Emerson Process Management 760004-A Internal, Pressure, Pressures, Regulator, Network test, 20 bit ADC test, 12 bit ADC test, Safety PCB test, Power supply test, Typical Operating

Instruction Manual

760004-A February 2002

Model NGA 2000 HFID

•Power supply test - Verifies that all internal DC voltages are within the required tolerances.

9.Set the desired oven setpoint in the range of 93°C to 204°C (200°F to 400°F).

•Network test - Checks the internal network interface.

•20 bit ADC test - Checks the 20-bit ADC on the Analysis Computer PCB by sending a DC signal through the Preamp PCB and reading the signal back with the 20-bit ADC.

•12 bit ADC test - Checks the 12-bit ADC on the Analysis Computer PCB by sending a DC signal and reading the signal back with the 12-bit ADC.

•Power Supply PCB test - Checks the presence of the Power Supply PCB by activating the 3-way air sole- noid.

•Safety PCB test - Checks the pres- ence of the Safety PCB by sending a command and reading it back.

•Case temperature test - Compares the temperature read between the Preamp temperature sensor and the case temperature sensor. They must be within 10°C of each other. This test sometimes fails if the case is opened. The sensor in the Preamp will take longer to cool off since it is in an en- closure. Re-running the self-test after thermal equilibrium will produce a positive result if the sensors are working properly.

•Oven/Sample Temperature test - Compares the temperature read be- tween the sample temperature sensor and the oven temperature sensor. They must be within 50°C of each other.

The self-test can be repeated at any time by activating the TEST softkey in the Self Test Results menu.

10.Wait for the Purge Air green LED to illu- minate.

11.Introduce the remaining supply gases. Perform leak check. (See Section 1-5 Specifications)

12.Set and verify the internal gas pressures.

Internal	Typical Operating
Pressure
	Pressures
Regulator
Burner Air	965 to 1103 hPa-gauge
	(14 to 16 psig)
Fuel	1516 to 1723 hPa-gauge
	(22 to 25 psig)
Sample	206 to 290 hPa-gauge
(non-adjustable)	(3.0 to 4.0 psig)

Purge air of the following specifications must be present:

Flow: 16 to 18 L/min.

Supply Pressure: 689 to 1378 hPa-gauge (10 to 20 psig)

Noncompliance could cause damage to the module. At the very least, the mod- ule's safety system, which requires a certain volume of purge air flowing through the case before allowing burner ignition, will not allow the instrument to operate. The lowest purge air flow/pressure setting possible during burner operation is preferable. Thus, the user should set the external purge air pressure initially at 689 hPa-gauge (10 psig). Check the Miscellaneous Control Parameters screen under Technical Di- agnostics, and note whether the Purge Gas (switch) variable is "ON." If it is "OFF," increase purge air supply by

69 hPa-gauge (1 psig), and recheck the Purge Gas variable until it reads "ON."

DO NOT EXCEED 1378 hPa-GAUGE (20 PSIG). If the maximum setting is reached,

3-2 Operation Rosemount Analytical Inc. A Division of Emerson Process Management