tekmar 544 Thermostat Installation - Manual (Page 25)

25 of 36 © 2008 D 544 - 07/08
Cooling Operation Section G
One-Stage PWM Cooling
W
a
rmer
Set
Cool
Cycle Length
Cool
The thermostat has one cooling contact.
For one stage cooling systems, use the Cool 1 contact to
operate the cooling equipment.
•
• Locate the COOL STG setting in the Adjust menu to set
the number of cooling stages.
One Stage Cooling
During each cooling cycle, the thermostat calculates a
required on time for the Cool 1 relay to satisfy the cooling
requirements of the zone.
•
• If more cooling is required, the on time is increased.
•
• If less cooling is required, the on time is decreased.
Heating / Cooling Interlock and Priority
To prevent frequent changes between heating and cooling,
use the Heating / Cooling Interlock setting. When the Mode
is set to Automatic, the thermostat waits for the interlock
time before switch over occurs.
•
• Locate the Interlock item in the Adjust menu
Fan Operation Section H
Fan Mode Fan 1 Contact operates together with… Description
None Dedicated Ventilation Dedicated Ventilation.
1 Cool Fan runs for Cooling.
2 Heat and Cool Fan runs for Heat and Cool.
Fan Mode
There are three modes of operation that determine the operation of the Fan contact.
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.
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.
The thermostat has a Fan contact that supports a wide
range of fan applications. Set the Fan Mode to determine
when the fan relay activates. See the Fan Mode table for details.
•
• Locate the Fan Mode 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 heating when both of the
following settings are made.
•
• Fan Mode must be set to 2.
and
• • H1 terminal unit must be set to either Coil or Furnace.