Nu-Way MDFL 3300 Installation And Maintenance Manual

Nu-Way MDFL 3300 Installation And Maintenance Manual Manual pdf 23 page image

BURNER OPERATING SEQUENCEThe MDFL burner operating sequence (refer to the controller sequence table below) begins with apre-purge period on full air. When gas is selected, the fuel is then supplied to the burner at start rateand ignition initiated. Start gas flame proving is followed by establishment of the main flame.When oil is selected, on completion of the pre-purge period the appropriate oil valve or valves open,ignition is initiated and the flame is established.In both cases, the burner controller will then continue to its normal operating position and theoperation of the burner will be controlled by the pressure and/or temperature requirements of theappliance.Time(seconds) LFL 1.333 DescriptionT1 40 Pre-purgeT2 6 Pre-ignitionT3 3 Safety lockout timeT4 Not applicable to two-stageor fully modulating operation Delay start rate to main flame – single stageT5 12 Delay start rate to main flame – multi-stageT6 12 Delay between main flame low & main flame high (two-stage burners)T7 18 Post-purgeT8 12 Air pressure switch interlockT9 91 Total start timeT total 106 Total controller cycle timeNote: The pre-purge times shown refer to the control box only. The time taken for the air damper tomove to the appropriate position will extend the total purge time up to a maximum of 157 seconds,depending on the firing rate and air requirements of the appliance.MDFL 3300 & MDFL 4000 Issue 2 08/08 Page 22