SYSTEM OPERATION
29
Heating CFM
OFF
100% CFM
100% CFM
1 min
OFF
Figure 50
•
provides only an OFF delay of one (1) minute at 100% of the cooling demand
Profile A(1)
50% CFM
1/2 min
100% CFM
100% CFM
1 min
OFF
OFF
Figure 51
•
ramps up to full cooling demand airflow by first stepping up to 50% of the full
demand for 30 seconds. The motor then ramps to 100% of the required airflow. A one (1)
minute OFF delay at 100% of the cooling airflow is provided.
Profile B(2)
100% CFM
OFF
OFF
•
ramps up to 85% of the full cooling demand airflow and operates there for
approximately 7 1/2 minutes. The motor then steps up to the full demand airflow. Profile C
also has a one (1) minute 100% OFF delay.
Profile C(3)
Figure 52
OFF
OFF
•
ramps up to 50% of the demand for 1/2 minute, then ramps to 85% of the full
cooling demand airflow and operates there for approximately 7 1/2 minutes. The motor
then steps up to the full demand airflow. Profile D has a 1/2 minute at 50% airflow OFF delay.
Profile D(4 or 5)
Figure 53
In general lower heating speeds will: reduce electrical con
-
sumption, lower operating sound levels of the blower, and
increase the outlet air temperature delivered to the home if heat
mode is running. If cooling mode is running the same airflow
adjustment will decrease the outlet air temperature delivered to
the home. The speeds available allow the blower performance
to be optimized for the particular homeowner’s needs.
LOW VOLTAGE WIRING - GENERAL INFORMATION
The Furnace functions with any thermostat that can be con
-
figured to provide 24VAC on Y for cooling calls and 24VAC
on W for Heating calls. Based on these simple inputs, internal
algorithms will decide how to control two stages of furnace
heat in addition to any single or multi stage outdoor heating /
cooling operation (the algorithms will handle dual fuel multi-
stage systems as well). The thermostat must be setup to
provide only a Y call when cooling is required and only a W
call when heating is required. This is generally accomplished
by selecting single stage heat / single stage cool mode during
setup (if setup is required). Do not set thermostat to heat pump
operation as system will not operate properly.
NOTE:
The only exception is if a single stage non-commu
-
nicating Heat Pump is connected to the furnace. Refer to
Non-Communicating Single Stage Heat Pump diagram for
details.
MODEL & TEMP RISE RANGE
(MID RISE)
CFM
RISE
CFM
RISE
CFM
RISE
CFM
RISE
RECOMMENDED CFM FOR 100%
FIRING RATE & EXPECTED
TEMPERATURE RISE
1080
50
1400
51
1430
50
1800
50
LOWEST RECOMMENDED CFM FOR
100% FIRING RATE & EXPECTED
TEMPERATURE RISE
830
65
1100
65
1100
65
1380
65
MAXIMUM CFM FOR100% FIRING
RATE & EXPECTED TEMPERATURE
RISE
1400
38
1400
51
1760
41
2200
41
MODEL & TEMP RISE RANGE
(MID RISE)
CFM
RISE
CFM
RISE
CFM
RISE
CFM
RISE
CFM
RISE
RECOMMENDED CFM FOR 100%
FIRING RATE & EXPECTED
TEMPERATURE RISE
1370
40
1400
51
1760
41
1780
50
1950
55
LOWEST RECOMMENDED CFM FOR
100% FIRING RATE & EXPECTED
TEMPERATURE RISE
990
55
1200
60
1320
55
1380
65
1670
65
MAXIMUM CFM FOR 100% FIRING
RATE & EXPECTED TEMPERATURE
RISE
1400
39
1400
51
1760
41
2200
41
2200
49
*MVM970603BNB*
25-55 (40)
*MVM970803BNB*
30-60 (45)
*MVM970804CNB*
25-55 (40)
*MVM971005CNB*
35-65 (50)
*MVM971205DNB*
35-65 (50)
*CVM970603BNB*
35-65 (50)
*CVM970803BNB*
35-65 (50)
*CVM970804CNB*
35-65 (50)
*CVM971005CNB*
35-65 (50)
