Carrier EK, 48EJ, EW, EY024-048 Unit Configuration Default Cooling Default Heating, Vav

Table 3 Ð Controls Options and Con®gurations (Non-Thermostat Applications)

UNIT CONFIGURATION	DEFAULT COOLING		DEFAULT HEATING
CV or VAV Unit with SPT Sensor	Unoccupied Cooling Ð 90 F (SPT)		Unoccupied Heating Ð 55 F (SPT)
	Occupied Cooling	Ð NA	Occupied Heating	Ð NA
CV Unit with SPT Sensor and Remote	Unoccupied Cooling Ð 90 F (SPT)		Unoccupied Heating Ð 55 F (SPT)
Start/Stop Switch	Occupied Cooling	Ð 78 F (SPT)	Occupied Heating	Ð 68 F (SPT)
VAV Unit Remote Start/Stop Switch Only	Unoccupied Cooling Ð 90 F (RAT)		Unoccupied Heating Ð 55 F (RAT)
	Occupied Cooling	Ð 55 F (SAT)	Occupied Heating	Ð 68 F (RAT)*
VAV Unit with SPT Sensor and Remote	Unoccupied Cooling Ð 90 F (SPT)		Unoccupied Heating Ð 55 F (SPT)
Start/Stop Switch	Occupied Cooling	Ð 55 F (SAT)	Occupied Heating	Ð 68 F (RAT)*

	LEGEND
CV	Ð Constant Volume
NA	Ð Not Available
RAT Ð Return-Air Temperature
SAT Ð Supply-Air Temperature
SPT Ð Space Temperature
VAV	Ð Variable Air Volume

*With DIP Switch No. 5 con®gured to OPEN (Occupied Heat Enabled).

NOTE: Space temperature sensor and remote start/stop switch are ®eld-supplied.

·control of modulating economizer damper to provide free cooling when outdoor conditions are suitable, using supply-air temperature as a control point

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

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

·support a ®eld test for ®eld checkout

·control of 2 stages of CV power exhaust

·	compressor Time Guard (power up, minimum off and on
	times)
·	compressor lockout during low supply-air temperature

Additional features are provided by accessing the stand- ard unit control board via software with a computer. These features are:

·electronic expansion board features (if installed)

·control board diagnostics

·ability to change supply air set point (economizer control)

·ability to change high outdoor temperature lockout set point (economizer control)

·ability to change power exhaust set points

NOTE: A CV unit without a thermostat requires a ®eld- supplied sensor for operation.

Features with Sensor Control of Unit (Stand-Alone Appli- cations Ð Unit control is limited to CV unoccupied default set points, 90 F for cooling, 55 F for heating. There are

2 sensor options available:

·T-55 sensor will monitor room temperature and provide unoccupied override capability (1 hour)

·T-56 sensor will monitor room temperature, provide un- occupied override capability (1 hour), and provide a tem- perature offset of 5° F.

Standard features are:

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

·cooling capacity control of 3 stages using economizer and 2 compressors to maintain space temperature to an occu- pied or unoccupied set point

·enable heating or cooling during unoccupied periods as required to maintain space temperature within the unoc- cupied set points

·adjustment of space temperature set points of ±5° F when using a T-56 sensor

Additional features with sensor control of unit (with com- puter access) are:

·365 day timeclock with backup (supports minute, hour, day of week, date, month, and year)

·daylight savings time function

·occupancy control with 8 periods for unit operation

·holiday table containing up to 18 holiday schedules

·ability to initiate timed override from T-55 or T-56 sensors for a timed period of 1 to 4 hours

·ability to use multiple space temperature sensors to aver- age the space temperature

·temperature compensated start to calculate early start times before occupancy

·access to the Display, Maintenance, Con®guration, Service, and Set Point data tables through network software

When the unit is equipped with a ®eld-supplied space temperature sensor and a remote contact closure (remote start/ stop) on the base control board, the occupied default set points will monitor unit operation. The occupied default set points are 78 F cooling and 68 F heating. See Fig. 14 for remote start/stop wiring.

NOTE: For units with a ®eld-supplied space temperature se- sor which have not had the base unit control board accessed via software to set an occupancy schedule, the remote start/ stop closure will allow the unit to operate in the pre- con®gured occupied default set points (based on return-air temperature) of 78 F cooling and 68 F heating. Without this feature, the unit will control to the unoccupied default set points of 90 F cooling and 55 F heating.

An electronic expansion board may be ®eld-installed to provide the following features:

·control of modulating economizer damper to maintain in- door air quality (IAQ) when outdoor conditions are suitable

NOTE: The IAQ sensor must be set for current output (4 to 20 mA), not voltage output. Ensure the jumper on the sensor is in the upper position. See Fig. 15.

·provide discrete inputs for fan status, ®lter status, ®eld- applied status, and demand limit

·provide an output for the external alarm light indicator

·provide power exhaust ®re outputs for direct control of modulated power exhaust stages during ®re or smoke modes

·control of smoke control modes including evacuation, smoke purge, pressurization, and ®re shutdown (modulating 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 loadshed commands or the state of the discrete input

·alarm monitoring of all key parameters

·CCN protocol

·provides CCN IAQ participation

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

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