A
M-TRAC1
IOM-55
May 2019
8
ADJUSTMENT POTS
There are a number of setting and calibration potentiometers (POT’s) located on the face of the
M-TRAC1. Modifications to these should only be performed by experienced and qualified
personnel.
TABLE 4
POT
Description
SP LMT
Limits the maximum discharge temperature set point.
CAL DTEMP
Discharge air sensor temperature calibration.
SP CAL
Setpoint dial calibration.
MIN FIRE
Adjusts the minimum valve output for low fire.
SERVICE POT
Manually sets burner firing rate for service. Located just above the centre.
When the service switch is on, this POT can be used to adjust the
modulating gas valve from low to high fire. When the service DIP switch is
on, light ‘D’ blinks irregularly.
2-10 Vdc
RESET RATIO
Sets the reset temperature range. This adjusts the amount of reset range
the 2-10 Vdc room thermostat will have. This allows an adjustment band
between 5
°
F and 50°F (3°C and 28°C).
PROFILE
VELOCITY
Allows a narrow adjustment for Profile pressure set point.
MULTIMETER TEST POINTS
The M-TRAC1 has readout test points for discharge air temperature, discharge set point and
profile plate velocity status.
Temperature readings are indicated by Vdc referenced to ground.
MAXIMUM DISCHARGE SET POINT LIMIT SETUP (SP LMT)
Regulations, design or authorities having jurisdiction may limit the maximum discharge air
temperature the appliance is allowed to reach. This may be set by the potentiometer SP LMT,
which is located below and to the right of the M-TRAC1 discharge set point knob. Vdc readout
= °C / 10. See Table 5.
CALCULATED SETPOINT (SPC)
The SPC measurement point is located just below the M-TRAC1 set point knob. This
temperature is the current operating set point after all applicable temperature resets have
been applied to primary or base set point. Vdc readout = °C / 10. See Table 5.
