Practical Tips Danffos

7/30/2019 Practical Tips Danffos

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Danoss A/S (AC-DSL/MWA), 10 - 2006 DKRCC.PF.000.G1.02 / 520H1459 125

Practicaltips

Fitters notes Practical tips

Page

Installation requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127

The installation process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133

This chapter is devided into two sections:


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3/20

Fitters notes Practical tips - installation requirements


Practicaltips

Contents Page

Installation requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129

Tubing must be kept clean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129

Particularly damaging impurities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129

Problems caused by moisture in the system. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129

Problems caused by atmospheric air. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130

Problems caused by oil and rerigerant breakdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130

Problems caused by other impurities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130

Component and material requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130

Components. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130

Impurities and moisture. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131

Copper tubing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131

Rerigerant requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131

C o m p r e s s o r o i l r e q u i r e m e n t s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 3 2


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128 DKRCC.PF.000.G1.02 / 520H1459 Danoss A/S (AC-DSL/MWA), 10 - 2006

Notes


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Practicaltips

More and more commercial rerigeration systemsand air conditioning plants o a similar size arebuilt up around hermetic and semihermeticcompressors. These compressors, as comparedto the open type, are normally more vulnerable

to impurities in the rerigerant system and toincorrect operating conditions.

Thereore, in modern rerigeration systems, thereare special demands on the quality o installationwork and commissioning.

Ac0_0003

Ac0_0010

A well-dimensioned, correctly installed andcorrectly commissioned rerigerant system isundamental to a reliable rerigeration systemwith a long operating lie.An absolute requirement on the rerigerant

system is that it shall remain completely ree ooreign bodies (impurities).Installation work must thereore be perormedwith a high degree o cleanliness. This appliesespecially to systems containing the newrerigerants.

Ac0_0037

Moisture

Atmospheric air

Soldering ux

Rust, copper oxide, scaleMetal swar

Unstable oils

Certain uorinated solutions (e.g. R11or carbon tetrachloride)

Dirt or dust o any description.

Installation requirements

Tubing must be kept clean

Particularly damagingimpurities

Water separation and ice ormation(blockage) in the expansion valve

Acid ormation

Ageing and breakdown o the oilCorrosion

Copper precipitation (dissolved copperrom tubing deposited on bright steelparts in the compressor)

Damage to the insulating lacquer onmotor windings.

Ac0_0027

Problems caused by moisture inthe system


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Ac0_0038

Aeration

Chemical reaction between rerigerantand oil

Increased condensing pressure.

Ac0_0046

Formation o organic and inorganic acids

Corrosion

Poor lubrication

Abnormal wearOil discolouration (darkening)

Sludge ormation

Leaking discharge valves because ooil carbon deposits

Increased discharge gas temperature

Compressor damage

Motor burnout

The other impurities mentioned can cause:

Accelerated chemical processes(breakdown)

Mechanical or electrical aults

High temperature accelerates the breakdownprocesses, thereore abnormally high condensingtemperatures and, especially, abnormally highdischarge pipe temperatures must be avoided.

For the reasons just mentioned, a number orequirements must be met. Some o these aredescribed in the next chapter.

Ac0_0047

Problems caused byatmospheric air

Problems caused by oiland rerigerant breakdown

Problems caused by otherimpurities

Ac0_0048

Compressors or rerigeration and heat pumpsystems are put through a comprehensive clea-

ning process by the manuacturer so that, prac-tically speaking, all traces o moisture and otherimpurities are removed.

All other components in the system should be othe same standard.

All components must ull cleanliness require-ments. In cases o doubt, components should bechecked.

Component andmaterial requirements

Components


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Practicaltips

Ac0_0001

Impurities that might appear i componentmanuacturers are less thorough than theyshould be:

Rust and scale (loose or embedded)

Old oil

Flux

Metal swar

Moisture

Ac0_0005

Moisture in smaller quantities in componentscan be removed by simultaneous heating andblowing through with dry nitrogen (N2).

It is almost pointless to try removing otherimpurities. Components containing such impu-

rities should not be used in systems withhalogenous rerigerants.

Ac0_0049

Special copper tubing must be used or reri-gerant systems, tubing that is completely cleanand dry. In addition, the ends o tubes must behermetically sealed.

Tubing other than the type just described mustnot be used in rerigerant systems, unless it ullsthe same cleanliness requirements.

All components must remain tightly sealed untilthe moment they are installed in the system.

Ac0_0006

Rerigerants should only be purchased romaccredited distributors.Rerigerants or hermetic systems must notcontain more than:

10 ppm = 0.001% water

100 ppm = 0.01% high-boiling rerigerant

0 ppm = 0% acid

15000 ppm = 1.5% non-condensablegases

Care must thereore be exercised when usingregenerated rerigerant.

Impurities and moisture

Copper tubing

Rerigerant requirements


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Ac0_0007

Compressor oil must be approved by thecompressor manuacturer and must not containmore than 25 ppm (0.0025%) water and 0% acid.

Compressor oil requirements


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Practicaltips

Fitters notes Practical Tips - The installation process

Contents Page

I n s t a l l a t i o n p r o c e s s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 3 5

Planning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135

L o c a t i o n o m a i n c o m p o n e n t s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 3 5

Installation o rerigeration system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135

Piping installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136

Location o other components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136

Compressors in parallel installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137

Important installation processes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137

Component storage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137

Pipe cutting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138

Pipe cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138

Silver soldering (brazing) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138

Phosphor solder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139

Use o inert gas when soldering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139Economic soldering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139

Be careul with the temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140

Flare connections (copper piping) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140

Evacuation, ushing and charging. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140

N e c e s s a r y e q u i p m e n t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 4 0

Vacuum pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141

Vacuum hoses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141

First evacuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142

System vacuum test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142

Flushing and provisional leak testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142

Second evacuation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142

Provisional setting o saety equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143

Checking the electrics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143

Rerigerant charging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143

Condensing pressure too high . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144

Setting and testing saety equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144

Conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144

Setting and testing regulation equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144

Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144

Setting the high-pressure control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144

Setting the low-pressure control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144


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Notes


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Practicaltips


Process:

Planning o component location andtubing layout

Setting up o main components

Piping and component installation

Evacuation

Flushing

Pressure testing

Leak testing

Charging

Setting saety equipment

Testing saety equipment

Setting controls

Testing the complete system andreadjusting controls, etc.

Ac0_0061

Ac0_0008

Installation must be planned so that

Damage to building sections, includingcold room insulation, is minimal.

Components are located unctionallycorrectly (e.g. adequate air ow tocompressor, condenser, evaporator).

Pipe runs are as short as easibly possible.

Installation process

Planning

Main components (compressor, condenser,evaporator, etc.) must be mounted securely inposition, using the accompanying brackets and inaccordance with the manuacturers instructions.

The compressor must always be secured toa horizontal base. I vibration dampers aresupplied, they must also be tted.

Ac0_0009

Location o main components

Ac0_0004

Installation must be as rapid as possible so thatsignicant quantities o moisture, air or otherimpurities have little chance o collecting in thesystem.

Compressors and lter driers should thereore beinstalled last, immediately beore evacuating andcharging the system.

All openings into the rerigerant system - withabsolutely no exception - must be completely

sealed against air and water vapour or theduration o any pauses that might occur ininstallation work.

Installation o rerigerationsystem


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Ac0_0002

As ar as possible, piping must be horizontal orvertical. The exceptions are:

Suction lines, which can be given a slight alltowards the compressor.

Discharge lines, which can have a slight all

away rom the compressor.

Pipe xing brackets, clips, etc. must be pitchedto suit the pipe diameter and load rom compo-nents mounted in the lines.

I vibration dampers are tted to the compressor,then suitable vibration eliminators should betted to suction and discharge piping.

Oil locks must be mounted in vertical suctionlines at a pitch o 1.5 to 5 m depending onrunning time per cycle. In systems withlarge load variations it can be necessary to

introduce double risers.Suction lines must also be installed to takeaccount o oil return to the compressor.

In systems with varying loads, the demandsare particularly critical at low loads.

Ac0_0011

All components should be installed so that theyare easily accessible or service and possiblerepair.

Controls and saety equipment must be locatedso that testing and adjustment can easily beperormed using ordinary tools.

Ac0_0012

Piping installation

Location o other components


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Practicaltips


Ac0_0036

Compressors in parallel must be installed withoil equalization between compressor crankcases,otherwise whichever compressor(s) run mostwill steal oil rom the other compressor(s). Oilequalization can be introduced by installing an

equalizing tube between oil sumps. In systemswith one equalizing tube, the tube must beinstalled between compressor oil sumps andmust be o such a diameter that both oil andrerigerant vapour are able to ow through itunhindered.

With two equalizing tubes (fg. 1)One tube must be installed between compressoroil sumps, the other between compressor vapourchambers (crankcases). When installing oilequalization in either o the orms described, thecompressors must be set up in exactly the samehorizontal plane.

Oil level controls (fg. 2)Oil equalization is also possible using oil levelregulators.I these are used, the compressors can beinstalled at dierent levels. However, levelcontrols are much more expensive thanequalizing pipes.

The ollowing components are necessary with oillevel regulation:

Oil separator (1)

Pressure equalizing valve (2)

Oil reservoir (3)

Oil lter (4)

Oil level regulator (5)

Remember that each compressor must beprotected with a high-pressure control, e.g. KP7.

Compressors in parallelinstallation

Ac0_0013

All components must have a temperature notlower than that o their surroundings - beorethey are opened. This prevents condensation inthe components.

For example, components must not be installedimmediately ater they have been brought rom acold service van into a warm room.

The processes that might give rise tocontamination o rerigerant systemsare:

Component storage

Pipe cutting

Cleaning pipe ends

SolderingFlare connections

Important installation processes

Component storage


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Ac0_0014

Tubing must be cut with a pipe cutter or be sawn.Never use any kind o lubricant/coolant.

Remove internal and external burrs with a specialdeburring tool.

Avoid copper swar entering the pipe.Use calibration tools to ensure the correctdiameter and roundness.

Blow through the pipe using a blast o drycompressed air or dry nitrogen.

Never use ordinary compressed air; it containstoo much moisture. Never blow through pipingby mouth.

Piping which has been prepared or later usemust be laid ready, with sealed ends, togetherwith the other components.

Ac0_0015

Ac0_0016

Silver solder consists o 30% silver, copper, zincand tin. The melting range is just over 655C toabout 755C.

Silver solder will bind only with clean, non-oxidized metal suraces.

Clean the pipe ends with a special brush andapply ux at once, immediately beore soldering.

Silver soldering ux must be suspended in spirit,never water.

Ac0_0017

Smear a thin layer o ux around the solderingpoint ater the parts have been joined.

Silver solder can then be used to permanently

join dierent materials, e.g. brass/copper andiron/copper.

Pipe cutting

Pipe cleaning

Silver soldering (brazing)


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Practicaltips


Phosphor solder consists o 2-15% silver withcopper and phosphor. The melting range is about640C to 740C.

Flux must not be used when making phosphorsolder connections.

Phosphor solder can only be used to join copperto copper.

Ac0_0018

Ac0_0019

At the high temperatures used in soldering,oxidation products (scale) orm immediately ithe pipe comes into contact with atmospheric airwhile soldering is taking place.

An inert gas must thereore be blown through

the system during soldering. Send a slight ow odry nitrogen or another kind o inert gas throughthe tubing.

Do not begin soldering until there is no more airin the component(s) concerned.

Start the operation with a strong ow o inertgas.

Closely observe that no air ow goes into thepipe with inert gas ow.

Reduce the ow to a minimum when soldering isstarted.

Maintain this slight ow o shielding gas duringthe whole soldering process.

Soldering must be perormed with oxygen andgas, with a slight oxygen decit and a relativelylarge burner jet.

The solder must not be applied until the meltingtemperature is reached on the parts beingconnected.

Never use more solder than necessary, otherwisethere is a risk o blocking the pipe partially orcompletely.

Solder quickly so that the oxygen absorptionproperty o the ux is not impaired, i.e. or nolonger than about 15 seconds.

Ac0_0020

Phosphor solder

Use o inert gas when soldering

Economic soldering


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Ac0_0021

The temperature must not be higher thannecessary.

Thereore draw the ame back slowly when themelting temperature is reached.

External ux residue must be removed bybrushing with hot water.

Alloys based on tin or lead are not recommendedas solders or rerigerant systems.

Ac0_0022

Use only approved rerigeration copper piping.

Cut ends at right angles to the piping.

Remove all internal and external burrs.

Make the are the right size, neither too small nortoo large.

Do not compress the are so severely that itbecomes hard.

Leave nal tightening up until actual installation.

Be careul with the temperature

Flare connections(copper piping)

Ac0_0023

Vacuum pump

Vacuum gauge

Charging bottle (or service cylindercontaining rerigerant)(Vacuum pump, vacuum gauge andcharging bottle can be obtainedassembled as an evacuation andcharging board.)

Charging hoses

Leak detector

Remove moisture, atmospheric air and inert gasrom the system when evacuating.

Steps to ollow:

On completing installation work, the next stepsare:

Evacuation and rerigerant charging

Leak testing

Starting up and adjustment.

Faults, which occur ater the system has beenstarted, can necessitate:

Repair o the system.

Evacuation, fushing and

charging

Necessary equipment


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Practicaltips


Ac0_0024

The vacuum pump should be capable o quicklybringing the system pressure down to about 0.05mbar.

Pump capacity, e.g. 20 l/minute. Eectiveevacuation requires large pipe diameters.

Thereore evacuation through Schraedervalves is not advisable. Use a Quick Connectoror compressors with process tube or use theprocess connectors on the compressor suctionand perhaps the discharge stop valve.

The valve spindle must be in its mid position.

Vacuum hoses and tubes must be as short aspossible and the diameter sufciently large.

Normally, an ordinary 1/4" charging hose notmore than 1 m in length can be used.

Evacuate in two stages with rerigerant ushingbetween.

The process o evacuation, ushing and chargingis described below.

Ac0_0025

Checking the vacuum pump and hosesa) Mount the charging hoses between

charging board and compressor. Shut o theconnections between charging hoses and

compressor.b) Start the pump and allow it to suck thepressure down as ar as possible.

c) Shut o the pump rom the rest o the system.d) Stop the pump.e) Read o and register the pressure on the

vacuum gauge. The pressure must not bemore than 0.05 mbar.

) Check to ensure that the vacuum can bemaintained. I not, replace charging hosesand/or leaking valves and/or vacuum oil in thevacuum pump.

Ac0_0026

Vacuum pump

Vacuum hoses


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Evacuation rom suction side o compressor andpossibly also the discharge side.

Charging hose(s) mounted between chargingboard and compressor.

All valves, incl. solenoid valves, open.

Automatic regulating valves at maximumopening.

Evacuate system, i possible down to thepressure previously indicated by the vacuumgauge.

Ac0_0028

To be perormed as described under Checkingthe vacuum pump and hoses.I any leakage is detected:

Approximately localize the leakage byshutting o sections o the system.Retighten are and/or ange connections.Repeat evacuation.

Repeat the test until vacuum is maintained orcontinue with the next point.

Ac0_0030

Apply rerigerant pressure to the system(approx. 2 bar overpressure).

Leak-test all connections.

I leakage is detected:

Use a recycling unit and vacuum pump to

remove rerigerant rom the system.

Repair the leakage.

Repeat the process until no system leakageremains.

I overpressure remains on the system,use the recycling unit to empty it orerigerant.

Then evacuate again as described under

First evacuation.This will urther remove any air and moistureremaining in the rerigerant system.

Ac0_0029

First evacuation

System vacuum test

Flushing and provisional leaktesting

Second evacuation


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Practicaltips


Ac0_0031

Check and set high-pressure control and anyother saety equipment, incl. motor protector(setting in accordance with scale values).

Ac0_0032

Check all wiring.

Test the control system with compressormotor disconnected.

Check the direction o rotation o the motor.Swap two phases i necessary.

Ater nal evacuation, the system can be chargedwith rerigerant.

A charging board can be used or the purposeand will, with sufcient accuracy, dose the correctquantity o rerigerant or the system. High

accuracy is needed in systems without receiver.I the system has a charging valve, rerigerantcan be supplied in the orm o liquid to the liquidline. Otherwise the rerigerant can be supplied asvapour to the compressor suction stop valve withthe compressor running.

Caution:Too little superheating during the chargingprocess can cause liquid hammer in thecompressor.

Charging must be continued until no vapourormation appears in the sight glass - unlessvapour ormation is due to other aults, see thesection Trouble shooting - Fault location.I the necessary quantity o rerigerant is notknown, use the method last described.

Here however, it is necessary the whole timeto check that the condensing pressure andsuction pressure remain normal and that the

Thermostatic expansion valve superheat is nottoo low.

Ac0_0033

Ac0_0034

Provisional setting o saetyequipment

Checking the electrics

Rerigerant charging


20/20


Ac0_0035

Too high a condensing pressure during thecharging process can mean that the system hasbeen overcharged with rerigerant and must bepartly drained.

Always use the recycling unit i it becomes

necessary to drain o rerigerant.

Ac0_0039

Final setting and testing o saety equipmentmust be perormed with all mechanical andelectrical equipment installed and the system

running.

The unctions must be checked with accurateinstruments. See also the chapter TroubleShooting , section Measuring Instrumentswith reerence to the instructions or the equip-ment concerned.

I a constant-pressure valve is installed, make acoarse setting.

Set the expansion valve superheat.

Using a pressure gauge, set the constantpressure valve.

Set the capacity regulator, i installed.

Set the thermostats (using a thermometer).

Ac0_0062

Ac0_0045

Increase the condensing pressure to

permissible maximum and use a pressuregauge to set the high-pressure control.

Reduce the suction pressure to thepermissible minimum and use a pressuregauge to set the low-pressure control.

Condensing pressure too high

Setting and testing saetyequipment

Conditions

Setting and testingregulation equipment

Procedure

Setting the high-pressure control

Setting the low-pressure control

Attention:When making the above settings,constantly check whether the systemis operating normally (pressure, etc.).

Finally - ensure that correct rerigerant identi-cation labels are afxed to the system in orderthat correct uture servicing is ensured.

Date post:	14-Apr-2018
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