L.B. White Guardian AD/AW060 Manuel Du Propriétaire page 24

24
Guardian LP or Natural Gas Heater
OPERATION SEQUENCE:
-- Line voltage is sent to transformer
-- Transformer terminal branches off line voltage to
ignition control terminal L1.
-- Transformer reduces line voltage to 24 VAC.
-- 24 VAC is sent to thermostat.
-- Thermostat closes and returns 24 volts to terminal W
on ignition control.
-- Red light on ignition control is illuminated.
-- Ignition control sends fl ame sense current to fl ame
sensor.
-- Ignition control module performs self safety check.
-- Internal components are tested.
-- Air proving circuit is tested
-- Control sends 24 VAC from terminal PSI/PS1 to air
proving switch.
-- Ignition control module begins ignition trial sequence.
-- Ignition control sends 120 volts from terminal IND
to motor. (Model AW325: Ignition control sends 120
volts to terminal 0 of motor relay. The relay closes,
and sends 120 volts from terminals 2 and 6 to start
the motor.
-- Motor starts.
-- Air proving switch closes and 24 volts are
returned to terminal PSO/PS2 of ignition control.
(AW models)
-- Motor stops
-- Ignition control module sends 120 volts to hot surface
igniter.
-- Igniter reaches ignition temperature in 17 seconds.
-- Ignition control restarts the fan motor .
(AD models)
-- Motor continues to operate.
-- Ignition control powers the igniter and igniter sparks.
(Both)
-- Ignition control sends 24 volts from terminal GV/MV
to high limit switch.
-- If limit switch contacts are closed, limit sends 24 volts
to gas control valve
-- Gas control valve opens
-- Ignition occurs.
-- Flame sense current is passed through burner fl ame
back to ignition control.
-- Igniter stays powered until ignition control proves
fl ame sense
-- Igniter then shuts down.
-- Gas control valve stays open
-- Room warms to desired temperature.
-- Thermostat is satisfi ed.
-- Heater shuts down.
-- Process starts again on a call for heat.
Owner's Manual • Guardian
THERE ARE 3 IGNITION TRIALS:
AW Models:
-- First two trials occur within 45 seconds
-- A third trial occurs in 15 minutes
AD Models:
-- 3 ignition trials occur in 45 seconds
-- 3 more trials occur in 15 minutes
Both:
-- If no ignition the control goes into lock-out
-- To retry, turn heater off and on.