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Integrated Control
EL280UH units are equipped with a two−stage integrated
control. This control manages ignition timing and fan off
delays based on selections made using the control DIP
switches. The control includes an internal watchguard fea-
ture which automatically resets the integrated control when
it has been locked out. After one hour of continuous ther-
mostat demand for heat, the watchguard will break and re-
make thermostat demand to the furnace and automatically
reset the control to relight the furnace.
DIP Switch Settings
Switch 1 −− Thermostat Selection −−
This unit may be used
with either a single−stage or two−stage thermostat. The
thermostat selection is made using a DIP switch which
must be properly positioned for the particular application.
The DIP switch is factory−positioned for use with a two−
stage thermostat. If a single−stage thermostat is to be used,
the DIP switch must be repositioned.
a −
Select OFF
" for two−stage heating operation con-
trolled by a two−stage heating thermostat (factory set-
ting);
b −
Select ON
" for two−stage heating operation con-
trolled by a single−stage heating thermostat. This set-
ting provides a timed delay before second−stage heat
is initiated.
Switch 2 −− Second Stage Delay (Used with Single−
Stage Thermostat Only) −−
This switch is used to deter-
mine the second stage on delay when a single−stage ther-
mostat is being used. The switch is factory−set in the OFF
position, which provides a 10−minute delay before second−
stage heat is initiated. If the switch is toggled to the ON
position, it will provide a 15−minute delay before second−
stage heat is initiated. This switch is only activated when
the thermostat selector jumper is positioned for SINGLE−
stage thermostat use.
Switches 3 and 4 −− Heating Blower−Off Delay −−
The
heating blower−on delay of 30 seconds is not adjustable.
The heating blower−off delay (time that the blower operates
after the heating demand has been satisfied) can be ad-
justed by moving switches 3 and 4 on the integrated con-
trol. The unit is shipped from the factory with a heating
blower−off delay of 90 seconds. The heating blower off
delay affects comfort and is adjustable to satisfy individual
applications. Adjust the blower off delay to achieve a sup-
ply air temperature between 90° and 110°F at the exact
moment that the blower is de−energized. Longer off delay
settings provide lower supply air temperatures; shorter set-
tings provide higher supply air temperatures.Table 11 pro-
vides the blower off timings that will result from different
switch settings.
TABLE 11
Heating Blower−Off Delay Switch Settings
Blower Off Delay
(Seconds)
Switch 3
Switch 4
60
Off
On
90
(factorysetting)
Off
Off
120
On
Off
180
On
On
Switch 5 −− Cooling Blower−Off Delay −−
The cooling
blower−off delay (time that the blower operates after the
cooling demand has been satisfied) can be adjusted by
moving switch 5 on the integrated control. The switch is fac-
tory−set in the OFF position, which provides a cooling blow-
er−off delay of 45 seconds. If the switch is toggled to the ON
position, it will provide a 2−second cooling blower−off delay
On−Board Link W951 Heat Pump (R to O)
On−board link W951 is a clippable connection between ter-
minals R and O on the integrated control. W951 must be cut
when the furnace is installed in applications which include a
heat pump unit and a thermostat which features dual fuel
use. If the link is left intact, terminal O" will remain ener-
gized eliminating the HEAT MODE in the heat pump.
On−Board Link W915 2 Stage Compr (Y1 to Y2)
On−board link W915 is a clippable connection between ter-
minals Y1 and Y2 on the integrated control. W915 must be
cut if two−stage cooling will be used. If the link is not cut the
outdoor unit will operate in second−stage cooling only and
the indoor blower will operate on high cool speed only.
