Page 7
NOTE -
During abnormal conditions such as low supply
voltage or low outdoor temperatures and the low fire pres
-
sure switch does not close, the combustion air inducer will
switch to high fire. After a 15 second pre-purge the high
fire pressure switch will close and the unit will begin op
-
eration on high fire. After 10 to 20 seconds of high fire
operation the unit will switch to low fire.
After the 15-second pre-purge period, the SureLight ig-
nitor warms up for 20 seconds after which the gas valve
opens for a 4-second trial for ignition. The ignitor ener
-
gizes during the 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 be-
tween 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-minute reset
period, the control will begin the ignition sequence again.
Two Stage Operation / Thermostat Selection DIP
Switch
The control can be utilized in two modes: SINGLE-STAGE
thermostat or TWO-STAGE thermostat. The thermostat
selection is made using a DIP switch and must be posi-
tioned for the particular application. DIP switch 1, labeled
T”STAT HEAT STAGE is factory-set in the OFF position for
use with a two-stage thermostat. Move the DIP switch to
ON for use with a single stage thermostat.
While in the single-stage thermostat mode, the burners
will always fire on first-stage heat. The combustion air in
-
ducer will operate on low speed and indoor blower will
operate on low heat speed. The unit will switch to second
stage heat after a “recognition period”. DIP switch 2, la
-
beled SECOND STAGE DELAY, is factory set in the OFF
position for a 7 minute recognition period. The switch can
be moved to the ON position for a 12 minute recognition
period, after which time the unit will switch to secondstage
heat.
While in the two-stage thermostat mode (two DIP switch
setting) the burners will fire on first-stage heat. The com
-
bustion air inducer will operate on low speed and indoor
blower will operate on low heat speed. The unit will switch
to second-stage heat on call from the indoor thermostat.
If there is a simultaneous call for first and second stage
heat, the unit will fire an first stage heat and switch to sec
-
ond stage heat after 30 seconds of operation. See Se
-
quence of Operation flow charts in the back of this manual
for more detail.
TABLE 1
SureLight
®
Control 5 Pin Terminal Designation
PIN#
Function
1
Ignitor
2
Combustion Air Inducer High
Speed
3
Combustion Air Inducer Low
Speed
4
Combustuion Air Inducer
Neutral
5
Ignitor Neutral
TABLE 2
SureLight
®
Control 12 Pin Terminal Designation
PIN#
Function
1
Gas Valve High Fire
2
Second Stage Prove Switch
3
Rollout In
4
Ground
5
24V Hot
6
Primary Limit In
7
Gas Valve Low Stage
8
Gas Valve Common
9
24V Neutral
10
Ground
11
Rollout Switch Out
12
1st Stage Prove Switch
TABLE 3
SureLight
®
Control 6 Pin Terminal Designation
PIN#
Function
1
Data Input From Motor
2
Common
3
Not Used
4
Data Output To Motor
5
5 Volt Bias Supply
6
Not Used
