Gentherm 5220 - Maintenance; Recommended Periodic Maintenance

28142 Rev 15 ADJUSTMENT
Gentherm Global Power Technologies Page 47
Measuring CO Emissions Levels
The model 5220 will not produce excessive amounts of CO if properly adjusted. Due to the
open exhaust system of TEG, the CO measurement must be in the free air state. In a free
air measurement, the allowable CO emission rate is 800 ppm. To be able to determine the
levels of air-free CO ppm, a combustion analyzer capable of measuring CO ppm and either
CO
2
percentage, or O
2
percentage, is needed.
The equations used to calculate the air-free stage of CO are:
• For Natural Gas when using as measured CO
2
percentage, and CO
ppm
:
• For Propane when using as measured CO
2 percentage, and COppm:
• When using as measured O
2 percentage, and COppm:
[1], [2], [3] as per CSA TIL R-10
Where: CO
AFppm
= Carbon monoxide, air-free ppm.
CO
ppm
= As-measured combustion gas carbon monoxide ppm.
O
2
= Percentage of oxygen in combustion gas
CO
2
= Percentage of carbon dioxide in combustion gas
The model 5220 does not produce excessive concentrations of CO if adjusted properly.
Fuel Pressure Adjustment
Once the air is adjusted, and if the fuel system and burner appear to be operating correctly,
the fuel pressure may be slightly adjusted to match the measured V
set
voltage with the
required V
set
value. Use Figure 26 to determine how much to adjust the fuel pressure.
Example:
Required V
set
=
14.1 V
Measured V
set
=
13.5 V
Difference
=
+0.6 V
Based on Figure 26, the fuel pressure must then be increased by 3.6 kPa (0.52 PSI).