Attach To Network Device Control - Carrier 19XRV Start-Up, Operation And Maintenance Instructions Manual

• if ICE BUILD TERMINATION is set to the TEMP
option and the ENTERING CHILLED WATER
temperature is less than or equal to the ICE BUILD
SETPOINT;
• if ICE BUILD TERMINATION is set to the CON-
TACTS option and the ICE BUILD CONTACT is
open;
• if the ICE BUILD TERMINATION is set to the BOTH
(temperature and contacts) option and the ENTERING
CHILLED WATER temperature is less than or equal
to the ICE BUILD SETPOINT and the ICE BUILD
CONTACT is open.
The ICE BUILD RECYCLE on the OPTIONS screen
determines whether or not the chiller will go into an ice
build RECYCLE mode.
• If the ICE BUILD RECYCLE is set to DSABLE
(disable), the PIC III reverts to normal (non-ice build)
temperature control when the ice build function is
terminated by satisfying one of the above conditions.
Once ice build is terminated in this manner, it will not
be reinitiated until the next ice build schedule period
begins.
• If the ICE BUILD RECYCLE is set to ENABLE, the
PIC III goes into an ICE BUILD RECYCLE mode,
and the chilled water pump relay remains energised to
keep the chilled water flowing when the compressor
shuts down. If the temperature of the LEAVING
CHILLED WATER later increases above the ICE
BUILD SETPOINT plus half the RECYCLE
RESTART DELTA T value, the compressor restarts,
controlling the chilled water/brine temperature to the
ICE BUILD SETPOINT.
5.28.3 - temperature control during ice build
During ice build, the capacity control algorithm shall use
the CONTROL POINT minus .8 K for control of the
LEAVING CHILLED WATER temperature. The ECW
CONTROL OPTION and any temperature reset option
shall be ignored, if enabled, during ice build. Also, the
following control options will be ignored during ice build
operation:
• ECW CONTROL OPTION and any temperature
reset options (configured on TEMP_CTL screen).
• 20 mA DEMAND LIMIT OPT (configured on
RAMP_DEM screen).
5.28.4 - termination of ice build
The ice build function terminates under the following
conditions:
1. Time Schedule — When the current time on the ice
build time schedule (OCCPC0S) is not set as an ice
build time period.
. Entering Chilled Water Temperature — Ice build ope-
ration terminates, based on temperature, if the ICE
BUILD TERMINATION parameter is set to 0 (TEMP),
the ENTERING CHILLED WATER temperature is
less than the ICE BUILD SETPOINT, and the ICE
BUILD RECYCLE is set to DSABLE. If the ICE
BUILD RECYCLE OPTION is set to ENABLE, a
recycle shutdown occurs and recycle start-up depends on
the LEAVING CHILLED WATER temperature being
greater than the water/brine CONTROL POINT plus
the RESTART DELTA T temperature.
48
3. Remote Contacts/Ice Level Input — Ice build operation
terminates when the ICE BUILD TERMINATION
parameter is set to 1 (CONTACTS) and the ICE
BUILD CONTACTS are open and the ICE BUILD
RECYCLE is set to DSABLE (0). In this case, the
ICE BUILD CONTACTS provide ice level termination
control. The contacts are used to stop the ice build
function when a time period on the ice build schedule
(OCCPC0S) is set for ice build operation. The remote
contacts can still be opened and closed to start and
stop the chiller when a specific time period on the ice
build schedule is not set for ice build.
4. Entering Chilled Water Temperature and ICE BUILD
Contacts — Ice Build operation terminates when the
ICE BUILD TERMINATION parameter is set to 
(BOTH) and the conditions described above in items
 and 3 for ENTERING CHILLED WATER tempe-
rature and ICE BUILD CONTACTS have occurred.
note: It is not possible to override the CHILLER START/
STOP, CONTROL POINT, and ACTIVE DEMAND LIMIT
variables from CCN devices (with a priority 4 or greater)
during the ice build period. However, a CCN device can
override these settings during -chiller lead/lag operation.
5.28.5 - Return to non-ice build operations
The ice build function forces the chiller to start, even if all
other schedules indicate that the chiller should stop. When
the ice build function terminates, the chiller returns to normal
temperature control and start/stop schedule operation. The
CHILLER START/STOP and CONTROL POINT return
to normal operation. If the CHILLER START/STOP or
CONTROL POINT has been forced (with a device of less
than 4 priority) before the ice build function started, when
the ice build function ends, the previous forces (of less than
4 priority) are not automatically restored.

5.29 - Attach to network device control

The Service menu includes the ATTACH TO NETWORK
DEVICE screen. From this screen, the operator can:
• enter the time schedule number (if changed) for
OCCPC03S, as defined in the NET_OPT screen
• attach the ICVC to any CCN device, if the chiller has
been connected to a CCN network. This may include
other PIC-controlled chillers.
• upgrade software
Fig. 13 shows the ATTACH TO NETWORK DEVICE
screen. The LOCAL parameter is always the ICVC module
address of the chiller on which it is mounted. Whenever
the controller identification of the ICVC changes, the change
is reflected automatically in the BUS and ADDRESS
columns for the local device. See Fig. 7. Default address for
local device is BUS 0 ADDRESS 1.
When the ATTACH TO NETWORK DEVICE screen is
accessed, information can not be read from the ICVC on
any device until one of the devices listed on that screen is
attached. The ICVC erases information about the module
to which it was attached to make room for information on
another device. Therefore, a CCN module must be attached
when this screen is entered.