tekmar 361 Mixing Control - Manual (Page 8)

Copyright © D 361 -
03/09
8 of 20
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 361 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 361 is operating at the MIX MIN
temperature, the system pump is cycled using Pulse Width Modulation
(PWM) with a 15 minute cycle length. By cycling the system pump and
controlling 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
361 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.
Section C: Boiler Operation
Section C1
General Operation
Section C2
Boiler Sensor
Placement
Section C1: General Operation
BOILER OPERATION
When the 361 determines that boiler operation is required, the Boiler contact terminals (9 and 10) 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 361 provide boiler protection. In this case, when the boiler is firing and the boiler temperature is below the BOIL MIN
setting, the 361 turns on the MIN segment and reduces the heating load on the boiler by limiting the output of the variable speed
injection pump. 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.
WWSD OCC
70
(21)
90
(32)
110
(43)
130
(54)
150
(66)
170
(77)
190
(88)
Outdoor Air Temperature
Supply W
ater
T
emperature
210 °F
(99 °C)
-20
(-29)
0
(-18)
20
(-7)
40
(5)
60
(16)
80 °F
(27 °C)
MIX DSGN
MIX MAX
MIX MIN
WWSD UNOCC MIX INDR
OUTDR DSGN
Mixing Characterized
Heating Curve
50
(10)
ROOM UNOCC
ROOM OCC