Haier GE NF80LS Service Manual page 9

RED LED
RECALL BUTTON
Figure 3. Integrated Control
(Automatic Hot Surface Ignition System)
Electronic Ignition
On a call for heat the integrated control monitors the
combustion air inducer pressure switch. The control board
will not begin the heating cycle if the pressure switch is
closed (by-passed). Once the pressure switch is determined
to be open, the combustion air inducer is energized. When
the differential in the pressure switch is great enough, the
pressure switch closes and a 15-second pre-purge begins.
If the pressure switch is not proven within 2-1/2 minutes,
the integrated control goes into Soft Lockout-Pressure
Switch mode for a 5-minute re-set period.
After the 15-second pre-purge period, the ignitor warms
up for 20 seconds during which the gas valve opens at
19 seconds for a 4-second trial for ignition. The ignitor
remains energized for the first 3 seconds during the 4
second trial. If ignition is not proved during the 4-second
period, the integrated control will try four more times with
1
ON
OFF
DEMAND
CAI
IGNITOR
GAS VALVE
INDOOR BLOWER
*Blower on time will be 30 seconds after flame is sensed. Blower off time will depend on "OFF TIME" Setting.
31-5000737 Rev. 0
BLOWER OFF DELAY
15
Pre -Purge Ignitor Warm-up
Figure 5. Electronic Ignition
an inter purge and warm-up time between trials of 35
seconds. After a total of five trials for ignition (including the
initial trial), the integrated control goes into Soft Lockout-
Flame Failure mode. After a 60-minute reset period, the
integrated control will begin the ignition sequence again.
Fan Time Control
Heating Fan On Time
The fan on time of 30 seconds is not adjustable.
Heating Fan Off Time
Fan off time (time that the blower operates after the heat
demand has been satisfied) can be adjusted by moving
the jumper to a different setting. The unit is shipped with
a factory fan off setting of 90 seconds. For customized
comfort, monitor the supply air temperature once the heat
demand is satisfied. Note the supply air temperature at the
instant the blower is de-energized.
Adjust the fan-off delay to achieve a supply air temperature
between 90° - 110° at the instant the blower is de-energized.
(Longer delay times allow for lower air temperature, shorter
delay times allow for higher air temperature). See Figure 4.
34
38
Trial for
Blower "On"*
Ignition
Delay
Page 9
Figure 4.
80 5 SEC
Post
Purge