Carrier 33ZCSECTRM General, Installation, Zone Controller Hardware - The zone controller

GENERAL

The zone controller is a single duct, fan powered, Variable Air Volume (VAV) terminal control with a factory-integrated controller and actuator. The zone controller maintains precise temperature control in the space by operating the terminal fan and regulating the flow of conditioned air into the space. Build- ings with diverse loading conditions can be supported by con- trolling reheat or supplemental heat.

The VAV Fan Terminal Zone Controller (33ZCFANTRM) provides dedicated control functions for series fan or parallel fan powered terminals, single duct terminals with 3 stages of heat, or as a primary controller for dual duct or zone pressure control applications.

The Single Duct Air Terminal Zone Controller (33ZCVAVTRM) provides dedicated control functions for sin- gle duct terminals with modulating heat or up to 2 stages of heat.

When the VAV Fan Terminal Zone Controller is used in conjunction with a secondary terminal and the 33ZCSECTRM secondary terminal zone controller, either dual duct or zone pressurization applications can be supported.

Carrier’s Linkage system is an integrated combination of Carrier Comfort Network (CCN) controllers for use with Sin- gle Duct air terminals and VAV Fan Powered terminals. The Single Duct air terminal and VAV Fan terminal zone control- lers are part of the Carrier ComfortID system.

Devices manufactured by Carrier which have Product Inte- grated Controls on the same communication bus as the zone controller, air handlers (such as the 39L,T), or large rooftop units do not require an external controller to function as part of a Carrier linkage system. These air handlers or large rooftop units feature factory-installed Product Integrated Control (PIC) controllers that are directly compatible with the system. Con- sult your local Carrier representative for the complete list of compatible air handlers. The Comfort System AirManager (CSAM) or the CC6400 supports linkage for non-Carrier de- vices or air handlers. Figure 1 shows an example of a Carrier linkage system.

INSTALLATION

General — The zone controller is a microprocessor-based direct digital control (DDC) controller for variable air volume (VAV) air terminals. It can be retrofitted on units manufactured by Carrier or other manufacturers to provide pressure- independent VAV control.

Each zone controller has the ability to function as a linkage coordinator for systems with up to 128 zones. As a linkage co- ordinator, a zone controller will retrieve and provide system in- formation to the air handling equipment and other zone con- trollers. A zone controller can function as a stand alone device by installing a primary supply air sensor.

The zone controller monitors differential pressure from an airflow pickup (or a pair of pickups) mounted on the terminal box. It compares the resulting signal to an airflow set point in order to provide pressure-independent control of the air passing through the terminal.

The zone controller is connected to a wall-mounted, field- supplied, space temperature sensor (SPT) in order to monitor zone temperature changes and satisfy zone demand.

On stand-alone applications or applications with heat, the zone controller must be connected to a field-supplied supply air temperature (SAT) sensor to monitor the temperature of the air delivered by the air terminal.

Carrier’s Network Service Tool can be connected to the sys- tem at the SPT sensor if CCN communication wiring is run to

the SPT sensor. The Network Service Tool can be used to ad- just set points, set operating parameters, and fully configure the zone controller or any device on the system.

Zone Controller Hardware — The zone controller

consists of the following hardware:

•terminal control module

•torque-limiting damper actuator

•airflow transducer (velocity sensor)

•plastic enclosure

•one no. 8 x 1/2-in. sheet metal screw (to prevent zone controller rotation)

NOTE: A filter is not provided for the airflow transducer. For installations on systems with a high degree of impuri- ties, an air filter can be purchased and installed on the trans- ducer high pressure pickup.

Figure 2 shows the zone controller physical details. Figures 3-5 show the 3 different types of zone controllers.

Field-Supplied Hardware — Each zone controller re- quires the following field-supplied components to complete its installation:

•air terminal unit

•space temperature sensor

•transformer — 24 vac, 40 va

•two no. 10 x 1/2-in. sheet metal screws (to secure SAT sensor to duct, if required)

•two no. 6-32 x 5/8-in. screws (to mount SPT sensor base to electrical box)

•contactors (if required for fan or electric heat)

•supply air temperature sensor (required for terminal with ducted heat)

•indoor air quality sensor (if required)

•relative humidity sensor (if required)

•one SPST (for each stage of electric heat, not required for Carrier fan terminals)

•valve and actuator for hot water heat (if required)

•delta pressure airflow pickup

NOTE: When selecting an airflow pickup, it is the designer's responsibility to select a sensor that provides the desired output at the design airflow.

•wire

•polyethylene tubing (for pressure pickup)

•bushings (required when mounting SAT sensor in a duct 6-in. or less in diameter)

•primary air temperature sensor (if required)

SPACE TEMPERATURE SENSOR — Each zone control- ler requires a field-supplied Carrier space temperature sensor. There are two sensors available for this application:

•33ZCT55SPT, Space Temperature Sensor with Override Button

•33ZCT56SPT, Space Temperature Sensor with Override Button and Set Point Adjustment

PRIMARY AIR TEMPERATURE SENSOR — A field- supplied, primary air temperature (PAT) sensor (part number 33ZCSENPAT) is used on a zone controller which is function- ing as a Linkage Coordinator for a non CCN/Linkage compati- ble air source.

SUPPLY AIR TEMPERATURE (SAT) SENSOR — On stand-alone applications or applications with ducted heat, the zone controller must be connected to a field-supplied supply air temperature (SAT) sensor (part number 33ZCSENSAT) to monitor the temperature of the air delivered by the air terminal. The zone controller will maintain the air temperature below the maximum air temperature in ducted heating applications.

2