y1 Modul. freecooling valve Modul. freecooling valve Cond. fan 1 inverter Cond. fan 3 inverter Y2 Modul. freecooling valve Cond. fan 4 inverter Y3 Cond. fan 1 inverter Cond. fan 3 inverter Cond. fan 1 inverter Cond. fan 3 inverter Y4 Cond. fan 2 inverter Cond. fan 4 inverter Cond. fan 2 inverter Cond. fan 4 inverter CAREL code rel. 2.7 of 23/12/09 14

33 pco Controller Instructions: MLC-SC-FC Chiller Rev.0

34 1. START-UP Before starting this type of unit, ensure that all personnel involved have read and understood the SAFETY chapter in this manual 1.Check that the unit shut-off valves are open. 2.With a closed type hydraulic circuit ensure that a suitably sized expansion vessel has been installed. 3.Check that the ambient temperature is within the range indicated on the unit's data plate. 4.Check that the main switch is in the OFF position ( O ). 5.Check that the unit power supply voltage is correct. 6.Power the unit by means of the line protection device. 7.Turn the unit main switch to the ON position ( I ). The control board buttons illuminate. 8.Check that water is flowing through the evaporator. 9.Check that the compressor discharge valves are open. 10. To start the unit press control board button to go menu list MENU LIST Press LIST to enter in MENU Press or to scroll the menu a maintenance I Input/output K -Clock s-setpount p-user c-manufactory h-summer/winter m-on_off unit q-history u-unit change Press m-on_off MENU to enter in MENU Press to enter in ON- OFF changing mode Press to return in MENU LIST If the unit is OFF press If the unit is ON Press or to switch ON or to switch OFF After the delay set on the electronic board; the refrigerant compressor will start. 11. The unit is now ready to start operating 12. Withhigh ambient temperature and hydraulic circuit water temperature significantly higher than the working value at the first start (e.g C) this means that the chiller is starting in overloaded conditions so the protections may trip. To reduce the overload you can progressively close (without closing it completely!) a valve at the chiller outlet to reduce the flow rate of water passing through it.gradually, as the water temperature in the hydraulic circuit approaches the working value. The valve can be opened again. If the unit remains stopped for several days, after turning the main switch to the ON position ( I ), wait for at least 4 hours before starting the unit

35 2 REGULATION AND CONTROL 2.1The pco terminal buttons Function Press once to poll the pco for active alarms.once the alarm cause has been removed, press the button again to reset the indication. Press once to enter the DIRECT menu loop. Used to return from the various menu loops to the main display mask. or Used to scroll through the various masks in a menu loop, when the cursor is in the HOME position.used to increase/decrease the value of a numerical field (configuration).used to scroll through the subsections of a mask.used to scroll through the various subsections in a menu loop. Moves the cursor to the various editable fields in a menu mask.provides access to a selected programming subsection.in some cases, this button must be pressed to confirm an operation Terminal LEDs LED Function Illuminated when an alarm situation is active. 2.2 Technical features The controller provides the following functions: temperature control on evaporator water inlet or outlet with PID or Neutral Zone logic; measurement and read-out on the display of the evaporator water inlet and outlet temperature values; measurement and read-out on the display of the condensation and evaporation pressure values; automatic rotation of the compressors start sequence (when unit has more than one compressor) to minimise the working time of each compressor; weekly programming display of alarm messages, including:high condensing pressure alarm;

36 low evaporation pressure alarm;freeze alarm on water at evaporator outlet; compressor fault alarm, and pump (if present); alarm for insufficient water flow through the evaporator; water inlet and outlet high temperature alarm; operating hours count of chiller and individual compressors with signal when the programmed maintenance hours are exceeded; alarm device for minimum/maximum voltage, incorrect phase sequence and phase imbalance beyond the permissible limit. (optional) There is also a voltage-free contact available for remotisation of a general alarm signal 2.3 Electrical cabinet forced ventilation All units are equipped with a ventilation system for the electrical cabinet Automatic restart In case of a power loss, when power is restored the unit will be ON if it was ON at the time of power loss, and OFF if it was OFF. 2.5 Access to programming MAIN MENU MENU LIST Press to enter in MENU LIST Press or to scroll the menu a maintenance I Input/output K -Clock s-setpount p-user c-manufactory h-summer/winter m-on_off unit q-history u-unit change Press to enter in MENU a-maitenance MENU Press or to scroll the maintenance menu parameter Press to return in MENU LIST i-input/ OUTPUT MENU Press or to scroll the input/output Info Press to return in MENU LIST

37 k-clock MENU Press or to scroll the clock Info Press to return in MENU LIST p-user MENU Press to insert the user password Press password to confirm the user Press or to set the user password Press or to scroll the user Menu list p Termoregolation x freecooling (not used) q-defrost (not used) r-varius Press to enter in MENU Press or to scroll the user parameter Press to enter in parameter changing mode Press parameter to confirm new user Press or to change the user parameter Press to return in MENU LIST

38 c-manufactory MENU Press to insert the manufactorer user password Press to confirm the manufactorer password Press or to set the manufactorer password Press or to scroll the manufactorer Menu list c Configuration g -parameter f-exv drivers (not used) t-timing v-default value Press to enter in MENU Press or to scroll the manufactorer parameter Press to enter in parameter changing mode Press to confirm new manufactorer parameter Press or to change the manufactorer parameter Press to return in MENU LIST

39 2.5.1 How to change the set-point s-setpoint MENU Press or to enter in setpoint changing mode Press to change the setpoint Press or to increase or decrease setpoint Press to confirm new setpoint Press to return in MENU LIST

40 2.6. Types of controlled compressors Inlet temperature control The temperature control depends on the values measured by the temperature probe located at the evaporator inlet, and follows proportional logic. Depending on the total number of compressors configured and the number of load steps per compressor, the control band set will be divided into a number of steps of the same amplitude. When the various thresholds are exceeded, a compressor load step will be activated The following relationships are applied to determine of the activation thresholds: Total number of control steps = Number of compressors + (Number of compressors * Number load steps/compressor). Proportional step amplitude = Proportional control band / Total number of control steps Step activation threshold = Control set point + (Proportional step amplitude * Progressive step [1,2,3, ]). Outlet temperature control A temperature dead zone is identified based on the set point and band. Temperature values between the set point and set point + band (STPM < Temperature < STPM+RBM) will not switch any compressors On/Off. Temperature values above set point + band (Temperature > STPM+RBM) will activate the compressors Temperature values below the set point (Temperature < STPM) will deactivate the compressors A temperature threshold is envisaged, for both cooling operation and heating operation, below/above which the devices installed will in any case be stopped, in order to avoid excessive cooling/heating output produced by the unit.

41 2.8 Antifreeze control Each pco unit can manage the antifreeze control function, as long as the evaporator water outlet temperature probe is connected and enabled. Antifreeze control is always active, even when the unit is off, in cooling and heating operation. The antifreeze alarm is a system alarm, and consequently in multi-board systems, when activated on any unit causes the total shutdown of the unit. The type of alarm reset can be selected, automatic or manual; if automatic reset is selected, the alarm signal will be delayed from the start of the main circulating pump, to give the unit time to pump all the chilled liquid and avoid alarms in the initial start-up phase. Antifreeze heater Each circuit features an antifreeze heater to prevent the activation of the alarm and consequently the shutdown of the unit. This heating element is activated and deactivated depending on a set threshold and hysteresis. The activation of a heating element in any of the circuits causes the shutdown of the active cooling devices, either compressors or freecooling devices 2.9 Supervision system The pco is able to manage supervision protocols.the supervision protocols can be as follows: CAREL MODBUS BACNET LONWORKS

42 ALARM TABLE AL001 Serious Alarm from Digital Input AL002 Antifreeze Alarm AL003 Evaporator Pump Thermal Overload AL004 Condenser Pump Thermal Overload AL005 Evaporator Flow Switch AL006 Condenser Flow Switch AL007 Main Fan Thermal Overload AL008 Evaporator Pump 2 Thermal Overload AL010 Low Pressure Switch Circuit 1 AL011 Low Pressure Switch Circuit 2 AL012 High Pressure switch Circuit 1 AL013 High Pressure Switch Circuit 2 AL014 Oil Differential Pressure Switch Circuit 1 AL015 Oil Differential Pressure Switch Circuit 2 AL016 Compressor 1 Thermal Overload AL017 Compressor 2 Thermal Overload AL018 Compressor 3 Thermal Overload AL019 Compressor 4 Thermal Overload AL020 Condenser Fan 1 Thermal Overload AL021 Condenser Fan 2 Thermal Overload AL023 High Pressure from Transducer Circuit 1 AL024 High Pressure from Transducer Circuit 2 AL030 Probe B1 Fault AL031 Probe B2 Fault AL032 Probe B3 Fault AL033 Probe B4 Fault AL034 Probe B5 Fault AL035 Probe B6 Fault AL036 Probe B7 Fault AL037 Probe B8 Fault AL040 Fan/Pump Maintenance AL041 Compressor 1 Maintenance AL042 Compressor 2 Maintenance AL043 Compressor 3 Maintenance AL044 Compressor 4 Maintenance AL045 Pump 2 Maintenance plan AL050 Unit 1 Offline plan AL051 Unit 2 Offline plan AL055 32k Clock Board Fault System AL056 Driver 1 Circuit 1 Offline AL057 Driver 2 Circuit 1 Offline AL058 Driver 1 Circuit 2 Offline AL059 Driver 2 Circuit 2 Offline AL060 Active Alarms on Unit

43 2.10 Alarm signals Alarms display During operation of the unit alarm conditions may occur which, depending on the hazard level, are managed by the pco by means of a simple warning signal or with the partial or complete shut down of the unit.when an alarm is signalled, the message OFF BY ALARM appears on the pco display and the red LED of button illuminates. ALARM MENU Press to enter in ALARM MENU Press to return in MAIN MENU Press or to scroll the active alarm Press to reset the alarm

44 Alarm masks Ref. Mask Reset Control action Input Notes AL No active alarm masks. AL01 Manual Unit complete stop Master ID1 It 'been pressed the emergency button or RVG alarm AL002 Manual Compressors stop Master The water outlet temperature is equal to or lower than the alarm threshold. AL003 Manual Unit complete stop Master ID4 Pump overload. AL005 Manual Unit complete stop Master ID2 Insufficient water flow through the evaporator (differential pressure switch). AL010 Manual Compressors 1/2 stop Master ID5 The pressure value is equal to or lower than the alarm threshold. AL011 Manual Compressors 3/4 stop Master ID8 The pressure value is equal to or lower than the alarm threshold. AL12 Manual Compressors 1/2 stop Master ID13 The pressure value is equal to or higher than the alarm threshold. AL13 Manual Compressors 3/4 stop Master ID14 The pressure value is equal to or higher than the alarm threshold. AL016 Manual Compressor 1 stop Master ID6 Compressor overload. 12/2014 GB 14

45 Ref. Mask Reset Control action Input Notes AL017 Manual Compressor 2 stop Master ID7 Compressor overload. AL018 Manual Compressor 3 stop Master ID9 Compressor overload. AL019 Manual Compressor 4 stop Master ID10 Compressor overload. AL23 Manual Compressor stop Master The pressure value is equal to or higher than the alarm threshold. AL24 Manual Compressor stop Master The pressure value is equal to or higher than the alarm threshold. AL032 Manual warning Master The probe measures an off range value: may be damaged, disconnected or shortcircuited. AL033 Manual Unit complete stop Master The probe measures an off range value: may be damaged, disconnected or shortcircuited. AL034 Manual Unit complete stop Master The probe measures an off range value: may be damaged, disconnected or shortcircuited. AL035 Manual warning Master The probe measures an off range value: may be damaged, disconnected or shortcircuited. AL036 Manual warning Master The probe measures an off range value: may be damaged, disconnected or shortcircuited.

46 AL037 Manual warning Master The probe measures an off range value: may be damaged, disconnected or shortcircuited.