Emerson Process Management IM-106-340 Alarms O2 Heater Open, Fault 5, Open Heater

Instruction Manual

IM-106-340, Rev. 4.0

May 2006

Figure 8-7. Fault 5, Open Heater

	HEATER T/C
DIAGNOSTIC	HEATER	SW2
ALARMS	O2 CELL	ON
	CALIBRATION

CALIBRATION RECOMMENDED

Oxymitter 4000

Fault 5, Open Heater

Figure 8-7shows the electronic assembly for an Oxymitter 4000 with a membrane keypad (upper view) and a Oxymitter 4000 with an LOI (lower view).

Membrane Keypad

When Fault 5 is detected, the HEATER LED flashes once, pauses for three seconds, and repeats.

TEST

POINTS

INC INC

HIGH LOW GAS GAS

DEC DEC

O2 CELL mV +

O2 CELL mv - HEATER T/C + HEATER T/C -

CAL

TEST GAS + PROCESS - % O2

TP1 TP2 TP3 TP4

TP5

TP6

J1 RED YEL GRN ORG

1.Remove power.

2.Remove the electronic assembly per "Electronic Assembly Replacement" in Section 9: Maintenance and Service.

3.Using a multimeter, measure the resistance across the terminals of heater connector, J8.

4.The measurement should be approxi- mately 72 ohms. If the heater is open, see "Heater Strut Replacement" in Section 9: Maintenance and Service.

KEYPAD

Alarms

O2 Heater Open

LOI 37260023

LOI

When Fault 5 is detected, the LOI displays the "O2 Heater Open" message.

1.Remove power. Unscrew and remove the LOI module from the electronic assembly.

2.Perform the diagnostic steps 2 through 4 shown for the membrane keypad.

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