Emerson Process Management OXYMITTER 4000 - Manual (Page 109)

Instruction Manual
IB-106-340C Rev. 4.1
July 2004
Rosemount Analytical Inc. A Division of Emerson Process Management Troubleshooting 8-13
Hazardous Area Oxymitter 4000
Alarms
O2 Temp Hi
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
37260027
Figure 8-11. Fault 9, High Heater Temp
i. Fault 9, High Heater Temp
Figure 8-11 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 9 is
detected, the HEATER LED flashes five
times, pauses for three seconds, and
repeats.
1. If the thermocouple produces a voltage
in excess of approximately 30.7 mV,
the high heater temp alarm activates.
2. The 4-20 mA signal returns to the
default value (4 or 20 mA).
3. This alarm is self-clearing. When tem-
perature control is restored and the
thermocouple voltage returns to the
normal range, the alarm clears.
4. If the temperature continues to rise, the
next alarm will be the high high heater
temp alarm.
LOI. When Fault 9 is detected, the LOI
displays the “O2 Temp Hi” message. Refer
to the comments and procedures in para-
graphs 1 through 4 above.
8