Maximum Flow Heat; Night Purge - Trane Tracer VV550 Installation, Operation And Maintenance Manual

Maximum Flow Heat

The controller enters maximum flow heat on receipt of a communicated command and
remains in maximum flow heat until the command changes.
The controller maintains the flow rate at the heating maximum flow setpoint.
shows controller operation during maximum flow heat.
Table 34.Controller operation during maximum flow
Primary air temperature
Cold air in duct;
Primary air temperature <
configured auto-changeover
setpoint minus 10°F
Warm air in duct;
Configured auto-changeover
setpoint < primary air temperature <
configured reheat enable setpoint
minus 5°F
Hot air in duct;
Configured reheat enable setpoint <
primary air temperature
a. Primary Air Temperature is derived from either the communicated Source Temperature, or the Primary/Discharge Air
Temperature sensor when configured for Primary Air Temperature. A communicated Application Mode of Max Heat forces the
controller to assume the primary is hot if neither the communicated Source Temperature or the local Primary Air Temperature
sensor is present. The default Primary Air Temperature does not come into play during Max Heat.

Night Purge

The controller enters night purge on receipt of a communicated command and remains
in night purge until this command is changed.
Night purge uses the occupied cooling setpoint regardless of the occupancy mode. All
ventilation requirements are waived during night purge. This operational sequence is
identical to pre-cool.
Construction (Temporary Heat)
The controller controls the air valve at the maximum heating flow setpoint when no valid
space temperature is detected on reset. All local and remote reheat is locked out. Fan
operation remains unaffected.
CNT-SVX17G-EN
a
Space
temperature
< active heating
setpoint
> active heating
setpoint plus
0.5°F
< active heating
setpoint
< active heating
setpoint
> active heating
setpoint plus
0.5°F
< active heating
setpoint
> active heating
setpoint plus
0.5°F
Primary airflow Fan control
control
Heating max flow Series On
setpoint Parallel On
Heating max flow Series On
setpoint Parallel Off
Heating max flow Series On
setpoint Parallel Off
Heating max flow Series On
setpoint Parallel On (w/
reheat)
Heating max flow Series On
setpoint Parallel Off
Heating max flow Series On
setpoint Parallel Off
Heating max flow Series On
setpoint Parallel Off
Sequence of Operations
Table 34
Reheat control
Reheat On
Reheat Off
Reheat Not
Present
Reheat On
Reheat Off
Reheat Off
Reheat Off
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