MGN 2800N HP 14
AIR DAMPER MOTOR - MODULATING
CONTROL BOX SEQUENCE & TIMING CHART
B
A
Start
Run
Off
Ready
For
Restart
Burner Motor
Ignition
Start Rate
Gas Valve
Main Gas Valve
(low flame on h/l)
High Flame
(h/l only)
Operation
T1
T2
T8
T3
T4
T5
T6
T7
T9
T total
Landis & Staefa SQM10
Motor SQM
10
Air Damper
Position
Cam
Factory
Setting
Full Air
Shut-off
2 0°
Low Flame
Air
3 20°
High Flame
Air
1 60°
The fully closed cam (2) is factory set and under normal circumstances should not require further adjustment.
Operation of the low and high flame air switches (cam 3 & 1) is made by manually adjustable cams. Setting
scales provided between the cams simplifies the adjustment. An additional scale at the end of the cam stack
serves as a position indicator.
The air damper assembly can be rotated manually by disconnecting from the drive motor using the lever ‘A’.
The cams should be adjusted by using the special C spanner ‘B’.
Timing
Segment
TMG 740-3 LFL1.3
Operating Mode
Timing
Segment
TMG 740-3 LFL1.3
Operating Mode
T1
40 40
Pre-purge
T6
6 12
Delay – Release to High
Flame / Modulation
T2
4 6
Pre-ignition
T7
10 18
Post-purge
T3
3
3
Safety Lockout Time
T8
8
12
Air Proving Switch Interlock
T4
Delay – Start Rate to Main Flame
T9
80
91
Total Start Time
T5
9
12
Delay – Start Rate to Main flame
T Total
90
106
Total Cycle Time of Controller
Note:
The pre-purge tomes shown above refers to the control box only. The air damper control will extend the total burner
purge time up to a maximum of 127 seconds depending on the firing rate and air requirements of the appliance.
