Boiler characterized heating curve – tekmar 363 Universal Reset Control Installation User Manual

Page 7

7 of 40

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BOILER DESIGN (Boil DSGN) (

RESET

RATIO

CHARACTERIZED

HEATING

CURVE

)

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

BOILER MINIMUM (Boil MIN)
(

RESET

RATIO

CHARACTERIZED

HEATING

CURVE

)

The Boil MIN is the lowest water temperature that the control is allowed
to use as a boiler target (Boil TRG)

temperature. During mild conditions,

if the 363 calculates a Boil TRG

temperature that is below the

Boil MIN

setting, the Boil TRG temperature is adjusted to be at least the Boil MIN
setting. During this condition, if the boiler is operating, the

Minimum

pointer turns on in the LCD while the Boil TRG

or the Boil SUP

temperature is viewed. If the installed boiler is designed for condensing
operation, set the Boil MIN adjustment to OFF.

BOILER MAXIMUM (Boil MAX)
(

RESET

RATIO

CHARACTERIZED

HEATING

CURVE

)

The Boil MAX is the highest water temperature that the control is allowed
to use as a Boil TRG temperature. If the control does target Boil MAX,
and the Boil SUP temperature is near the Boil MAX temperature, the
Maximum pointer turns on in the LCD while the Boil TRG or the Boil SUP
temperature is viewed. At no time does the control operate the boiler
above 248˚F (120˚C).

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

Boiler 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.

BOILER SETBACK (Boil SETB) (

RESET

RATIO

)

The Boil SETB is the amount that the boiler 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.

BOILER INDOOR (Boil INDR)
(

CHARACTERIZED

HEATING

CURVE

)

The Boil 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 boiler zones. This single setting
replaces the Boil STRT water temperature and OUT STRT

air tempera-

ture settings used by the

Reset Ratio.

BOILER ROOM OCC & UNOCC (Boil ROOM)
(

CHARACTERIZED

HEATING

CURVE

)

The Boil ROOM is the desired room temperature for the boiler zones and
it provides a parallel shift of the

Characterized Heating Curve. The room

temperature desired by the occupants is often different from the de-
signed indoor temperature (Boil INDR). If the room temperature is not
correct, adjusting the Boil ROOM

setting increases or decreases the

amount of heat available to the building. If the

Setback / None DIP switch

is set to

Setback, a Boil ROOM setting must be made for both the

Occupied and UnOccupied modes.

BOILER TARGET TEMPERATURE (Boil TRG)
(

RESET

RATIO

CHARACTERIZED

HEATING

CURVE

)

The Boil TRG temperature is determined from either the

Characterized

Heating Curve or the Reset Ratio settings and the outdoor air tempera-
ture. The control displays the temperature that it is currently trying to
maintain as the boiler supply temperature. If the control does not
presently have a requirement for heat, it displays “- - -” in the LCD.

Boil Max + 1/2 Boiler Differential

Boil Max - 1/2 Boiler Differential

Boil W

ate

r Te

era

tur

Pointer On

Boil MAX

(21)

(32)

110

(43)

130

(54)

150

(66)

170

(77)

190

(88)

Outdoor Air Temperature

Supply W

ater

emperature

210

(99)

-20

(-29)

(-18)

(-7)

(5)

(16)

(27)

Boil DSGN

Boil MAX

Boil MIN

WWSD Unocc

Boil IND

OUT DSGN

Boiler Characterized

Heating Curve

WWSD Occ

(10)

Boil ROOM Occ

Boil ROOM UnOcc

Pointer On

Boil MIN

Boil Wat

er Te

mpe

ratu

Boil Min + 1/2 Boiler Differential

Boil Min - 1/2 Boiler Differential