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TABLE 9
Low Heat Blower Speeds
Thermostat
Demand
Blower
Speed
Adjustments
DIP Switch Settings
Low Heat
(R to W1)
14
15
16
+ 15%
On
Off
On
+ 7.5%
On
Off
Off
Normal
Off
Off
Off
- 7.5%
On
On
Off
- 15%
On
On
On
Switches 14 through19 -- Heating Mode Blower Speed
-- Switches 14 through 19 are used to select heating mode
blower motor speeds. These switches are factory set at
the OFF position which provides 100 % of normal speed
during HIGH HEAT demand, 70% of normal speed during
MIDRANGE HEAT demand and 40% of normal speed
during LOW HEAT demand. Switches 14, 15 and 16 are
used to adjust the LOW FIRE blower motor speed. Switch-
es 17, 18 and 19 are used to adjust the HIGH FIRE blower
motor speed. FIGURE 6 and TABLE 9 and TABLE 10 pro-
vides the heating mode blower speeds that will result from
different switch settings. FIGURE 6 indicates the effect the
DIP switch settings have upon the heating airflow at vari
-
ous furnace firing rates. Refer to blower tables at the front
of this manual for corresponding
cfm values.
TABLE 10
High Heat Blower Speeds
Thermostat
Demand
Blower Speed
Adjustments
DIP Switch Settings
High Heat
(R to W1 &
W2)
17
18
19
+ 15%
On
Off
On
+ 7.5%
On
Off
Off
Normal
Off
Off
Off
- 7.5%
On
On
Off
- 15%
On
On
On
Low Fire
Dip Switches
14, 15, 16
High Fire
Dip Switches
17, 18, 19
Airflow Determination
Identify blower speed adjustment points at low and high fire
Airflow will lie on straight line between these two points and will fall within
the shaded area as shown
EXAMPLE -7.5% at low fire +7.5% at high fire
35%
50%
60%
70%
80%
90%
100%
RATE (%)
+15%
+7.5%
-7.5%
-15%
Nominal
-15%
Nominal
-7.5%
+7.5%
+15%
Increasing
Airflow
FIGURE 6
