ABB AO2040 - Page 336

336 AO2000 CONTINUOUS GAS ANALYZERS | OI/AO2000-EN REV. B
Pressure regulator fault
Unstable pressure values
• Adjust external pressure of the supply gases such that the output varia-
ble
for instrument air (output) is approx. 60 %,
for combustion air (Air) is approx. 55 %,
for combustion gas (H2) is approx. 42 %.
• Have the pressure regulator modules checked.
Pressure regulator output variables not equal to set points
Air
Output variable ≤ 50 %
• Reduce combustion air primary
pressure.
Output variable ≥ 90 %
• Increase combustion air primary
pressure
H2
Output variable ≤ 40 %
• Reduce combustion gas primary
pressure.
Output variable ≥ 90 %
• Increase combustion gas primary
pressure.
Input
Output variable ≤ 50 %
• Reduce sample gas inlet pressure
Output
Output variable ≤ 50 %
• Increase the instrument air pressure
• Clean air jet injector (see page 281).
• Reduce length of the gas discharge
line or increase cross-section.
Output variable ≥ 90 %
• Reduce instrument air pressure.
Zero drift
Sample gas line contaminated
• Clean sample gas line.
Combustion air catalyst is not operating adequately
• Reduce hydrocarbon content.
• Exchange catalyst.
Combustion gas line contaminated
• Clean combustion gas line.