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6. MEASURES AND CHECKS BEFORE START-UP
Multibloc
Gas train
6.1 2-Stage or modulating burners
Ensure that the ignition and ionisation electrodes are correctly ajusted.
The sketch (see separate page) shows the correct measurements.
Gas quality
Ensure that the burner head is meant for the gas quality to be used
(see fig.).
Venting
The gas line is vented by loosening the screw on the test nipple for the
inlet pressure. Connect a plastic hose and conduct the gas into the
open air.
After having vented the gas line tighten the screw again.
Electric function test:
Ensure that phase and neutral are not reversed. The gas shut-off cock
should be closed.To prevent the gas pressure switch from locking out,
it should be linked temporarily.
After the main switch has been switched on and the thermostats have
been adjusted, the pre-purging period begins (30-35sec.). At the end of
this period the pre-ignition period starts (0,5-2,5 sec. depending on the
design of the gas control). The gas valve is energized and opens and
flame is established. At the end of the safety time (2-3 sec.) the gas
control locks out. The solenoid valve and the motor will be ”dead”. Re-
move the link from the gas pressure switch after the test is finished.
Note on 2-stage and modulating burners that during the pre-purging
period the damper opens to the set value for air on stage 2 and just be-
fore the end of the pre-purging period it goes down to the air setting for
stage 1. On some burners under 350kW the pre-purging mainly takes
place with the air damper set for stage 1.
NOTE! Applies only to gas burner control LFL1.
When using LPG (Propane) the burner should be connected for post-
purging. Move the connection on terminal 6 to terminal 7 in the base of
LFL1.
Leakage control
When making a leakage control of the gas supply system, the solenoid
valve should be closed. Connect a pressure gauge to the test nipple
Pa, see fig. The test pressure in the system should be 1,5x max. inlet
pressure or min. 150 mbar. If any leakage, locate the source by means
of soapy water or a leak location spray. After tightening repeat the test.
Inner assembly
