Carrier 23XL Specifiche Scaricare il pdf (Pagina 22)

9. Either return to Step 4 to select another period or over

ride or press EXIT

again to leave the current time

schedule screen and save the changes.

10. Holiday Designation may be found in the Service Op-

eration section, page 36. You must assign the month, day,

and duration for the holiday. The Broadcast function in

the Brodefs table also must be enabled for holiday pe-

riods to function.

TO VIEW AND CHANGE SET POINTS (Fig. 23)

1. To view the Set Point table, at the Menu screen press

SETPOINT

2. There are 4 set points on this table: Base Demand Limit;

LCW Set Point (leaving chilled water set point); ECW

Set Point (entering chilled water set point); and ICE BUILD

Set Point (PSIO Software Version 13 or higher). Only one

of the chilled water set points can be active at any time.

The type of set point and the ICE BUILD CONFIGU-

RATION are activated in the Service menu.

3. Press NEXT

or PREVIOUS to highlight the desired

set point entry.

4. Press SELECT to modify the highlighted set point.

5. Press INCREASE or DECREASE to change the se-

lected set point value.

6. Press ENTER to save the changes and return to the

previous screen.

SERVICE OPERATION — To view the menu-driven pro-

grams available for Service Operation, see Service Opera-

tion section, page 36. For examples of LID display screens,

see Table 3.

PIC System Functions

NOTE: Throughout this manual, words printed in capital let-

ters and italics are values that may be viewed on the LID.

Operating values for HFC-134a refrigerant, when appli-

cable, follow the HCFC-22 value and are enclosed in brack-

ets. See Table 3 for examples of LID screens. Point names

are listed in the Description column. An overview of LID

operation and menus is given in Fig. 17-23.

CAPACITY CONTROL — The PIC controls the machine

capacity by modulating the slide valve in response to chilled

water temperature changes away from the CONTROL POINT.

The CONTROL POINT may be changed by a CCN network

device, or is determined by the PIC adding any active chilled

water reset to the chilled water SETPOINT. The PIC uses the

PROPORTIONAL INC (Increase) BAND, PROPORTIONAL

DEC (Decrease) BAND, and the PROPORTIONAL ECW (En-

tering Chilled Water) GAIN to determine how fast or slow

to respond. CONTROL POINT may be viewed/overridden

on the Status table Status01 selection.

ENTERING CHILLED WATER CONTROL — If this op-

tion is enabled, the PIC uses ENTERING CHILLED WATER

temperature to modulate the slide valve instead of LEAV-

ING CHILLED WATER temperature. ENTERING CHILLED

WATER control option may be viewed/modiﬁed on the Equip-

ment Conﬁguration table Conﬁg selection.

DEADBAND — This is the tolerance on the chilled water/

brine temperature CONTROL POINT. If the water tempera-

ture goes outside of the DEADBAND, the PIC opens or closes

the slide valve in response until it is within tolerance. The

PIC may be conﬁgured with a 0.5 to 2° F (0.3 to 1.1° C)

DEADBAND. DEADBAND may be viewed or modiﬁed on

the Equipment Service table, Service1 table.

For example,a1F(0.6 C) deadband setting controls the

water temperature within ±0.5° F (0.3° C) of the control point.

This may cause frequent slide valve movement if the chilled

water load ﬂuctuates frequently. A setting of 1 F (0.6 C) is

the default setting.

PROPORTIONAL BANDS AND GAIN — Proportional band

is the rate at which the slide valve position is corrected in

proportion to how far the CHILLED WATER/BRINE tem-

perature is from the control point. Proportional gain deter-

mines how quickly the slide valve reacts to how quickly the

temperature is moving from CONTROL POINT.

Fig. 23 — Example of Set Point Screen

1 2 ... 17 18 19 20 21 22 23 24 25 26 27 ... 103 104

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