Table of Contents
Advertisement
Integrated
Control
Conventional Thermostat (non-communicating)
EL297UHV units are equipped with a two-stage, variable
speed integrated control. This control manages ignition
timing, heating mode fan off delays and indoor blower
speeds based on selections made using the control dip
switches and jumpers. The control includes an internal
watchguard feature which automatically resets the ignition
control when it has been locked out. After one hour of con-
tinuous thermostat demand for heat, the watchguard will
break and remake thermostat demand to the furnace and
automatically reset the control to relight the furnace.
Note: All communicating settings are set at the communi-
cating thermostat. See thermostat installation instruction.
In a communication system all DIP switch and clippable
link settings are ignored. For conventional thermostats
proceed with DIP switch and clippable link settings as out-
lined in the following.
Heating Operation 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 appli-
cation. 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 controlled by a
two-stage heating thermostat (factory setting);
b. Select "ON" for two-stage heating operation controlled by
a single-stage heating thermostat. This setting 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 de-
termine the second stage on delay when a single-stage
thermostat is being used. The switch is factory-set in the
OFF position, which provides a 7-minute delay before
second-stage heat is initiated. If the switch is toggled to
the ON position, it will provide a 12-minute delay before
second-stage heat is initiated. This switch is only activat-
ed when the thermostat selector jumper is positioned for
Single stage thermostat use.
Switches 3 and 4 -- Blower-Off Delay -- The blower-on
delay of 30 seconds is not adjustable. The blower-off delay
(time that the blower operates after the heating demand
has been satisfied) can be adjusted by moving switches 3
and 4 on the integrated control. The unit is shipped from
the factory with a blower-off delay of 90 seconds. The
blower off delay affects comfort and is adjustable to sat-
isfy individual applications. Adjust the blower off delay to
achieve a supply air temperature between 90° and 110°F
at the exact moment that the blower is de-energized. Lon-
ger off delay settings provide lower supply air tempera-
tures; shorter settings provide higher supply air tempera-
tures. TABLE 4 provides the blower off timings that will
result from different switch settings.
DIP
Switch
Settings
Blower Off Delay Switch Settings
Blower Off Delay
Seconds
60
90 (factory)
120
180
Indoor Blower Operation DIP Switch Settings
Switches 5 and 6 -- Cooling Mode Blower Speed -- The
unit is shipped from the factory with the dip switches po-
sitioned for high speed (4) indoor blower motor operation
during the cooling mode. TABLE 5 provides the cooling
mode blower speeds that will result from different switch
settings. Switches 5 and 6 set the blower cfm for second-
stage cool. The integrated control automatically ramps
down to 70% of the second-stage cfm for first-stage cfm.
Refer to tables for corresponding cfm values. See Product
Specifications for more detailed blower cfm tables.
Cooling Mode Blower Speeds
Speed
Low
Medium Low
Medium High
High (factory)
Switches 7 and 8 -- Cooling Blower Speed Adjustment
-- The unit is shipped from the factory with the dip switches
positioned for NORMAL (no) adjustment. The dip switches
may be positioned to adjust the blower speed by +10% or
-10% to better suit the application. TABLE 6 below pro-
vides blower speed adjustments that will result from dif-
ferent switch settings. Refer to tables for corresponding
cfm values. See Product Specifications for more detailed
blower cfm tables.
Cooling Blower Speed Adjustment
Adjustment
+10% (approx)
Factory Default
-10% (approx)
Switches 9 and 10 -- Cooling Mode Blower Speed
Ramping -- Blower speed ramping may be used to en-
hance dehumidification performance. The switches are
factory set at option A which has the greatest effect on de-
humidification performance. TABLE 7 provides the cooling
mode blower speed ramping options that will result from
different switch settings. The cooling mode blower mode
blower speed ramping options are detailed on the next
page.
Page 44
TABLE 4
Switch 3
Switch 4
On
Off
Off
Off
Off
On
On
On
TABLE 5
Switch 5
Switch 6
On
On
Off
On
On
Off
Off
Off
TABLE 6
Switch 7
Switch 8
On
Off
Off
Off
Off
On
Hide quick links:
Advertisement
Table of Contents
