19
OPTIMAL START — The control will compute a time period
(in minutes) to start Occupied Mode Warm-up prior to start of
the Occupied Mode schedule, to arrive at Occupied set points
just as Occupied period begins. Optimal Start is Mode 26.
Optimal Start is allowed only if the RAT is less than Occu-
pied Heating Set Point (VAV units), or if the space temperature
is less than the Occupied Heating Set Point (CV units). The
control checks the return air/space temperature, the time for
start of Occupied period (day, hr), and the time for last Unoccu-
pied period (day, hr). The control computes a biased start time
period to meet the needs of the Optimal Start. The control ini-
tiates the Occupied Heating function at the calculated time. The
fan is energized and heating starts. If Warm-Up function is still
required as Time Schedule changes to Occupied period, Warm-
up Heating will continue until OHSP is satisfied (even in
VAV system which has NOT been configured for Occupied
Heating).
Configuration — To enable Optimal Start, press
to
enter into the Service function. Enter the password. Press
to enter into the User Configuration subfunction.
Scroll down to OSEN. The current configuration will be
shown.The default is 0 (disabled). Press
to enable the
Optimal Start. The acceptable range of values is 0 and 1, where
0 is disabled and 1 is enabled.
When Optimal Start is enabled, 3 other set points should be
configured to allow Optimal Start to work correctly. They are
Building Factor, 24-hr Unoccupied Factor, and Set Point Bias.
To set the Building Factor, press
to enter into the
Service function. Enter the password. Press
to
enter into the AOSS (Adaptive Optimal Start/Stop) subfunc-
tion. Scroll down to BLDF. The current set point will be
shown. The default is 10%. The acceptable range of values is 1
to 100%. To change the set point, enter the new number (exam-
ple:
) and press
.
To set the 24-Hr Unoccupied Factor, press
to en-
ter into the Service function. Enter the password. Press
to enter into the AOSS (Adaptive Optimal Start/
Stop) subfunction. Scroll down to UOCF. The current set point
will be shown. The default is 15%. The acceptable range of
values is 0 to 99%. To change the set point, enter the new num-
ber (example:
) and press
.
To set the Set Point Bias, press
to enter into
the Service function. Enter the password. Press
to
enter into the AOSS (Adaptive Optimal Start/Stop) subfunc-
tion. Scroll down to SETB. The current set point bias will be
shown. The default is 2 F. The acceptable range of values is 1
to 10 F. To change the set point, enter the new number (exam-
ple:
) and press
. See Table 17.
OPTIMAL STOP (CV Units Only) — The control will com-
pute a time period prior to end of the current Occupied period,
then allow space temperature to drift up/down to the Expanded
Occupied Set Point by end of scheduled Occupied period. Op-
timal Stop is Mode 29.
The control will calculate a bias time (in minutes) that will
be subtracted from end-of-Occupied time. The control will al-
low the space temperature set point value to be adjusted by the
Set Point Bias and then adjust required stages of capacity to
permit drift in space temperature.
Configuration — To enable Optimal Stop, press
to
enter into the Service function. Enter the password. Press
to enter into the User Configuration subfunction.
Scroll down to OSEN. The current configuration will be
shown. The default is 0 (disabled). Press
to enable the
Optimal Stop. The acceptable range of values is 0 and 1, where
0 is disabled and 1 is enabled.
When Optimal Stop is enabled, 3 other set points should be
configured to allow Optimal Stop to work correctly. They are
Building Factor, 24-hr Unoccupied Factor, and Set Point Bias.
To set the Building Factor, press
to enter into
the Service function. Enter the password. Press
to
enter into the AOSS (Adaptive Optimal Start/Stop) subfunc-
tion. Scroll down to BLDF. The current set point will be
shown. The default is 10%. The acceptable range of values is 1
to 100%. To change the set point, enter the new number (exam-
ple:
and press
.
To set the 24-Hr Unoccupied Factor, press
to enter
into the Service function. Enter the password. Press
to enter into the AOSS (Adaptive Optimal Start/
Stop) subfunction. Scroll down to UOCF. The current set point
will be shown. The default is 15%. The acceptable range of
values is 0 to 99%. To change the set point, enter the new num-
ber (example
) and press
.
To set the Set Point Bias, press
to enter into
the Service function. Enter the password. Press
to
enter into the AOSS (Adaptive Optimal Start/Stop) subfunc-
tion. Scroll down to SETB. The current set point bias will be
shown. The default is 2 F. The acceptable range of values is 1
to 10 F. To change the set point, enter the new number (exam-
ple
) and press
. See Table 17.
An optional Maximum Allowable Stop Time function is
available. Service Tool, CCN Building Supervisor, or Comfort-
WORKS® is required to change this parameter. The set point
name is OSMT. The default is 60 minutes. The range is 10 to
120 minutes. The Maximum Allowable Stop Time will limit
how long Optimal Stop can be active.
Table 17 — Configuring Adaptive Optimal Start-Stop (AOSS) (Stop available only on CV)
ENTER
ENTER
ENTER
ENTER
ENTER
ENTER
ENTER
ENTER
DESCRIPTION
HOW TO CONFIGURE AT HSIO
SET POINT
RANGE
Enable AOSS
OSEN
Enable = 1; Disable = 0
Set Building Factor
BLDF
1 to 100%
Set 24-Hr Unoccupied Factor
UOCF
0 to 99%
Select Set Point Bias
SETB
1 to 10 F (.6 to 5.6 C)