2.4.
2.4.
Automated functions in a modulating burner, oil fuel
Automated functions in a modulating burner, oil fuel
2.4.1
2.4.1
Sequence point 1. Prerequisites for start-up
Sequence point 1. Prerequisites for start-up
.
Failures and interlocks are reset
.
Limit switch on burner flange is closed
.
Control unit is reset (lockout indicator at symbol
◄
)
.
Control switch in position 2, 3, 4 or 5 (A) *M*
.
Contact of burner switch-on/switch-off level in capacity controller is closed or it is by-
passed with manual operation position 3, 4 or 5 of control switch (A)
.
Contact of boiler thermostat or pressurestat closed
.
Preheater control switch in position 1 (heating ON)
.
Required start signal from the limit switch of the switching point II in the servomotor to
terminal 8 in the control unit
.
oil temperature > min. or temperature controller (min.) by-passed (light fuel oil)
.
Contact C/NC of differential air pressure switch is closed (differential air pressure <
min.)
.
Contacts of the low oil pressure switch connected to the control circuit are closed
.
External contacts connected to the control circuit are closed
.
Start signal at terminal 12 in control unit.
2.4.2
2.4.2
Sequence point 1.1. Start-up (lockout indicator of the control unit is at symbol
◄
)
Sequence point 1.1. Start-up (lockout indicator of the control unit is at symbol
◄
)
.
Control loop closes
.
Control program (sequence switch) of control unit starts.
.
Checking of the flame detection circuit is in process
2.4.3
2.4.3
Sequence point 2
Sequence point 2
.
Fan motor starts
.
Oil pump motor starts
.
Main oil valve opens and purging of nozzle valve with warm oil begins.
.
After the differential air pressure switch has changed over its contact to position C/
NO pre-ignition begins (differential air pressure > min.).
2.4.4
2.4.4
Sequence point 3. Lockout indicator of the control unit is at symbol
▲
Sequence point 3. Lockout indicator of the control unit is at symbol
▲
.
Servomotor runs to switching point I (air dampers are open)
.
Sequence switch does not operate during the running time.
2.4.5
2.4.5
Sequence point 4. Servomotor has run to switching point I (Air smapers are open)
Sequence point 4. Servomotor has run to switching point I (Air smapers are open)
.
Start signal from the limit switch of switching point I to terminal 8 in control unit.
Otherwise the start-up program interrupts and the control unit remains (symbol
▲
)
waiting for start signal (no failure).
.
Pre-purge (22,5 s) with nominal air quantity begins.
16 (77)
RPMARINES 30820641GB
2. Burner operation
