Emerson Rosemount Oxymitter 4000 Instruction Manual page 105

Instruction Manual
IM-106-340, Rev. 4.3
July 2017
Figure 8-9. Fault 7, High Case Temp
DIAGNOSTIC
CALIBRATION RECOMMENDED
HEATER
CALIBRATION
KEYPAD
Oxymitter 4000
Fault 7, High Case Temp
Figure 8-9 shows the electronic assembly for an
Oxymitter 4000 with a membrane keypad (upper
view) and an Oxymitter 4000 with an LOI (lower
view).
Membrane Keypad
When Fault 7 is detected, The HEATER LED
flashes three times, pauses for three seconds,
and repeats.
1. If the case temperature exceeds [185°F
(85°C)], the temperature control will shut
off and the 4-20 mA signal output will go to
the default value.
2. This signifies that the environment where
the Oxymitter 4000 is installed exceeds the
ambient temperature requirements or that
heat due to convection is causing case
temperature to rise above the limit.
3. Placing a spool piece between the stack
flange and the Oxymitter 4000 flange may
eliminate this problem.
4. If a spool piece does not solve the problem,
relocation is the only solution.
LOI
When Fault 7 is detected, the LOI displays the
"Board Temp Hi" message. Refer to the
comments in paragraphs 1 through 4 above.
8-13