Installations Instructions

44
CIRCULATOR BLOWER SPEEDS
WARNING
T O AVOID PERSONAL INJURY OR DEATH DUE TO ELECTRICAL SHOCK ,
TURN OFF POW ER TO THE FURNACE BEFORE CHANGING SPEED TAPS .
This furnace is equipped with an ECM circulator blower. The
heating blower speed is shipped set at “B”, and the cooling blower
speed setting is “D”. These blower speeds should be adjusted
by the installer to match the installation requirements so as to
provide the correct heating temperature rise and correct cooling
CFM.
Use the dual 7-segment LED display adjacent to the DIP switches
to obtain the approximate airflow quantity. The airflow quantity
is displayed as a number on the display, rounded to the nearest
100 CFM. The display alternates airflow delivery indication and
the operating mode indication.
Example: The airflow being delivered is 1225 CFM. The display
indicates 12. If the airflow being delivered is 1275, the display
indicates 13.
1. Determine the tonnage of the cooling system installed
with the furnace. If the cooling capacity is in BTU/hr divide
it by 12,000 to convert capacity to TONs.
Example: Cooling Capacity of 30,000 BTU/hr.
30,000/12,000 = 2.5 Tons
2. Determine the proper air flow for the cooling system. Most
cooling systems are designed to work with air flows
between 350 and 450 CFM per ton. Most manufacturers
recommend an air flow of about 400 CFM per ton.
Example: 2.5 tons X 400 CFM per ton = 1000 CFM
The cooling system manufacturer’s instructions must be checked
for required air flow. Any electronic air cleaners or other devices
may require specific quantity of air, consult installation instruc-
tions of those devices for requirements.
3. Knowing the furnace model, locate the high stage cooling
air flow table. Look up the cooling air flow determined in
step 2 and find the required cooling speed and adjustment
setting.
Example: A DM97MC0603BN** furnace installed with
a 2.5 ton air conditioning system. The air
flow needed is 1000 CFM. Looking at the
cooling speed chart for DM97MC0603BN**,
find the air flow closest to 1000 CFM. A
cooling airflow of 1000 CFM can be
attained by selecting the cooling speed
“C” and the adjustment to “normal”.
Model Tap
Low
St age
Cool
High St age
Cool
100%
Heat
*CFM
Low heat
CFM for
2 st age
A
398 599 953 667
B
557 817 1059 740
C 696 1007 1158 808
D 810 1212 1260 881
A
403 629 1202 855
B 540 806 1316 923
C
705 1023 1389 1033
D 819 1230 1396 1063
A
513 789 1228 867
B 660 967 1337 939
C 791 1182 1430 1016
D
913 1375 1516 1077
A 564 820 1818 1256
B
784 1133 1870 1292
C 982 1464 1910 1316
D
1259 1736 1957 1358
A 547 867 1891 1329
B 831 1160 1940 1362
C
1020 1467 1968 1390
D 1278 1910 2028 1440
A
433 656 938 687
B 541 790 950 751
C
686 972 986 814
D 806 1195 992 874
A 405 624 1057 758
B 549 808 1146 815
C 678 994 1256 882
D 784 1177 1349 946
A
556 837 1234 889
B
714 1022 1325 944
C 838 1206 1442 1019
D 991 1475 1528 1068
A
524 784 1759 1209
B 744 1078 1797 1249
C
927 1388 1840 1277
D 1185 1766 1881 1300
*100% CFM shown. CFM will vary proportionally with the gas valve B TU/H input.
*CVM970803BN
*CVM970804CN*
*CVM971005CN*
*MVM971005CN*
*MVM971205DN*
*CVM970603BN
*MVM970603BN*
*MVM970803BN*
*MVM970804CN*
4. Continuous fan speed is selectable at 25%, 50%, 75%
or 100% of the furnace’s maximum airflow capability.
Example: If the furnace’s maximum airflow capability
is 2000 CFM, the continuous fan speed at
25% will be 0.25 x 2000 or 500 CFM.
5. Locate the blower speed selection DIP switches on the
integrated control module. Select the desired “cooling”
speed tap by positioning switches 1 and 2 appropriately.
Select the desired “adjust” tap by positioning switches 9
and 10 appropriately. Refer to the DIP switch chart for
switch positions and their corresponding taps. Verify CFM
by noting the number displayed on the dual 7-segment
LED display.
6. The multi-speed circulator blower also offers several
custom ON/OFF ramping profiles for cooling. These
profiles may be used to enhance cooling performance
and increase comfort level. The ramping profiles
are selected using DIP switches 7 and 8. Refer to the
bullet points below for a description of each ramping
profile. Verify CFM by noting the number displayed on
the dual 7-segment LED display.