tekmar 360 Mixing Control - Manual (Page 8)

© 2009 D 360 - 03/09 8 of 20
MIXING DESIGN (MIX DSGN)
The MIX DSGN temperature is the supply water temperature required to heat the mixing zones when the outdoor air is as cold as
the OUTDR DSGN temperature.
MIXING MAXIMUM (MIX MAX)
The MIX MAX sets the highest water temperature that the control is allowed to calculate as the MIX TARGET temperature. If the
control does target the MIX MAX setting, and the MIX temperature is near the MIX MAX, the MAX segment will be displayed in the
LCD while either the MIX TARGET temperature or the MIX temperature is being viewed.
MIXING MINIMUM (MIX MIN)
The MIX MIN is the lowest temperature that the control is allowed to use
as a MIX TARGET temperature. During mild conditions, if the 360 cal-
culates a MIX TARGET temperature that is below the MIX MIN setting,
the MIX TARGET temperature is adjusted to match the MIX MIN set-
ting. During this condition, the MIN segment will be displayed in the LCD
when either the MIX TARGET or MIX temperature is being viewed. If an
indoor sensor is used, and the 360 is operating at the MIX MIN tempera-
ture, the system pump is cycled using Pulse Width Modulation (PWM)
with a 15 minute cycle length. By cycling the system pump and control-
ling the flow of supply water, the control provides an average supply
water temperature to the system. This average temperature is equal to
the original MIX TARGET. This minimizes overheating of the zone while
the control is operating at the MIX MIN temperature.
WARM WEATHER SHUT DOWN (WWSD) OCC & UNOCC
When the outdoor air temperature rises above the WWSD setting, the
360 turns on the WWSD segment in the display. When the control is in
Warm Weather Shut Down, the Mixing Demand pointer is displayed if
there is a demand. However the control does not operate the heating
system to satisfy this demand. If the control is in setpoint mode, the
WWSD feature is not functional.
BOILER OPERATION
When the 360 determines that boiler operation is required, the Boiler contact terminals (7 and 8) close. While the Boiler contact is
closed, the burner segment in the LCD is displayed.
BOILER MINIMUM (BOIL MIN)
Most boilers require a minimum water temperature in order to prevent flue gas condensation. The BOIL MIN adjustment is set to
the boiler manufacturer’s minimum recommended operating temperature. Only when the boiler temperature is measured by a boiler
sensor can the 360 provide boiler protection. In this case when the boiler is firing and the boiler temperature is below the BOIL MIN
Setting the 360 turns on the MIN segment and reduces the heating load on the boiler by limiting the output of the mixing valve. If
the installed boiler is designed for low temperature operation, set the BOIL MIN adjustment to OFF.
BOILER PROTECTION
Refer to section A for a description of boiler protection.
Section C: Boiler Operation
MIX MAX
MIX DSGN
OUT DSGN
WWSD Occ
MIX ROOM Occ
MIX ROOM UnOcc
WWSD UnOcc
210
(99)
190
(88)
170
(77)
150
(66)
130
(54)
110
(43)
90
(32)
70
(21)
(50°F)
(10°C)
-20
(-29)
0
(-18)
20
(-7)
40
(5)
60
(16)
80
(27)
Outdoor Air Temperature
Supply W
a
ter T
e
mperatur
e
Mixing Characterized
Heating Curve
Mixing Characterized
Heating Curve
MIX MIN
MIX INDR
Section C1: General Operation
Section C1
General
Operation
Section C2
Boiler Sensor
Placement