L.B. White AD100 Owner's Manual page 20

SPARK IGNITION OPERATION SEQUENCE:
— 220 volts is sent to transformer and to ignition control
terminal L1.
— 24 volts is sent from transformer to the thermostat.
— A call for heat occurs.
— Thermostat returns 24 volts to ignition control terminal
W.
— Red light on ignition control is illuminated.
— Ignition control performs an internal safe start check.
-- Internal components are tested.
-- Ignition control sends 24 volts from terminal PS1 to
the air proving switch.
— Ignition control begins safety lockout timing.
— Ignition control sends 220 volts from terminal IND to
start the fan motor for prepurge.
-- Air proving switch is checked for proper operation.
-- Air proving switch closes and 24 volts are returned
to ignition control terminal PS2.
— Ignition control powers the igniter and igniter sparks.
— Ignition control sends 24 volts to gas control through
high limit switch.
— Ignition occurs.
-- Igniter continues to spark until flame proving
occurs.
-- Igniter spark is discontinued.
-- Gas valve stays open.
— Room warms to desired temperature.
-- Thermostat is satisfied.
-- Heater shuts down.
— Process begins again on call for heat.
20
MULTIPLE IGNITION TRIAL SEQUENCE
— First trial for ignition takes approximately 10 seconds
— Two more trials for ignition will occur.
-- Second and third trial follow immediately if first
trial fails.
— Ignition control starts a 15 minute "Wait" period to allow
ignition interruption to pass.
— Ignition control repeats 3 Ignition attempts after 15
minute wait period
— If ignition control does not prove flame after third Trial, the
control goes into safety lockout (3 flash pattern).
-- Igniter shuts down
-- Fan motor stops
-- Gas valve closes
— Tp retry ignition, reset the ignition system by:
-- Unplugging the brood heater and plug it back in
-- OR --
-- Turn Thermostat to "Off" or "No Heat" and then
back to above room temperature