Teledyne gfc 7000ta operation manual Fault Diagnosis with Test Functions, Source, System Reset

Troubleshooting	Model GFC7000TA Carbon Dioxide Analyzer
Table 11-1: Warning Messages – Indicated Failures (cont.)
WARNING	FAULT CONDITION	POSSIBLE CAUSES
MESSAGE
SAMPLE TEMP	Sample temperature is < 10oC or >	Ambient temperature outside of specified range
WARN	100oC.	Failed bench heater
		Failed bench temperature sensor
		Relay controlling the bench heater
		Failed relay board
		I2C bus
SOURCE	Occurs when CO2 Ref is <1250	GFC wheel stopped
WARNING	mVDC or >4950 mVDC.	Failed sync/demod board
		If status LED’s on the sync/demod board ARE flashing the
	Either of these conditions will result	cause is most likely a failed:
	in an invalid M/R ratio.	IR source
		Relay board
		I2C bus
		IR photo-detector
SYSTEM RESET	The computer has rebooted.	This message occurs at power on. If you have not cycled the
		power on your instrument:
		o Failed +5 VDC power,
		o Fatal error caused software to restart
		o Loose connector/wiring
WHEEL TEMP	The filter wheel temperature is	Blocked cooling vents below GFC Assembly. Make sure that
WARNING	controlled at 68 ± 2 °C	adequate clear space beneath the analyzer.
		Analyzer’s top cover removed
		Wheel heater
		Wheel temperature sensor
		Relay controlling the wheel heater
		Entire relay board
		I2C bus

10.1.2. Fault Diagnosis with TEST Functions

Besides being useful as predictive diagnostic tools, the test functions viewable from the front panel can be used to isolate and identify many operational problems when combined with a thorough understanding of the analyzer’s theory of operation (see Section 10).

The acceptable ranges for these test functions are listed in the “Nominal Range” column of the analyzer Final Test and Validation Data Sheet (p/n 04307) shipped with the instrument. Values outside these acceptable ranges indicate a failure of one or more of the analyzer’s subsystems. Functions whose values are still within the acceptable range but have significantly changed from the measurement recorded on the factory data sheet may also indicate a failure. A worksheet has been provided in Appendix C to assist in recording the value of these test functions.

Table 11-2 contains some of the more common causes for these values to be out of range.

Teledyne Analytical Instruments 221