Start-Up/Recycle Operation; Temperature Control During Ice Build; Termination Of Ice Build; Return To Non-Ice Build Operations - Carrier 17 Start Up & Operation Manual

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 con-
figured 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 WA-
TER 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 (tem-
perature 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 RECYCLE OP-
TION is set to ENABLE, when ice build terminates, 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) tem-
perature increases above the ICE BUILD SETPOINT plus
the RECYCLE RESTART DELTA T value, the compressor
will restart and control the CHILLED WATER/BRINE
TEMPERATURE to the ICE BUILD SETPOINT.

TEMPERATURE CONTROL DURING ICE BUILD

—During ice build, the capacity control algorithm uses the
WATER/BRINE CONTROL POINT minus 5 F (2.7 C) to con-
trol the LEAVING CHILLED WATER temperature. The ECW
CONTROL OPTION and any temperature reset option are
ignored during ice build. The 20 mA DEMAND LIMIT op-
tion 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 SETPOINT.
If the ICE BUILD RECYCLE OPTION is set to EN-
ABLE, 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 RESTART 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 con-
tacts) option and the previously described conditions for
ENTERING CHILLED WATER temperature and remote
contacts have occurred.
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 enter-
ing 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 or upgrade
software.
Figure 23 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. 17.
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.
ATTACHING TO OTHER CCN MODULES — If the ma-
chine PSIO has been connected to a CCN Network or other
PIC controlled chillers through CCN wiring, the LID can be
used to view or change parameters on the other controllers.
Other PIC machines can be viewed and set points changed
(if the other unit is in CCN control), if desired from this par-
ticular LID module.
43
— On the Serv-