Instruction Manual

748297-E June 2003

Model NGA2000 HFID

3-6 SAFETY SYSTEM

The HFID Analyzer Module safety system will not allow ignition or continuous burner function unless the following conditions are pre- sent:

•The internal purge gas pressure is at least 380 hPa - gauge (5.5 psig). (Moni- tor display message, Purge Gas Pres- sure in Physical Measurements menu, for proper setting.)

•Flow rate for purge air in is at least

16 L/min. and case pressure is greater than 0.5 inches of water. (Monitor dis- play message, Purge Gas (ON) in Mis- cellaneous Control Parameters menu for correct state. Proper sealing hardware must be used in order to obtain the re- quired purge air in flow rate and case pressure).

•Five case volumes of purge air have been achieved and the three above conditions are present. The time dura- tion to achieve a safe system is a mini- mum of 6 min. The elapsed time can be monitored in the Technical Startup Ana- lyzer menu. (Monitor the Purge Air Green LED (ON), Purge Control Status (ON), or Purge Air Alarm for indication of the state of the safety system.)

As stated above, proper sealing hardware is crucial to the successful operation of the safety system. Therefore, a specific torque sequence (shown in Figure 3-3 on page 3-8) must be followed when the front panel of the module is being reinstalled after removal. All front and rear panel screws must be installed.

Note

Do not over-torque rear panel screws.

3-6 Startup and Operation

Rosemount Analytical Inc. A Division of Emerson Process Management