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LMV2635.EN.202001_V2
4.5 Control panel
The control panel includes all electrically controlled operation, monitoring and
control units of the burner, air fan, gas train, boiler and other secondary connected
devices. The electric circuits of all devices and units are connected to the control
panel in such a way that the total system can operate safely.
These circuits can be classified into the following main groups:
•
Boiler/safety circuit.
•
Thermostat (start) circuit.
•
Burner control.
•
Load control.
•
External control (Fiduface).
•
Failure indicator lights.
•
Motor groups/fuses.
•
Control switches and reset buttons.
•
Optional CO
2
-circuit and CO-detector circuit.
4.6 Control switches and reset buttons on the control panel
The control panel includes a few switches and press button valves:
•
Fire on/off switch.
•
Selector switch for load control with the following two options:
1 = Automatic, modulated by load controller.
2 = External, the burner load and on/off status is controlled by the climate or
process computer.
•
Reset, resets all failures.
The following control panel switches are optional:
•
Selector switch gas/oil.
•
Selector switch heat/steam.
•
CO
2
dosing on/off.
•
Flue gas valve open/closed.
4.7 Frequency control
A circuit in the control panel controls the air fan electromotor. A frequency control
unit, not included on the control panel, controls the air fan rotational speed based on
the burner load. The speed is controlled directly from the burner control unit by
sending a 0-10 V/4-20 mA signal to the frequency control unit.
Common settings:
Frequency for low flame approx. 25 Hz (= ± 1400 cycles).
Frequency for high flame approx. 50 Hz (= ± 2800 cycles).
