Emerson Process Management OXYMITTER 4000 - Manual (Page 114)

Instruction Manual
IB-106-340C Rev. 4.1
July 2004
8-18 Troubleshooting Rosemount Analytical Inc. A Division of Emerson Process Management
Hazardous Area Oxymitter 4000
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
37260032
Alarms
O2 Cell Bad
LOI
KEYPAD
Figure 8-16. Fault 14, Invalid Constant
n. Fault 14, Invalid Constant
Figure 8-16 shows the electronic assembly
for a Hazardous Area Oxymitter 4000 with
a membrane keypad (upper view) and a
Hazardous Area Oxymitter 4000 with an
LOI (lower view).
Membrane Keypad. When Fault 14 is
detected, the CALIBRATION LED flashes
twice, pauses for three seconds, and
repeats.
1. After a calibration has been performed,
the electronics calculates a cell con-
stant value.
2. If the cell constant value is outside of
the range, -4 mV to 10 mV, the alarm
will activate. See paragraph 9-2, Cali-
bration, and verify the last calibration
was performed correctly.
3. Power down the Hazardous Area
Oxymitter 4000 and remove it from the
stack.
4. Replace the cell per paragraph 9-4h,
Cell Replacement.
LOI. When Fault 14 is detected, the LOI
displays the “O2 Cell Bad” message. Refer
to the comments and procedures in para-
graphs 1 through 4 above.