Trane Voyager 27½ to 50 Ton Installation, Operation And Maintenance Manual page 59

closed. The RTRM will cycle second stage
on and off as required while keeping
stage one energized.
The supply fan is energized
approximately 1 second before the
electric heat contactors. When the space
temperature rises above the heating
setpoint, the RTRM deenergizes the
supply fan and all electric heat contactors.
Supply Air Tempering
This feature is available only with
Tracer™ or with systems using
programmable zone sensors (CV only
with economizer). For gas and electric
heat units in the Heat mode but not
actively heating, if the supply air
temperature drops to 10 F below the
occupied zone heating temperature
setpoint, one stage of heat will be
brought on to maintain a minimum
supply air temperature. The heat stage is
dropped if the supply air temperature
rises to 10 F above the occupied zone
heating temperature setpoint.
RT -PRC007-EN
Controls
Auto Changeover
When the System Mode is "Auto, " the
mode will change to cooling or heating
as necessary to satisfy the zone cooling
and heating setpoints. The zone cooling
and heating setpoints can be as close as
2 F apart.
Unoccupied Zone Temperature Control
Cooling and Heating
Both cooling or heating modes can be
selected to maintain Unoccupied zone
temperature setpoints. For Unoccupied
periods, heating or primary cooling
operation can be selectively locked out at
the remote panels or TRACER.
Conventional Thermostat Interface
Conventional Thermostat Interface (CTI)
is a standard part of the RTRM. The CTI
will allow only two steps of heating or
cooling. The CTI provides zone
temperature control only and is mutually
exclusive of the Trane Communications
Interface (TCI).
Control Sequences of
Operation Common to Both
VAV and CV Units
Ventilation override (VOM)
Applying 24 volts to one of the three
Ventilation Override inputs manually
activates ventilation override. One input
is provided to request the pressurize
mode, the second input to request the
purge mode, and the third input to
request the exhaust mode.
If more than one mode is requested at
the same time, the pressurize request will
have priority followed by purge. When
any ventilation override mode is active,
all heating and cooling is turned off. For
the case where the unit is required to turn
off, the emergency stop input is used. The
ICS can also initiate any ventilation
override mode.
Affected Function
Pressurize
1
Heat/Cool off
IGV/VFD open/full
speed
Supply Fan on
Exhaust Fan off
Economizer open
VAV Boxes forced open
Mode and Priority
Purge Exhaust
2 3
off off
open/full open/full
speed speed
on off
on on
open closed
forced open normal operation
59