Honeywell DBC2000 Series - WIRING DIAGRAMS FOR EXTERNAL EQUIPMENT; Ignition and Firing Rate Control Wiring Examples; Flame Detector Wiring Configurations

ENS7003R0 KO06 2010
OPERATION
1. NORMAL OPERATION
Power SW and Controllers
Operation of BC2000 and device Indicator LED *
Power SW ON,
Limit SW OM
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.
●○○○○○○○
Controller ON 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.
●○○○○●●○
Controller OFF 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.
* 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.