Emerson OXYMITTER 4000 - Manual (Page 115)

Instruction Manual
IB-106-340 Rev. 3.0
December 2003
Rosemount Analytical Inc. A Division of Emerson Process Management Troubleshooting 8-11
Oxymitter 4000
LOI
KEYPAD
DIAGNOSTIC
ALARMS
TEST
POINTS
HEATER T/C
HEATER
O2 CELL
CALIBRATION
CALIBRATION RECOMMENDED
O2 CELL mV +
O2 CELL mv -
HEATER T/C +
HEATER T/C -
INC INC
DEC DEC
HIGH
GAS
LOW
GAS
CAL
TEST GAS +
PROCESS -
% O2
SW2
TP1
J1
TP2
TP3
RED YEL GRN ORG
TP4
TP5
TP6
ON
37260025
Alarms
Board Temp Hi
Figure 8-9. Fault 7, High Case Temp
g. 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 de-
tected, The HEATER LED flashes three
times, pauses for three seconds, and re-
peats.
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 re-
quirements or that heat due to convec-
tion 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 dis-
plays the “Board Temp Hi” message. Refer
to the comments in paragraphs 1 through 4
above.