Graco EcoQuip 2 - Page 27

Troubleshooting
Problem Problem
Problem
Cause Cause
Cause
Solution Solution
Solution
Theabrasiveballvalveis
closed.
SeeSettingUptheEquipment,page14.
Theabrasivemeteringvalve
isnotproperlyset.
SeeSettingUptheEquipment,page14.
Thepotdoesnothavea
suf󰘰cientamountofabrasive.
SeeRe󰘰llingthePotwithAbrasive,page21.
Thepinchvalvedoesnot
open.
Engagetheblastcontrolswitch(B)andcheckforactuation
ofthepinchvalve.Ifthereisnoactuation,disconnectthe
orangetubingatthepinchvalve.Ifthepinchvalveopensand
sourceairiscomingfromtheorangetubing,con󰘰rmthatthe
tubingiscorrectlyrouted.Ifthepinchvalvedoesnotopen,
replaceit.Ifthepinchvalveopensandthereisnosourceair
comingfromthetubing,inspectthemuf󰘱ersonthe4-way
valvefordebris.Ifdebrisisnotpresent,cleanorreplacethe
4-wayvalve.
Thereisanobstructioninside
thepotorinsidetheabrasive
hosebetweenthepotandthe
enclosure.
FollowDrainingthePot,page22,followedbythe
PressureReliefProcedure,page10.Withtheabrasive
hosedisconnected,inspecttheinteriorofthepinchhose
forobstructionsordebrisandreplaceifnecessary(see
ReplacingthePinchHose,page32).Removethetri-clamp
fromthebottomofthepot.Inspectthebottomofthepotand
theabrasivehoseforobstructionsordebris.
Thepotpressureistoolow.Withtheblastcontroldisengaged,allowthepottopressurize
andwaitforthepumptostall.Ifthepotpressuregaugedoes
notreach185psi(12.75bar,1.275MPa),seethe“Unableto
󰘰llorpressurizethepotwithwater”problemlistedinthistable.
WhileinBLASTmode,
withtheblastcontrol
switch(B)engaged,
airis󰘱owingfromthe
nozzlebutlittleorno
abrasiveis󰘱owingfrom
thenozzle.
Theblastpressureistoohigh.
Iftheblastpressuregaugereads160psi(11.03bar,1.10
MPa)orgreater,itmaynotbepossibletoachievegreater
than15CPMontheMediaTrak.Thisismorecommonwith
󰘰nemeshabrasiveusage.Decreasetheblastpressureto
100psi(6.9bar,0.69MPa)toseeifCPMcanbeincreased.
Theairsupplyisinadequate.
Makesuretheaircompressoriscapableofsupplying
theminimumair󰘱owrequirementforyoursystem(see
TechnicalSpeci󰘰cations,page67).Makesuretheairinlet
pressuregaugereads100-175psi(6.8–12bar,0.68–1.2
MPa).Ifthegaugedoesnotread100–175psi,checktheair
compressorforpropersetup.
Themainairregulatoris
malfunctioningorisstuck
open.
Disassemblethemainairregulatorandcheckfor
obstructions.Replaceorrepairpartsasnecessary(see
EnclosureBoxParts,page50).
Theelectricblastcontrol
circuitismalfunctioning.
Unplugthehosecableatthecontrolbox.Iftheblaststops,
inspectthehosecableforshortedwiring.Checkcontinuity
throughtheelectricblastcontrolswitch(B)(theswitchis
normallyopen).Checkforcontinuityacrossconnectorsof
therecessedplugsonthecontrolbox(thereshouldbeno
continuity).Ifallaboveitemsarefunctional,replacethe
4-Waysolenoidvalve.
Theblastcontrolswitch
(B)isnotengaged,but
blastingoccurs.
Thepneumaticblastcontrol
circuitismalfunctioning.
Engagetheemergencystop(Q).Ifblastingstops,checkthe
blastcontrolswitch(B)bydisconnectingtheyellowtubeat
theenclosuremalequickdisconnect.Thereshouldbeno
signalairunlessyouengagethecontrolswitch.Iftheswitch
isfunctioning,removetheexhaustmuf󰘱ersfromthe4-way
andcheckfordebris,cleanports,andreplacethemuf󰘱ers
ifnecessary.Ifallaboveitemsarefunctional,replacethe
4-waysolenoidvalve.
3A3489E
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