Refrigerator User Manual

START-UP/RECYCLE OPERATION — If the chiller is not
running when ice build activates, then the PIC checks the
following parameters, based on the ICE BUILD TERMINA-
TION value, to avoid starting the compressor unnecessarily:
•ifICE BUILD TERMINATION is set to the temperature
only option (zero) and the ENTERING CHILLED WATER
temperature is less than or equal to the ICE BUILD SET
POINT;
•ifICE BUILD TERMINATION is set to the contacts only
option (1) and the remote contacts are open;
• if the ICE BUILD TERMINATION is set to the both tem-
perature and contacts option (2) and ENTERING CHILLED
WATER temperature is less than or equal to the ICE BUILD
SET POINT 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
OPTION 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 TEMPERATURE increases above the ICE BUILD SET
POINT plus the RECYCLE RESTART DELTA T value, the
compressor will restart and control the CHILLED WATER/
BRINE TEMPERATURE to the ICE BUILD SET POINT.
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
OPTION and any temperature reset option are ignored dur-
ing 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
operation, based on temperature, shall occur if the
ICE BUILD TERMINATION is set to the ice build
termination temperature option (0) and the ENTERING
CHILLED WATER TEMPERATURE is less than the
ICE BUILD SET POINT.IftheICE BUILD RECYCLE
OPTION is set to ENABLE
, a recycle shutdown occurs
and recycle start-up shall be based onLEAVING CHILLED
WATER temperature being greater than the WATER/
BRINE CONTROL POINT plus RECYCLE RESTART
DELTA T.
3. Remote Contacts/Ice Level Input — Termination of
compressor operation occurs when ICE BUILD TERMI-
NATION is set to the contacts only option (1) and the
remote contacts are open. In this case, the contacts are
provided for ice level termination control. The remote con-
tacts can still be opened and closed to start and stop the
chiller when the Ice Build Time Schedule is UNOCCU-
PIED. The contacts 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 the temperature and
contacts (2) option and the previously described condi-
tions 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)
during the ice build period is not possible. However, over-
riding can be accomplished with CCN during two chiller lead/
lag.
RETURN TO NON-ICE BUILD OPERATIONS — Upon
termination of ice build, the chiller 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 — On the Serv-
ice menu, one of the selections is ATTACH TO NETWORK
DEVICE. This table serves the following purposes:
• to upload new parameters when switching the controller
to HFC-134a refrigerant.
• to upload the Occupancy Schedule Number (if changed)
for OCCPC03S software (version 09 and later), as defined
in the Service01 table
• to attach the LID to any CCN device, if the chiller 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 22 illustrates the ATTACH TO NETWORK
DEVICE table. The Local description is always the PSIO
module address of the chiller 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 automat-
ically. See Fig. 17.
Whenever the ATTACH TO NETWORK DEVICE table
is entered, no information can be read from the LID on any
device until you attach one of the devices listed on the
display. The LID erases information about the module to which
it was attached to make room for information on another de-
vice. Therefore, a CCN module must be attached when this
screen is entered. To attach a device, highlight it using the
SELECT
softkey and then press the ATTACH softkey. The
message, ‘‘UPLOADING TABLES, PLEASE WAIT’’ dis-
plays. The LID then uploads the highlighted device or
module. If the module address cannot be found, the mes-
sage, ‘‘COMMUNICATION FAILURE’’ appears. The LID
then reverts to the ATTACH TO DEVICE screen. Try
another device or check the address of the device that
would not attach. The upload process time for each CCN
module is different. In general, the uploading process takes
3 to 5 minutes. Before leaving the ATTACH TO NET-
WORK DEVICE screen, select the LOCAL device. Other-
wise, the LID will be unable to display information on the
local chiller.
CHANGING REFRIGERANT TYPES — To select refrig-
erant type, go to the Control Test table. Whenever the
refrigerant type is changed, the ATTACH TO NETWORK
DEVICE table must be used. After changing the refrigerant
type in the Control Test table, move to the ATTACH TO NET-
WORK DEVICE table. Make sure the highlight bar is
located on the LOCAL selection. Press the ATTACH
soft-
key. The information in the PSIO module will now be up-
loaded. The default screen will appear. The new refrigerant
type change for the controller is complete.
37