Bryant 986TB - Page 34

34
Table 9 − AC
4
and Heating Air Delivery − CFM (Bottom Return
5
with Filter) (Continued)
Unit Size AC/CF Switch Settings External Static Pressure (ESP)
SWx3 SWx2 SWx1 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
66120
AC Default: OFF OFF OFF 1850 1855 1860 1855 1850 1830 1805 1775 1750 1730
CF Default: OFF OFF OFF 930 925 915 900 885 See note 4
AC (SW2)
CF (SW3)
OFF OFF ON 765 745 740 705 680 See note 4
OFF ON OFF 930 925 915 900 885 See note 4
OFF ON ON 1095 1100 1110 1105 1085 See note 4
ON OFF OFF 1265 1255 1265 1280 1275 1285 1270 1260 1250 1230
ON OFF ON 1465 1455 1470 1465 1465 1470 1455 1450 1435 1415
ON ON OFF 1850 1855 1860 1855 1850 1830 1805 1775 1750 1730
ON ON ON 2200 2200 2200 2190 2185 2170 2145 2085 1990 1890
AC SW2: Maximum Clg Airflow
2
2200 2200 2200 2190 2185 2170 2145 2085 1990 1890
Heating
(SW1)
High Heat Airflow
3
1815 1820 1825 1820 1815 1795 1775 1745 1720 1700
Low Heat Airflow
3
1640 1640 1645 1650 1645 1645 1630 1620 1600 1580
1. Set SW15 to ON for nominal 400 CFM/ton (+15% airflow).
Set SW43 to ON for nominal 325 CFM/ton (7% airflow).
Set both SW15 and SW43 to ON for nominal 370 CFM/ton (+7% airflow).
The above adjustments in airflow are subject to motor horsepower range/capacity.
2. Maximum cooling airflow is achieved when switches SW21, SW22, SW23 and SW15 are set to ON, and SW43 is set to OFF.
3. All heating CFM's are when low heat rise adjustment switch (SW13) and comfort/efficiency adjustment switch (SW14) are both set to OFF.
4. Ductwork must be sized for highheating CFM within the operational range of ESP. Operation within the blank areas of the chart is not re
commended because highheat operation will be above 1.0 ESP.
5. All airflows on 21" (533 mm) casing size furnaces are 5% less on side return only installations.
6. Return air above 1800 CFM on 24.5" (622 mm) casing sizes requires two sides, one side and bottom, or bottom only to allow sufficient air
flow to the furnace.
7. Airflows over 1800 CFM require bottom return, twoside return, or bottom and side return; otherwise excessive watt draws may result. A
minimum filter size of 20" x 25" (508 x 635 mm) is required.
986TB