tekmar 401 House Control Installation - Manual (Page 19)

19 of 28 © 2011 D 401 - 07/11
Sequence of Operation
tekmarNet ® System Section A
tekmarNet ® is a family of products that use communication
to operate the HVAC system in a comfortable and efficient
manner. The House Control is the central component in
a tekmarNet
® system and requires tekmarNet ® 2 (tN2)
Thermostats to be directly connected to the control.
The tekmarNet ® 4 (tN4) Expansion terminals can link the
House Control with other tekmarNet ® components:
Wiring Centers 313, 314, 315, 316 - Add additional zones
tN2 and tN4 Thermostats - Add thermostats
tN4 Timer 033 - Adds 4 programmable schedules
tN4 User Switch 479 - Provides a system override for
vacations and holidays
tN4 Setpoint Control 161 - Control hot tubs, pools and
more •
•
•
•
•
Boiler Temperature Reset Operation Section B
Boiler Call -------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------
Boil Exp
Calls
When a device connected to the House Control calls for
heat, the House Control registers a Boil call for hydronic
heating on the boiler loop.
When a device connected to the tN4 Boil Expansion
terminals calls for heat, the House Control registers a Boil
Expansion call for hydronic heating on the boiler loop.
Boiler Target ----------------------------------------------------------------------------------------- -----------------------------------------------------------------------------------------
When there are no Boiler calls, the boiler target in the View
menu on the display will show ‘– – –’ to indicate there is
no requirement for boiler operation.
Once a Boiler Call is present, a boiler target is determined by
the control using the boiler heating curve (boiler minimum,
boiler design and outdoor design settings) together with
indoor temperature feedback from the thermostats. The
heating curve operates based on the principle that a buildings
heat loss increases with colder outdoor temperatures. The
calculated Boiler Target will be shown in the View menu
on the display.
Boiler Minimum
The House Control protects non-condensing boilers from
sustained flue gas condensation through the Boiler Minimum
setting. The boiler minimum is the lowest temperature that
the control is allowed to use as a boiler target temperature.
If the boiler is operating at the boiler minimum temperature,
the “MIN” segment is turned on in the display when viewing
either the boiler supply temperature or the boiler target
temperature.
Boiler Heating Curve
(70°F Outdoor,
Boiler Minimum)
Decreasing Outdoor Temperatures
Increasing W
a
ter T
e
mperatures
(Outdoor Design,
Boiler Design)
Boiler Maximum
The control has a fixed boiler maximum temperature of
+10°F (+5.5°C) higher than the Boiler Design setting for
the Boiler Heating Curve. When this occurs, the “MAX”
segment will display when viewing the boiler target or
boiler supply temperature in the view menu. The control
will operate the boiler so that the boiler supply temperature
will never exceed 210°F (99.0°C).
Boil
Calls