Ice Build Control — The ice build control option auto- matically sets the CONTROL POINT of the chiller to a temper- ature that allows ice building for thermal storage.

NOTE: For ice build control to operate properly, the PIC II must be in CCN mode.

NOTE: See Fig. 17 and 18 for more information on ice build- related menus.

The PIC II can be configured for ice build operation.

•From the SERVICE menu, access the EQUIPMENT SERVICE table. From there, select the OPTIONS screen to enable or disable the ICE BUILD OPTION. See Table 2, Example 17.

•The ICE BUILD SETPOINT can be configured from the SETPOINT display, which is accessed from the PIC II main menu. See Table 2, Example 9.

•The ice build schedule can be viewed or modified from the SCHEDULE table. From this table, select the ice build schedule (OCCPC02S) screen. See Fig. 19 and the section on Time Schedule Operation, page 20, for more information on modifying chiller schedules.

The ice build time schedule defines the period(s) during which ice build is active if the ice build option is enabled. If the ice build time schedule overlaps other schedules, the ice build time schedule takes priority. During the ice build period, the CONTROL POINT is set to the ICE BUILD SETPOINT for temperature control. The ICE BUILD RECYCLE and ICE BUILD TERMINATION parameters, accessed from the OPTIONS screen, allow the chiller operator to recycle or ter- minate the ice build cycle. The ice build cycle can be config- ured to terminate if:

•the ENTERING CHILLED WATER temperature is less than the ICE BUILD SETPOINT. In this case, the opera- tor sets the ICE BUILD TERMINATION parameter to 0 on the OPTIONS screen.

•the REMOTE CONTACT inputs from an ice level indi- cator are opened. In this case, the operator sets the ICE BUILD TERMINATION parameter to 1 on the OPTIONS screen.

•the chilled water temperature is less than the ice build set point and the remote contact inputs from an ice level indicator are open. In this case, the operator sets the ICE BUILD TERMINATION parameter to 2 on the OPTIONS screen.

•the end of the ice build time schedule has been reached.

ICE BUILD INITIATION — The ice build time schedule (OCCPC02S) is the means for activating the ice build option. The ice build option is enabled if:

•a day of the week and a time period on the ice build time schedule are enabled. The SCHEDULE screen shows an X in the day field and ON/OFF times are designated for the day(s),

•and the ICE BUILD OPTION is enabled.

The following events take place (unless overridden by a higher authority CCN device).

•CHILLER START/STOP is forced to START.

•The CONTROL POINT is forced to the ICE BUILD SET-

POINT.

•Any force (Auto) is removed from the ACTIVE DEMAND LIMIT.

NOTE: A parameter’s value can be forced, that is, the value can be manually changed at the CVC/ICVC by an operator, changed from another CCN device, or changed by other algo- rithms in the PIC II control system.

NOTE: The Ice Build steps do not occur if the chiller is config- ured and operating as a lag or standby chiller for lead/lag oper- ation and is actively being controlled by a lead chiller. The lead chiller communicates the ICE BUILD SET POINT, the desired CHILLER START/STOP state, and the 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 chiller is not running when ice build activates, the PIC II checks the follow- ing conditions, based on the ICE BUILD TERMINATION value, to avoid starting the compressor unnecessarily:

•if ICE BUILD TERMINATION is set to the TEMP 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 option and the remote contacts are open;

•if the ICE BUILD TERMINATION is set to the BOTH (temperature and contacts) option and the ENTERING CHILLED WATER temperature is less than or equal to the ICE BUILD SETPOINT and the remote contacts are open.

The ICE BUILD RECYCLE on the OPTIONS screen deter- mines whether or not the chiller will go into an ice build RE- CYCLE mode.

•If the ICE BUILD RECYCLE is set to DSABLE (dis- able), the PIC II reverts to normal temperature control when the ice build function terminates.

•If the ICE BUILD RECYCLE is set to ENABLE, the PIC II goes into an ICE BUILD RECYCLE mode and the chilled water pump relay remains energized to keep the chilled water flowing when the ice build function termi- nates. If the temperature of the ENTERING CHILLED WATER increases above the ICE BUILD SETPOINT plus the RECYCLE RESTART DELTA T value, the compres- sor restarts and controls the chilled water/brine tempera- ture to the ICE BUILD SETPOINT.

TEMPERATURE CONTROL DURING ICE BUILD — During ice build, the capacity control algorithm shall use the CONTROL POINT minus 5 F (–2.8 C) for control of the LEAVING CHILLED WATER temperature. (See Table 2, ex- ample 10, the CAPACITY CONTROL parameter on the CA- PACITY screen.) The ECW CONTROL OPTION and any tem- perature reset option shall be ignored, if enabled, during ice build. The AUTO DEMAND LIMIT INPUT shall also be ignored if enabled during ice build.

•ECW CONTROL OPTION and any temperature reset options (configured on TEMP_CTL screen).

•20 mA DEMAND LIMIT OPT (configured on RAMP_DEM screen).

TERMINATION OF ICE BUILD — The ice build function terminates under the following conditions:

1.Time Schedule — When the current time on the ice build time schedule (OCCPC02S) is not set as an ice build time period.

2.Entering Chilled Water Temperature — Compressor operation terminates, based on temperature, if the ICE BUILD TERMINATION parameter is set to 0 (TEMP), the ENTERING CHILLED WATER temperature is less than the ICE BUILD SETPOINT, and the ICE BUILD RECYCLE is set to DSABLE. If the ICE BUILD RECY- CLE OPTION is set to ENABLE, a recycle shutdown oc- curs and recycle start-up depends on the LEAVING CHILLED WATER temperature being greater than the water/brine CONTROL POINT plus the RESTART DELTA T temperature.

3.Remote Contacts/Ice Level Input — Compressor opera- tion terminates when the ICE BUILD TERMINATION parameter is set to 1 (CONTACTS) and the remote con- tacts are open and the ICE BUILD RECYCLE is set to DSABLE (0). In this case, the contacts provide ice level termination control. The contacts are used to stop the ice build function when a time period on the ice build sched- ule (OCCPC02S) is set for ice build operation. The re- mote contacts can still be opened and closed to start and

43

Page 42 Page 44
Page 43
Image 43
Carrier XRV, 19XR specifications Point
Page 42 Page 44

19XR, XRV specifications

The Carrier 19XR and 19XRV chillers are sophisticated cooling solutions that represent the forefront of HVAC technology. Designed for large commercial and industrial applications, these chillers provide exceptional performance, energy efficiency, and reliability, making them ideal for a variety of environments ranging from hospitals to manufacturing facilities.

One of the most significant features of the Carrier 19XR and 19XRV chillers is their advanced scroll compressor technology. These units employ a tandem scroll design that enhances efficiency while minimizing operational noise. This makes them ideal for urban environments where noise restrictions may be in place. Moreover, the compressors are equipped with variable speed drive options in the 19XRV model, which allows for greater energy savings by adjusting cooling output based on real-time demand.

In addition to their advanced compressors, the 19XR and 19XRV units incorporate the Carrier GreenChoice refrigerant, which has a lower global warming potential compared to traditional refrigerants. This innovative choice not only meets regulatory requirements but also contributes to sustainability goals, making these chillers a responsible choice for environmentally conscious organizations.

The units are engineered with a robust heat exchanger design, which enhances heat transfer efficiency and overall system performance. This ensures optimal operation even in extreme conditions. They feature a microprocessor-based control system that allows for precise monitoring and control of the chiller’s performance, enabling operators to make real-time adjustments to maximize energy efficiency.

The Carrier 19XR and 19XRV chillers also prioritize serviceability. The design incorporates easy access to key components, simplifying maintenance procedures and reducing downtime. This focus on maintainability extends the lifespan of the equipment, leading to lower lifecycle costs.

In terms of connectivity, these chillers are equipped with advanced Building Management System (BMS) integration capabilities. This allows for seamless monitoring and control of the chillers using a centralized platform, facilitating energy management and operational optimization.

Overall, the Carrier 19XR and 19XRV chillers stand out in the market for their blend of cutting-edge technology, energy efficiency, and user-friendly features. They are engineered to meet the demanding needs of modern commercial and industrial applications, making them a preferred choice for facility managers seeking reliable cooling solutions.
Top Page Image Contents