Linkage; Alarm Handling - Carrier 48PG03-16 Controls, Start-Up, Operation, Service And Troubleshooting Instructions

Global Schedule Broadcast (BROD→B.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 (BROD→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.O→SCH.N)
This configuration determines what schedule the control may
follow.
SCH.N = 0
SCH.N = 1
SCH.N = 65--- 99
Accept Global Holidays? (SCH.O→HOL.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.O→OV.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.O→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? (SCH.O→OV.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.

Linkage

ComfortLinkt controls do not require any configuration settings
to establish linkage with a Linkage Coordinator. This is done
automatically when the 48/50PG unit's bus and element address
are configured in the Linkage Coordinator's LINKAGE
configuration table. The linkage information that is supplied to
the ComfortLink unit by the Linkage Coordinator is as follows:
S Reference zone temperature
S Reference zone occupied biased heating and cooling set
points
S Reference zone unoccupied heating and cooling set
points.
S Composite occupancy mode
The control is always occupied.
The control follows its internal
time schedules. The user may en-
ter any number between 1 and 64
but it will be overwritten to "1" by
the control as it only has one
internal schedule.
The control is either set up to re-
ceive to a broadcasted time
schedule set to this number or the
control is set up to broadcast its
internal time schedule (B.GS) to
the network and this is the global
schedule number it is broadcast-
ing. If this is the case, then the
control still follows its internal time
schedules.
The 48/50PG unit will control the equipment based on this
information and in return will provide the Linkage Coordinator
with the following data:
S Operating mode - - Cooling, Heating, Free Cooling, Fire
Shutdown Evacuation, or Off
S Supply- -air temperature
Optimal Start Bias time (Based on worst case zone)
S
This synchronization of data optimizes the efficiency of the
48/50PG unit and the zones to operate at peak system
performance at all times. This information can be seen in linkage
maintenance tables of the Linkage Coordinator and the RTU; it is
updated at approximately 1- -minute intervals.
For information on set up and configuration see the Space
Temperature Control- -CCN Linkage text in the Controls Quick
Start section of this book.
For additional information on the Linkage Coordinator or Zone
Controllers, please refer to their appropriate manuals.

Alarm Handling

There are a variety of different alerts and alarms in the system.
Alerts are indicated by TXXX (where XXX is the alert number)
on the display and generally signify that the improperly
functioning circuit can restart without human interaction. If an
alarm occurs, indicated by AXXX (where XXX is the alarm
number), the damaged circuit will generally not restart without an
alarm reset via the Scrolling Marquee display or CCN.
The response of the control system to various alerts and alarms
depends on the seriousness of the particular alert or alarm. In the
mildest case, an alert does not affect the operation of the unit in
any manner. An alert can also cause a "strike." A "striking" alert
will cause the circuit to shut down for 15 minutes. This feature
reduces the likelihood of false alarms causing a properly working
system to be shut down incorrectly. If three strikes occur before
the circuit has an opportunity to show that it can function
properly, the circuit will strike out, causing the shutdown alarm
for that particular circuit. Once activated, the shutdown alarm can
only be cleared via an alarm reset.
However, circuits with strikes will be given an opportunity to
reset their strike counter to zero. As discussed above, a strike
typically causes the circuit to shut down. Fifteen minutes later,
that circuit will once again be allowed to run. If the circuit is able
to run for 1 minute, its replacement circuit will be allowed to shut
down (if not required to run to satisfy requested stages).
However, the "troubled" circuit must run continuously for a user
defined time (Configuration→COOL→RST.C)
detectable problems before the strike counter will be reset to zero.
Default value is 5 minutes.
CCN Alarm Broadcast
Operators of CCN networks might not want to be notified of
"striking" alerts for refrigerant circuits until the circuit has been
shut down due to 3 strikes. Set the cooling configuration of Alert
Each Strike (Configuration→COOL→ALM.N on display,
ALM_NOW on CCN) to YES to broadcast each circuit strike
alert. Set Alert Each Strike to NO to broadcast only circuit shut
down. Alert Each Strike configuration is ignored during Service
Test and all alerts are broadcast.
Alarm Relay Output
The alarm relay output is a normally open 24 vac output between
field connection terminal board terminals C and X. Selection of
which alerts and alarms will result in closing of the alarm relay
may be set in the
(Configuration→ALM.O). Setting a configuration to YES will
result in the alarm output relay, ALRM, status of ON and 24 vac
between C and X when that particular condition is in an alarm
state. Setting a configuration to NO will result in no action by the
alarm output relay for that particular condition.
76
with no
Alarm Relay Configuration