30
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 Temperature
Compensated Start mode is set, 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 when
temperature compensated start begins, the Unoccupied Free Cool
mode will be stopped.
NOTE: The maximum minutes Start Bias can be is 180.
Carrier Comfort Network (CCN)
R
Configuration
It is possible to configure the ComfortLink control to participate as
an element of the Carrier Comfort Network (CCN) system 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 ConfigurationCCN. See Appendix A.
CCN Address (CCN.A)
This configuration is the CCN address the rooftop is assigned.
CCN Address (CCN.B)
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 (BRODB.TIM)
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 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 stand
alone, the user may want to set this to ON to accomplish the
daylight/savings function.
CCN OAT Broadcast (BRODB.OAT)
If this configuration is set to ON, the control will periodically
broadcast its outside-air temperature at a rate of once every 30
minutes.
Global Schedule Broadcast (BRODB.GS)
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 (BRODB.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.OSCH.N)
This configuration determines what schedule the control may
follow.
SCH.N = 0 The control is always occupied.
SCH.N = 1 The control follo ws its internal
time schedules. The user may
enter any number between 1
and 64 but it will be overwritten
to “1” by the co nt rol as it onl y
has one internal schedule.
SCH.N = 65---99 The co ntro l is either set up to
receive to a broadcasted time
schedule set to t his number or
the control is set up to
bro ad c as t it s internal ti me
schedule (B.GS)tothenetwork
and this is the global schedule
number it is broadcasting. If this
is the case, then the control still
foll ow s its internal time
schedules.
Accept Global Holidays? (SCH.OHOL.G)
If a device is broadcasting the time on the bus, it is possible to accept the
time yet not accept the global holiday from the broadcast message.
Override Time Limit (SCH.OOV.TL)
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 (SCH.OOV.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? (SCH.OOV.SP)
If a space sensor is present, then it is possible to override an
unoccupied period by pushing the override button on the T55 or
T56 sensor. This option allows the user to disable this function by
setting this configuration to NO.
Demand Limit
Demand Limit Control may override the cooling algorithm to limit
or reduce cooling capacity during run time. The term Demand
Limit Control refers to the restriction of machine capacity to
control the amount of power that a machine will use. This can save
the owner money by limiting peaks in the power supply. Demand
limit control is intended to interface with an external network
system. This is through a CCN Loadshed POC Device or writing
to network points.
To limit stages through network writes, the points Run Status
COOLMAX.C and Run StatusHEATMAX.H are forced
on the network through CCN points MAXCSTGS and
MAXHSTGS respectively. Force these to the desired maximum
stages of cooling/dehumidification and heating, respectively. When
there is no force on these points, they automatically reset to allow
all cooling/dehumidification and heating stages to be used. These
points are reset at power--on/reset (POR).
When using the Loadshed POC to do Demand Limiting, the cool
and heat stage limits under both Redline and Loadshed conditions
can be set individually with configuration decisions. If the active
stages is greater then the loadshed or redline configurations when a
loadshed or redline command is given, the unit will remove stages.
ConfigurationCCNLDSHS.GRP
This is the Loadshed Group Number and corresponds to the
loadshed supervisory devices that resides elsewhere on the CCN
network and broadcasts loadshed and redline commands to its
associated equipment parts. This variable will default to zero which
is an invalid group number. This allows the loadshed function to be
disabled until configured.
ComfortLINK v1.X
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