Repair manual

Burner Setup Cub 200/300
16 ghi_tx001317gb.fm
3 Burner Setup
3.1 Control Board Sequence of Operation
Periods The burner controller has several periods it sequences through during normal
operation. These periods are described below.
.
Period Action or Function
Prepurge (T1) As soon as the control switch (SW) is turned ON, the prepurge period
begins. It lasts approximately 10 seconds.
During this period:
 The fan blows air into the combustion chamber to expel any resid-
ual exhaust gases.
 The ignition transformer (TR) turns ON and remains ON. It pro-
duces a continuous spark across the electrodes so that any resid-
ual fuel is ignited and burned off.
 The flame control unit (cad cell) (PH) checks for presence of a
flame. If a consistent flame is detected, the ignition sequence is
interrupted and the heater locks out.
Ignition (T2) After the prepurge period, the ignition period begins. It lasts
approximately 15 seconds.
During this period:
 The fan runs.
 The ignition transformer (TR) is ON, producing a continuous spark
across the electrodes.
 The fuel solenoid (SV) opens and the fuel is ignited. The fuel sole-
noid will remain open if the cad cell (PH) detects a flame within 1
second from the start of this period. If no flame is detected, the fuel
solenoid closes and the heater locks out.