Settings for marathon
®
burners with mechanical linkage
dreizler A 3001 E - 18.12.2015 | A 2070 - 1.12 | EN - 09.11.2012
38
The symmetrical angle range
1 of the air damper should not be altered during alignment.
Later corrections should be carried out in the range of the gas damper and should be based on the basic
settings. The shaft (axis) of the air damper is the drive shaft of the servomotor. Functional movement pro-
cesses of the gas damper to the air damper can be derived here for the linkage.
Lead up and follow up of the gas flow is corrected by adjusting the angle
2 and/or adjusting the leverage
length of the gas damper lever.
12.4 First start-up of the burner on the boiler
12.4.1 Function check of the control process via limiter switch
Bleed the gas line.
Open and close the gas shut-off valve in quick succession.
Override the gas pressure switch.
NOTICE:
This will result in a presence of gas without the burner igniting.
Carry out the function check for the burner up to ignition and opening of the main solenoid valve.
NOTICE:
Do so with the ball tap closed.
This will eliminate the possibility of the burner continuing on to control run operation and forming the main
flame.
12.4.2 Burner start-up in MIN position
The burner is activated via the thermostat. The automatic firing sequence control programme starts up.
NOTICE:
Should the burner not ignite, the gas damper setting must be checked in case of too little gas flow.
If the main flame ignites at position MIN, activate position MAX on the boiler thermostat or burner ter-
minal board for burner adjustment.
The servomotor runs in MAX poaition and the burner increases to full load.
Any occurrence of combustion pulsation might have the following causes:
a) Excessive burner load for the boiler. Should this be the case, then the load must be reduced on the gas
pressure governor of actuator SKP25.
b) The gas damper opens significantly faster than the air damper due to an unsatisfactory leverage ratio
between the gas damper adjustment lever and the air damper adjustment lever. Should this be the
case, then the leverage ratio must be adjusted so that combustion air will be supplied before the com-
bustion gas. Alternatively, both components can be adjusted to function concurrently.
c) Conbustion air volume is too large. Should this be the case, then combustion air flow must be adjusted
at the pre-throttling valve. Preset combustion air flow by way of the suction side manual damper in the
air box, and double lock after alignment.