Daikin EWAQ016BAW Installation And Operation Manual

Also see for EWAQ016BAW: Service manual

Contents

Daikin EWAQ016BAW Installation And Operation Manual Manual pdf 16 page image

Installation and operation manual11 EWAQ016~064BAW + EWYQ016~064BAWPackaged air-cooled water chiller4PW70082-1C – 2013.07The default value of pre-pressure (Pg) responds to 7 m heightdifference.If the height difference of the system is lower than 7 m AND thevolume in the system is less than the maximum allowed value atthat pre-pressure (Pg) (see chart above), then NO pre-pressure(Pg) adjustment is required.Example 1The unit is installed 5 m below the highest point in the watercircuit. The total water volume in the water circuit is 250 l.In this example, no action or adjustment is required.Example 2The unit is installed at the highest point in the water circuit. Thetotal water volume in the water circuit (no glycol used) is 420 l.Result:■ Since 420 l is higher than 340 l, the pre-pressure must bedecreased (see table above).■ The required pre-pressure is:Pg=(H/10+0.3) bar=(0/10+0.3) bar=0.3 bar■ The corresponding maximum water volume can be read fromthe graph: approximately 490 l.■ Since the total water volume (420 l) is below the maximumwater volume (490 l), the expansion vessel suffices for theinstallation.4 Setting the pre-pressure of the expansion vesselWhen it is required to change the default pre-pressure of theexpansion vessel (1 bar), keep in mind the following guidelines:■ Use only dry nitrogen to set the expansion vessel pre-pressure.■ Inappropriate setting of the expansion vessel pre-pressurewill lead to malfunction of the system. Therefore, the pre-pressure should only be adjusted by an installer.4.5.5. Protecting the water circuit against freezingFrost can cause damage to the hydraulic system. As this unit isinstalled outdoors and thus the hydraulic system is exposed tofreezing temperatures, care must be taken to prevent freezing of thesystem.Optional water piping heater tapeRefer to "3.1. Check that you have all optional equipment" on page 3.All hydraulic parts are insulated to reduce heat loss. Insulation mustbe foreseen on the field piping.A heater tape is winded around the piping to protect vital parts of thehydraulic system inside the unit.This heater tape will only protect internal parts of the unit. It can notprotect field installed parts outside the unit.Field heater tape must be foreseen by the installer.Use of glycolRefer to "[8-04] Freeze-up prevention" on page 21.Depending on the expected lowest outdoor temperature, make surethe water system is filled with a weight concentration of glycol asmentioned in the table below.Caution: "Use of glycol"Also refer to "5.3. Final check and test run" on page 22.NOTICEHowever in case of power failure, above mentioned optioncan not protect the unit from freezing.If power failure can happen at times the unit is unattendedor if you did not select this option, Daikin recommendsadding glycol to the water system.Minimum outdoor temperature Glycol (a)(a) See "[A-04] Glycol concentration setting" on page 21 for special settings whenusing ethylene glycol.–5°C 10%–10°C 15%–15°C 20%WARNINGETHYLENE GLYCOL IS TOXICINFORMATION(a)The concentrations mentioned in the table above will notprevent the medium from freezing, but prevent thehydraulics from bursting.CAUTION: Use of glycol■ In case of over-pressure when using glycol, be sure toconnect the safety valve to a drain pan in order torecover the glycol.Connecting a drain pipe is not required if no glycol isused. The discharged water is then drained via thebottom of the unit.■ Using more than 40% glycol will damage the unit.NOTICECorrosion 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 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 glycol’s corrosion inhibitor;■ that it has to be made sure the glycol is compatiblewith the used materials in the system.INFORMATIONBe 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.