Daikin VRV-WIII Installation Manual

Contents

5 English5. Carry out complete cooling/thermal insulation of water piping andoutdoor dehumidification. If complete cooling or thermal insula-tion has not been carried out, any damage may be caused duringsevere winter due to freezing, in addition to thermal loss.6. When you stop operation during night or winter, it is necessary totake measures to prevent water related circuits from natural freez-ing in the area the ambient temperature drops below 0°C (by waterdrain off, keeping the circulation pump running, warming up by aheater, etc.) Freezing of water related circuits may result in anydamage to the plate type heat exchanger. Therefore, please takeappropriate measures depending on the circumstances of use.(Refer to figure 7)1. Example of piping2. Water inlet piping3. Strainer (sold separately as an accessory)4. Air discharge plug (for joint use with cleaning port)5. Cleaning device6. Strainer for pump7. Automatic air discharge valve8. Water outlet piping9. Joint use with water draining plug10. Plate type heat exchanger11. Outside unit7-2 Before starting a test run1. Before starting a test run, please make sure that the piping workhas been carried out in a proper manner. Especially, make surethat the strainer, air discharge valve, automatic water supply valve,expansion tank and cistern are positioned at their places correctly.2. After water has been completely filled in, first run the pump only,and then make sure that no air has been caught in the water cir-culation system and the water flow rate is correct. If any air hasbeen caught or the flow rate is not enough, the plate type heatexchanger may freeze. Measure any water pressure loss beforeand after the outside unit and make sure that the flow rate is asdesigned. In case of any abnormal, stop the test run immediatelyand carry out trouble shooting to resolve the trouble.3. Following the installation manual, carry out a test run of the out-side unit.4. After the test run has been completed, inspect the strainer at theinlet piping of the outside unit. Clean it if it is dirty.7-3 Daily service and maintenance1. Management of water qualityThe plate type heat exchanger has a structure that does not permitdismantling and cleaning, or replacing any parts. Please pay atten-tion carefully to the quality of water to be used for the plate typeheat exchanger in order to prevent corrosion and sticking of scale.The water to be used for the plate type heat exchanger should haveat least the quality as specified in the table below.When using any corrosion prevention agent, scale depressantagent, etc, such agent should have no corrosive features againststainless steel and copper.2. Management of chilled water flow rateIf the chilled water flow rate is not enough, it will result in the freez-ing damage to the plate type heat exchanger. Check for any clog-ging of the strainer, any air being caught, any reduction in the flowrate due to failure of circulation pump by measuring the tempera-ture and pressure differences at the inlet and outlet ports of theplate type heat exchanger. If the aged difference in the tempera-ture or pressure has increased beyond the proper range, the flowrate should have decreased. Stop the operation and remove thecause before restarting the operation.3. Steps to be taken when a freezing protection device was activatedWhen the freezing protection device should be activated duringoperation, remove the cause without fail before restarting theoperation. If the freezing protection device has been once acti-vated, a partial freezing has occurred. If you restart the operationwithout removing the cause, the plate type heat exchanger will beclosed and the ice cannot be melted, and in addition, the freezingprocess will be repeated resulting in any damage to the plate typeheat exchanger, leading to any such accidents that the refrigerantstarts leaking or water starts entering the refrigerant circuit.7-4 Water qualityWater quality standards for chilled water, hot water and make-upwater (4) (6)[NOTES](1) The circle marks in the columns for corrosion or scale to develop.(2) Corrosion has a tendency to occur when water temperature ishigh (40°C or higher), and if metals with no protective coatingwhatever are directly exposed to water, it would be a good idea totake effective measures against corrosion such as adding a cor-rosion inhibitor or deaeration treatment.(3) In a condenser water circuit that uses a closed cooling tower, theclosed circuit circulating water and make-up water must satisfy itswater quality standards for the hot water system, and passingwater and make-up water must satisfy those for the circulationtype cooling water system.(4) The supply water must be clean tap water, industrial water orclean underground water.Do not use purified or softened water.(5) The fifteen items in the table above represent typical causes ofcorrosion and scale.(6) Once through water may cause corrosion.Do not use once through water.7-5 Maintenance of plate type heat exchangerThe performance of a plate type heat exchanger may decline due toscale accumulation. It may be damaged by freezing due to the dropof flow rate. For this reason, it is necessary to carry out programmedmaintenances at a regular interval in order to prevent the scale frombeing generated.1. Before entering the season for use, carry out the followinginspections:1) Conduct a water quality test and make sure that it is within thestandard.2) Clean the strainer.3) Make sure that the flow rate is correct.4) Make sure that the operational conditions (pressure, flow rate,outlet temperature, etc.) are normal.Item (5)Cooling water system (3) Hot water system (2) Tendency (1)Circulation systemCirculationwater Make-upwaterCirculationwater(20°C ~60°C)Make-upwater Corrosion ScaleStandard itemspH(25°C) 6.5 to 8.2 6.0 to 8.0 7.0 to 8.0 7.0 to 8.0 { {Electrical Conductivity(mS/m)(25°C) Less than80 Less than30 Less than30 Less than30 { {Chloride ions(mgcl –/L) Less than200 Less than50 Less than50 Less than50 {Sulfate ions(mgSO42- /L) Less than200 Less than50 Less than50 Less than50 {Acid consumption (pH4.8 )(mgCaCO3 /L) Less than100 Less than50 Less than50 Less than50 {Total hardness(mgCaCO3 /L) Less than200 Less than70 Less than70 Less than70 {Calcium hardness(mgCaCO3 /L) Less than150 Less than50 Less than50 Less than50 {Ionic-state silica(mgSiO2 /L) Less than50 Less than30 Less than30 Less than30 {Reference itemsIron (mgFe/L) Less than1.0 Less than0.3 Less than1.0 Less than0.3 { {Copper (mgCu/L) Less than0.3 Less than0.1 Less than1.0 Less than0.1 {Sulfate ion(mgS 2- /L)Shall notbedetectedShall notbedetectedShall notbedetectedShall notbedetected {Ammonium ion(mgNH4+/L) Less than1.0 Less than0.1 Less than0.3 Less than0.1 {Residual chlorine(mgCl/L) Less than0.3 Less than0.3 Less than0.25 Less than0.3 {Free carbon dioxide(mgCO2 /L) Less than4.0 Less than4.0 Less than0.4 Less than4.0 {Stability index 6.0 to 7.0 — — — { {