93
Temperature Compensated Start
This logic is used when the unit is in the unoccupied state. The
control will calculate early Start Bias time based on Space
Temperature deviation from the occupied cooling and heating
set points. This will allow the control to start the unit so that
the space is at conditioned levels when the occupied period
starts. This is required for ASHRAE 90.1-2013 compliance. A
space sensor is required for non-linkage applications.
SETTING UP THE SYSTEM
The settings for temperature compensated start can be found in
the local display under Configuration
UNIT.
TCST-Cool Factor (TCS.C)
This is the factor for the start time bias equation for cooling.
TCST-Heat Factor (TCS.H)
This is the factor for the start time bias equation for heating.
NOTE: Temperature compensated start is disabled when these
factors are set to 0.
TEMPERATURE COMPENSATED START LOGIC
The following conditions must be met for the algorithm to run:
• Unit is in unoccupied state.
• Next occupied time is valid.
• Current time of day is valid.
• Valid space temperature reading is available (sensor or
DAV-Linkage).
The algorithm will calculate a Start Bias time in minutes using
the following equations:
If (space temperature > occupied cooling set point)
Start Bias Time = (space temperature – occupied cooling
set point)* TCS.C
If (space temperature < occupied heating set point)
Start Bias Time = (occupied heating set point – space tem-
perature)*TCS.H
• When the Start Bias Time is greater than zero, the algorithm
will subtract it from the next occupied time to calculate the
new start time. When the new start time is reached, the Tem-
perature Compensated Start mode is set (Operating
Modes
MODE
T.C.ST), the fan is started and the unit
controlled as in an occupied state. Once set, Temperature
Compensated mode will stay on until the unit goes into the
Occupied mode. The Start Bias Time will be written into the
CCN Linkage Equipment Table if the unit is controlled in
DAV mode. If the Unoccupied Economizer Free Cool mode
is active (Operating Modes
HVAC = “UNOCC FREE
COOL”) when temperature compensated start begins, the
Unoccupied Free Cool mode will be stopped.
Carrier Comfort Network
®
(CCN)
It is possible to configure the ComfortLink controls to partici-
pate as an element of the Carrier Comfort Network (CCN) sys-
tem directly from the local display. This section will deal with
explaining the various programmable options which are found
under the CCN sub-menu in the Configuration mode.
The major configurations for CCN programming are located in
the local displays at Configuration
CCN. See Table 73.
CCN Address (CCNA)
This configuration is the CCN address the rooftop is assigned.
CCN Bus Number (CCNB)
This configuration is the CCN bus the rooftop is assigned.
CCN Baud Rate (BAUD)
This configuration is the CCN baud rate.
CCN Time/Date Broadcast (TM.DT)
If this configuration is set to ON, the control will periodically
send the time and date out onto the CCN bus once a minute. If
this device is on a CCN, network then it will be important to
make sure that only one device on the bus has this configura-
tion set to ON. If more than one time broadcaster is present,
problems with the time will occur.
NOTE: Only the time and date broadcaster can perform daylight
savings time adjustments. Even if the rooftop is standalone, the
user may want to set this to ON to accomplish the daylight/savings
function.
CCN OAT Broadcast (OAT.B)
If this configuration is set to ON, the control will periodically
broadcast its outside-air temperature at a rate of once every
30 minutes.
CCN OARH Broadcast (ORH.B)
If this configuration is set to ON, the control will periodically
broadcast its outside air relative humidity at a rate of once ev-
ery 30 minutes.
Table 73 — CCN Configuration
ITEM EXPANSION RANGE UNITS CCN POINT
TCS.C Temp.Cmp.Strt.Cool Factr 0 to 60 min TCSTCOOL
TCS.H Temp.Cmp.Strt.Heat Factr 0 to 60 min TCSTHEAT
ITEM EXPANSION RANGE UNITS CCN POINT DEFAULT
CCN CCN CONFIGURATION
CCNA CCN Address 1 to 239 CCNADD 1
CCNB CCN Bus Number 0 to 239 CCNBUS 0
BAUD CCN Baud Rate 1 to 5 CCNBAUDD 3
BROD CCN BROADCST DEFINITIONS
TM.DT CCN Time/Date Broadcast ON/OFF CCNBC On
OAT.B CCN OAT Broadcast ON/OFF OATBC Off
ORH.B CCN OARH Broadcast ON/OFF OARHBC Off
OAQ.B CCN OAQ Broadcast ON/OFF OAQBC Off
G.S.B Global Schedule Broadcst ON/OFF GSBC Off
B.ACK CCN Broadcast Ack'er ON/OFF CCNBCACK Off
SC.OV CCN SCHEDULES-OVERRIDES
SCH.N Schedule Number 0 to 99 SCHEDNUM 1
HOL.T Accept Global Holidays? YES/NO HOLIDAYT No
O.T.L. Override Time Limit 0 to 4 HRS OTL 1
OV.EX Timed Override Hours 0 to 4 HRS OVR_EXT 0
SPT.O SPT Override Enabled ? YES/NO SPT_OVER Yes
T58.O T58 Override Enabled ? YES/NO T58_OVER Yes
GL.OV Global Sched. Override ? YES/NO GLBLOVER No
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