EngA C-TRAC3 Installation, Operation And Maintenance Manual page 12

A
C-TRAC3
Economizer Mode flashes when the C-TRAC3 is in this mode. The modulating output from terminal ED can
rise above the minimum position to modulate the mixing dampers and maintain the required discharge air
temperature.
Cooling Mode indicates the mechanical cooling staged output contacts are available to begin enabling the
5 stages of mechanical cooling. All stages have minimum run time, minimum off time, and inter-stage
timing. As well, there may be an optional choice of a modulating cooling output signal if a modulating
compressor or other device such as a modulating chilled water coil is desired.
Dual Mode is a function used on equipment where the heating mode and the cooling or economizer
modes operate at the same time with independent set points.
Ex: multi-zone applications, or de-humidification functions.
No Mode will flash when the C-TRAC3 is not allowed to run the heating (HS not powered), cooling (A not
powered) or economizer (E powered). This generally occurs because of external controls, ambient
lockout, flame failure, etc. The C-TRAC3 can be preprogrammed to eliminate certain modes. For example
a makeup air unit does not have an economizer mode.
Blower Delay is to indicate the blower is preparing to start, but has internal timers to allow for the
dampers to open, or to warm up the heat exchanger.
Manual Control Mode indicates the C-TRAC3 is being controlled by SMC software directly.
Compressor Disabled refers to the mechanical cooling being disabled by the SMC software.
Temperature outside dead band means the temperature is no longer at setpoint and the C-TRAC3 is
attempting to resolve the error.
Mode Change Blocked indicates the C-TRAC3 wishes to change modes (ex economizer to cooling) but the
mode is blocked due to an external signal control, or no such mode exists.
Cooling Mode Blocked indicates the mechanical cooling mode is disabled from either low ambient
temperatures or terminal A not being powered.
Low Limit will flash when the unit has failed because of low discharge temperature, usually associated
with flame failure.
Open Sensor will blink and disable unit operation if the discharge or ambient sensor has failed (open
resistance). This is an optional setting, which may include sensor #2.
Heat Fail will flash if the gas fired heater has failed to ignite. The C-TRAC3 monitors the burner operation
with terminals PVE (pilot valve) and FRE (flame relay), and can be configured to shut down and lock out
the system on a flame failure. Some heaters may be configured for automatic re-light up to 3x before the
C-TRAC3 will go into heat fail. Electric heaters have a feedback, after the safety switches (high limits, air
switch and door switch), to terminal PVE which must prove within 1 minute, after the fan has started.
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