Note:
The relationship between RSTR and RENd
(RSTR > RENd or RSTR < RENd) determines
whether an increase in temperature sensed
at Sn-1 increases or decreases the RSP. The
examples shown in Figure 14 (RSTR > RENd)
show RSP increases when the temperature
increases at the Sn-1 Master sensor.
The following figure shows a Reset Range Start
Temperature value of 50 (°F) selected.
Figure 18: Reset Range Start Temperature Selection
screen
5.
In the
Reset Range End Temperature Selection
screen, press
Up
or
Down
to select the Reset End
Temperature value (sensed at the Master sensor
Sn-1). The Reset End Temperature (RENd) value and
the RSTR value establish the temperature range
over which the RSP is calculated. RSTR and RENd are
sensed at the Sn-1 Master sensor (typically outdoor
air temperature). RENd defines the low limit of
the temperature range and corresponds with the
MXSP. As the outdoor air temperature increases
above the RENd, the RSP is driven from the MXSP
towards MNSP. See Figure 14. Press
Next
to save
your selection and go to the next screen.
The following figure shows a Reset Range End
Temperature value of 0 (°F) selected.
Figure 19: Reset Range End Temperature Selection screen
6.
In the
Shutdown High Temperature Selection
screen, press
Up
or
Down
to select the Shutdown
High Temperature value (sensed at the Master
sensor Sn-1). Shutdown High Temperature (SdHI)
value establishes a high temperature limit (sensed
at the Master sensor) at which relay outputs go to
OFF and analog outputs go to the Output at Setpoint
(OSP) value for all outputs in your control system
that reference the Reset Setpoint sensor (rES). SdHI
is typically used for heating systems to shutdown
(relay) or limit (analog) output at high outdoor air
temperatures. Press
Next
to save your selection and
go to the next screen.
The following figure shows an Shutdown High
Temperature value of 65 (°F) selected.
Figure 20: Shutdown High Temperature Selection screen
7.
In the
Shutdown Low Temperature Selection
screen, press
Up
or
Down
to select the Shutdown
Low Temperature value (sensed at the Master sensor
Sn-1). Shutdown Low Temperature (SdLO) value
establishes a low temperature limit (sensed at the
Master sensor) at which the relay outputs go to OFF
and the analog outputs go to the Output at Setpoint
(OSP) value for all outputs in your control system
that references the Reset Setpoint sensor (rES). SdLO
is typically used for cooling systems to shutdown
(relay) or limit (analog) output at low outdoor air
temperatures. Press
Next
to save your selection and
go to the next screen.
The following figure shows no Shutdown Low
Temperature value selected.
Figure 21: Shutdown Low Temperature Selection screen
8.
In the
Unoccupied Setback Selection
screen,
press
Up
or
Down
to select the Setback value
for the controlled condition (temperature or
humidity) during scheduled Unoccupied times. The
selected Setback (SbK) value determines a (floating)
unoccupied setback value (RSP + SbK) for all of the
relay and analog outputs that reference the rES
sensor. The unoccupied Setback value (RSP + SbK) is
referenced during all scheduled unoccupied times.
Press
Next
to save your selection and go to the next
screen.
Note:
To use the Setback feature in your
control system, you must also set up the (real)
time and day of week, and a weekly occupied/
for more information and
setup procedures.
Note:
Setback set point temperature does
not exceed MXSP or go lower than MNSP. In
reset, MNSP and MXSP are limits to set point
excursion.
The following figure shows a Setback value of
-10 (°F) selected.
Figure 22: Unoccupied Setback Selection screen
System 450 Series Reset Control Modules with Real-Time Clock and Relay Output Installation Guide
11
