Carrier Aquaforce 30XA302 Installation, Operation And Maintenance Instructions

Also see for Aquaforce 30XA Series: Installation instructions Operation instructions User guide

Contents

327 - WATER CONNECTIONSATTENTION: Before carrying out any water connectionsinstall the water box purge plugs (one plug per water boxin the lower section - supplied in the control box).For size and position of the heat exchanger water inlet andoutlet connections refer to the certified dimensional drawingssupplied with the unit.The water pipes must not transmit any radial or axial forceto the heat exchangers nor any vibration.The water supply must be analysed and appropriate filtering,treatment, control devices, isolation and bleed valves andcircuits built in, to prevent corrosion, fouling and deteriora-tion of the pump fittings. Consult either a water treatmentspecialist or appropriate literature on the subject.7.1 - Operating precautionsThe water circuit should be designed to have the least num-ber of elbows and horizontal pipe runs at different levels.Below the main points to be checked for the connection:• Comply with the water inlet and outlet connectionsshown on the unit.• Install manual or automatic air purge valves at allhigh points in the circuit(s).• Use a pressure reducer to maintain pressure in thecircuit(s) and install a relief valve as well as an expan-sion tank.• Install thermometers in both the entering and leavingwater connections.• Install drain connections at all low points to allow thewhole circuit to be drained.• Install stop valves, close to the entering and leavingwater connections.• Use flexible connections to reduce the transmission ofvibrations.• Insulate all pipework, after testing for leaks, both toreduce heat gains and to prevent condensation.• Cover the insulation with a vapour barrier.• Where there are particles in the fluid that could foulthe heat exchanger, a screen filter should be installedahead of the pump. The mesh size of the filter must be1.2 mm (see ‘Typical water circuit diagram’).• Before the system start-up verify that the watercircuits are connected to the appropriate heatexchangers (e.g. no reversal between evaporator andcondenser).• Do not introduce any significant static or dynamicpres-sure into the heat exchange circuit (with regardto the design operating pressures).• Before any start-up verify that the heat exchange fluidis compatible with the materials and the water circuitcoating.• The use of different metals on hydraulic piping couldgenerate eletrolytic pairs and consequently corrosion.Verify then, the need to install sacrificial anodes.In case additives or other fluids than those recommen-ded by Carrier are used, ensure that the fluids are notconsidered as a gas, and that they belong to class 2, asdefined in directive 97/23/EC.Carrier recommendations on heat exchange fluids:• No NH4+ ammonium ions in the water, they are verydetrimental for copper. This is one of the most impor-tant factors for the operating life of copper piping.A content of several tenths of mg/l will badly corrodethe copper over time.• Cl- Chloride ions are detrimental for copper with a riskof perforations by corrosion by puncture. If possiblekeep below 125 mg/l.• SO42- sulphate ions can cause perforating corrosion, iftheir content is above 30 mg/l.• No fluoride ions (<0.1 mg/l)• No Fe2+ and Fe3+ ions with non negligible levels ofdis-solved oxygen must be present. Dissolved iron< 5 mg/l with dissolved oxygen < 5 mg/l.• Dissolved silicon: silicon is an acid element of waterand can also lead to corrosion risks. Content < 1 mg/l.• Water hardness: > 0.5 mmol/l. Values between 1 and2.5 can be recommended. This will facilitate scaledeposit that can limit corrosion of copper. Values thatare too high can cause piping blockage over time. Atotal alkalimetric titre (TAC) below 100 is desirable.• Dissolved oxygen: Any sudden change in wateroxy-genation conditions must be avoided. It is asdetrimen-tal to deoxygenate the water by mixing itwith inert gas as it is to over-oxygenate it by mixing itwith pure oxygen. The disturbance of the oxygenationconditions encourages destabilisation of copperhydroxides and enlargement of particles.• Electric conductivity 10-600 μS/cm• pH: Ideal case pH neutral at 20-25 °C7.5 < pH < 9.If the water circuit must be emptied for longer than onemonth, the complete circuit must be placed under nitrogencharge to avoid any risk of corrosion by differential aeration.ATTENTION: Filling, completing and draining the watercircuit charge must be done by qualified personnel, using theair purges and materials that are suitable for the products.Charging and removing heat exchange fluids should bedone with devices that must be included on the watercircuit by the installer. Never use the unit heat exchangersto add heat exchange fluid.