Daikin AZQS100B8V1B - Checking Refrigerant Piping; Checking Refrigerant Piping: Setup; To Check for Leaks

6Installation
Installerreferenceguide
14
AZQS100~140B8V1B+AZQS100~140B7Y1B
Splitsystemairconditioners
4P3855291–2014.08
6.4.9 Todetermineifoiltrapsarerequired
Ifoilflowsbackintotheoutdoorunit'scompressor,thismightcause
liquidcompressionordeteriorationofoilreturn.Oiltrapsintherising
gaspipingcanpreventthis.
If Then
Theindoorunitisinstalled
higherthantheoutdoor
unit
Installanoiltrapevery10m(height
difference).
a
b
10 m
aRisinggaspipingwithoiltrap
bLiquidpiping
Theoutdoorunitis
installedhigherthanthe
indoorunit
OiltrapsareNOTrequired.
6.5 Checkingtherefrigerantpiping
6.5.1 Aboutcheckingtherefrigerantpiping
Theoutdoorunit'sinternalrefrigerantpipinghasbeenfactorytested
for leaks. You only have to check the outdoor unit's external
refrigerantpiping.
Beforecheckingtherefrigerantpiping
Makesuretherefrigerantpipingisconnectedbetweentheoutdoor
unitandtheindoorunit.
Typicalworkflow
Checking the refrigerant piping typically consists of the following
stages:
1 Checkingforleaksintherefrigerantpiping.
2 Performing vacuum drying to remove all moisture, air or
nitrogenfromtherefrigerantpiping.
If there is a possibility of moisture being present in the refrigerant
piping (for example, rainwater may have entered the piping), first
carryoutthe vacuumdryingprocedure below untilallmoisture has
beenremoved.
6.5.2 Precautionswhencheckingthe
refrigerantpiping
INFORMATION
Also read the precautions and requirements in the
followingchapters:
▪ Generalsafetyprecautions
▪ Preparation
NOTICE
Use a 2stage vacuum pump with a nonreturn valve that
can evacuate to a gauge pressure of −100.7 kPa (5 Torr
absolute).Makesurethepumpoildoesnotflowoppositely
intothesystemwhilethepumpisnotworking.
NOTICE
Use this vacuum pump for R410A exclusively. Using the
same pump for other refrigerants may damage the pump
andtheunit.
NOTICE
▪ Connectthe vacuumpump toboththeserviceportof
the gas stop valve and the service port of the liquid
stopvalvetoincreaseefficiency.
▪ Makesurethatthegasstopvalveandliquidstopvalve
are firmly closed before performing the leak test or
vacuumdrying.
6.5.3 Checkingrefrigerantpiping:Setup
a
c
f
b d e
R410A
a Pressuregauge
b Nitrogen
c Refrigerant
d Weighingmachine
e Vacuumpump
f Stopvalve
6.5.4 Tocheckforleaks
NOTICE
DoNOTexceedtheunit'smaximumworkingpressure(see
"PSHigh"ontheunitnameplate).
NOTICE
Make sure to use a recommended bubble test solution
from your wholesaler. Do not use soap water, which may
causecrackingofflarenuts(soapwatermaycontainsalt,
which absorbs moisture that will freeze when the piping
gets cold), and/or lead to corrosion of flared joints (soap
water may contain ammonia which causes a corrosive
effectbetweenthebrassflarenutandthecopperflare.
1 Chargethesystemwithnitrogengasuptoagaugepressureof
at least 200 kPa (2 bar). It is recommended to pressurize to
3000kPa(30bar)inordertodetectsmallleaks.
2 Check for leaks by applying the bubble test solution to all
connections.
3 Dischargeallnitrogengas.
INFORMATION
Afteropeningthestopvalve,itispossiblethatthepressure
intherefrigerantpipingdoesNOTincrease.Thismightbe
causedbye.g.the closed state of the expansion valvein
theoutdoorunitcircuit,butdoesNOTpresentanyproblem
forcorrectoperationoftheunit.