15
20039847GB
See drawings Nos. A-421 K and A-442K
6.3. 2-Stage Burners (H-Burners), KP-6 H-2
The ”H” burners are equipped with a control switch 0-1-2. Switch in position 1 the burner
operates at stage 1 only controlled by control device. Switch in position 2 the burner operates
normally controlled by control devices.
When the control device (18) calls for heat an electric arc is created between ignition electrodes
(12) and the air damper servomotor (15) opens the air damper from ”closed” position (position
”
II
” of the limit switch in servomotor) to the position of stage 1 (position ”
III
” of the limit switch in
servomotor). Burner motor (6), which drives the fan (5) and the oil pump (4), starts.
After the pre-purge period has elapsed solenoid valve (7) opens. The oil spraying from the
nozzle is ignited by the electric arc. Ignition ends after the time determined by the control unit.
The burner operates at stage 1.
If the flame is not ignited within the safety time, the control unit locks out in the flame failure
position and the burner shuts down, and will not start before resetting the control unit. If the
flame is extinguished during normal operation, solenoid valve (7) closes. The burner makes one
normal attempt to start. If the flame is not ignited within the safety time, the control unit locks out
in the flame failure position and the burner shuts down, and will not start before resetting the
control unit i.e. by pressing the reset button on the control unit.
When boiler temperature or pressure exceeds the set value for control device of stage 2 (19),
the burner operates at stage 1. When the boiler temperature or pressure is below the set value
for control device of stage 2 (19), the quantity of air increases and the solenoid valve (8) closes
when the limit switch in servomotor is in position ”
V
” (pump pressure increases). The air damper
opens to the position of stage 2 (position of the limit switch ”
I
” in servomotor). The burner
operates at stage 2. When the temperature or pressure exceeds the set value for control device
of stage 2 (19), the burner switches on to the position of stage 1. When the temperature or
pressure exceeds the set value for control device of stage 1 (18), the burner shuts down (air
damper closes).
Set the control device of stage 2 (19) to a 5-10
°
C lower temperature than the control device of
stage 1 (18). If the control device of stage 2 (19) is set to a higher temperature than the control
device of stage 1 (18), the burner starts at stage 1, but operates the whole operation period at
stage 2 and shuts down direct from stage 2, when the set value for control device of stage 1 (18)
will be exceeded.
6.4. 2-Stage Burner (”H” Burner) with Preheater, KP-6 LH
When the control device (18) calls for heat, the preheater (20) heats the oil up to approx. +70
°
C.
When the oil has reached the required temperature, an electric arc is created between the
ignition electrodes (12) and the air damper servomotor (15) opens the air damper from the
”closed” position (position of the limit switch ”
II
” in servomotor) to the position of stage 1
(position of the limit switch ”
III
” in servomotor). The operation continues as on burners without
preheater.
