A
M-TRAC1
IOM-55
May 2019
11
DAMPER CONTROL
The inlet damper actuator(s) is enabled through output terminal DM. The M-TRAC1 allows time
for the dampers to open prior to starting the supply blower.
BLOWER CONTROL
The M-TRAC1 uses output terminal SA to control the supply air fan. There are, however, a
number of internal and/or external components that may be required to be functional prior to
starting the blower. Proof of air flow is confirmed by the profile pressure sensor.
In some applications continuous airflow is more important than temperature control. The
M-TRAC1 has two blower control program options. They are referred to as
airflow
priority, and
comfort
priority. See Table 7 for the differences between the two priorities. Priority type is
selected by DIP switch 7.
For the comfort priority program, minimum airflow is defined as 60% of required airflow.
Airflow priority is defined as 40% of required airflow.
TABLE 7
Priority Level
Status
Comfort
Air Flow
Heat switch off.
Low airflow
Lock out in 50 seconds.
Blower will remain on until the
discharge air temperature falls
below 40˚F (4°C).
Flame failure, with
discharge temperature
greater than 40°F (4˚C).
Burner and blower off.
Burner off, blower continues to run.
Heat on, but sensing a high
air velocity condition.
Unit will shutdown after
60 seconds.
Burner will lockout after 60
seconds. Blower will remain on
until the discharge air temperature
falls below 40˚F (4°C).
Heat on, with the high limit
control open.
Unit will shutdown after 4
seconds.
Burner will lockout after 4 seconds.
Blower will remain on until the
discharge air temperature falls
below 40˚F (4°C).
BURNER CONTROL
The M-TRAC1 outputs a 0 to 10 Vdc signal to a modulating actuator / ball valve assembly to
control and maintain a defined discharge air temperature setpoint. 10Vdc is the maximum
firing rate (high fire).
