
ー8ー
9Troubleshooting
Trouble
Malfunction
oftable
lifting
Electricity
Valve
Reverserotationofthemotor Exchangetwoofthreecables
Slowspeed
oftable
lifting
Pump Underspecifiedcapacityowing
togearwheelwearofpump Replacethepump.
Malfunction
oftable
lowering
Electricity Disconnectionorpoor
contactingoftheliftingvalve Check,referringtotheelectriccircuit.
Repair.
Slowspeed
oftable
lowering
Liftingvalve
Cloggedfilterofthevalve
Spooltroubleinthevalve Cleanorreplacethefilter.
Repeatliftingandlowering.
Incaseofdefectivespool,replacethe
valve.
Naturalfall
after
stopping
Cylinder Oilleakagefromabrokenseal
inthecylinder Repairthecylinder.
(Replacetheseal.)
Knocking
whiletable
lifting
Liftingunit Loosenessofpins
Defectiverotatingofwheels
formoving
Repairorreplacethemainunitor
lubricate.
Lubricateorreplacethewheel.
Noisewhile
liftingand
lowering
Liftingunit Lubricationshortageatpins
andholes
Wearofbushingsorapins.
Lubricate.
Replacethebushingsorthepins.
Hydraulic
oil Airabsorptionowingto
hydraulicoilshortage Supplyhydraulicoil.
Liftingvalve
Foreignobjectinthespoolof
theliftingvalve
Spooltrouble
Removetheforeignobjectfromthe
liftingvalve.
Replacetheliftingvalve.
Checkvalve
Foreignobjectinthecheck
valve.
Defectworkingfaceofthe
checkvalve.
Replacethecombinationpump.
Pipingjoint Oilleakagefromthehigh
pressurehoseorpipes Retighteneachjoint.
Replacethesealingtape.
Liftingvalve
Openingmalfunction Overhaulorreplacethevalve.
Liftingunit Aforeignobjectontheguide
rail. Removetheforeignobject.
Lowering
valve Improperadjustmentofflow
rateoftheloweringvalve Adjusttheloweringspeedwiththe
loweringvalve
Motor Underspecifiedmotoroutput Replacethemotororcheckthevoltage
Filter Cloggedfilter Cleanthefilter,replacehydraulicoil
Cylinder Oilleakagefromabrokenseal
inthecylinder Repairthecylinder.
(Replacetheseal.)
Alwaysopenvalveowingtoa
foreignobjectinthelifting
valve
Removetheforeignobjectorreplace
theliftingvalve
Hydraulic
oil Oilshortage Supplyhydraulicoil.(Whenthetableis
atthehighestposition,oilshouldbe
10mmupfromthefiltersurface.)
Pump Malfunctionattheratedrelief
valvepressure Replacethepump.
Improperpressureadjustment
withthereliefvalve Setthepressureasdesignatedby
adjustingthereliefvalve.
(Doaslessaspossibleinprinciple)
Poorcontactingofthemagnet
switch Checktheswitchcontactandreplaceit
withanewone(withcase)ifnecessary.
Malfunctionofthemagnet
switch Coilburnout
Poorcontactingoftheswitchorcable
disconnecting
Thermalrelayisworking.
Singlephaseoperation Verifythreephaseoperation
Cause Countermeasure