GE CGA 351, Руководство пользователя

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Service and Maintenance 5-5
December 2004
Checking the Oxygen
Sensor
If the thermocouple voltage was within the normal range, the
troubleshooting sequence should continue here.
Note:
For information regarding component locations and/or wiring
connections in an optional enclosure, see Appendix C.
1.
Disconnect the oxygen sensor (
O2
) leads (white
+
,
-
) from
terminal block
TB2
.
2.
Using a digital multimeter, measure the resistance between the
two disconnected oxygen sensor leads.
3.
If the measurement indicates an open loop (OL), adjust the clips to
make certain they are making good contact with the oxygen sensor
and take another reading. If an open loop is still measured, the
oxygen sensor is defective and must be replaced.
Note:
A cold sensor will always indicate an open loop (OL).
If the oxygen sensor tests good, proceed to the next section to
continue the troubleshooting procedure.
Checking the Sensor
Furnace
If the sensor furnace operating temperature was too low, the
troubleshooting sequence should resume here.
Note:
For information regarding component locations and/or wiring
connections in an optional enclosure, see Appendix C.
1.
Disconnect the sensor furnace (
HEATER
) leads (white
1
,
2
) from
terminal block
TB2
.
2.
Using a digital multimeter, measure the resistance across the
disconnected sensor furnace leads. One of the conditions listed in
Table 5-3 below should occur.
Note:
The sensor furnace impedance may also be checked in the
User Program . Proceed to the Diag>Impedance prompt, as
described on page 4-37 (also, see Figure 3-2 on page 3-9),
and display the current value.
3.
If the sensor furnace is good, reconnect the sensor furnace leads to
terminal block
TB2
.
Based on the recommended action in Table 5-3 above, proceed to the
appropriate section for further instructions.
Table 5-3: Sensor Furnace Resistance Reading
Resistance Reading Recommended Action
approx. 66 ohms
The sensor furnace is good - check the
furnace voltage input (see page 5-6).
open loop (OL)
The sensor furnace is bad - replace the
sensor furnace (see page 5-18).
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