FAULTED CHILLER OPERATION Ð If the lead chiller shuts down because of an alarm (*) condition, it stops com- municating with the lag and standby chillers. After 30 sec- onds, the lag chiller becomes the acting lead chiller and starts and stops the standby chiller, if necessary.

If the lag chiller faults when the lead chiller is also faulted, the standby chiller reverts to a stand-alone CCN mode of operation.

If the lead chiller is in an alarm (*) condition (indicated

on the LID ), the RESET softkey is pressed to clear the

alarm, and the lead chiller is placed in CCN mode, the lead chiller communicates and monitors the run status of the lag and standby chillers. If both the lag and standby chillers are running, the lead chiller does not attempt to start and does not assume the role of lead chiller until either the lag or standby chiller shuts down. If only one chiller is running, the lead chiller waits for a start request from the operating chiller. When the con®gured lead chiller starts, it assumes its role of lead chiller.

LOAD BALANCING Ð When the LOAD BALANCE OP- TION (LEAD/LAG screen) is enabled, the lead chiller sets the ACTIVE DEMAND LIMIT in the lag chiller to the lead chiller's COMPRESSOR MOTOR LOAD value. This value has limits of 40% to 100%. When setting the lag chiller AC- TIVE DEMAND LIMIT, the WATER/BRINE CONTROL POINT is modi®ed to a value of 3° F (1.67° C) less than the lead chiller's WATER/BRINE CONTROL POINT value. If the LOAD BALANCE OPTION is disabled, the ACTIVE DEMAND LIMIT and the WATER/BRINE CONTROL POINT are forced to the same value as the lead chiller.

AUTO. RESTART AFTER POWER FAILURE Ð When an auto. restart condition occurs, each chiller may have a delay added to the start-up sequence, depending on its lead/lag con- ®guration. The lead chiller does not have a delay. The lag chiller has a 45-second delay. The standby chiller has a 90-second delay. The delay time is added after the chiller water ¯ow veri®cation. The PIC controls ensure that the guide vanes are closed. After the guide vane position is con®rmed, the delay for lag and standby chillers occurs before ener- gizing the oil pump. The normal start-up sequence then con- tinues. The auto. restart delay sequence occurs whether the chiller is in CCN or LOCAL mode and is intended to stag- ger the compressor motor start-up times. This helps reduce the in-rush of demand on the building power system.

Ice Build Control Ð Ice build control automatically sets the chilled WATER/BRINE CONTROL POINT of the chiller from a normal operation set point temperature to a tempera- ture that allows an ice building operation for thermal storage.

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

The PIC can be con®gured for ice build operation by chang- ing entries on the:

·CONFIG screen, accessed from the SERVICE menu

·OCCPC02S screen (ice build time schedule), accessed from the SCHEDULE menu

·SETPOINT screen, accessed from the SETPOINT menu.

Figures 15 and 16 show how to access each screen.

The ice build time schedule de®nes the periods during which the ice build option can be activated, if the ice build option is enabled. If the ice build time schedule overlaps other sched- ules, the ice build time schedule takes priority. During an ice

build period, the WATER/BRINE CONTROL POINT is set to the ICE BUILD SETPOINT (SETPOINT screen) for tem- perature control.

The ICE BUILD RECYCLE OPTION and ICE BUILD TERMINATION parameters are on the CONFIG screen. The ice build recycle option can be enabled or disabled from this screen; the ice build termination value can be set to 0, 1, or 2, depending on the factor that determines termination (tem- perature, contacts, or both). Ice build termination can occur when:

·the ENTERING CHILLED WATER temperature is less than the ICE BUILD SETPOINT

·the REMOTE CONTACTS INPUT (STATUS01 screen) is opened based on input from an ice level indicator

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

ICE BUILD INITIATION Ð The ice build option is acti- vated via the ice build time schedule on the OCCPC02S screen. If the current time is set as an ice build time on the OCCPC02S screen and the ICE BUILD OPTION on the CONFIG screen is enabled, then the ice build option is active and the fol- lowing events automatically take place (unless overridden by a higher authority CCN device):

1.CHILLER START/STOP is forced to START.

2.The WATER/BRINE CONTROL POINT is forced to the

ICE BUILD SETPOINT.

3.Any force (Auto) on the ACTIVE DEMAND LIMIT is removed.

NOTE: Items 1-3 (shown above) do not occur if the chiller is con®gured and operating as a lag or standby chiller for lead/lag operation and is actively controlled by a lead chiller. The lead chiller communicates the ICE BUILD SETPOINT, desired CHILLER START/STOP state, and ACTIVE DE- MAND LIMIT to the lag or standby chiller as required for ice build, if con®gured to do so.

START-UP/RECYCLE OPERATION Ð If the chiller 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 the ICE BUILD TERMINATION parameter is set to 0 (temperature only), and the ENTERING CHILLED WA- TER temperature is less than or equal to the ICE BUILD SETPOINT;

·if the ICE BUILD TERMINATION parameter is set to 1 (contacts only) and the remote contacts are open;

·if the ICE BUILD TERMINATION parameter is set to 3 (both temperature and contacts), 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 OPTION determines whether or not the PIC goes into a RECYCLE mode. If the ICE BUILD RECYCLE OPTION is set to DSABLE (disable) when the ice build terminates, the PIC reverts to normal temperature control duty. If the ICE BUILD RECYCLE OPTION is set to ENABLE, when ice build terminates, the PIC goes into an ice build recycle mode and the chilled water pump relay re- mains energized to keep the chilled water ¯owing. If the EN- TERING CHILLED WATER (brine) temperature increases above the ICE BUILD SETPOINT plus the RECYCLE RESTART DELTA T value, the compressor restarts and controls the chilled water/brine temperature to the ICE BUILD SETPOINT.

40

Page 39 Page 41
Page 40
Image 40
Carrier 17EX specifications ICE Build Setpoint
Page 39 Page 41

17EX specifications

The Carrier 17EX is recognized as an innovative air conditioning solution that combines efficiency with advanced technology. This model is designed to meet the increasing demands of residential and commercial cooling needs while maintaining environmental consciousness.

One of the standout features of the Carrier 17EX is its impressive Seasonal Energy Efficiency Ratio (SEER) rating. With a SEER rating that often exceeds 17, this unit ensures optimized energy consumption, significantly lowering operational costs for users. The incorporation of advanced compressor technology allows the system to adjust its cooling output based on the specific needs of the environment, thus providing both comfort and energy savings.

The Carrier 17EX utilizes a variable-speed inverter-driven compressor that enhances its performance and adaptability. This technology allows the air conditioning unit to operate at different speeds, intelligently adjusting to changing load conditions. As a result, the system runs more efficiently and quietly, providing a more consistent comfort level without the abrupt temperature swings associated with traditional units.

In addition to efficiency, the Carrier 17EX also prioritizes reliability and durability. The unit comes with a robust cabinet that protects the components from weather elements, ensuring longevity and consistent performance. The innovative design integrates a corrosion-resistant finish and robust insulation, which further enhances the unit's resilience in various environmental conditions.

For users concerned about indoor air quality, the Carrier 17EX includes advanced filtration systems designed to capture allergens and airborne particles. This feature is particularly beneficial for individuals with respiratory issues, ensuring that the air circulated within the space is clean and healthy.

Moreover, the Carrier 17EX is equipped with smart technology capabilities, allowing users to control their systems remotely through smartphones or other smart devices. This connectivity not only provides convenience but also empowers homeowners to optimize their energy use by adjusting settings on the fly, ensuring efficient operation even when they are away from home.

Overall, the Carrier 17EX stands out in the marketplace for its exceptional energy efficiency, advanced technology, and commitment to providing reliable and effective cooling solutions. Its combination of modern features makes it a preferred choice for those looking to enhance comfort while being mindful of energy consumption and environmental impact.
Top Page Image Contents