tekmar 363 Universal Reset Control Installation - Manual (Page 13)

13 of 40 Copyright © D 363 -
12/08
MIXING SETBACK (MIX SETB)
(
RESET RATIO )
The MIX SETB is the amount that the mixing supply water temperature is
reduced when the 363 is placed into an
UnOccupied mode, using an
internal or an external setback as described in Section A. This setting is only
available if the
Reset Ratio DIP switch is selected and Setback/None DIP
switch is set to Setback.
MIXING INDOOR (MIX INDR)
(
CHARACTERIZED HEATING CURVE
)
The MIX INDR is the room temperature used in the original heat loss
calculations for the building. This setting establishes the beginning of the
Characterized Heating Curve for the mixing zones. This single setting
replaces the MIX STRT water temperature and OUT STRT
air temperature
settings used by the Reset Ratio.
MIXING MINIMUM (MIX MIN)
(
CHARACTERIZED HEATING CURVE )
The MIX MIN is the lowest temperature that the control is allowed to use as
a MIX TRG temperature. During mild conditions, if the 363 calculates a MIX
TRG temperature that is below the MIX MIN setting, the MIX TRG temperature
is adjusted to match the MIX MIN setting. During this condition, the
Minimum pointer turns on in the LCD when either the MIX TRG temperature
or the MIX SUP temperature is being viewed.
If either an Indoor Sensor or a Room Temperature Unit (RTU) are used and the 363 is operating at the MIX MIN temperature, the Mixing
Pump (P2) is cycled using Pulse Width Modulation (PWM) with a 15 minute cycle length. By cycling the Mixing Pump (P2) and controlling
the flow of supply water, the control provides an average supply water temperature to the mixing system. This average temperature is
equal to the original MIX TRG. This minimizes overheating of the zone while the control is operating at the MIX MIN temperature.
MIX ROOM OCC & UNOCC (MIX ROOM)
(
CHARACTERIZED HEATING CURVE )
The MIX ROOM is the desired room temperature for the mixing zones and it provides a parallel shift of the Characterized Heating Curve.
The room temperature desired by the occupants is often different from the design indoor temperature (MIX INDR). If the room
temperature is not correct, adjusting the MIX ROOM
setting increases or decreases the amount of heat available to the building. If the
Setback / None DIP switch is set to Setback, a MIX ROOM setting must be made for both the Occupied and UnOccupied modes.
MIXING TARGET TEMPERATURE (MIX TRG)
(
RESET RATIO & CHARACTERIZED HEATING CURVE
)
The MIX TRG temperature is determined from either the Characterized Heating Curve or the Reset Ratio settings and the outdoor air
temperature. The control displays the temperature that it is currently trying to maintain as the mixing supply temperature. If the control
does not presently have a requirement for heat, it displays “- - -” in the LCD.
MIXING PUMP (P2) OPERATION
The Mixing Pump (P2) contact (terminal 11) closes whenever there is a Mixing Demand and the 363 is not in WWSD. During WWSD,
the Mixing Pump is operated based on the EXERCISE setting in the Adjust Menu .
BOILER MINIMUM PROTECTION (Boil MIN)
The 363 is capable of providing boiler protection from cold mixing system
return water temperatures. If the boiler supply temperature is cooler than
the Boil MIN setting while the boiler is firing, the 363 reduces the output from
the mixing device. This limits the amount of cool return water to the boiler
and allows the boiler supply temperature to recover.
Section D2 —Mixing Device
MIXING DEVICE SELECTION (MIXING)
The 363 can supply a lower water temperature to part of the heating system by varying the speed of an injection pump or modulating
a mixing valve. This selection is made under the MIXING item in the
Adjust Menu.
Sequence, Section D
70
(21)
90
(32)
110
(43)
130
(54)
150
(66)
170
(77)
190
(88)
Outdoor Air Temperature
Supply W
ater
T
emperature
210
(99)
-20
(-29)
0
(-18)
20
(-7)
40
(5)
60
(16)
80
(27)
MIX DSGN
MIX MAX
MIX MIN
WWSD Unocc MIX IND
OUT DSGN
Mixing Characterized
Heating Curve
WWSD Occ
50
(10)
MIX ROOM Occ
MIX ROOM Unocc