Daikin EBHQ006BAV3 Installation Manual

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Daikin EBHQ006BAV3 Installation Manual Manual pdf 22 page image

Installation manual20 EBHQ006+008BAV3 + EKCBX/H008BAV3Unit for air to water heat pump system4PW64602-1A – 09.201010.5. Protecting the water circuit against freezingFrost can damage the unit. As this unit is installed outdoors and thusthe hydraulic system is exposed to freezing temperatures, care mustbe taken to prevent freezing of the system. All hydraulic parts areinsulated to reduce heat loss. Insulation must be foreseen on the fieldpiping.The unit is already equipped with several features to prevent freezing.■ The software contains special functions using pump and backup heater to protect the complete system against freezing. Thisfunction will only be active when the unit is off.However in case of power failure, above mentioned features cannot protect the unit from freezing.If power failure can happen at times the unit is unattended,Daikin recommends adding glycol to the water system. Refer toCaution: "Corrosion of the system due to presence of glycol" onpage 20Refer to "[4-04] Freeze protection function" on page 33.Depending on the expected lowest outdoor temperature, makesure the water system is filled with a weight concentration ofglycol as mentioned in the table below.Also refer to "Pre-run checks" on page 42.NOTICE■ The unit is only to be used in a closed water system.Application in an open water circuit can lead toexcessive corrosion of the water piping.■ Never use Zn-coated parts in the water circuit.Excessive corrosion of these parts may occur ascopper piping is used in the unit's internal watercircuit.■ When using a 3-way valve in the water circuit.Preferably choose a ball type 3-way valve toguarantee full separation between domestic hot waterand floor heating water circuit.■ When using a 3-way valve or a 2-way valve in thewater circuit. The recommended maximumchangeover time of the valve should be less than 60seconds.Minimum outdoortemperature Glycol (a)(b)(c)–5°C 10%–10°C 15%–15°C 20%–20°C 25%–25°C 30%WARNING(a) ETHYLENE GLYCOL IS TOXIC(b) The concentrations mentioned in the tableabove will not prevent the medium fromfreezing, but prevent the hydraulics frombursting.(c) The maximum allowed water volume is thenreduced according to the figure "Checking themaximum allowed water volume" on page 19CAUTION■ For installations with a domestic hot water tank,the use of propylene glycol, including necessaryinhibitors, is only allowed if classified asCategory 3 according to EN1717 or equivalentbased on national regulations.■ In case of over-pressure when using glycol, besure to connect the safety valve to a drain pan inorder to recover the glycol.Connecting a drain pipe is not required if noglycol is used. The discharged water is thendrained via the bottom of the unit.CAUTIONCorrosion of the system due to presence of glycolUninhibited glycol will turn acidic under the influence ofoxygen. This process is accelerated by presence of copperand at higher temperatures. The acidic uninhibited glycolattacks metal surfaces and forms galvanic corrosion cellsthat cause severe damage to the system.It is therefore of extreme importance:■ that the water treatment is correctly executed by aqualified water specialist;■ that a glycol with corrosion inhibitors is selected tocounteract acids formed by the oxidation of glycols;■ that in case of an installation with a domestic hotwater tank, only the use of propylene glycol, includingnecessary inhibitors classified as Category 3according to EN1717 or equivalent based on theapplicable legislation is allowed. In other installationsthe use of ethylene glycol is permitted as well;■ that no automotive glycol is used because theircorrosion inhibitors have a limited lifetime and containsilicates which can foul or plug the system;■ that galvanized piping is not used in glycol systemssince its presence may lead to the precipitation ofcertain components in the glycolís corrosion inhibitor;■ that it has to be made sure the glycol is compatiblewith the used materials in the system.NOTICEBe aware of the hygroscopic property of glycol: it absorbsmoisture from its environment.Leaving the cap off the glycol container causes theconcentration of water to increase. The glycolconcentration is then lower than assumed. And inconsequence, freezing can happen after all.Preventive actions must be taken to ensure minimalexposure of the glycol to air.