Siemens LMV5 Quick Start Manual page 178

Step by Step Commissioning of the O2 Trim System 6-2
After verifying that the PLL52 Module, QGO20 Oxygen sensor, and ambient / stack temperature
sensors (if used) are wired correctly, and that lean-tuned Fuel-Air Ratio Curves have been
entered across the firing range, the O2 trim system can be commissioned and activated.
The following steps will serve as a guide for the commissioning process:
Note: A combustion analyzer is required to measure CO when setting the O2 Guard curve.
Most combustion analyzers read dry %O2, whereas the QGO20 Sensor reads wet O2.
The dry value will always be a higher % than the wet value.
Always use the %O2 displayed on the AZL52 for setting up the O2 trim.
1) Verify that lean-tuned Fuel-Air Ratio Control curves have been set across the firing
range for the fuel that will be trimmed. Both gas and oil can be O2 trimmed, or one
and not the other. Typically, gas is trimmed and oil is monitored since oil is usually
the back-up fuel. For either fuel, verify that the Fuel-Air Ratio curve has at least 10
points equally distributed across the firing range.
2) Verify that the load percentage on each Fuel-Air Ratio control point accurately
represents the fuel flow into the burner. This is critical to the O2 trim function. A fuel
flow meter or a manometer to measure burner pressure will be required to do this.
With the LMV52 in standby (Phase 12):
a. Set all relevant O2 trim parameters.
Complete explanations for all O2 trim parameters the can be found
in two different areas of Section 4-2:
Parameters & Display> O2 Module, and
Parameters & Display> O2 ContrGuard.
b. Under Parameters & Display > O2 Module, set O2 sensor to QGO20.
c. Under Parameters & Display > O2 Module, set the supply air temperature
sensor and the flue gas temperature sensor to the type of sensor that is
being used, if any.
These sensors are not necessary for the O2 trim operation but are necessary
for the efficiency calculation.
If they are configured and not connected, the O2 trim will not activate.
d. Under Parameters & Display > Ratio Control, set which actuators or VSD are
to be air influenced. Typically, this is only the Air Actuator.
These parameters have to be set for both fuels if O2 trim is to be used for
both fuels.
e. Under Parameters & Display > O2 Contr/Guard > Gas/Oil Settings,
set OptgMode to man deact.
f. If the O2 trim is being commissioned on gas, under Parameters & Display>
O2 Contr/Guard> Gas/Oil Settings>Type ofAirChange set to Like P air.
For light oil, set Type ofAirChange to like theory.
g. If the O2 trim is being commissioned on gas, under Parameters & Display >
O2 Contr/Guard > Gas/Oil Settings > Type of Fuel is set to naturalGasH
(above 960 Btu / Scfh) or naturalGasL below 960 Btu / Scfh).
For light oil, Type of Fuel , Oil EL should be selected.
h. Under Parameters & Display > O2 Contr/Guard > Gas/Oil Settings set
O2 CtrlThreshold to the load value (%) of Point 2 or higher if desired.
i. Under Parameters & Display > O2 Contr/Guard > Gas/Oil Settings set
LowfireAdaptPtNo 2 (combustion curve point 2) or higher if desired.
LMV5 QSG Rev 4 Sec 6 Pg 4 www.scccombustion.com