28142 Rev 15 ADJUSTMENT
Gentherm Global Power Technologies Page 46
Measured
V
SET
Measured
CO
State Adjustment Required
> V
SET REF
< 800ppm
TEG is over-
fired
Air shutter unchanged. Turn fuel pressure down
to decrease V
SET
. Wait 15-20 minutes, then re-
evaluate.
> 800ppm
Not enough
air
Open air shutter until CO falls below 800ppm.
Leave fuel pressure unchanged. Wait 15-20
Minutes, then re-evaluate.
< V
SET REF
< 800ppm
TEG is
under-fired
Turn fuel pressure up to increase V
SET
. Air
shutter unchanged. Wait 15-20 minutes, then
re-evaluate.
> 800ppm
Not enough
air
Open air shutter until CO falls below 800ppm.
Leave fuel pressure unchanged. Wait 15-20
Minutes, then re-evaluate.
= V
SET REF
± 0.2V
< 800ppm
TEG is
properly
tuned.
Tighten regulator adjustment screw locknut,
replace cap. Tighten air shutter screws. Record
final readings, return TEG to RUN mode,
reconnect the load, and close the cabinet.
> 800ppm
Not enough
air, TEG is
under-fired
Open air shutter and increase fuel pressure
slightly. Wait 15-20 Minutes, then re-evaluate
Figure 25 – TEG Tuning Guide
Example:
The TEG has been running for more than 90 minutes and is connected in SETUP mode. The
breaker connecting the TEG to the load and station battery is switched off. The TEG is running
on natural gas at 140 kPa. Ambient temperature is 10°C, so target power is 218W. This
corresponds to a target V
SET
of 14.8V. A combustion analyzer is used to read CO levels of
7900ppm, and the measured V
SET
from the TEG is 15.3V. There is no flame in the exhaust.
Since the measured V
SET
of 15.3V is greater than our target of 14.8V, and the CO is higher
than 800ppm, we know from the table above that the TEG is not getting enough air. The
correct response is to open the air shutter in small increments until we see the CO drop below
800ppm. V
SET
will also drop, and we can re-evaluate both the voltage and emissions after
waiting 15-20 minutes for readings to settle.
Suppose after waiting 20 minutes, we return and read V
SET
at 14.7V, with CO at 520ppm.
Since our measured V
SET
is within 0.2V of our required 14.8V, and our CO is under 800ppm,
the TEG is properly tuned and making rated power for the ambient temperature. We can
tighten the regulator adjustment locknut, replace the regulator cap, tighten the air shutter
screws, record our final readings, return the TEG to RUN mode, reconnect the load and station
battery, close the cabinet, and perform final checks before leaving the site.
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