Carrier 33ZCSECTRM Specifikace stáhnout pdf (Strana 11)

LINKAGE

Linkage is defined as the process that links the terminals

and air source to form a coordinated HVAC system. Linkage

allows the air source to respond to changing conditions in the

zones. Linkage also allows the terminals to respond properly to

changes in the air source operating mode. Linkage operation is

different between a CCN device that supports linkage (i.e.,

48/50 series, E series, F series, M series or PIC controlled air

handler unit, PIC, AirManager™, Comfort Controller), versus

that which does not support Linkage.

CCN Air Sources or Air Sources Which Sup-

port Linkage —

All terminals that are serviced by an air

source are linked together to form a single virtual load to the air

source. As such, the linked system provides the following in-

formation to the air source equipped with a CCN control that

supports linkage:

• weighted average temperature of all zones serviced by

the air source

• weighted average occupied temperature of all occupied

and biased occupied zones serviced by the air source

• weighted average of all the occupied and unoccupied

heating and cooling space temperature set points for all

the zones serviced by the air source

• composite Occupancy information

To account for variations in the size of the space serviced by

each zone, the space temperature and set point information pro-

vided to the air source is weighted. The weighting is propor-

tional to the size of the zone and is determined by the config-

ured maximum cooling capacity (CFM) for each zone. Only

those zones with a valid temperature are be included in the

polling process.

In each linked system, one zone controller should be identi-

fied as the linkage master. The linkage master periodically

polls the other zones in the group to acquire their temperature,

set points, occupancy information, and damper position. The

linkage master processes this information into a composite

view of the system and sends this information to the air source.

These modes determine the operating and control modes of

the zone controller. The operating mode will be used to provide

status information about the zone controller’s operation. The

control modes will be used to affect the operation of the

corresponding control functions (airflow, heating, and fan con-

trol). The current operating and control modes will be based on

the following inputs: the air source mode, the temperature con-

trol requirement of the zone, and the terminal type.

The air terminal operating mode will indicate the current

HVAC mode of operation. The modes and their meanings are

defined in Table 6.

AIR TERMINAL MODES — The heating mode will deter-

mine whether the heat function should be enabled or disabled.

The fan control will control the fan as required for heat.

The air source mode is used by the zones to determine their

terminal operating mode and which minimum and maximum

airflow requirements to utilize. For stand-alone units without

linkage, the supply air temperature sensor performs this func-

tion. The optimal start bias time will be used by the occupancy

control in each terminal to adjust the terminal’s occupied start

time.

If the Linkage Master zone controller is enabled, then that

zone controller will poll the indicated number of zones, includ-

ing itself. With the information obtained, the linkage master

will calculate the system control information and send them to

the air source at the indicated address. The linkage master com-

putes the composite occupancy, set point, and zone temperature

data.

The linkage master calculates a static pressure reset value

based on the damper positions of the linked zones. The static

pressure reset value will be based upon the position of the most

open damper in the system and is limited to a maximum allow-

able reset value. This value will then be sent to the air source

by variable name.

Non–CCN Air Sources or Air Sources That Do

Not Support Linkage —

In systems with Non–CCN

central air sources or central air sources which do not support

Linkage, the zone coordination function of Linkage can still be

provided by the Linkage function contained within a master

zone controller. In these cases, the zone configured as the Link-

age Master will determine the operational mode of the air

source through its own airflow sensor and a primary air tem-

perature measurement. A field-supplied primary air tempera-

ture sensor (33ZCSENPAT) is required. The modes that can be

determined are either Cooling, Heating, free cooling, or Off.

Table 6 — Air Terminal Operating Modes

AIR TERMINAL

OPERATING MODE

AIR TERMINAL ACTION

OFF

No active control of temperature or CFM in the zone.

VENT

Temperature requirement of the zone is satisfied. Minimum cooling CFM or damper position is maintained.

VENT and FAN

Temperature requirement of the zone is satisfied and CFM is below fan ON limit (parallel fan only).

COOL

Zone Controller is attempting to cool the zone by using supply air.

DEHUMIDIFY

Zone Controller is attempting to dehumidify the zone by overriding temperature control CFM requirements.

IAQ

Zone Controller is attempting to increase zone ventilation by overriding temperature control CFM requirements.

HEAT

Zone Controller is attempting to heat the zone by using supply air or local heating.

WARMUP

Zone Controller is attempting to heat the space during the morning warm up period.

REHEAT

Zone Controller is attempting the heat the zone by locally re-heating the supply air (single duct only).

PRESSURE

Zone Controller is participating in the pressurization mode of the system.

EVACUATION

Zone Controller is participating in the evacuation mode of the system.

1 2 ... 6 7 8 9 10 11 12 13 14 15 16 ... 43 44

Komentáře k této Příručce

Žádné komentáře

Carrier 33ZCSECTRM Specifikace Strana 11

Komentáře k této Příručce

Související produkty a manuály pro Split-systém klimatizace Carrier 33ZCSECTRM