Additional Tips For Commissioning - Siemens LMV3 series Technical Instructions

LMV Series

Additional Tips for Commissioning


Using a fuel flow meter (temporary or permanent) for commissioning is always a good idea. If
the fuel input (heat output) increases linearly with firing rate, the PID loop in any load control
will be much more effective. A temporary, insertion type flow meter is available from SCC Inc.
for this purpose.

If burner head pressure must be used as a last resort to estimate firing rate, bear in mind that
head pressure does not increase with gas flow in a linear manner. There is a square root
relationship between the differential pressure across the burner head and the gas flow. This
relationship is very similar to how the pressure varies across a fixed orifice with an increase or
decrease in flow. Also, furnace pressure must be accounted for by hooking up both sides of the
manometer, one side to the burner head pressure and one side to the furnace pressure.

Carbon monoxide (CO) is produced when combustion is incomplete, typically due to the flame
being too rich or too lean. CO is potentially explosive when mixed with air in the right
proportions. For CO to be explosive in air, it must reach a concentration of at least 12.5%
(125,000 ppm) with an ignition source present.

If a burner is commissioned properly, actuator curves should increase smoothly with increasing
load (firing rate). Curves should always be smooth, with no sharp corners.

The best and fastest method to commission a burner with an LMV3 is to set up a small table
where the technician can have his laptop, AZL, fuel flow meter, and external flue gas analyzer all
within arm's reach. This allows the curve points to be input rapidly and accurately. If the
information is entered in the laptop point by point, a very nice startup report will also be
generated.

The ACS410 software is not as fast as using the AZL to commission the LMV3. Since this is the
case, the ACS410 is typically not used to commission the LMV3. However, the ACS410 is very
valuable when used to download a startup report (all parameter settings, fault and lockout
history, in English) and also when used to download parameter backups (the machine-language
parameter set from the LMV3). It is recommended to download both of these files after
commissioning, so that there is a backup record of all parameter and curve settings.

Pressing the Enter button and any other button on the AZL at the same time will cause the LMV3
to immediately close the fuel valves and lockout.
SCC Inc. Page 23
Technical Instructions
Document No. LV3-1000
Section 4