Figure 8-7. Fault 5, Open Heater - Emerson Oxymitter 4000 Instruction Manual

Oxymitter 4000
DIAGNOSTIC
ALARMS
CALIBRATION RECOMMENDED
TEST
POINTS
INC INC
HIGH LOW
GAS GAS
DEC DEC
KEYPAD
Alarms
O2 Heater Open

Figure 8-7. Fault 5, Open Heater

Rosemount Analytical Inc. A Division of Emerson Process Management
HEATER T/C
HEATER SW2
O2 CELL
CALIBRATION
O2 CELL mV +
TP1
O2 CELL mv -
TP2
HEATER T/C +
TP3
HEATER T/C -
TP4
CAL
TEST GAS + TP5
PROCESS -
TP6
% O2
LOI
37260023
e. Fault 5, Open Heater
Figure 8-7 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 5 is de-
tected, the HEATER LED flashes once,
J1
pauses for three seconds, and repeats.
1. Remove power.
2. Remove the electronic assembly per
3. Using a multimeter, measure across
4. The measurement should be approxi-
LOI. When Fault 5 is detected, the LOI dis-
plays the "O2 Heater Open" message.
1. Remove power. Unscrew and remove
2. Perform the diagnostic steps 2 through
Instruction Manual
IB-106-340 Rev. 3.0
December 2003
paragraph 9-4d, Electronic Assembly
Replacement.
the heater connector J8.
mately 72 ohms. If the heater is open,
see paragraph 9-4h, Heater Strut
Replacement.
the LOI module from the electronic as-
sembly.
4 shown for the membrane keypad.
Troubleshooting 8-9