Instruction Manual

Watlow EZ-ZONE
®
PM Limit Controller • 88 • Appendix
Indication Description Possible Cause(s) Corrective Action
[Li;h1] Limit High
Sensor input above high limit
set point
•Temperatureisgreaterthanlimitset
point
•LimitoutputslatchandrequireReset
•Incorrectalarmsetpoint
•Checkcauseofovertemperature
•Clearlimit
•Establishcorrectlimitsetpoint
NoDisplay NodisplayindicationorLED
illumination
•Powertocontrollerisoff
•Fuseopen
•Breakertripped
•Safetyinterlockswitchopen
•Separatesystemlimitcontrolacti-
vated
•Wiringerror
•Incorrectvoltagetocontroller
•Turnonpower
•Replacefuse
•Resetbreaker
•Closeinterlockswitch
•Resetlimit
•Correctwiringissue
•Applycorrectvoltage,checkpart
number
No Serial Communi-
cation
Cannot establish serial com-
munications with the con-
troller
•Addressparameterincorrect
•Incorrectprotocolselected
•Baudrateincorrect
•Parityincorrect
•Wiringerror
•EIA-485converterissue
•IncorrectcomputerorPLCcommuni-
cations port
•Incorrectsoftwaresetup
•Terminationresistormayberequired
•Setuniqueaddressesonnetwork
•Matchprotocolbetweendevices
•Matchbaudratebetweendevices
•Matchparitybetweendevices
•Correctwiringissue
•Checksettingsorreplaceconverter
•Setcorrectcommunicationport
•Correctsoftwaresetuptomatchcon-
troller
•Place120ΩresistoracrossEIA-485
on last controller
Temperature runway Process value continues to
increase or decrease past
set point.
•Controlleroutputincorrectlypro-
grammed
•Thermocouplereversewired
•Controlleroutputwiredincorrectly
•Shortinheater
•Powercontrollerconnectiontocon-
troller defective
•Controlleroutputdefective
•Verifyoutputfunctioniscorrect(heat
or cool)
•Correctsensorwiring(redwirenega-
tive)
•Verifyandcorrectwiring
•Replaceheater
•Replaceorrepairpowercontroller
•Replaceorrepaircontroller
[`100]DeviceError
[rEtn]
Controller displays internal
malfunction message at
power up.
•Controllerdefective
•Misswiredinputorgroundloop
•Replaceorrepaircontroller
•Correctwiringorremovegroundloop
circuit
Menus inaccessible
Unable to access [`SEt],
[OPEr], [FCty] or [ProF]
menus or particular prompts
in Home Page
•LockoutorSecuritysettoincorrect
level
•Digitalinputsettolockoutkeypad
•Customparametersincorrect
•ChecklockoutsettinginFactoryPage
•Changestateofdigitalinput
•ChangecustomparametersinFactory
Page
EZ-Key/s doesn’t
work
EZ-Key does not activate re-
quired function
•EZ-Keyfunctionincorrect
•EZ-Keyfunctioninstancenotincor-
rect
•Keypadmalfunction
•VerifyEZ-KeyfunctioninSetupMenu
•Checkthatthefunctioninstanceis
correct
•Replaceorrepaircontroller
[ual;l]
Value to low
Value to low to be displayed
in4digitLEDdisplay
<-1999
•Incorrectsetup •Checkscalingofsourcedata
[ual;h]
Value to high
Value to high to be displayed
in4digitLEDdisplay
>9999
•Incorrectsetup •Checkscalingofsourcedata