Carrier EY024-048, EW Ð Field Control Remote Start/Stop, Ð Indoor Air Quality Sensor Conguration

R

Y1

Y2

W1

W2

G

C

X

CONTROL

BOX

LEGEND

Field Supplied Wiring

REMOTE

START/STOP

SWITCH

(FIELD-SUPPLIED)

VARIABLE AIR VOLUME (VAV) APPLICATIONS

Features with Stand-Alone Applications Ð 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 con- trolled 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 external 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 sensor). During the on period, the supply fan runs continu- ously. During the off period, the supply fan will be activated if the return air sensor is outside of the set points and will run log enough to accurately sample the space temperature. The supply fan will then continue to run until any heating or cooling load is satis®ed, 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

Fig. 14 Ð Field Control Remote Start/Stop

JUMPER CONNECTION

FOR VOLTAGE OUTPUT

JUMPER CONNECTION

FOR CURRENT OUTPUT

Fig. 15 Ð Indoor Air Quality Sensor Con®guration

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

When the unit is accessed via a PC equipped with Com- fortWorks™, Building Supervisor, or Service Tool software, or accessory LID-2B, 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 communi- cation bus. See Fig. 16. The timeclock has a 10-hour mini- mum back-up time to provide for unit power off for servic- ing unit or during unexpected power outages. For complete Carrier Comfort System (CCS) or Carrier Comfort Network (CCN) features and bene®ts, refer to the product literature.

the off period for a ®xed length of time.

Base unit control supports a Heat Interlock Relay (®eld supplied) to fully open the VAV terminal devices during heat- ing 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 cooling when outdoor conditions are suitable, using supply-air tem- perature as a set point

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

·provide power exhaust output to an external power ex- haust controller

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

·support a ®eld test for ®eld check out

·support linkage to DAV systems

·cooling capacity control of up to 6 stages plus economizer with compressors and unloaders to maintain supply air tem- perature set point during occupied periods

·control of one stage of heat to maintain return-air tem- perature at heating set point during occupied periods

·provide a variable frequency drive high voltage relay out- put to enable VFD

·control of heat interlock relay

·compressor Time Guard override (power up, minimum off and on times)

With the addition of a remote start/stop switch heating or cooling is enabled during unoccupied periods as required to maintain space temperature to within unoccupied set points.

Additional features may be provided with Electronic Access to Unit Control Board. These features are:

·additional control board diagnostics

·electronic expansion board features (if installed)

·control of the economizer damper and indoor fan to obtain unoccupied free cooling

·365-day timeclock with backup (supports minute, hour, day, month, and year)

·holiday table containing up to 18 holiday schedules

·occupancy control with 8 periods for unit operation

·support a set of display, maintenance, con®guration, serv- ice, and set point data tables for interface with Building Supervisor, ComfortWorks, or Service Tool software soft- ware or accessory LID-2B

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