4.1 Overview. Emerson NGA2000 TO2

M AINTENANCE AND T ROUBLESHOOTING

4

WARNING: ELECTRICAL SHOCK HAZARD

Disconnect power to the module(s) prior to replacing components.

This equipment should not be adjusted or repaired by anyone except properly qualified service personnel.

4.1 OVERVIEW

The CLD Analyzer Module requires very little maintenance during normal operation.

Occasionally, the intake fan screen may require cleaning, refer to Section 4.3.

Also, the detector's reaction chamber and sapphire window may require cleaning, refer to

Section 4.7.

White crystal deposits on the windows of the reaction chamber and plugging of capillaries and vent are usually due to sample contaminates such as ammonia reacting with the high ozone levels and NO components. To eliminate the contaminates, the sampling system should be reworked or a preventive maintenance program developed (if dropout is not excessive). Another source of crystalline formation is contaminated air.

Several components may require replacement. These are discussed in the following sections.

4.2 F

USES

The main power fuse may require replacement.

NOTE Before replacing the fuse, remove power to the Analyzer Module.

See Figure 1-2 for the location of the Power Supply Board main power fuse, which protects

24 VDC input to the module.

748410-A

August 1999

Chemiluminescense Detector Analyzer Module

Rosemount Analytical NGA 2000

27

4

M AINTENANCE AND T ROUBLESHOOTING

Ozonator

659494

NO/NOx Solenoid

655263

Thermostat

657298

Converter Assembly 655250

See Figure 4-2

PCB Insulators

Transistor

655264

Driver

Board

655620

Signal

Board

655580

Insulator

Computer Analysis

Board 655520

Sample

Pressure

Sensor

655253

Ozone

Pressure

3

Sensor

655254

Flow Sensor

902931

Glass Tube

Connectors

1

Fan Guard

Pressure Switch 655215

Ozonator Power Supply

657716

Fan Guard

Fan

655245

2

EMI Shield

Detector Assembly 658160

See Figure 4-3

Detector Case

Insulator

Power Supply

Board 657520

Flow Balance

Metering Valve

903207

Sample

Regulator

655269

Fuse, Power

903347

LON/Power

Module

3 Ground wires from ozonator shown.

2 Flow direction of intake fan (shown) is into case. Flow direction of exhaust fan is out of case.

1

Fan guard between fan and EMI filter is on the intake fan only (shown).

F IGURE 4-1. CLD M ODULE A SSEMBLY

28

Chemiluminescense Detector Analyzer Module

Rosemount Analytical NGA 2000

748410-A

August 1999