OPERATION
1. NORMAL OPERATION
Power SW and Controllers
Power SW ON,
Limit SW OM
Controller ON
Controller OFF
* For LED indication, ○ means 'off' ● means 'illuminated' ◐ means 'blinking'.
* The LEDs are arranged in the following order: Standby, Purge, Ignition, Pilot, Main, Modulate, Flame and Alarm atthe left
front side of the DBC2000E.
Operation of BC2000 and device
The power supply voltage is applied across Terminal 1, and 2.
When no flame signal is present, the combustion airflow switch is
opened (T14=OFF) and safety lockout circuit is closed (ON), it is
possible to start.
The blower is energized (T3). Firing rate goes to PURGE position.
Air flow switch closes (T14=ON) as soon as air flow is present.
The pre-purge timer starts counting as soon as PURGE interlock is
closed (T16=ON).
After the completion of pre-purge timing, firing rate goes to
START position.
The ignition wait timer starts counting as soon as the START
position interlock is closed (T17=ON).
After completion of the ignition wait timing, the Ignition sequence
starts. The Ignition transformer is energized. The Intermittent and
Interrupted pilot valve outputs are energized (T5 and T6).
When a flame is detected after the ignition trial has ended
(Safety1), the pilot stabilization time starts.
After completion of the pilot-stabilization time, the Main valves
are energized (T7=ON). Note: Enhanced Model: also (T12=ON).
The Main trial for ignition takes place (Safety2).
After completion of the main trial time, Interrupted pilot valve is
deenergized (t5=OFF). The Main stabilization time starts.
After completion of the main stabilization time, the firing rate
goes to modulation position and releases control to an external
modulation device.
The intermittent pilot valve and main valves are deenergized
(T6=OFF and T7=OFF). Note: Enhanced Model: also (12=OFF)".
Firing rate moves to PURGE position.
The post-purge timing takes place.
After the completion of the postpurge time, the blower is
deenergized and firing rate moves to START position.
After the air flow switch goes OFF, DBC2000E returns to the
STANDBY condition, waiting for the next heat demand.
Indicator LED *
●○○○○○○○
●●○○○○○○
●○●○○○●○
●○○●○○●○
●○○○●○●○
●○○○●○●○
●○○○○●●○
●●○○○○○○
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ENS7003R0 KO06 2010