Ice Build Initiation; Start-Up/Recycle Operation; Temperature Control During Ice Build; Return To Non-Ice Build Operations - Carrier 19EF Series Start Up & Operation Manual

ICE BUILD INITIATION — The Ice Build Time Schedule
provides the means for activating ice build. The ice build
time table is named OCCPC02S.
If the Ice Build Time Schedule is OCCUPIED and the ICE
BUILD OPTION is ENABLED, then ice build is active and
the following events automatically take place (unless over-
ridden by a higher authority CCN device):
1. Force CHILLER START/STOP to START.
2. Force WATER/BRINE CONTROL POINT to the ICE
BUILD SETPOINT.
3. Remove any force (Auto) on the ACTIVE DEMAND
LIMIT.
NOTE: Items 1-3 (shown above) shall not occur if the chiller
is configured and operating as a lag or standby chiller for
lead/lag and is actively controlled by a lead chiller. The lead
chiller communicates the ICE BUILD SETPOINT, desired
CHILLER START/STOP state, and ACTIVE DEMAND
LIMIT to the lag or standby chiller as required for ice build,
if configured to do so.
START-UP/RECYCLE OPERATION — If the machine is
not running when ice build activates, then the PIC checks
the following parameters, based on the ICE BUILD
TERMINATION value, to avoid starting the compressor
unnecessarily:
• if ICE BUILD TERMINATION is set to the TEMPERA-
TURE ONLY 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 CONTACTS
ONLY OPTION and the remote contacts are open;
• if the ICE BUILD TERMINATION is set to the BOTH
(temperature and contacts) option and ENTERING CHILLED
WATER temperature is less than or equal to the ICE BUILD
SETPOINT and remote contacts are open.
The ICE BUILD RECYCLE OPTION determines whether
or not the PIC will go into a RECYCLE mode. If the ICE
BUILD RECYCLE OPTION is set to DSABLE (disable)
when the ice build terminates, the PIC will revert back to
normal temperature control duty. If the ICE BUILD RE-
CYCLE OPTION is set to ENABLE, when ice build termi-
nates, the PIC will go into an ICE BUILD RECYCLE mode
and the chilled water pump relay will remain energized to
keep the chilled water flowing. If the entering CHILLED
WATER/BRINE TEMPERATURE increases above the ICE
BUILD SETPOINT plus the RECYCLE DELTA T value,
the compressor will restart and control the CHILLED WATER/
BRINE TEMPERATURE to the ICE BUILD SETPOINT.
TEMPERATURE CONTROL DURING ICE BUILD — Dur-
ing ice build, the capacity control algorithm uses the WATER/
BRINE CONTROL POINT minus 5 F (2.7 C) to control the
LEAVING CHILLED WATER temperature. The ECW OP-
TION and any temperature reset option are ignored during
ice build. The 20 mA DEMAND LIMIT OPTION is also
ignored during ice build.
TERMINATION OF ICE BUILD — Ice build termination
occurs under the following conditions:
1. Ice Build Time Schedule — When the Ice Build Time
Schedule transitions to UNOCCUPIED, ice build opera-
tion shall terminate.
2. ECW TEMPERATURE — Termination of compressor op-
eration, based on temperature, shall occur if the ICE BUILD
TERMINATION is set to the ICE BUILD TERMINA-
TION TEMP option and the ENTERING CHILLED WA-
TER temperature is less than the ICE BUILD SET-
POINT. If the ICE BUILD RECYCLE OPTION is set to
ENABLE, a recycle shutdown occurs and recycle start-
up shall be based on LEAVING CHILLED WATER tem-
perature being greater than the WATER/BRINE CON-
TROL POINT plus RECYCLE DELTA T.
3. Remote Contacts/Ice Level Input — Termination of com-
pressor operation occurs when ICE BUILD TERMINA-
TION is set to CONTACTS ONLY OPTION and the re-
mote contacts are open. In this case, the contacts are provided
for ice level termination control. The remote contacts can
still be opened and closed to start and stop the chiller when
the Ice Build Time Schedule is UNOCCUPIED. The con-
tacts are used to stop the ICE BUILD mode when the Ice
Build Time Schedule is OCCUPIED.
4. ECW TEMPERATURE and Remote Contacts — Termi-
nation of compressor operation shall occur when ICE
BUILD TERMINATION is set to BOTH (temperature and
contacts) option and the previously described conditions
for ECW TEMPERATURE and remote contacts have oc-
curred.
NOTE: Overriding the CHILLER START/STOP, WATER/
BRINE CONTROL POINT, and ACTIVE DEMAND LIMIT
variables by CCN devices (with a priority less than 4) dur-
ing the ice build period is not possible. However, overriding
can be accomplished with CCN during two chiller lead/lag.
RETURN TO NON-ICE BUILD OPERATIONS — Upon
termination of ice build, the machine shall return to normal
temperature control and start/stop schedule operation. If the
CHILLER START/STOP or WATER/BRINE CONTROL
POINT has been forced (with a priority less than 4), prior to
entering ice build operation, then chiller START/STOP and
WATER/BRINE CONTROL POINT forces will be
removed.

Attach to Network Device Control

ice menu, one of the selections is ATTACH TO NETWORK
DEVICE. This table serves the following purposes:
• to upload the Occupancy Schedule Number (if changed)
for OCCPC03S, as defined in the Service01 table
• to attach the LID to any CCN device, if the machine has
been connected to a CCN Network. This may include other
PIC controlled chillers.
• to change to a new PSIO or LID module.
Figure 20 illustrates the ATTACH TO NETWORK DE-
VICE table. The Local description is always the PSIO mod-
ule address of the machine the LID is mounted on. When-
ever the controller identification of the PSIO is changed, this
change is reflected on the bus and address for the LOCAL
DEVICE of the ATTACH TO DEVICE screen automati-
cally. See Fig. 14.
Whenever the ATTACH TO NETWORK DEVICE table
is entered, the LID erases information on the module to which
it was attached in order to make room for another device.
Therefore, it is then required to attach to a CCN module when
this screen is entered, even if the LID is attached back to the
original module. When the ATTACH softkey is pressed, the
message ''UPLOADING TABLES, PLEASE WAIT'' flashes.
The LID will then upload the highlighted device or module.
If the module address cannot be found, the message ''COM-
MUNICATION FAILURE'' will appear. The LID will then
revert back to the ATTACH TO DEVICE screen. The upload
process time for various CCN modules is different for each
module. In general, the uploading process will take 3 to
5 minutes.
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— On the Serv-