Carrier 48EW, 48AW, 48EK Indoor Air Quality Sensor Configuration, Field Control Remote Start/Stop

JUMPER CONNECTION

FOR VOLTAGE OUTPUT

JUMPER CONNECTION

FOR CURRENT OUTPUT

Fig. 25 — Indoor Air Quality Sensor Configuration

REMOTE

START/STOP

SWITCH

(FIELD-SUPPLIED)

R

Y1

Y2

W1

W2

G

C

X

CONTROL

BOX

LEGEND

Field Supplied Wiring

Fig. 26 — Field Control Remote Start/Stop

An electronic expansion board may be field-installed to pro- vide the following features:

•provide discrete inputs for fan status, filter status, field- applied status, and demand limit

•provide an output for the external alarm light indicator

•provide power exhaust fire outputs for direct control of modulated power exhaust stages during fire or smoke modes

•control of smoke control modes including evacuation, smoke purge, pressurization, and fire shutdown (modu- lating power exhaust required)

When the unit is connected to the CCN (Carrier Comfort Network), the following expansion board features can be utilized:

•perform Demand Limit functions based on CCN load- shed commands or the state of the discrete input

•alarm monitoring of all key parameters

•CCN protocol

See Carrier TEMP or VVT® (Variable Volume and Tem- perature) literature for complete TEMP (single zone) or VVT (multi-zone) application information.

Features with Sensor Control of Unit (Network Applica- tions) — The base control board provides, as standard, a con- nection for use with a Carrier VVT system and can also be in- tegrated into a Carrier Comfort Network.

When the unit is accessed via a PC equipped with ComfortWORKS®, Building Supervisor, Service Tool soft- ware, or accessory Remote Enhanced Display, the following features can be accessed:

•on-board timeclock can be programmed

•occupancy schedules can be programmed

•unit set points can be changed

•alarms can be monitored

This access is available on the base control board via a RJ-11 phone jack or a 3-wire connection to the communication bus. See Fig. 27. The timeclock has a 10-hour minimum back- up time to provide for unit power off for servicing unit or dur- ing unexpected power outages. For complete Carrier Comfort System (CCS) or Carrier Comfort Network (CCN) features and benefits, refer to the product literature.

VARIABLE AIR VOLUME (VAV) APPLICATIONS

Features with Stand-Alone Applications — The units, as shipped, are operable as stand-alone units with the addition of a timeclock to establish unit start and stop times.

Heating and cooling in both on and off modes is controlled to default values by the base unit control. Set points may be changed with appropriate input devices.

The control has an on-board occupancy schedule which can be set using an input device and eliminates the need for an ex- ternal timeclock.

During both the on and off periods, cooling operation is controlled to the supply air setting and heating is controlled to the return air setting (or to the optional space temperature sen- sor). During the on period, the supply fan runs continuously. During the off period, the supply fan will be activated if the re- turn air sensor is outside of the set points and will run long enough to accurately sample the space temperature. The supply fan will then continue to run until any heating or cooling load is satisfied, at which point it will turn off.

The use of a space sensor will allow for supply air reset to conserve energy and maintain comfort. If equipped with an override feature, the sensor will allow operation during the off period for a fixed length of time.

Base unit control supports a Heat Interlock Relay (field sup- plied) to fully open the VAV terminal devices during heating operation.

Standard features of a VAV unit with a remote start/stop switch are:

•control board diagnostics

•control of an outdoor condenser fan based upon outdoor air temperature

•control of modulating economizer to provide free cool- ing when outdoor conditions are suitable, using supply- air temperature as a set point

•support of remote occupied/unoccupied input to start or stop the unit

•provide power exhaust output to an external power exhaust controller

•support supply-air temperature reset to offset supply air set point

•support a field test for field check out

•support linkage to DAV (digital air volume) systems

•cooling capacity control of up to 6 stages plus econo- mizer with compressors and unloaders to maintain sup- ply air temperature set point during occupied periods

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