tekmar 545 Thermostat Installation - Manual (Page 30)

© 2008 D 545 - 07/08 30 of 40
Dedicated Ventilation
A dedicated ventilation system has a fan dedicated for
ventilation only. This is also common when using Heat
Recovery Ventilation (HRV) or Energy Recovery Ventilation
(ERV). Use the Fan contact to operate dedicated ventilation
fans. Fan Mode None must be selected when using
dedicated ventilation.
•
• Locate the Fan Mode item in the Adjust menu and set
to None.
• • Locate the F1 Vent item in the Adjust menu and set
to On.
• • Locate the Fan item in the Adjust menu for each event
(Wake, Unoccupied, Occupied, Sleep) and set the fan
operating percentage.
Fan Pre and Post Purge
To prevent the fan from operating before the coil reaches
the proper temperature, the operation of the fan can be
delayed. Likewise the operation of the fan may continue
after the heating or cooling has been completed.
•
• All fan settings are found in the Adjust menu.
Coil or Duct Sensor Not Installed Operation
•
• During a call for heating, the fan turns on after the Fan
Delay time expires.
• • After heating or cooling, the fan turns off after the Fan
Purge time expires.
Coil Sensor Installed Operation
•
• During a call for heating, the fan turns on after the coil
temperature exceeds the Heat Coil Minimum temperature
setting.
• • During a call for cooling, the fan turns on after the
coil temperature falls below the Cool Coil Maximum
temperature setting.
• • After Heating, the fan turns off after the Fan Purge time
setting expires.
• • After Cooling, the fan immediately turns off.
Duct Sensor Installed Operation
•
• During a call for heaing or cooling, the fan turns on after
Fan Delay time expires.
• • After Heating the fan remains on until the duct
temperature falls below the Heatpurge Fan setting.
• • After Cooling, the fan remains on until the temperature
rises above the Coolpurge Fan setting.
Freeze Protection
The thermostat provides freeze protection to the heating or
cooling coil when a duct or coil sensor is present. During
cooling, if the temperature falls below 37°F (3°C), the
compressor shuts off while the fan continues to operate.
During ventilation, if the coil or duct sensor temperature
falls below 37°F (3°C), the fan shuts off.
Off
Freeze Protection
Cooling
3°C 37°F
On
Freeze Protection
Cooling
3°C 37°F
Cool
On
Cool
Off
On On
Ventilation Pre-vent
When the building is Unoccupied or in a Sleep period,
ventilation may be reduced or set to Off. As a result, stale
air may build up in the building. When transitioning to a
Wake or Occupied period, the dedicated ventilation may
be run continuously for a period of time to introduce fresh
air into the building.
•
• Locate the Ventilation Pre-vent item in the Adjust menu.
Intermittent Fan
The intermittent fan operation ensures the Fan contact
operates for a minimum percentage of each cycle. This
allows the fan to circulate air throughout the building.
The fan operates based upon the Fan Mode selected. If
the heating or cooling systems are shut off and the fan
has not yet met the minimum percentage on time, the fan
continues to run.
Intermittent Fan and Dedicated Ventilation cannot be used
at the same time.
•
• Locate the Fan item in the Adjust menu for each event
(Wake, Unoccupied, Occupied, Sleep) and set the
minimum fan operating percentage.
Fan Operation During Heating
The Fan contact operates during first and / or second stage
heating when both of the following settings are made.
•
• Fan Mode must be set to 2.
and
•
• H1 and / or H2 terminal unit must be set to either Coil
or Furnace.