Oxymitter 4000

 

HEATER T/C

 

DIAGNOSTIC

HEATER

SW2

ALARMS

O2 CELL

ON

 

 

CALIBRATION

 

CALIBRATION RECOMMENDED

Instruction Manual

IB-106-340 Rev. 3.0

December 2003

e. Fault 5, Open Heater

Figure 8-7shows 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,

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

pauses for three seconds, and repeats.

1.

Remove power.

2.

Remove the electronic assembly per

 

paragraph 9-4d,Electronic Assembly

 

Replacement.

3.

Using a multimeter, measure across

 

the heater connector J8.

4.

The measurement should be approxi-

 

mately 72 ohms. If the heater is open,

KEYPAD

Alarms

O2 Heater Open

LOI

37260023

Figure 8-7. Fault 5, Open Heater

see paragraph 9-4h,Heater Strut

Replacement.

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 as- sembly.

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

Rosemount Analytical Inc. A Division of Emerson Process Management

Troubleshooting 8-9