A
M-TRAC1
IOM-55
May 2019
13
OPERATION
EXHAUST FAN INTERLOCKING
There are a number of different exhaust interlocking options available. Always refer to the
wiring diagram and unit function sheet to determine the exact type of interlocking used.
The AL output contact may be switched from an alarm output to a exhaust fan enable output
contact for control of reverse interlock control systems (DIP sw #2). In this mode terminal AL
will close on proof of supply air flow.
MODULATING VALVE LIGHT OFF POSITION
The appliance the M-TRAC1 is controlling may use either a fast opening (solenoid) safety shut
off valve, or a slow opening (hydraulic) valve. To ensure the modulating valve is positioned
correctly for initial ignition and avoid high fire ignition, DIP switch 5 is factory set depending on
the type of safety shut off valve.
The M-TRAC1 is designed to ignite the burner at approximately 40% of full fire (non-adjustable).
The positioning time delay allows the modulating valve actuator time to reach the correct light
off position before an ignition attempt is made.
Set DIP switch 5 to “on” when ever the main gas valve is a slow opening. For fast opening valve,
set DIP switch 5 to the “off” position.
LOW FIRE
The M-TRAC1 may control a broad range of burner sizes, all with unique minimum firing rates
(low fire). The ball valve actuator minimum position voltage to set low fire is adjusted using the
built in M-TRAC1 POT labeled “Min Fire”. The POT can be adjusted from 0 to 40% of full fire,
and is located immediately to the right of the discharge air setpoint knob.
CALIBRATION
While the heater and M-TRAC1 is factory tested and calibrated, field conditions may affect
airflow and sensor readings. After making any calibration adjustment, it may take a few
minutes for the M-TRAC1 to reflect the changes. After this time, turn the appliance off for a
few seconds, and then turn the appliance back on. Re-confirm the calibration.
