Watlow EZ-ZONE
®
PM PID Controller
•
89
•
Appendix
Indication
Description
Possible Causes
Corrective Action
Process doesn’t control to set
point
Process is unstable or never
reaches set point
• Controller not tuned correctly
• Control mode is incorrectly set
• Control set point is incorrect
• Perform autotune or manually
tune system
• Set control mode appropriately
(Open vs Closed Loop)
• Set control set point in appro
-
priate control mode and check
source of set point: remote, idle,
profile, closed loop, open loop
Temperature runway
Process value continues to in-
crease or decrease past set
point.
• Controller output incorrectly
programmed
• Thermocouple reverse wired
• Controller output wired incor
-
rectly
• Short in heater
• Power controller connection to
controller defective
• Controller output defective
• Verify output function is correct
(heat or cool)
• Correct sensor wiring (red wire
negative)
• Verify and correct wiring
• Replace heater
• Replace or repair power con
-
troller
• Replace or repair controller
[`100]
Device Error
[rEtn]
Controller displays internal mal-
function message at power up.
• Controller defective
• Replace or repair controller
Menus inaccessible
Unable to access
[`SEt]
,
[OP-
Er]
,
[FCty]
or
[ProF]
menus
or particular prompts in Home
Page
• Security set to incorrect level
• Digital input set to lockout
keypad
• Custom parameters incorrect
• Check lockout setting in Fac
-
tory Page
• Change state of digital input
• Change custom parameters in
Factory Page
EZ-Key doesn’t work
EZ-Key does not activate re-
quired function
• EZ-Key function incorrect
• EZ-Key function instance not
incorrect
• Keypad malfunction
• Verify EZ-Key function in Setup
Menu
• Check that the function in
-
stance is correct
• Replace or repair controller
