Carrier EW, 48EJ, EK, EY024-048 installation instructions GND Ð Ground, Terminal Block

Page 21

IMPORTANT: THE VAV (variable air volume) units use variable frequency drives, which generate, use and can radiate radio frequency energy. If units are not in- stalled and used in accordance with these instructions, they may cause radio interference. They have been tested and found to comply with limits of a Class A com- puting device as de®ned by FCC (Federal Communi- cations Commission) regulations, Subpart J of Part 15, which are designed to provide reasonable protection against such interference when operated in a commer- cial environment.

The unit must be electrically grounded in accordance with local codes and NEC ANSI/NFPA 70 (National Fire Protection Association).

Affix crankcase heater sticker (located in the installers packet) to unit disconnect switch.

Voltage to compressor terminals during compressor op- eration must be within the voltage range indicated on the unit nameplate. On 3-phase units, phases must be balanced within 2%. Contact local power company for correction of improper voltage or phase imbalance. Unit failure due to op- eration of unit on improper line voltage or with excessive phase imbalance constitutes abuse and may cause damage to unit electrical components.

On 208/230-v units, transformer no. 1 is wired for 230-v. If 208/230-v unit is to be run with 208-v power supply, the transformer must be rewired as follows:

1.Remove cap from red (208 v) wire.

2.Remove cap from spliced orange (230 v) wire. Discon- nect orange wire from black unit power wire.

3.Cap orange wire.

4.Splice red wire and black unit power wire. Cap wires.

IMPORTANT: BE CERTAIN UNUSED WIRES ARE CAPPED. Failure to do so may damage the transformers.

FIELD CONTROL WIRING Ð The unit can use either a Carrier-approved thermostat or a CCN (Carrier Comfort Network) compatible temperature sensor. Thermostats are used on CV (constant volume) units only. Control box diagrams are shown in Fig. 18 and 19.

Thermostat Wiring (CV Only) Ð Install a Carrier-approved accessory thermostat assembly (per current price pages) ac- cording to the installation instructions included with the ac- cessory or these instructions. Locate the thermostat on a solid interior wall in the conditioned space to sense the average temperature.

Route the thermostat cable or equivalent single leads of colored wire from the subbase terminals to the low-voltage connection as shown on unit label wiring diagram and in Fig. 20.

NOTE: For wire runs up to 50 ft, use no. 18 AWG (American Wire Gage) insulated wire (35 C minimum). For 50 to 75 ft, use no. 16 AWG insulated wire (35 C minimum). For over 75 ft, use no. 14 AWG insulated wire (35 C mini- mum). All wire larger than no. 18 AWG cannot be directly connected at the thermostat and will require a junction box and splice at the thermostat.

Set heat anticipators to 0.1 for all voltages.

Sensor Wiring (CV or VAV) Ð The temperature sensor is wired into the unit control board. See Fig. 21.

The unit is controlled with a T-55 or T-56 (CV only) zone sensor. Terminal TH (T-56) or T1 (T-55) on the sensor is connected to T1 of the base module board. Terminal COM (T-56) or T2 (T-55) on the sensor is connected to T2 on the base module board. If a T-56 set point override sensor is used, the override connection SW on the sensor is connected to T3 on the base module board.

If more than sensor is being used and averaged, sensors must be wired in multiples of 4 or 9. See Fig. 22.

Heat Interlock Relay Ð VAV units require a ®eld-supplied heat interlock relay (HIR) to drive the air terminal wide open when in heat mode. Heat Interlock relay part number is HN61KK041.

 

LEGEND

GND Ð Ground

NEC

Ð National Electrical Code

TB

Ð Terminal Block

NOTE: Maximum wire size for TB1 is 500 MCM.

Fig. 17 Ð Field Power Wiring Connections

 

 

LEGEND

 

 

C

Ð

Compressor/Contactor

IF

Ð

Indoor Fan

CB

Ð Circuit Breaker

OF

Ð Outdoor Fan

DIP

Ð

Dual In-Line Package

PEC

Ð

Power Exhaust Controller

FU

Ð

Fuse

TB

Ð

Terminal Block

HR

Ð

Heater Relay

TRAN Ð

Transformer

Fig. 18 Ð Control Box Diagram (Sizes 024-034)

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Contents Installation, Start-Up Service Instructions Instructions on Field Fabricate DuctworkDegrees and Inches Unit Leveling Tolerances DimensionsRoof Curb Sizes Weight Unit OperatingSize 48EJE038 Ft-in 48EJ,EKD03848EJ,EKD044 48EJE044Base Unit Dimensions, 48EW,EY024-034 Base Unit Dimensions, 48EW,EY038-048 48EJ,EK,EW,EYD028 48EJ,EK,EW,EYD030 Unit Weight 48EJ,EK,EW,EYD02448EJ,EK,EW,EYD034 48EJ,EK,EW,EYD038Unit 48EJ,EK,EW,EY Physical Data4442/4602 4668/4828 4955/5115 Air Distribution Ð Thru-the-Bottom Combustion Fan Housing Location VAV Unit Configuration Default Cooling Default HeatingField Control Remote Start/Stop Make Electrical Connections CCN SIOLED Electrical Data RLA LRAFLA LRA MCA Mocp FLA FLA LRAHacr NEC044 QtyHeating, Air Conditioning Minimum Circuit AmpsTerminal Block GND Ð GroundPEC DIPManufacturer Cable Part no CCN Connection Approved Shielded Cables2413 or 8772Color Code Recommendations Make Outdoor-Air Inlet AdjustmentsRED WhiteAdding Seal Strip to Top of Hood Sides Adding Foam Strip to Hood Side Mounting Angle With Tabs Attached to Filter Track Assembly Psychrometric Chart for Enthalpy Control Barometric Relief Damper and Power Exhaust Mounting Details Pressure Transducer Locations START-UP VFD Supply Air Pressure Set Point Pressure Control VFDSET Point Potentiometer Signal Levels Direct Digital Controls DIP Switch ConguraBuilding Pressure Signal Level VdcPower Exhaust Default Set Points DIP Switch CongurationDIP Switch Factory Settings Airflow 17,000 16,00018,000 19,000528 572 615 656 695 733 769 805 Motor Limitations Fan Performance Ð Power ExhaustESP Standard Efficiency MotorsAir Quantity Limits Sequence of OperationUser Dened Set Points GAS HEATING, Variable AIR Volume VAV Units DEG. F Reset COMHIR Device Pressurization Smoke Purge Evacuation Fire Shutdown Smoke Control ModesCooling Capacity Staging Table, CV Units With 2 Compressors StagesCompressor Manufacturer Lubricant LubricationTypical Gas Heating Section Evaporator Fan Service and ReplacementCondenser-Fan Adjustment Evaporator-Fan Motor ReplacementProtective Devices Belt Tension AdjustmentGas Valve IFC AHAIfcb TranTypical Power Schematic 48EJ,EK,EW,EY024-034 208/230-3-60 Typical VAV 115-v Control Circuit Typical CV 115-v Control Circuit Typical VAV 24-v Control Circuit Typical CV 24-v Control Circuit Troubleshooting Typical Refrigerant Circuiting 48EJ,EK,EW,EY038,044 Typical Refrigerant Circuiting 48EJ,EK,EW,EY048 IGC Control Heating and Cooling Control Board LED Alarms IGC Control Board LED AlarmsI/O Channel Designations Base Module Ð VAV I/O Channel Designations Base Module Ð CVTerminal no Assignment SPTPackaged Service Training START-UP Checklist General
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EW, EY024-048, EK, 48EJ specifications

The Carrier 48EJ, 48AW, 48EK, 48AJ, and 48EY024-068 are cutting-edge rooftop air conditioning units designed for commercial applications. These models are renowned for their reliability, energy efficiency, and innovative technologies aimed at providing optimal indoor comfort.

One of the standout features of these units is their advanced cooling and heating capabilities. They employ a multi-stage compressor system that allows for precise temperature control, accommodating various load requirements. This flexibility is particularly beneficial in commercial settings where the cooling load can fluctuate throughout the day.

Energy efficiency is paramount in today’s environmental landscape, and Carrier has ensured that these models meet stringent efficiency standards. They incorporate high-efficiency scroll compressors, which significantly reduce energy consumption while delivering powerful performance. The units are also equipped with variable speed fans that adjust airflow based on demand, further optimizing energy use.

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The Carrier 48EJ, 48AW, 48EK, 48AJ, and 48EY models utilize advanced controls and connectivity features, allowing for easy integration into building management systems. This connectivity enables remote monitoring and control, facilitating quick response to changing conditions and simplifying maintenance tasks.

Noise reduction is another key characteristic of these models. They are designed with sound-absorbing insulation and low-noise fan blades to ensure quiet operation, making them suitable for noise-sensitive environments such as schools and hospitals.

These units are also available with various options for air filtration and dehumidification. The use of high-efficiency air filters enhances indoor air quality by trapping dust, pollen, and other airborne particles. Enhanced dehumidification capabilities ensure that spaces remain comfortable even in humid conditions.

In conclusion, the Carrier 48EJ, 48AW, 48EK, 48AJ, and 48EY024-068 rooftop units are engineered to offer exceptional performance, energy efficiency, and durability. With their advanced technologies and user-friendly features, they stand out as reliable solutions for meeting diverse commercial cooling and heating needs, making them a popular choice for many businesses.
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