Mixing reset ratio – tekmar 363 Universal Reset Control Installation User Manual

Page 12

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Copyright © D 363 -

12/08

Section D1—General Mixing Operation

MIXING DEMAND

A mixing demand

is generated by applying a voltage between 24 and 240

V (ac) across the

Mix Demand terminals (1 and 2). Once voltage is

applied, the

Mix Demand pointer is displayed in the LCD. If the 363 is not

in WWSD, the 363 closes the

Mix P2 contact and the Boil P1 contact. The

control turns on the boiler pump and mixing pump segments in the LCD.
The 363 calculates a MIX TRG supply temperature based on the outdoor
air temperature and settings. If required, the 363 operates the boiler in
order to provide heat to the mixing device.

MIXING START (MIX STRT)

(

RESET

RATIO

)

The MIX STRT temperature is the mixing supply water temperature that
the heating system requires when the outdoor air temperature equals the
OUT STRT

air temperature.

OUTDOOR START (OUT STRT)

(

RESET

RATIO

)

The OUT STRT temperature is the outdoor air temperature at which the
control provides the MIX STRT supply water temperature to the system.

OUTDOOR DESIGN (OUT DSGN)
(

RESET

RATIO

&

CHARACTERIZED

HEATING

CURVE

)

The OUT DSGN is the outdoor air temperature that is the typical coldest
temperature of the year where the building is located. This temperature
is used when doing heat loss calculations for the building.

MIX DESIGN (MIX DSGN)
(

RESET

RATIO

&

CHARACTERIZED

HEATING

CURVE

)

The MIX DSGN temperature is the supply water temperature required to
heat the mixing zones when the outdoor air is as cold as the Outdoor
Design temperature.

MIXING MAXIMUM (MIX MAX)
(

RESET

RATIO

&

CHARACTERIZED

HEATING

CURVE

)

The MIX MAX sets the highest water temperature that the control is
allowed to calculate as the MIX TRG temperature. If the control does
target the MIX MAX setting, and the MIX SUP

temperature is within 5˚F

(3˚C) of the MIX MAX, the

Maximum pointer is displayed in the LCD while

either the MIX TRG temperature or the MIX SUP

temperature is

being viewed.

WARM WEATHER SHUT DOWN (WWSD) OCC & UNOCC
(

RESET

RATIO

&

CHARACTERIZED

HEATING

CURVE

)

When the outdoor air temperature rises above the WWSD setting, the 363 turns on the

WWSD pointer in the display. When the control

is in Warm Weather Shut Down, the

Mix Demand pointer is displayed if there is a demand. However, the control does not operate the

heating system to satisfy this demand. The control does respond to either a

DHW Demand or a Setpoint Demand and operates as

described in Section C.

Section D —Mixing Reset

Section D1

General Mixing

Operation

Section D2

Mixing Device

Section D3

Alternate Mixing

Demands

1

2

Mix

Demand

24 to 240 V (ac)

Outdoor Air Temperature

70

(21)

90

(32

110

(43)

130

(54)

150

(66)

170

(77)

190

(88)

Supply W

ater

T

emperature

210

(99)

-20

(-29)

0

(-18)

20

(-7)

40

(5)

60

(16)

80

(27)

MIX DSGN

MIX MAX

MIX STRT

OUT STRT

WWSD Unocc

WWSD Occ

MIX SETB

OUT DSGN

Mixing Reset

Ratio

No

rm

al

Se

tb

ac

k

Mix MAX

Mixed Su

pp

ly

W

ate

r Temper

atu

re

Pointer On

Pointer On

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