Watlow EZ-ZONE PM - Manual (Page 91)

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