Carrier NP034-074 specifications Control Board Component Arrangement

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LEGEND

CLO Ð Compressor Lockout

PÐ Plug

SC Ð Safety Circuit

Fig. 64 Ð Control Board Component Arrangement

Symptom: Evaporator fan will not operate.

1.Turn unit power off and disconnect plug P1 from the con- trol board.

2.Install a jumper across Pin R and Pin G at plug P1 on the control board.

3.Turn unit power on and check if the indoor (evaporator) fan contactor (IFC) coil has been pulled in. If the con- tactor has not been pulled in, check the voltage across the IFC coil. If there is voltage at this point, the IFC con- tactor is defective. If there is no voltage, proceed to Step 4.

4.Turn unit power off and disconnect plug P4 from the con- trol board.

5.Turn unit power on and check for continuity across Pin 6 and Pin 3 at plug P4 on the control board. If there is no continuity, the board is defective. Replace control board. If there is continuity, then there is a bad con- nection between the board and plug P4. Correct the connection.

6.Turn unit power off. Reconnect plug P1 (if troubleshoot- ing is complete) and plug P4.

Symptom: Condenser fan no. 1 will not operate.

1.Turn unit power off. Disconnect plugs P1 and P3 from the control board.

2.Check for continuity between Pin 8 at plug P3 on the con- trol board and Pin Y1 at plug P1 on the control board. If there is no continuity, the board is defective. If there is continuity, either the connection is bad between plug P3 and the control board or the problem is external to the board. Reconnect plug P1 (if troubleshooting is com- plete) and plug P3 to the board.

Symptom: Condenser fan no. 2-5 will not operate.

1.Check operation of condenser fan no. 1. If fan no. 1 op- erates properly, the problem is external to the board.

Symptom: Compressor no. 1 will not operate.

1.Turn unit power off. Disconnect the 2 wires attached to the terminals marked SC1.

2.Check continuity between the 2 wires. If there is no continuity, the problem is external to the control board (possibly the pressure switches). If there is continuity, pro- ceed to Step 3.

3.Reconnect the wires removed in Step 1.

4.With the unit power still off, disconnect plug P1 from con- trol board. Install a jumper wire across Pin R and Pin Y1 at plug P1 on the control board.

5.Connect a voltmeter across the coil for compressor no. 1 contactor.

6.Energize unit and monitor the voltage for a few seconds.

IMPORTANT: Do not run compressor too long.

7.a. If proper voltage is indicated at the contactor, but con- tactor fails to close, replace contactor.

b.If voltage is indicated for a few seconds (i.e., the con- tactor momentarily pulls in and is then deenergized), the compressor lockout (CLO) logic has shut down the unit. This is an indication that the board is not sens- ing proper compressor current, or that one of the safe- ties has tripped. Proceed to Step 8 to verify compres- sor lockout logic operation.

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Contents Installation, Start-Up Service Instructions Contents GeneralRigging Label Ð Physical Data 034, 044 Units Ð Physical Data 054-074 Units Operating Weights of Options and Accessories Weight Distribution and Center of GravityÐ Roof Curb 034, 044 Units Ft-inÐ Roof Curb 054-074 Units DegÐ Condenser Section Roof Curb 054-074 Units Only 054,064 270 105¤8 074 255 101¤16Economizer Settings Install Outdoor HoodsOutdoor-Air Inlet Adjustments Unit Sizes 034Unit Size Weight Ð Base Unit Dimensional Drawing 50DJ,DK,NP034,044 Units 8700 3946 5969 19-7 6717 Ð Base Unit Dimensional Drawing 50DJ,DK,NP054-074 Units Weight Ft-inDrain Location Selection Approx Deg AT 50% RHField Wire Routing Field Electrical ConnectionsField Power Wiring Connections Electrical Data, 034 Units 93.8 110 10.0 15.2 99.4 125 15.0 22.0 106.2 90.8 110 10.0 15.2 96.4 125 15.0 22.0 103.211.0 81.2 100 10.0 14.0 84.2 11075.6 10.0 12.2 80.0 100 15.0 18.0 85.8 73.6 10.0 12.2 78.0 100 15.0 18.0 83.865.8 67.8Electrical Data, 044 Units 109.5 125 10.0 15.2 115.1 15.0 22.0 121.9 150 106.5 125 10.0 15.2 112.1 15.0 22.0 118.9 15011.0 96.9 125 10.0 14.0 99.9 12586.1 110 10.0 12.2 90.5 15.0 18.0 96.3 84.1 110 10.0 12.2 88.5 15.0 18.0 94.376.3 100 10.0 11.0 78.3 100Electrical Data, 054 Units 10.0 15.2 150.8 200 15.0 22.0 157.6 20.0 28.0 163.6 10.0 15.2 144.8 175 15.0 22.0 151.6 200 20.0 28.0 157.615.0 21.0 129.6 175 20.0 27.0 135.6 17510.0 12.2 121.5 150 15.0 18.0 127.3 20.0 22.0 131.3 10.0 12.2 116.5 150 15.0 18.0 122.3 20.0 22.0 126.315.0 17.0 104.3 125 20.0 22.0 109.3 125Electrical Data, 064 Units 10.0 15.2 166.8 200 15.0 22.0 173.6 20.0 28.0 179.6 225 10.0 15.2 160.8 200 15.0 22.0 167.6 20.0 28.0 173.615.0 21.0 145.6 175 20.0 27.0 151.6 20010.0 12.2 131.8 150 15.0 18.0 137.6 175 20.0 22.0 141.6 10.0 12.2 126.8 150 15.0 18.0 132.6 20.0 22.0 136.6 17515.0 17.0 114.6 150 20.0 22.0 119.6 150Electrical Data, 074 Units 10.0 15.2 188.0 250 15.0 22.0 194.8 20.0 28.0 200.8 10.0 15.2 182.0 225 15.0 22.0 188.8 250 20.0 28.0 194.815.0 21.0 166.8 225 20.0 27.0 172.8 22510.0 12.2 151.0 200 15.0 18.0 156.8 20.0 22.0 160.8 10.0 12.2 146.0 175 15.0 18.0 151.8 200 20.0 22.0 155.815.0 17.0 133.8 175 20.0 22.0 138.8 175Field Control Thermostat Wiring Field Wiring for Building Pressurization and Smoke Purge Installing Flue/Inlet Hoods 48 Series Units Only Gas Piping DetailsFlue Hood PRE-START-UP Gas Manifold Pressure 48 Series Units Only Ð Field-Supplied Evaporator-Fan Pulley Data, 034,044 UnitsÐ Field-Supplied Evaporator-Fan Pulley Data, 054-074 Units Air Quantity Limits cfmInitial Check GeneralHEATING, Units Without Economizer Service CompressorsLiquid Service VALVES, Filter DRIERS, and Sight Glasses Power Exhaust MOTORS, PULLEYS, and BeltsEVAPORATOR-FAN MOTORS, PULLEYS, and Belts Burner Section Detail 48 Series Units Only Modulating Power Exhaust Damper Motor LubricationAdjustments Belt Installation and TensioningCondenser FAN Adjustment Pulley Alignment Charging Chart, 044 Units System One Condenser Fan Running Charging Chart, 064 Units System All Condenser Fans Running Auxiliary Switch Stroke Adjustment Main Burner Removal 48 Series Units OnlyProtective Devices Compressor ProtectionEconomizer Motor Checkout Electric Heat 50 Series Units OnlyGas Heat 48 Series Units Only Economizer Control Board Checkout TestDetailed Check Control Board Component Arrangement Page Compressor Lockout Connections ACC Gas Heat Sections 48DJ,NP034,044 Units Gas Heat Sections 48DJ,NP054-074 Units Gas Heat DK034,044 Units Gas Heat DK054-074 Units Typical Wiring Schematic 48/50DJ,50DW Units 054-074 Shown Typical Wiring Schematic 48/50DJ,50DW Units 054-074 Shown Typical Wiring Schematic 48/50DK,50DY Units 054-074 Shown Typical Wiring Schematic 48/50DK,50DY Units 054-074 Shown Page Page Page Page Packaged Service Training Page Model no Serial no Date Technician OUTDOOR-AIR TemperatureRETURN-AIR Temperature Supply Voltage L1-L2

NP034-074 specifications

The Carrier NP034-074 is an advanced rooftop unit designed for commercial heating, ventilation, and air conditioning (HVAC) applications. This unit is part of Carrier’s extensive range of rooftop units that are known for their energy efficiency, reliability, and innovative features. The NP034-074 series is particularly recognized for its robust performance in diverse environmental conditions, making it ideal for a variety of commercial building types.

One of the standout features of the NP034-074 is its high-efficiency compressor. Equipped with a scroll compressor, the unit offers enhanced performance and quieter operation compared to traditional reciprocating compressors. This design not only improves energy efficiency but also reduces operating costs over time. The unit is designed to meet or exceed the latest efficiency standards, ensuring that businesses can enjoy optimal indoor comfort while keeping energy consumption low.

The NP034-074 also integrates advanced control technologies that provide users with greater flexibility and ease of operation. The intuitive control system allows for precise temperature management and can be easily integrated with building automation systems. This enables users to monitor and adjust settings remotely, ensuring consistent and efficient climate control throughout the facility.

Another key characteristic of the NP034-074 is its robust construction. Built to withstand various weather conditions, the unit features a galvanized steel cabinet with a powder-coated finish for corrosion resistance. Its design also facilitates easy access for maintenance and service, which minimizes downtime and operational interruptions.

In terms of air distribution, the NP034-074 incorporates a powerful blower system that ensures even and effective airflow throughout the space. This design improves indoor air quality by enhancing ventilation while maintaining comfort levels. Additionally, the unit can be customized with options such as economizers and variable speed fans to optimize performance based on specific building needs.

The NP034-074 is a versatile and reliable choice for businesses looking to enhance their HVAC systems. With its combination of energy efficiency, advanced technology, and robust construction, this rooftop unit stands out as a top choice for commercial climate control solutions.
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