Carrier 19XL specifications Start-Up/Shutdown/Recycle, Sequence Fig

6.Press NEXT to highlight the holiday table that you

wish to view or change. Each table is one holiday pe- riod, starting on a speci®c date, and lasting up to 99 days.

7.Press SELECT to access the holiday table. The Con-

®guration Select table now shows the holiday start month and day, and how many days the holiday period will last.

8.Press NEXT or PREVIOUS to highlight the month, day, or duration.

9.Press SELECT to modify the month, day, or duration.

10.Press INCREASE or DECREASE to change the se- lected value.

11.Press ENTER to save the changes.

12.Press EXIT to return to the previous menu.

Fig. 23 Ð Example of Holiday Period Screen

START-UP/SHUTDOWN/RECYCLE

SEQUENCE (Fig. 24)

Local Start-Up Ð Local start-up (or a manual start-up)

is initiated by pressing the LOCAL menu softkey which is

on the default LID screen. Local start-up can proceed when Time Schedule 01 is in OCCUPIED mode, and after the in- ternal 15-minute start-to-start and the 3-minute stop-to-start inhibit timers have expired (on PSIO software Version 08 and lower or a 1-minute stop-to-start timer on PSIO Soft- ware Version 09 and higher).

The chiller start/stop status point on the Status01 table may be overridden to start, regardless of the time schedule, in order to locally start the unit. Also, the remote contacts may be enabled through the LID and closed to initiate a start-up.

Whenever the chiller is in LOCAL control mode, the PIC will wait for Time Schedule 01 to become occupied and the remote contacts to close, if enabled. The PIC will then per- form a series of pre-start checks to verify that all pre-start alerts and safeties are within the limits shown in Table 3. The run status line on the LID now reads ``Starting.'' If the checks are successful, the chilled water/brine pump relay will be energized. Five seconds later, the condenser pump relay is energized. Thirty seconds later the PIC monitors the chilled water and condenser water ¯ow switches, and waits until the WATER FLOW VERIFY TIME (operator con®gured, default 5 minutes) to con®rm ¯ow. After ¯ow is veri®ed, the chilled water/brine temperature is compared to CONTROL POINT plus DEADBAND. If the temperature is less than or equal to this value, the PIC will turn off the condenser pump relay

AÐ START INITIATED Ð Prestart checks made; evaporator pump started

BÐ Condenser water pump started (5 seconds after A)

CÐ Water ¯ows veri®ed (30 seconds to 5 minutes maximum after B). Chilled water temperatures checked against con- trol point. Guide vanes checked for closure. Oil pump started; tower fan control enabled.

DÐ Oil pressure veri®ed (30 seconds minimum, 300 seconds maximum after C)

EÐ Compressor motor starts, compressor ontime and serv- ice ontime start, 15-minute inhibit timer starts (10 seconds after D), total compressor starts advances by one, number of starts over a 12-hour period advances by one

FÐ SHUTDOWN INITIATED Ð Compressor motor stops, com- pressor ontime and service ontime stops, 3-minute inhibit timer starts on PSIO Software Version 08 and lower and 1-minute inhibit timer starts for PSIO Software Version 09 and higher.

GÐ Oil pump and evaporator pumps deenergized (60 seconds after F). Condenser pump and tower fan control may con- tinue to operate if condenser pressure is high. Evaporator

pump may continue if in RECYCLE mode.

O/A Ð Restart permitted (both inhibit timers expired) (minimum of 15 minutes after E; [minimum of 3 minutes after F on PSIO Software Version 08 and lower] [minimum of 1 minute after F on PSIO Software Version 09 and higher]

Fig. 24 Ð Control Sequence

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