Page 9
TABLE 1
SureLight BOARD J156 (J2) TERMINAL
DESIGNATIONS
PIN #
FUNCTION
1
Combustion Air Inducer Line
2
Ignitor Line
3
Combustion Air Inducer Neutral
4
Ignitor Neutral
TABLE 2
SureLight BOARD J58 (J1) TERMINAL
DESIGNATIONS
PIN #
FUNCTION
1
High Limit Output
2
Not Used
3
24V Line
4
Not Used
5
Rollout Switch In
6
24V Neutral
7
High Limit Input
8
Ground
9
Gas Valve In
10
Pressure Switch Out
11
Rollout Switch Out
12
Gas Valve Out
a−Electronic Ignition (See Figure 8)
On a call for heat the SureLight control monitors the com
bustion air inducer prove switch. The control will not begin
the heating cycle if the prove switch is closed (by−passed).
Once the prove switch is determined to be open, the com
bustion air inducer is energized. When the differential in the
prove switch is great enough, the prove switch closes and a
15−second pre−purge begins. If the prove switch is not
proven within 2−1/2 minutes, the control goes into Watch
guard−Pressure Switch mode for a 5−minute re−set period.
After the 15−second pre−purge period, the SureLight ignitor
warms up for 20 seconds during which the gas valve opens
at 19 seconds for a 4−second trial for ignition. The ignitor
stays energized during the 4 second trial until flame is
sensed. If ignition is not proved during the 4−second period,
the control will try four more times with 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 control
goes into Watchguard−Flame Failure mode. After a 60−min
ute reset period, the control will begin the ignition sequence
again.
The SureLight control board has an added feature that pro
longs the life of the ignitor. After a successful ignition, the
SureLight control utilizes less power to energize the ignitor
on successive calls for heat. The control continues to ramp
down the voltage to the ignitor until it finds the lowest
amount of power that will provide a successful ignition. This
amount of power is used for 255 cycles. On the 256th call
for heat, the control will again ramp down until the lowest
power is determined and the cycle begins again. Each time
120V is removed and then re−applied, the control re−starts
the learning process.
b−Fan Time Control
The fan on time of 45 seconds is not adjustable. Fan off
time (time that the blower operates after the heat demand
has been satisfied) can be adjusted by setting the dip
switches located on the SureLight integrated control. The
unit is shipped with a factory fan off setting of 90 seconds.
For customized comfort, monitor the supply air tempera
ture once the heat demand is satisfied. Note the supply air
temperature at the instant the blower is de−energized. Ad
just the fan−off delay to achieve a supply air temperature
between 90° − 110° at the instant the blower is de−ener
gized. (Longer delay times allow for lower air temperature,
shorter delay times allow for higher air temperature). See
figure 4.
FANOFF TIME ADJUSTMENT
To adjust fan−off timing, flip dip switch to desired setting.
60sec.
90sec.
120sec.
180sec.
(Black square indicates switch position)
OFF
OFF
OFF
OFF
ON
ON
ON
ON
OFF
OFF
OFF
OFF
2
2
2
2
1
1
1
1
FIGURE 4
