Model NGA2000 NDIR

Instruction Manual

748332-F April 2003

SECTION 4

MAINTENANCE AND TROUBLESHOOTING

DANGER

ELECTRICAL SHOCK HAZARD

Servicing requires access to live parts which can cause death or serious injury. Refer servicing to qualified personnel.

4-1 OVERVIEW

NDIR Analyzer Module components that may require cleaning or replacement include:

•all printed circuit boards

•power fuse

•the module fan

•the chopper motor

•the source

•the detector

•flow sensor

•case temperature sensor

•Analysis cells and optical components

•RTD - detector temp. controller

•thermal fuse

The only components that may require adjustment are the oscillator tune and shutter

balance adjustments. These are factory-set, and should be adjusted only in the following cases:

if the operator has changed sources, oscillator board or detector

if the operator disassembles the bench to any degree.

Also available for maintenance adjustment through the Front Panel display and keypad are the source current, preamplifier gain (referred to as Signal Gain on the sub-menu) and the modulation check.

4-2 PCB REPLACEMENT

Refer to Figure 4-1 on page 4-2 for locations of the Signal, Micro, Power Supply, Oscillator and optional Pressure Compensation boards.

All PCBs, except the Oscillator Board and the LON Power Board, are secured to a side of the analyzer module that folds out while interconnect wiring is still in place. Remove the securing screws and fold out the entire panel.

To remove a particular board on the fold-out panel, label and unplug all interconnect wiring, and remove securing hardware. (See to Figure 4-1 on page 4-2.) Do the reverse to install a new board. Use caution when installing connectors by observing correct position (polarity) and alignment of pins.

Rosemount Analytical Inc. A Division of Emerson Process Management

Maintenance and Troubleshooting 4-1