Instruction Manual
IB-106-340C Rev. 4.1
July 2004
8-10 Troubleshooting Rosemount Analytical Inc. A Division of Emerson Process Management
Hazardous Area Oxymitter 4000

LOI

KEYPAD

DIAGNOSTIC
ALARMS
TEST
POINTS
HEATERT/C
HEATER
O2 CELL
CALIBRATION
CALIBRATION RECOMMENDED
O2 CELL mV +
O2 CELL mv -
HEATERT/C +
HEATERT/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
37260024
AlarmsVery Hi O2 Temp
Figure 8-8. Fault 6, High High Heater Temp
f. Fault 6, High High Heater Temp
Figure 8-8 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 6 is
detected, the HEATER LED flashes twice,
pauses for three seconds, and repeats.
1. T he high high heater temp alarm will
activate when the thermocouple pro-
duces a voltage of 37.1 mV
[900°C (1652°F)].
2. T he triac and the temperature control
may be at fault.
3. Rem ove power. Allow Hazardous Area
Oxymitter 4000 to cool for five minutes.
Restore power.
4. If the condition repeats, replace the
electronic assembly per paragraph
9-4c.1, Electronic Assembly
Replacement.
LOI. When Fault 6 is detected, the LOI
displays the “Very Hi O2 Temp” message.
1. T he very high O2 temperature alarm
will activate when the thermocouple
produces a voltage of 37.1 mV
[900°C (1652°F)].
2. T he triac and the temperature control
may be at fault.
3. Rem ove power. Allow the Oxymitter
4000 to cool for five minutes. Restore
power.
4. If the condition repeats, replace the
electronic assembly per paragraph
9-4c, Electronic Assembly Replace-
ment.