tekmar 545 Thermostat Installation - Manual (Page 29)

29 of 40 © 2008 D 545 - 07/08
Cooling Operation Section G
One-Stage PWM Cooling
W
a
rmer
Set
Cool
Cycle Length
Cool
Cool Groups Section H
Cool Group 1 Cool Group 2
Master Master Member Member Member
tN4
The 545 thermostat has one cooling contact.
Use the Cool 1 contact to operate the cooling equipment.
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
You can manually set whether heating or cooling has
priority.
•
• Locate the Priority item in the Adjust menu.
If set to heating, all zones in the cooling group must be
satisfied for heating before the interlock time allows the
thermostat to automatically switch over to cooling. If any
heating is required, cooling is terminated and heating
resumes.
If set to cooling, the operation is reversed.
The thermostat can operate with other thermostats on a
tN4 network in a cool group. When operating as a cool
group, the air temperature readings of all the thermostats
in the group are averaged. A single thermostat controls the
operation of the cooling equipment and is called the cool
group master. This operation is based on the averaged
temperature of all the thermostats in the cool group.
• • To view the average temperature, go the View menu
and select Cool Average.
This is only available on the cool group master.
In a cool group, one thermostat is assigned as the cool
group master. The cool group master operates the cooling
equipment for the group. The other thermostats are assigned
as members of the cool group. Cool groups are assigned
using a number 1 through 16 and there can be up to a
maximum of 16 cool groups on the entire tN4 network.
• • To assign a thermostat as the cool group master of
group 1, go to the Adjust menu. Select Cool Master and
set to 01.
• • To assign a thermostat as a cool group member of group
1, go to the Adjust menu. Select Cool Member item and
set to 01.
• • Repeat the same steps to set up additional cooling
groups.
Fan Operation Section I
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.
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.