tekmar 363 Universal Reset Control Installation - Manual (Page 4)

4 of 40 Copyright © D 363 -
12/08
Section A —General Operation
POWERING UP THE CONTROL
When the Universal Reset Control 363 is powered up, the control displays the control type number in the LCD for 2 seconds. Next, the
software version is displayed for 2 seconds. Finally, the control enters into the normal operating mode and the LCD defaults to displaying
the current outdoor air temperature.
CHARACTERIZED HEATING CURVE OR RESET RATIO
The 363 has two methods of varying the supply water temperature based on the outdoor air
temperature. The installer can select either a
Characterized Heating Curve or a Reset Ratio.
Characterized Heating Curve
The Characterized Heating Curve method of controlling the supply water temperature
based on outdoor air temperature and optionally indoor temperature is the most accurate.
The control takes into account the type of terminal unit that the system is using. Since
different types of terminal units transfer heat to a space using different proportions of
radiation, convection and conduction, the supply water temperature must be controlled
differently. Once the control is told what type of terminal unit is used, the control varies the
supply water temperature according to the type of terminal unit. This improves the control
of the air temperature in the building.
Reset Ratio
The Reset Ratio method of controlling the supply water temperature is based solely on the
outdoor air temperature. This method does not take into account the type of terminal unit
that the heating system is using and therefore is not as accurate as a
Characterized Heating
Curve.
TERMINAL UNITS (Boil TERM / MIX TERM)
When using a Characterized Heating Curve, the control requires the selection of a terminal
unit. The terminal unit determines the shape of the Characterized Heating Curve according
to how the terminal unit delivers heat into the building space. The 363 provides for selection
between six different terminal unit types: two types of hydronic radiant floor heat, fancoil, fin–
tube convector, radiator, and baseboard.
Hydronic Radiant Floor (HRF 1)
HRF1 is a heavy, or high mass, hydronic radiant floor system. This type of a hydronic radiant
floor is embedded in either a thick concrete or gypsum pour. This heating system has a large
thermal mass and is slow acting.
Hydronic Radiant Floor (HRF 2)
HRF2 is a light, or low mass, hydronic radiant floor system. Most commonly, this type of
radiant heating system is either attached to the bottom of a wood sub floor, suspended in
the joist space, or sandwiched between the subfloor and the surface. This type of radiant
system has a relatively low thermal mass and responds faster than a high mass system.
Fancoil (COIL)
A fancoil terminal unit or air handling unit (AHU) consists of an hydronic heating coil and
either a fan or blower. Air is forced across the coil at a constant velocity by the fan or blower
and is then delivered into the building space.
Sequence of Operation
Characterized Heating Curve
Outdoor DSGN
Increasing W
ater
T
emperature
MIX or BOIL DSGN
Decreasing Air Temperature
MIX or
BOIL
INDR
Increasing W
ater
T
emperature
MIX or BOIL DSGN
Reset Ratio
Outdoor DSGN
MIX or
BOIL
STRT
Decreasing Air Temperature
OUT STRT
Section A
General Operation
Page 4 - 6
Section B
Boiler Reset
Page 6 - 8
Section C
Domestic Hot
Water/Setpoint
Page 9 - 11
Section E
Storage
Page 15 -16
Section D
Mixing Reset
Page 12 - 15
HRF 2
COIL
HRF 1