http://danfoss.ipapercms.dk/refrigerationandairconditioning/RA/CoolingMatters/IE/CoolingMattersVolume12012/RSS.ashxRefrigeration and Air Conditioning PagesFri, 20 Apr 2012 08:45:48 +0200http://danfoss.ipapercms.dk/refrigerationandairconditioning/RA/CoolingMatters/IE/CoolingMattersVolume12012/http://danfoss.ipapercms.dk/refrigerationandairconditioning/RA/CoolingMatters/IE/CoolingMattersVolume12012/?Page=1http://danfoss.ipapercms.dk/refrigerationandairconditioning/RA/CoolingMatters/IE/CoolingMattersVolume12012/?Page=1Cooling Matters Danfoss News for the Refrigeration & Air Conditioning Industry • ExhibitionNews-AlookbackatDanfossatMostraConvegno • Products-PSHrangeofheatpumpscrollcompressors • Refrigerants-ProductsforammoniaandCO2forSupermarkets • FittersNotes-PressureControls Volume 1 • 20122012-04-20T08:45:48+02:00http://danfoss.ipapercms.dk/refrigerationandairconditioning/RA/CoolingMatters/IE/CoolingMattersVolume12012/?Page=2http://danfoss.ipapercms.dk/refrigerationandairconditioning/RA/CoolingMatters/IE/CoolingMattersVolume12012/?Page=2Editorial The refrigeration and air conditioning industry has made tremendous progress over the past two decades in reducing the use of ozone-depleting refrigerants. The original targets of the Montreal Protocol, established in 1987 to reduce emissions of ozone depleting substances, are being met and exceeded. Another consequence of these initiatives is that during the 1990s and the early part of the present century, there was considerable uncertainty regarding future refrigerant options. Now a path has started to appear, defined by the global agenda on climate change and global warming. Seen from a global perspective, the tendency is that the industry is moving more and more toward natural refrigerants where this is technologically feasible. Synthetic refrigerants are still likely to play a large role in the refrigeration and air conditioning industry, but this will be in minimal charge systems and with new low GWP substances. Parameters such as efficiency, safety, environmental impact, relatively short atmospheric lifetimes, chemical properties and economy all influence the choice of future refrigerant options. In this issue of Cooling Matters we look at the products and solutions offered by Danfoss for natural refrigerants such as ammonia and carbon dioxide (CO2). We also introduce the newest edition to our range of PSH scroll heatpump compressors and review the products presented at the recent Mostra Convegno exhibition in Italy. We continue with our Fitters Notes series, this time looking at Pressure Controls. Finally, we introduce you to the free on-line training platform, Danfoss Learning. Hydrocarbonproductstype designationchange 2 ExhibitionNews-MostraConvegno 3 PSHheatpumpscrollcompressor rangeextended Ammonia-thenaturalchoice 4 6 Change in type designation for specific hydrocarbon products. Specific refrigeration control products released for use with hydrocarbon refrigerantsaretohavetheletter"E"removedfromthetypedesignation. The products affected by this change are shown in thetableopposite. Thisisonlyachangeinthe typedesignationthespecifications and code numberswillremainthesame. Old type designation EVRE BMLE SGIE SGNE NRVE NRVHE DCLE DMLE New type designation EVR BML SGI SGN NRV NRVH DCL DML Contents CO2refrigerantuseinSupermarkets increasing. 8 FittersNotes-PressureControls 9 DanfossLearning-Thefreeon-line trainingplatform 12 22012-04-20T08:45:48+02:00http://danfoss.ipapercms.dk/refrigerationandairconditioning/RA/CoolingMatters/IE/CoolingMattersVolume12012/?Page=3http://danfoss.ipapercms.dk/refrigerationandairconditioning/RA/CoolingMatters/IE/CoolingMattersVolume12012/?Page=3Every two years sees the staging of the Internationally Important Mostra Convegno Expocomfort, with this years event being held on 27th to 30th March in Milan. Once again Danfoss was in attendence presenting our latest products and solutions for both Air Conditioning and Refrigeration. New VZH: the breakthrough in high efficient compressor solution for all commercial applications. ThenewPerformer®VZH,R410A scroll compressor, second generationoflargesizevariable speed scroll compressor after the release of VSH in January 2010,willopennewhorizonfor all commercial applications. Firstvariablespeedcompressor achieving 25TR at standard ARI conditions, VZH will also provideunmatchedperformancelevels. The Danfoss stand was divided into 2 main areas, one for Air Conditioning products and the other for Refrigeration products. IntheAirConditioningsectionproductsdisplayedincluded compressors, heat exchangers and controls whilst in the Refrigeration area were packaged condensing units, compressors,commercialandindustrialcontrolsalongwith electroniccontrolsfortheFoodRetailindustry. Danfossalsoparticipatedintheseminarswithpresentations on "Heat pump and liquid injection technology", Variable speedforHVAC,closecontrol,industrialapplicationsandalso Turborcompressorsandapplications. Highlightsfromtheshowincluded: Optyma Plus™ New Generation Condensing Units As already introduced in a previous edition of Cooling Matters the new generation ofthesilentPlug&Playseries ofOptymaPlus™Condensing units were displayed at the stand. Optyma Plus™ New Generation offers the same robust quality with added technology, for outdoor cooling units. Further information is available on the local Danfoss websites: www.danfoss.com/optymaplus PSH commercial heat pump scroll compressors After the Performer® PSH038-077 heating optimized R410A scroll compressor release in November 2011, Danfoss announcestheavailabilityofnewmodelstocompletethePSH range. Six additional displacements are now ready for heat pumpmarketsinsmallercapacities.Thecompleterangenow coversheatingcapacitiesfrom19to80kWat-7˚Cevap.,50˚C cond.,superheat2K,subcooling5Kratingpoint. Further information is available in the following article and the article in Cooling Matters volume 2 2011. Reduce the Energy Consumption of your Refrigeration, Heat Pump and Air Conditioning Systems With the new ETS 6 valve, Danfoss’rangeofETSelectrically operated expansion valves has justgotevenstronger.Designed to control liquid injection into evaporators, the ETS range improves energy efficiency in refrigeration,heatpumpsandair conditioningsystems. Increasingenvironmentalconcern,andtighterCO2emission and energy consumption regulations have made air conditioning,heatpumpandrefrigerationunitmanufacturers lookfornewwaystoimprovetheenergyefficiencyoftheir systems.Theelectronicexpansionvalve,whichcanadaptto theexactcapacitydemandsofasystem,isonecomponent that’smakingapositivedifferencetotheenergyconsumption. Heat exchangers Rapidlyrisingrawmaterialandrefrigerantprices;environmental regulations and taxes; how to remain profitable inanincreasinglycompetitivemarketplace.Today’smanuOther compressors at the show included the new SH295 Performer® scroll compressor for air conditioning, MLZ refrigerationscrollcompressorandtheSLV15CNK.2variable speedcompressorforrefrigerantR290. AKS 4100/4100U with the Guided Radar technology, adapted and qualified to Refrigeration Applications. ThenewAKS4100/4100ULiquidLevelSensorwithGuided Radar technology was one of the products from Danfoss Industrial Refrigeration, also on show were the ICF valve stationandtheICMdirectmotorcontrolledvalvecomplete withanICADactuator. Further information on all of these products can be found in the article on products for ammonia on page 6. Exhibition News 3 Danfoss showcases latest products and solutions at Mostra Convegno Expocomfort2012-04-20T08:45:48+02:00http://danfoss.ipapercms.dk/refrigerationandairconditioning/RA/CoolingMatters/IE/CoolingMattersVolume12012/?Page=4http://danfoss.ipapercms.dk/refrigerationandairconditioning/RA/CoolingMatters/IE/CoolingMattersVolume12012/?Page=4Exhibition News facturershavealottothinkabout. Danfoss shows the way forward with a new generation of heat exchangers that addresses all these concerns. Our Micro Plate andMicroChannelHeatExchangers generate significant savings for producers and at the same time, reducesensitivitytorisingprices. Take Control of Your Refrigeration Applications with the ERC Range Flexible and easy to install, Danfoss’ERCelectronicrefrigerator controllers are designed to reduce energy consumption. Presented at the show the latest to join the range, the ERC 101 is designed for a broad range of applications, while the 103 isidealforcommercialfreezers,counter-topbottlecoolers andtherefurbishmentmarket. Extremely versatile, the ERC 103 can be used as an electronic stand-alone controller, or it can be integrated witharemotedisplayorspindle.Withinputfrommultiple sensors, the cost-efficient controller saves energy by controlling the compressor, light, fan and defrost mechanismoperationsforoptimumefficiency. Electronic controls for Food Retail Onshowwhereaselectionofelectroniccontrolsforfood retail applications including the new AK-SC355 system controller, the brand new multifunctional pack controller AK-PC 781dedicatedtoCO2installations as well as compressor controls andgasdetectors. Danfoss Learning - Your online access point to knowledge For 2 years, Danfoss has been developing a training platform - Danfoss Learning - which aims to suit professional training requirements withfocusonRefrigeration& Air Conditioning techniques, products, applications and services. The Platform was introducedtovisitorsattheshow. Whetheryouareaninstaller,wholesaler,student,technician ordeveloperatanOEM,youcansignuptotheplatformand enrolinthecourses.Thisplatformisavailableonline24/7, anytime from everywhere. Users can access self study courses (e-lessons) as well as face-to-face training courses andvirtualclassrooms. YoucanfindoutmoreaboutDanfossLearninginourfinal articleonpage12. For further information, including literature, on any of the products or solutions exhibited at Mostra Convegno please visited the dedicated danfoss website at ; www.danfoss.com/mostra Dedicated heat pump scroll compressors Danfoss Commercial Compressors announces the extension of the recent Performer® PSH heat pump scroll compressor range AfterthePerformer®PSH038-077heating optimized R410A scroll compressorreleaseinNovember2011,Danfoss announces the availability of new modelstocompletethePSHrange.Six additional displacements are now readyforheatpumpmarketsinsmaller capacities. The complete range now covers heating capacities from 19 to 80kWat-7˚Cevap.,50˚Ccond.,superheat5K,subcooling5Kratingpoint. The features and technology make this range suitable for sanitary water, radiators(bothretrofitandnewinstallation)andfancoilapplications. OEM Products Heatrelease HeatRecoveryUnits (Condensingupto65˚C) Water Radiator (Retrofit,Condensingup to60˚C) Radiator (New,Condensingupto 50˚C) SanitaryHotWater (Condensingupto65˚C) Source AirSource (Evaporatingdown to-25˚C Ground(Brine) (Evaporatingdown to-10˚C 42012-04-20T08:45:48+02:00http://danfoss.ipapercms.dk/refrigerationandairconditioning/RA/CoolingMatters/IE/CoolingMattersVolume12012/?Page=5http://danfoss.ipapercms.dk/refrigerationandairconditioning/RA/CoolingMatters/IE/CoolingMattersVolume12012/?Page=5Condensing Temperature (°C) Innovative liquid injection technology offers new possibilities within the heating market 65°C water at -25°C ambient thanks to extended operating envelope Equipmentmanufacturerswillbenefit fromtheliquidinjectionthatdeliversa widertemperatureenvelope. Incomparisontogasoroilfurnacesfor spaceheatingandHotSanitaryWater (HSW) production, a heat pump system offers very large energy savingsupto50%.Butuntilnow,most heatpumpswerelimitedinoperating temperatures. The Performer®PSH compressor with liquid injection technology offers an increased operating envelope. With 65°C saturated condensing temperature it allows for safe Hot Sanitary Water production and comfortable space heating evenwith old radiator systems. And with low evaporating temperatures down to -30°C it can be applied in colder regions. Thankstoitsextendedmap,theHeat Pump is able to operate all year long and doesn’t need a furnace backup. Simulationsdemonstratea10%energy saving with Heat Pump when equipped with PSH versus ones with furnacebackup. Simpler and more efficient solution for OEMs 25% cost reduction*: The Performer® PSH019-039 requires fewer components in the system and saveeconomizer,EXVorextrapiping, which successfully reduces the application costs. The new integrated liquid injection valve and controller makes it simpler for designing and manufacturingheatpumps. * Compared to vapor injection 20% more compact: BasedonaR410Arefrigerantunit,heat exchanger size will be smaller comparedtoR407Csystems.Itreduces installationspace. Energy efficient solution with Eco-label The Performer® PSH019-039 range achieves more than the required 65 60 55 50 45 40 35 30 25 20 15 -35 -30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 Confirmed PSH envelope Evaporating Temperature (°C) Operating Envelope for light commercial PSH Heating Efficiency for air to water heat pumps Outdoorcondition Indoorcondition ECOlabelCOPrequirementonunits Compressorworkingcondition COPrequirementoncompressor DanfossPSH019 DanfossPSH023 DanfossPSH026 DanfossPSH030 DanfossPSH034 DanfossPSH039 Inletdrybulb2˚C Inletwebbulb1˚C Inlet30˚ / outlet 35˚C 3.1(W/W) -7˚C/40˚C/5K/4K 3.4(W/W) 3.77(+12%) 3.79(+12%) 3.90(+15%) 4.05(+15%) 4.11(+15%) 4.10(+18%) Inletdrybulb2˚C Inletwebbulb1˚C Inlet40˚ / outlet 45˚C 2.6(W/W) -7˚C/50˚C/5K/4K 2.9(W/W) 2.95(+4%) 2.95(+8%) 3.15(+8%) 3.16(+8%) 3.20(+8%) 3.22(+10%) Table 1 compressor COP for Eco label (3.4W/W).Alldisplacementswilloffera minimum 3.77 COP and up 4.11 dependingonmodelsinAirtoWater heatpumps(seetable1). Innovation leads to benefits: 30% higher reliability ThePerformer®PSH038-077hasanew builtinoperatingcontrolsystem(OCS) which pilots the liquid injection and protectsthecompressorbykeepingit within operating limits. The system alsostoresoperatingdataandevents for improved servicing. The OCS reduces downtime and cuts system warrantycosts. Lower sound levels, higher comfort The largest Performer® PSH complies withthemarketrequirementsandlegislationwhenitcomestosoundlevels. Thecompressorgeneratesbyaverage 3dB(A)lowersoundlevelthanequivalent products. All large commercial PSH compressors (038-051-066-077) arestandardequippedwithapatented surface sump heater - integrated insulationwhichlargelycontributesto the sound reduction. All commercial PSH019-039 compressors are compatiblewiththeSurfaceSumpHeater andwehighlyrecommendthisoption forend-userbestcomfort. Danfoss offers an optimized scroll compressor range for use in residentialandcommercialheatpumpsfrom 5 to 240 kW. Thanks to the Perform- er® HHP compressors for refrigerant R407Cwitharangeof5to14kWand the Performer® PSH scroll compres- sor for commercial heat pumps with models from 20 to 80kW that can be combinedintandemandtrioconfigurationupto240kW. OEM Products 52012-04-20T08:45:48+02:00http://danfoss.ipapercms.dk/refrigerationandairconditioning/RA/CoolingMatters/IE/CoolingMattersVolume12012/?Page=6http://danfoss.ipapercms.dk/refrigerationandairconditioning/RA/CoolingMatters/IE/CoolingMattersVolume12012/?Page=6Products Ammonia – the natural choice for present and future demands ICM direct motor controlled valve ICS pilot controlled servo valve Pilot valve ICAD actuator Top cover Function module and top cover Function module Theuseofammoniaasarefrigerantbeganinthemid-19th century and it is probably best known today for its use in industrialrefrigerationapplications.Itisanaturalsubstance with zero ODP and zero GWP, this in combination with its efficiencymakesammoniaoneofthemostenvironmentally friendly refrigerants available. There are, however, some compatibility,toxicityandflammabilityissueswhichmean installations using ammonia are governed by national regulationstoensurethatsafetyisnotcompromised. With its abundant availability, low price and the proper safetyprecautionstaken,thebenefitsofammoniaarecompelling so it continues to be the refrigerant of choice for large storage applications, food processing plant and breweriesetc. Thereareon-goingeffortstodeveloplow-chargeammonia systems in order to utilise the beneficial thermodynamic andenvironmentalpropertiesofammonia. Theseeffortsinclude: • Development of low-charge systems and associated controlalgorithms. • Optimisationofheatexchangers. • DX(DirectExpansion)systems. • Cascadesystemsorcombinationwithsecondarysystems withCO2asabrine. Danfoss is one of the principal suppliers of industrial refrigerationcomponentsforthesefacilitiesandwecontinue to design and develop innovative products for this industrysector. Main Valves The modular ICV concept, discussed in Cooling Matters volume 1 – 2011, offers low weight and compact design making them easy to install. Direct coupled connections greatly reduce the potential for leaks and the modular design makes servicing quick and simple. The innovative v-portdesignoffershighersuctionpressuresettingsleadingtoenergysavings. 6 Common valve housing Common valve housing ICV modular valve programme Valve stations Based on advanced technology the ICF control solution incorporates several functions, in one housing, which can replace a series of conventional mechanical, electro- mechanicalandelectronicallyoperatedvalves.Thissolution not only provides a number of advantages in the design phasebutalsointheinstallation,serviceandmaintenance. When using TIG/MIG welding technology it is possible to install the ICF solution without removal of the function modulesfromthehousing. Supplied as a complete assembly, it is leak tested at high pressure and its functions are tested under factory controlled conditions. One code number equals one applicationsolution. ICF control solution2012-04-20T08:45:48+02:00http://danfoss.ipapercms.dk/refrigerationandairconditioning/RA/CoolingMatters/IE/CoolingMattersVolume12012/?Page=7http://danfoss.ipapercms.dk/refrigerationandairconditioning/RA/CoolingMatters/IE/CoolingMattersVolume12012/?Page=7Liquid Level AsintroducedinCoolingMattersVolume3-2011thenew AKS4100/4100URadarLiquidLevelSensorusestheproven TDRtechnology(TimeDomainReflectometry)fullyadapted to the Industrial Refrigeration segment and ensuring reliabilityandhighaccuracy. All sensors in the new AKS 4100/4100U family are easy to install and fully flexible. No on-site calibration is needed, andtheprobelengthcaneasilybeadjustedonsite. Due to the very easy on-site adjustment procedure, with AKS 4100 you will experience significant time savings duringinstallation. TheGDproductsfeaturereliable,realtimecontinuousmonitoring.Noblockedfilters,tubesortechnical/maintenance problemsexperiencedbyairsampling/aspiratedsystems. ForammoniathetypeGDAoffersarangeofproductsfrom 0-100ppmupto0-30,000ppm. Danfoss solution for DX ammonia applications Traditionally ammonia is used in "flooded" systems where therefrigerantremainsinaliquidstate.However,itisalso possibletouseammoniainadirectexpansion(DX)system wherebyanexpansiondevicefacilitatesachangeofstateof therefrigerantfromliquidtovapour. A combination of a motorised valve (ICM/AKVA) and an electronic controller (EKC 315A) together with a pressure sensorandatemperatureprobehelpsmeetthechallenge ofusingammoniaincompactDXchillers.Thesystemhasa veryshortresponsetime,anditmaintainsaverystable,low superheatlevelunderallloadconditions,therebyminimising theriskofliquidflowbacktothecompressorandmaximising energyefficiency. AKS 4100/4100U Liquid Level Sensors Gas Detectors Althoughammonia’sdistinctiveodourmakesit‘self-alarming’ whenaleakoccurs,socialsensitivityandstrictregulations make it essential to install gas detectors. The Danfoss Gas Detection program, type GD is a range of products designedtomeetallindustrialrefrigerationapplications. GD sensors incorporate an interchangeable pre-calibrated sensorboard,whichmakesitveryeasytoreplacethesensor whenserviceorcalibrationisrequired. ICM/AKVA & EKC 315A for DX ammonia applications ThesearejustsomeoftheproductsandsolutionsDanfoss canofferforammoniarefrigerationsystems,otherproducts inourrangeincludeexpansiondevices,solenoidvalves,line components, pressure and temperature regulators, stop and regulating valves, safety valves, electro mechanical controls, electronic controls and transmitters, variable speeddrivesandheatexchangers. Contact your official Danfoss Wholesaler or local Danfoss Salesofficeforassistancewithyourammoniarefrigeration systemneeds. For further information on natural refrigerants please visit the Danfoss Solutions Ready website @ www.danfoss.com/SolutionsReady/ Other Cooling Matters articles on natural refrigerants can be found on the local Danfoss website @ www.danfoss.co.uk/coolingmatters GD Gas detectectors Products 72012-04-20T08:45:48+02:00http://danfoss.ipapercms.dk/refrigerationandairconditioning/RA/CoolingMatters/IE/CoolingMattersVolume12012/?Page=8http://danfoss.ipapercms.dk/refrigerationandairconditioning/RA/CoolingMatters/IE/CoolingMattersVolume12012/?Page=8Refrigerants Increasing Interest for CO2 Refrigeration – and not only from an Economic Perspective It is no longer only the Scandinavian countries,whoshowinterestforrefrigerationsystemswithCO2astherefrigerant. More supermarket chains in Great BritainareinstallingCO2systemsandit is also spreading to other European countries. Lately the Danish Danfoss sales company has experienced an interestfromSouthAmericancountries, who would like to learn more about howtobuildvariousCO2systems. Historically CO2 systems have been seen as a Scandinavian phenomenon because it was considered that CO2 was only feasible in relatively cold climates. However, it has become apparent that it can compete against traditional refrigeration plant even in the warmest months in Denmark wheretheretheenergyconsumption shouldbehigher. ItishowevernotonlyDanfosswhois oftheconvictionthatCO2systemscan befeasibleinmanydifferentclimates. Thelargesupplierofrefrigerationsolutions to supermarkets, Carrier, is installing more and more CO2 systems. Inanarticlepublishedonthewebsite www.r744.comonthe7thofDecember 2011theysaythattheirstudiesshowthat CO2 installations can be feasible in climateswithanaveragetemperatureofup to20-26˚C.Theyfurthermoresaythatin 2012theywillstarttestsontheirsecond generationoftranscriticalCO2systemsto provethattheyareatleastasenergyeffective as traditional HFC refrigeration plantinallEuropeanclimates. IIllustration1,whichshowsthepossible efficiency savings in comparison to R404Asystemshasbeenreviseddueto installation of both medium and low temperatureCO2systemsthathasproven the feasibility of using CO2 in all climates. Thenewinterest,thatDanfossisexperiencing, is not based on instant economic savings or profitability but more from an environmental aspect. The two South American countries - Chile and Brazil, from where the installers came to Danmark to learn thesystemshavebeentroughtheyfelt better equipped to return to their homecountriesandstartbuildingCO2 refrigeration plant. Because of the climates in Brazil and Chile the most profitable type of installation would probablybeacascadesystem.Examples ofboosterandcascadesystemscanbe seenattheendofthisarticle. Fromabroaderperspectivethereare moreadvantageswithaCO2installation than just the economical profitability that you get up front together with lessdamagingimpactontheenvironment when you compare CO2 with HFC. In the cooling process a CO2 system develops an amount of heat which givesyouthepossibilityforheatreclaim, whichcanbeusedforheadingofthe remainingbuildings. Theheatsurpluscanalsobeusedfor heat driven air condition systems (sorption) which can then be used as airconditioninthebuildings. As many synthetic refrigerants are imposedwithadutyorareintheriskofhavingdutiesaddedcompanieswhoswitch to CO2 will also be minimizing the economicalrisklinkedwithusingarefrigerantregulatedbypoliticalmeasures. EstablishingaCO2installationtodayis slightly more expensive than a traditional HFC refrigeration plant but thereareindicationsthatthecostsare becomingmorealike. Illustration 1 shows average yearly temperatures and expected possible savings comparing to a plant with R404A. (Source: Map made by http://globalis. gvu.unu.edu) moreaboutCO2systems,haveclimates which hardly make CO2 installations profitable from just an energy consumption perspective. Further more thesecountriesdonothavedutieson theenvironmentallydamagingrefrigerants as for example R404a, duties that are implemented in many Europeancountries. ThedriverbehindtheinterestforCO2 inChileandBrazilisonthecontrarya focus on the environment. There is fromsocietyalargefocusonthefact thatwehavetoshowmoreconsideration to the environment in many differentprocesses.Thereforetheinstallers experience an increasing interest for CO2 systems from supermarket chains, because this will make them abletoreducetheir"CarbonFootprint" considerably. This also gives the supermarketstheopportunitytoportray themselveswithagreenprofile. InDenmarktheinstallersexperienced, ho2012-04-20T08:45:48+02:00http://danfoss.ipapercms.dk/refrigerationandairconditioning/RA/CoolingMatters/IE/CoolingMattersVolume12012/?Page=9http://danfoss.ipapercms.dk/refrigerationandairconditioning/RA/CoolingMatters/IE/CoolingMattersVolume12012/?Page=9Transcritical Booster System Cascade System For further infromation on CO2 please visit the Danfoss dedicated website at www.danfoss.com/co2 where you will find information on products and applications for CO2 including the recently updated leaflet "Components for CO2 applications in Industrial Refrigeration" (DKRCI.PA.000.D3.02) Pressure Controls The actual pressure in the system at the point monitored by the pressure control is usually provided via a branch line or – if the pressure control is installed directly on a line – applied directly to the pressostat. The pressure actuates a potentialfree set of contacts that can be used to control a device such as a compressor or a fan. areusuallyfittedclosetothecompressor on the suction side, are most often used to protect the compressor by switchingitoffifthereisnotenough refrigerant.Thereasonforthisisthata loss of refrigerant in the system can lead to a variety of problems. For example,suctiongascoolingisreduced, which especially with compressors thatrelyentireonsuctiongascooling isamajorproblem. with the refrigerant. This can lead to insufficient lubrication. It is thus very beneficialtoswitchoffthecompressor asaprecautionarymeasureifthelow pressure level drops sharply, in order to avoid compressor damage or total failureofthecompressor.Itshouldbe noted that the low-pressure control can also shut off the compressor for reasons other than a shortage of refrigerant.Ifaproblemwithlow-pressure control-off occurs, the service fittershouldalwayscheckthevolume flow rate of the media cooled in the evaporator.Ifitistoolowduetosome other malfunction, there is probably notashortageofrefrigerant.Asimple example here would be a defective evaporator fan or a defective pump with a water chiller unit (refrigerant/ water evaporator). In the latter case, however,theflowswitchinthewater circuit should have also tripped, as otherwise there would be a risk of evaporatoricing(andbreaking). The job of a pressure control Whatarethesecontrolsgoodfor,and why are they necessary? Let’s start with the function of a low-pressure control in a compressor refrigeration system. Low-pressure controls, which Inaddition,compressoroilalwaysescapes in addition to the refrigerant when there is a refrigerant leak becauseitisconstantlypassingthrough the entire refrigeration circuit along Fitters Notes 9 Refrigerants Ifthisisconvertedtodrivenkmina moderncar,releasing99g.CO2per km. (eg Golf Blue Motion) this equals: • 193mio.km.or • Almost13,000carsyearlyemission at15,000km/year Danfossisagloballeaderwithinenergy efficientsolutionswhichhelptoreduce CO2 and thereby fight the global climate changes. Today Danfoss already offers many solutions that can reduce theamountofCO2releasedintotheatmosphere.Youcanreadmoreabutthe solutions on the international web pagewww.solutionsready.danfoss.com, whereexcitingarticlesontechnologies withincoolingoffood,airconditioning, regulationofelectricalengines,heating ofbuildingsandsolutionsforrenewable resources. Technologies that can help fighttheclimatechangesandalsomake modernlivingpossibleinthefuture.2012-04-20T08:45:48+02:00http://danfoss.ipapercms.dk/refrigerationandairconditioning/RA/CoolingMatters/IE/CoolingMattersVolume12012/?Page=10http://danfoss.ipapercms.dk/refrigerationandairconditioning/RA/CoolingMatters/IE/CoolingMattersVolume12012/?Page=10Fitters Notes Pump-down and pump-out circuits A low-pressure control can also be usedforcontrolpurposes.Forexample, itisusedinpump-downandpump-out circuits(whicharecommonly usedin refrigerationsystems)toswitchoffthe system when the compressor is switchedoffforcontrolreasons(such aswhentheswitch-offtemperatureof thethermostatisreached).Thisoccurs whenthepressureresultingfromclosing the liquid solenoid valve while the compressorcontinuestorunhasbeen suckeddownfromtheliquidsolenoid valve through the evaporator all the waytothesuctionside. at the front of the system, which can distinctlyincreaseaccessibilityandease of servicing. By contrast, a cartridgetype pressure control is the solution preferred by mass-production manufacturersbecauseitsfixedsettingcannot easilybemodifiedinthefieldbyunauthorisedpersons.Inaddition,cartridgetypepressurecontrolsareusuallyvery inexpensive. Withanautomaticreset(DWK)version, itisalwayspossibleforthesystemto beswitchedonagainautomaticallyafter the pressure decreases by a certain amount.Withamanualresetbyhand (DBK)KP,amanualresetmustbeperformedafteraprotectiveswitch-off.It must be possible to initiate this reset by hand without using a tool. Finally, withamanualresetbytool(SDBK)device atoolisnecessarytoperformamanual reset. Condenser fan control Anotherpossibilityonthehigh-pressure sideistouseapressurecontroltocontrol the condenser fan. This provides an economical alternative to a variablespeedfancontrolforensuringthatthe condensing pressure does not drop too low, especially in cold weather. Thisoption isespecially attractivefor very small commercial refrigeration systems, which are naturally quite cost-sensitive,aswellasforlargersystemswiththree-phasefansforwhich a variable-speed controller can be verycostly. Contact rating Animportantconsiderationwhenusing pressure controls with potential-free contactsisthecontactrating.Thiscan be confusing at first because manufacturers generally specify three differentcontactratings.Whichvalue should you be guided by? The three values are normally given for the followingcases:apureohmload(the highest load is traditionally possible in this case), a partially inductive load, andapurelyinductiveload.Anexample ofapureohmload(loaddesignation: AC1)isanelectrical(resistance)heater fordefrosting.Anexampleofapartially inductiveload(AC3)isanelectricmotor (whichalsoincludescompressors). CLASS N 1 When a certain threshold value is passed,thelow-pressurecontrolshuts off the system. When the switch-on temperature of the room thermostat has been reached again after a while and the solenoid valve opens, the pressure in the suction line rises and the low-pressure control starts the compressor again when the pressure exceedsitsswitch-onpoint. High-pressure safety controls (DWK – DBK – SDBK) Oneapplicationforhigh-pressurecontrols is the high-pressure protection. The EN 378 standard specifies that a high-pressurecontrolmustalwaysbe fitted in a commercial refrigeration system.Itspurposeistoswitchoffthe compressor, which is normally the primary source of pressure in a compressor refrigeration system. If the allowableoperatingpressurehasbeen reachedandanoverpressuresituation arises,thecompressorisswitchedoff by the high-pressure control and the pressure on the high-pressure side decreases. High-pressure safety controls for this purposeareclassifiedintothreetypes: withautomaticreset(DWK),withmanual resetbyhand(DBK)andbytool(SDBK). Ontheotherhand,acoil(AC15),such asthecoilofasolenoidvalve,actsas aninductiveloadonthecontactsofa pressurecontrol. Electrical connection A standard pressure control with changeover contacts normally has threecontactstowhichtheconductors oftheelectricalcablecanbeconnected. Thefunctionsofthesethreecontacts are‘phasein’,‘fault’,and‘phaseout(to the motor)’. If only two contacts are wired,itdoesnotmakeanydifference which of the two phase contacts is connectedtoeachconductor. The ‘fault’ contact is rarely used. It could possibly be used for a fault indication,suchasdr2012-04-20T08:45:48+02:00http://danfoss.ipapercms.dk/refrigerationandairconditioning/RA/CoolingMatters/IE/CoolingMattersVolume12012/?Page=11http://danfoss.ipapercms.dk/refrigerationandairconditioning/RA/CoolingMatters/IE/CoolingMattersVolume12012/?Page=11thefaultfunction,aconnectioncanbe madetocontact2(pleasenotethatin caseofpumpdownthefaultcontactis active).Hereitisimportanttonotethe connectionsfortheKP7high-pressure controlarenotthesame.Althoughthe ‘phase in’ connection is still contact 1, the ‘phase out’ connection is contact 2,whilecontact4isforthefaultsignal. This may appear confusing, but it is easy to explain the logic of this for service fitters, using the KP pressure controlasanexample.Afterremoving theplasticcover,youwillseethesetof contactsattheright.Theyarelabelled ‘1’,‘2’and‘4’.WithaKP1low-pressure control, contact 4 is at the top and contact2isatthebottom.Theswitchoffconditionoccurswhenthepressure drops(forexample,duetoashortage of refrigerant). As the bellows of the pressurecontrolalwaysmovesupward with increasing pressure (the bellows expands) and downward with decreasing pressure, switch-off must occurwhenitmovesdownward.This meansthatcontacts1and4ofaKP1 shouldbeusedfortheconnectingcircuit between the AC mains and the compressor. Refrigeration circuit connection When connecting a wall-mounted pressure control to the refrigeration circuit, you should pay particular attentiontothefactthathigh-pressure controls for safety functions (such as KP7W, KP7B, KP7S, and KP7BS) must always be connected using a branch linewithaninsidediameterofatleast 4 mm. In other words, 6-mm copper tubing must be used. Of course, it is also possible to use a special plastic connection line for refrigeration systems,suchashasbecomefashionable in the last 15 years, with an inside diameterofatleast4mm. plateattacheddirectlytothebellowsin ordertosimulateanupwardmotionof the bellows (increased pressure). This testshouldbeperformedwithextreme care,anditshouldonlybeperformed underexceptionalcircumstances. IP protection class TheIPprotectionclasscanalsobean important consideration, depending on local circumstances and ambient conditions. The first digit of the IP protection class code (e.g. ‘IP54’) stands for the degree of protection against object penetration, while the seconddigitstandsforthedegreeof protectionagainstwater.AnIPclassof IP4xmeansthatitmustnotbepossible forawirewithadiameterof1mmto penetratethedevice.IPx4meansthat the device is suitable for use with splashedwaterfromalldirections. Generallyspeaking,itcanbesaidthat the higher the protection class, the betterthedeviceisprotectedagainst dust,dirtparticlesandmoisture. StandardDanfossKPpressurecontrols have a protection class of IP33 with respect to the effects of dust and moisture if they are not fitted with a top cover. If the top cover provided withthecontrolisfitted,theprotection classisincreasedtoIP44. A protection class of IP55 can be achievedbyusinganaccessoryprotectivehousing.IfanevenhigherIPprotection class is desired, you can use the RT series, which is designed for especiallyharshenvironments. The controls in this series have a protectionclassof54to66,depending onthemodel. Pressostats for condenser fan control andlow-pressurecontrolscanalsobe connected using capillary tubing, although many system builders always use 6-mm copper tubing or alternativeplastictubingforallpressure controls for the sake of appearance and to avoid unintentional blockage orpinchingofcapillarytubing. Manual testing A manual test of switch operation should only be performed in exceptionalcases.Ifsuchatestisabsolutely necessary,itcanbeperformedwitha KP pressure control by inserting a screwdriverfromthefrontside. Use the screwdriver to raise the steel Bycontrast,withaKP7high-pressure controltheswitch-offoccurswhenthe bellowsmovesupward.Ascontact4is alwaysatthetopandcontact2isalways at the bottom, the conductors must be connected to contacts 1 and 2 in thiscase.Inthecaseofadualpressure control,whichcombinesahigh-pressure control and a low-pressure control (with the exception of the Danfoss KP7BS, which contains two high-pressure controls – DBK and SDBK), there areversionswithalow-pressurefault contact or two fault contacts (highpressure and low-pressur2012-04-20T08:45:48+02:00http://danfoss.ipapercms.dk/refrigerationandairconditioning/RA/CoolingMatters/IE/CoolingMattersVolume12012/?Page=12http://danfoss.ipapercms.dk/refrigerationandairconditioning/RA/CoolingMatters/IE/CoolingMattersVolume12012/?Page=12Internet News Danfoss Learning Your online access to knowledge For2years,Danfosshasbeendevelopingatrainingplatform-DanfossLearning- whichaimstosuitprofessionaltrainingrequirementswithfocusonRefrigeration& AirConditioningtechniques,products,applicationsandservices.Theprogramhas been designed to build, update and upgrade technical competency skills and thereforehelpmaximizeperformance. Whether you are an installer, wholesaler, student, technician or developer at an OEM, you can sign up to the platform and enrol in the courses. This platform is availableonline24/7,anytimefromeverywhere.Userscanaccessself-studycourses(e-lessons)aswellasface-to-facetrainingcoursesandvirtualclassrooms. Wanttostartyourtrainingprogramnow?Visitourdedicatedwebsiteat www.learning.danfoss.co.ukandsignuptodayin3simplesteps; • Step1–Sign-upasanewmember:youwillgetapersonalUsernameandPassword • Step2–Loginandyou’llbedirectedtoyourpersonalhomepage • Step3–Enrolinacourse…andstartyourlearningexperiencewithDanfossLearning Registrationandaccesstotheon-linecontentofDanfossLearningiscompletelyfree. Therearecurrently19eLessonmodulesavailableinEnglishtohelpyouimproveyourrefrigerationskills.TheseincludeBasic Refrigeration Techniques, Basic Compressors, Carbon Dioxide as a Refrigerant, Cold Room Modules, Refrigeration Fundamentalsandmanymore. Visit Danfoss Learning today and get started. Free registration and free eLessons at www.learning.danfoss.co.uk Contact DANFOSSA/S Nordborgvej81 6430 Denmark WWW-Address:>www.danfoss.com E-mailAddress:>danfoss@danfoss.com Danfosscanacceptnoresponsibilityforpossibleerrorsincatalogues,brochuresandotherprintedmaterial.Danfossreservestherighttoalteritsproductswithoutnotice.Thisalsoappliestoproductsalreadyon orderprovidedthatsuchalterationscanbemadewithoutsubsequentialchangesbeingnecessaryinspecificationsalreadyagreed.Alltrademarksinthismaterialarepropertyoftherespectivecompanies.Danfoss andtheDanfosslogotypearetrademarksofDanfossA/S.Allrightsreserved.2012-04-20T08:45:48+02:00