Cooling Unit for Producing Chilled Water. Envicooler. Operation and Maintenance Instructions. Air handling with the focus on LCC

Transcription

1 Cooling Unit for Producing Chilled Water Air handling with the focus on LCC

2 Address and telephone list for calling for service Supplier: IV Produkt Box 3103 SE VÄXJÖ, Sweden Street address: Sjöuddevägen 7 Phone: +46 (0) Telefax: +46 (0) Seller:... Service:... Post address:... Post address:... Telephone:... Telephone:... Other:... System Data Type of unit:... Order number:... Year manufactured:... Supply voltage:... Refrigerant:... SAQ approved HP:... Hydrostatic test:...

3 Air handling with the focus on LCC Page 3 Contents 1. The Cooling and Heat Pump System General How the Cooling Circuit Works How the Controller Works 4 2. Summary of Specific Rules in the Refrigerant Act One-piece Units containing less than 3 kg of Refrigerant One-piece Units containing more than 3 kg of Refrigerant One-piece Units containing a total of more than 10 kg of Refrigerant 6 3. Operating Instructions for Components and Assembled Equipment Regulations for Commissioning Checklist 8 4.Maintenance Instructions and Procedures General Requirements by Authorities according to the Refrigerant Act Periodic Inspection 9 5. Fault Tracing and Searching for Leakage Fault-tracing Schedule Searching for Leakage Flow Diagram for the Refrigerant System Technical Specification Appendices 8:1 Pressure and Tightness Tests - Refrigerant Circuit 8:2 Safety Equipment 8:3 Commissioning Report 8:4 Pressure and Tightness Tests - Liquid Circuits

4 Page Air handling with the focus on LCC 1. The Cooling and Heat Pump System 1.1 General All cooling and heat pump systems operate according to the same principle. The system moves the heat content in a medium, such as air, water, gas, etc. from one space where the heat isn t wanted or needed, to another place where it is possible to utilise the heat, or get rid of it. Your system has been designed and installed to meet given performance requirements. We ve selected and combined special components to meet these requirements with optimum safety and at lowest possible total cost. We ve designed the system according to specific fundamental prerequisites, which must exist for it to operate. These prerequisites should not be altered without first checking that the system can cope with this change. 1.2 How the Cooling Circuit Works See the flow diagram. The refrigerant in the cooling circuit absorbs heat from the component being chilled while it passes through the evaporator. As its pressure drops, the refrigerant evaporates and transforms from liquid to gas. The cold suction gas that now has absorbed heat from the cooled space/medium is sucked back into the compressor where it is compressed and heats up. In all fully hermetic compressors, the suction gas is also used to cool the electric motor that drives the compressor. The refrigerant now contains heat from the component being chilled, heat from the compressor motor and heat generated by compression. The refrigerant is in the form of hot gas when it leaves the compressor and circulates to the condenser where it gives off its heat. The refrigerant then condenses as it cools, transforming from gas to liquid. This occurs repeatedly in a totally closed system, until the temperature in the chilled/heated medium drops/rises to its set point. 1.3 How the Controller Works Interlocking EVC is interlocked across an external start signal Operation The selector switch S1 is used for initiating start-up (yellow LED is lit). When the temperature at the heating medium sensor drops below the preset value, a signal is transmitted across the stepping switch to start the compressors in a preset starting order so as to maintain the preset temperature. The in-operation condition of each compressor is indicated across the stepping switch. Output terminal blocks are provided for in-operation indication.

5 Air handling with the focus on LCC Page Compressor Protection If the safety circuit alarm trips the compressor will stop and a red LED will light up. A flow monitor supervises the water flow in the cooling medium circuit. On insufficient flow the monitor stops the compressors and initiates an alarm across a stepping switch. The flow monitor alarm can be reset by setting the selector switch S1 in the 0 position. The safety circuit alarm will trip if any of the following four conditions arises: High pressure in the system, HP Low pressure in the system, LP Tripped protective motor switch Q Tripped thermocouple in the compressor The group alarm safety circuit has output terminal blocks. If the safety circuit alarm trips repeatedly, get in touch with an authorised refrigeration service company Technical Description The compressor power cubicle of the EVC unit contains the following: Main switch Protective motor switch Contactors Auxiliary relays Controller Selector switch Flow monitor The cubicle is mounted inside the EVC unit and has been internally prewired and tested at the factory. Safety circuit alarm If a red LED is lit, the safety circuit of the relevant compressor has tripped. To reset the safety circuit Press the reset button on the high pressure switch or low pressure switch. Reset the protective motor switch. XC440C C1 C2 C3 C4 ((!)) 1 2 Flow monitor alarm If a buzzer sounds and a red LED is lit, the flow monitor alarm has tripped. AL prg SET EVC Selector switch O = EVC switched off I = EVC start mode To reset the flow monitor alarm Press the switch to O; then press it to I again. I O Size Rec. fuse Rec. cable section EVC-1610 EVC-2410 EVC-3110 EVC-4020 EVC-4820 EVC-6220 EVC-7830 EVC AT 25 AT 35 AT 50 AT 50 AT 63 AT 80 AT 100 AT 4 mm 2 6 mm 2 10 mm 2 16 mm 2 16 mm 2 25 mm 2 35 mm 2 50 mm 2 o C Dixell In-operation indication A red LED indicates that the compressors are running. Running period compressors Press and hold the clock button for at least 3 sec. Shows the running period of each compressor. Set point To show the set point: press the SET key. To change the set point: press the SET key for at least 2 sec. Alter the setting by pressing the arrow up or arrow down key. Then press the SET key to save your setting. Input cables LJ L1 L2 L3 N PE Power supply 3*x 400 V + N 50 Hz External start signal Potential-free, NO Group alarm Potential-free, NO In-operation indication C1, C2, C3 Potential-free, NO *) If the order of phases is wrong, the machine will run unusually loud.

6 Page Air handling with the focus on LCC 2. Summary of Specific Rules in the Refrigeration Act 2.1 One-piece Units containing less than 3 kg of Refrigerant The maintenance and service of these units should be carried out with good judgement and a certain degree of responsibility. This means, for example, that if you discover a leak, you must not charge the refrigeration circuit with additional refrigerant unit the leak has been sealed. Furthermore, you must always take care of refrigerant that you ve emptied from the unit either by reusing it or sending it to an appropriate facility for destruction. As far as service and maintenance are concerned, no qualifications stipulated by authorities are required of the technician who carries out this work. Although common sense and good judgement are important when servicing the unit. If servicing calls for a modification of the refrigerant circuit, only a certified refrigeration technician shall be permitted to carry out this work. No reporting to the authorities is required in conjunction with these cooling units. One-piece cooling units charged with 3 kg or less refrigerant are treated in system calculations as if they didn t contain any refrigerant at all. This means that you can add or include any number of one-piece cooling units of the type described above in a system, without being required to take increased refrigerant volume into consideration. 2.2 One-piece Units containing more than 3 kg of Refrigerant Besides complying with the above, the units and components of these systems shall be inspected in accordance with local standards and regulations at least once a year. The responsibility for seeing to it that this inspection is carried out rests on the owner of the system. A permit/authorisation for this is required for all permanent installations. 2.3 One-piece Units containing a total of more than 10 kg of Refrigerant Besides complying with the above, entries concerning the performance and maintenance of the units and components of these systems must be entered in a journal. The responsibility for seeing to it that such a journal is kept up-to-date rests on the owner. This journal must then be sent to an inspectorate for scrutiny once a year. If each circuit is charged with refrigerant in excess of 10 kg, special requirements are made on the equipment in the system.

7 Air handling with the focus on LCC Page 7 3. Operating Instructions for Components and Assembled Equipment 3.1 Regulations for Commissioning All wiring shall be completed prior to commissioning. The cooling medium and heating medium flows shall be adjusted according to specifications and these settings shall be entered in the Commissioning Report. Only qualified technicians shall be allowed to commission the system according to an accompanying checklist complete with commissioning record. A copy of the Commissioning Record shall first be signed by the technician who has commissioned the unit, then be signed by the seller and after that be sent in to IV Produkt. The validity of the product warrantee is conditional on the system having been correctly commissioned. No modifications in the machine are permissible during the warrantee period without the approval by IV Produkt. Follow the fault tracing directions in the fault tracing schedule before you contact a service representative for servicing the unit under warrantee. This will prevent any unnecessary service calls.

8 Page Air handling with the focus on LCC 3.2 Checklist 1. Check the power supply. Make sure that the phase leads are wired to the correct terminal. Make sure that the zero lead and the earth lead are wired. 2. Check that input cables from an external control cubicle are wired to the correct terminal and in the correct manner according to the wiring diagram, e.g: shielded cable wiring to correct terminal in motors terminal block screws are tightened 3. Switch off ALL protective motor switches 4. Switch in the power supply and fuses. 5. Feel the compressors to make sure that the crankcase heating is switched in. 6. Check that the water connections are complete and that there is water. 7. Switch in the pumps. Make sure that they discharge in the right direction. 8. A pump that won t start: check the wiring diagram. If it is interlocked: Temporarily cancel the interlock. 9. Check the pump data against the motor protection and the diagram. 10. Make sure that the water system has been carefully purged of air. 11. Check that water is flowing in the circuit. The measurement valves are on the EVC. See flow data in EVC specification. 12. When the flow is correctly set, lock the valves. 13. If you ve cancelled any interlock in order to start the pumps, restore it. 14. Check that the transducer is wired to the to the right measurement point. 15. Check that the sensor is at the correct location according to the diagram and that it works properly. 16. Check that the protective motor switch and the time relay are correctly set according to the Commissioning Report. 17. Now run through all the control functions according to their functional description in the wiring diagram. Both AHU and EVC WITHOUT STARTING THE COMPRESSORS. 18. It is important that the oil in the compressor crankcase is warm before the compressor is switched in. The crankcase heat should be switched in well in advance of commissioning (2 3 hours) to allow the oil to reach a temperature of at least 30 C ca.the temperature can be measured externally on the bottom of the compressor. 19. Connect the manometer mount on the service outlet; purge the air hoses. NOTE: Type of refrigerant 20. Start up the AHU and the EVC. Now test the compressors separately and follow the commissioning record. Let the compressors run for a while before you begin measuring, approx.10 minutes. Test the safety functions 21. After the compressors have been tested separately, test all of them at the same time. Review the commissioning record. 22. Now let the unit run until it stops as intended according to the preset control function. 23. Send one set of the commissioning records to: IV Produkt.

9 Air handling with the focus on LCC Page 9 4. Maintenance Instructions and Procedures 4.1 General This section of the instructions is intended for general use. We ve worded it in such a way so as to enable you to carry out simple periodical inspections of the system and to show you simple checks that you can carry out before having to call for qualified service help in the event of a malfunction. If more advanced troubleshooting in the system is necessary, you will find the information you need in the accompanying wiring diagrams and special instructions for the components of the system. 4.2 Requirements by Authorities according to the Refrigerant Act An inspector from an accredited company shall in accordance with Local Cooling Standards, inspect one-piece cooling units containing more than 3 kg of refrigerant. All service and modification of the cooling system and charged or emptied refrigerant shall be recorded in the journal. If the total volume of refrigerant exceeds 10 kg (Note! The total volume of all the units in the building), this must be reported to the local Environmental and Public Health Authorities and an annual report must be submitted to them. 4.3 Periodic Inspection 1. Appoint someone or qualified staff to be responsible for periodical inspections of the cooling system. Make sure that these technicians possess knowledge of how the system operates and where system components are located. 2. The system is designed to operate automatically.the Commissioning Record indicates the settings at which the system was set when it was commissioned. Make sure that the settings on the thermostats, controllers, pressure switches and other adjustable components have not been altered by someone who lacks knowledge about how the system operates. 3. See to it that the machine room or other component locations are kept clean. 4. Certain components in the system may require open space for contact with the surrounding air to operate properly. Make sure that this open space is not temporarily or permanently blocked in any way. If any of these components is equipped with an air filter or dirt filter, check these filters every third month. Replace filters whenever needed. 5. The cooling unit does not normally require any lubrication, oil changes or the like. In cases where special regulations pertain to any specific system component, this is explained in the instructions for that component. 6. The system and its components shall be inspected by qualified service technicians at least once a year. The inspection should include the following: Check the refrigerant system for tightness. Check that the system hasn t sustained any serious corrosion damage. Check that the safety equipment is in good condition. 7. Keeping a journal. Entries shall be made every time each system is charged or emptied of refrigerant, the results of searches for leakage and other measures in conjunction with inspecting and servicing the refrigerant circuit and its operation. 8. Are you uncertain about anything regarding your cooling system? If so, get in touch with your supplier! Sometimes it s better and cheaper to call once too often than too seldom.

10 Page Air handling with the focus on LCC 5. Fault Tracing and Searching for Leakage 5.1 Fault-tracing Schedule SYMPTOM POSSIBLE CAUSE REMEDIAL MEASURE Too high temperature in cooled component/medium The power supply has been interrupted. No flow or poor flow across the evaporator. The thermostat/control equipment is incorrectly set/faulty. The compressor doesn t work. Check the control/safety switches and fuses. Check that nothing is blocking the flow. Check that the system is well purged of air. Adjust the setting or replace the equipment. See under Compressor The compressor doesn t work. The power supply has been interrupted. The safety circuit has switched out the compressor. Pressure switches, temperature monitor, flow monitor, antifrosting protection or motor protection. Faulty compressor. Check the control/safety switches and fuses. Check and reset if required. Determine the fault. Replace the compressor. The low-pressure switch switches out the compressor. Too little refrigerant. No flow or poor flow across the evaporator. Too high glycol content. Faulty expansion valve. Faulty low-pressure switch. There is a leak in the system. Seal the leak and charge with refrigerant. Check the flow. Check the static pressure in the expansion vessel. Check the circulation pump. Check the glycol content. Check, replace. Check, replace. The high-pressure switch switches out the compressor. No flow or poor flow across the condenser. Too much refrigerant in the system. Faulty high-pressure switch. Check the flow across the condenser. Check the static pressure in the expansion vessel. Check the circulation pump. Reduce the refrigerant volume. Check, replace. Substantial frosting on the evaporator. The expansion valve is incorrectly set/ faulty. Too little refrigerant. The evaporator is fouled. Check, replace. Check in the sight glass. The system is leaking; seal the leakage; charge with refrigerant. Check the flow, filter if fitted, clean the evaporator if needed.

11 Air handling with the focus on LCC Page Searching for Leakage A search to detect leakage in the system should be made at least once per calendar year as a preventive measure. This leakage search should be recorded and entered in the journal. The cooling system can develop a leak. This becomes apparent first by impaired cooling performance or the system won t operate at all due to a momentary leakage. If you suspect refrigeration leakage, check the level of refrigerant in the sight glass of the system. The sight glass is located in the fluid pipe by the refrigerating machine. If you see bubbles continuously forming in the sight glass, and the cooling performance of the system is at the same time poor, the probable cause is that the system is leaking. If you see one or two or just a few bubbles in the sight glass when the machine starts up, and notice that it operates with reduced output or operates normally does not necessarily mean that the refrigerant volume is too low. IF BUBBLES APPEAR IN THE SIGHT GLASS AND THE PERFORMANCE OF THE SYSTEM IS NOTICEABLY BAD CALL AN AUTHORISED SERVICE REPRESEN- TATIVE FOR HELP. Keep in mind that refrigerant must not be released into the atmosphere and that escaping refrigerant can cause burns if it comes into contact with skin. If it becomes necessary to make modifications in the refrigerant circuit, the staff doing this work must wear the proper protective equipment. MODIFICATIONS IN THE REFRIGERANT SYSTEM MUST ONLY BE CARRIED OUT BY AN ACCREDITED INSPECTORATE A COMPANY WITH A REQUIRED PERMIT

12 Page Air handling with the focus on LCC 6. Flow Diagram for the Refrigerant System 1. KK Cooling compressor 2. VO Oil heater 3. GP High-pressure switch 4. MU Measurement tapping of Schrader valve 5. KD Liquid cooling condenser 6. SG Sight glass 7. FT Drying filter 8. MU Measurement tapping of Schrader valve 9. VS Thermostatic expansion valve with external pressure compensation 10. EV Liquid cooler 11. MU Measurement tapping of Schrader valve 12. GP Low pressure switch

13 Air handling with the focus on LCC Page Technical Specification Specification Cooling Unit for liquid Size 1610, 2410, 3110, 4020, 4820, 6220, 7830, 9330 EVC-a EVC: Cooling power (Pk) kw Condenser power (Pvv) kw Compressors (Qty) each Cooling circuits (Qty) each Cooling medium Water temp. +7/+12.5 C l/s Internal pressure in kpa connection point Connection diameter (dy) mm Rec. cooling medium volume (min) l Heating medium Water temp. +31/+39 C l/s Internal pressure in kpa connection point Connection diameter (dy) mm Refrigerant HFC 407C kg/circuit kg/circuit kg/circuit Total kg Electrical data Recommended fuse AT Casing Version size A A A B B B C C Weight kg

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15 Air handling with the focus on LCC Industriventilation Produkt AB, Box 3103, SE Växjö, Sweden Phone: +46 (0) E-D