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Siemens Building Technologies
Basic Documentation LMV5...
CC1P7550en
HVAC Products
4 Burner control
13.08.2004
4.2.4 Selection of fuel
The fuel selector is given priority and has 3 positions: INT, GAS and OIL. It is connected
directly to the LMV5... basic unit.
It is possible to switch between oil and gas firing.
If the fuel selector is set to INT, either of the 2 sources can be selected: BACS
or
AZL5…
The type of fuel is selected via the menu on the AZL51…
The selection is only possible when the fuel selector is set to INT (or when no selector
is connected).
Fuel selection is continuously stored via power-Off, so that a valid fuel selection is pre-
sent when power returns.
Selection of fuel via ebus (through BACS) is only possible when the fuel selector on the
LMV51... basic unit is set to INT and, on the AZL5…, fuel selection via BACS has been
selected.
Note:
Fuel selection via BACS should be cyclically repeated.
There is no definition of priorities between fuel selection via ebus and fuel selection via
the AZL5…, which means that the selection made last will be used.
After fuel changeover, the burner control maintains or changes to standby
(
→
normal start). Now, a new start is made (provided there is demand for heat), firing
on the selected type of fuel.
If
→
direct start has been parameterized, fuel changeover can also take place on shut-
down in Phase 76. The fan will not be switched off.
Selection of fuel with
the fuel selector on the
LMV5...
Selection of fuel
on the AZL5...
Selection of fuel via
BACS (modbus /ebus
Fuel changeover