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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
COOL") when temperature compensated start begins, the
Unoccupied Free Cool mode will be stopped.
Carrier Comfort Network
It is possible to configure the ComfortLink controls to participate
as an element of the Carrier Comfort Network (CCN) system di-
rectly 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 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 de-
vice is on a CCN, network then it will be important to make sure
that only one device on the bus has this configuration 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 every
30 minutes.
HVAC = "UNOCC FREE
®
(CCN)
CCN. See Table 75.
CCN OAQ Broadcast (OAQ.B)
If this configuration is set to ON, the control will periodically
broadcast its outside air quality reading at a rate of once every 30
minutes.
Global Schedule Broadcast (G.S.B)
If this configuration is set to ON and the schedule number
(SCH.N) is between 65 and 99, then the control will broadcast the
internal time schedule once every 2 minutes.
CCN Broadcast Acknowledger (B.ACK)
If this configuration is set to ON, then when any broadcasting is
done on the bus, this device will respond to and acknowledge.
Only one device per bus can be configured for this option.
Schedule Number (SCH.N)
This configuration determines what schedule the control may
follow.
SCH.N = 0
The control is always occupied.
SCH.N = 1
The control follows its internal time schedules.
The user may enter any number between 1 and
64 but it will be overwritten to "1" by the con-
trol as it only has one internal schedule.
SCH.N = 65-99
The control is either set up to receive to a
broadcast time schedule set to this number or
the control is set up to broadcast its internal
time schedule (G.S.B) to the network and this is
the global schedule number it is broadcasting.
If this is the case, then the control still follows
its internal time schedules.
Accept Global Holidays? (HOL.T)
If a device is broadcasting the time on the bus, it is possible to ac-
cept the time yet not accept the global holiday from the broadcast
message.
Override Time Limit (O.T.L)
This configuration allows the user to decide how long an override
occurs when it is initiated. The override may be configured from 1
to 4 hours. If the time is set to 0, the override function will become
disabled.
Timed Override Hours (OV.EX)
This displays the current number of hours left in an override. It is
possible to cancel an override in progress by writing "0" to this
variable, thereby removing the override time left.
SPT Override Enabled? (SPT.O)
If a space sensor is present, then it is possible to override an unoc-
cupied period by pushing the override button on the T55 or T56
sensor. This option allows the user to disable this function by set-
ting this configuration to NO.
T58 Override Enabled? (T58.O)
The T58 sensor is a CCN device that allows cooling/heating set
points to be adjusted, space temperature to be written to the roof-
top unit, and the ability to initiate a timed override. This option al-
lows the user to disable the override initiated from the T58 sensor
by setting this option to NO.
Global Schedule Override? (GL.OV)
If the control is set to receive global schedules, then it is also pos-
sible for the global schedule broadcaster to call out an override
condition as well. This configuration allows the user to disable the
global schedule broadcaster from overriding the control.
97
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Table of Contents
Troubleshooting
