Carrier 50VT-A installation instructions Check for Refrigerant Leaks, Start-Up Adjustments

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PRE-START-UP

!WARNING

FIRE, EXPLOSION, ELECTRICAL SHOCK AND ENVIRONMENTAL HAZARD

Failure to follow this warning could result in personal injury, death or property damage.

1.Follow recognized safety practices and wear protective goggles when checking or servicing refrigerant system.

2.Relieve and recover all refrigerant from system before touching or disturbing compressor plug if refrigerant leak is suspected around compressor terminals.

3.Do not remove compressor plug until all electrical sources are disconnected and tagged.

4.Never attempt to repair soldered connection while refrigerant system is under pressure.

5.Do not use torch to remove any component. System contains oil and refrigerant under pressure.

To remove a component, wear protective goggles and proceed as follows:

a.Shut off electrical power to unit and install lockout tag.

b.Relieve and reclaim all refrigerant from system using both high- and low-pressure ports.

c.Cut component connecting tubing with tubing cutter and remove component from unit.

d.Carefully unsweat remaining tubing stubs when necessary. Oil can ignite when exposed to torch flame.

Use the Start-Up Checklist supplied at the end of this book and proceed as follows to inspect and prepare the unit for initial start-up:

1.Remove all access panels (see Fig. 21).

2.Read and follow instructions on all DANGER, WARNING, CAUTION, and INFORMATION labels attached to, or shipped with, unit.

3.Make the following inspections:

a.Inspect for shipping and handling damages such as broken lines, loose parts, disconnected wires, etc.

b.Inspect for oil at all refrigerant tubing connections and on unit base. Detecting oil generally indicates a refrigerant leak. Leak-test all refrigerant tubing connections using electronic leak detector, or liquid-soap solution. If a refrigerant leak is detected, see following Check for Refrigerant Leaks section.

c.Inspect all field and factory-wiring connections. Be sure that connections are completed and tight. Ensure wires do not touch refrigerant tubing or sharp sheet metal edges.

d.Inspect coil fins. If damaged during shipping and handling, carefully straighten fins with a fin comb.

4.Verify the following conditions:

a.Make sure that outdoor-fan blade is correctly positioned in fan orifice.

b.Make sure that air filter(s) is in place.

c.Make sure that condensate drain pan and trap are filled with water to ensure proper drainage.

d.Make sure that all tools and miscellaneous loose parts have been removed.

5.Each unit system has 2 Schrader-type ports, one low-side Schrader fitting located on the suction line, and one

high-side Schrader fitting located on the compressor discharge line. Be sure that caps on the ports are tight.

START-UP

Checking Cooling and Heating Control Operation

Start and check the unit for proper control operation as follows: (1.) Place room thermostat SYSTEM switch or MODE

control in OFF position. Observe that blower motor starts when FAN mode is placed in FAN ON position and shuts down when FAN MODE switch is placed in AUTO position.

(2.) Thermostat:

When the room temperature rises to a point that is slightly above the cooling control setting of the thermostat, the thermostat completes the circuit between thermostat terminal R to terminals Y, O and G.These completed circuits through the thermostat connect contactor coil (C) (through unit wire Y) and Indoor Fan board (through unit wire

G)across the 24-v. secondary of transformer (TRAN).

(3.) Place system switch or MODE control in HEAT position. Set control above room temperature. Observe that compressor, outdoor fan, and indoor blower motors start. Observe that heating cycle shuts down when control setting is satisfied.

(4.) When using an automatic changeover room thermostat place both SYSTEM or MODE control and FAN mode switches in AUTO positions. Observe that unit operates in Cooling mode when temperature control is set to “call for Cooling” (below room temperature), and unit operates in Heating mode when temperature control is set to “call for Heating” (above room temperature).

NOTE: Once the compressor has started and then has stopped, it should not be started again until 5 minutes have elapsed. The defrost board has a built-in 5 minute delay between cycles. The 5 minute compressor delay also applies to heat pump heating mode.

Step 1 — Check for Refrigerant Leaks

Proceed as follows to locate and repair a refrigerant leak and to charge the unit:

1.Locate leak and make sure that refrigerant system pressure has been relieved and reclaimed from both high- and low-pressure ports.

2.Repair leak following Refrigerant Service procedures.

NOTE: Install a bi-flow filter drier whenever the system has been opened for repair.

3.Add a small charge of R-410A refrigerant vapor to system and leak-test unit.

4.Recover refrigerant from refrigerant system and evacuate to 500 microns if no additional leaks are not found.

5.Charge unit with Puron (R-410A) refrigerant, using an electronic scale. Refer to unit rating plate for required charge.

Step 2 — Start-Up Adjustments

Complete the required procedures given in the Pre-Start-Up section before starting the unit. Do not jumper any safety devices when operating the unit. Do not operate the unit in Cooling mode when the outdoor temperature is below 40_F (4_C) (unless accessory low-ambient kit is installed).

IMPORTANT: Three-phase, scroll compressors are direction oriented. Unit must be checked to ensure proper compressor 3-phase power lead orientation. If not corrected within 5 minutes, the internal protector will shut off the compressor. The 3-phase power leads to the unit must be reversed to correct rotation. When

50VT-- A

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Contents Safety Considerations Table of ContentsIntroduction Receiving and InstallationCheck Equipment Provide Unit Support50VT-A24-30 Unit Dimensions 50VT-A36-60 Unit Dimensions Large Curb Inspection Rig and Place UnitRigging/Lifting of Unit See Fig Unit Falling HazardPersonal Injury Hazard Select and Install DuctworkProvide for Condensate Disposal Install Electrical ConnectionsHigh-Voltage Connections Unit Component Damage HazardAccessory Electric Heaters Installation Special Procedures for 208-V OperationStandard Connections Control Voltage ConnectionsMinimum Airflow for Reliable Electric Heater Operation CFM Physical Data Unit 50VT-AConnection Wiring Schematics 208/230-1-60 Cont. Ladder Wiring Schematics 208/230-1-60 50VT a Cont. Ladder Wiring Schematics 208/230-3-60 Connection Wiring Diagram Cont. Ladder Wiring Diagram START-UP Start-Up AdjustmentsCheck for Refrigerant Leaks Checking Cooling and Heating Control OperationIndoor Airflow and Airflow Adjustments Checking and Adjusting Refrigerant ChargeTwo Cooling Fan Speeds Set-up Dehumidification feature used Unit Operation HazardColor Coding for Indoor Fan Motor Leads Single Speed Cooling With Higher Electric Heat SpeedContinuous Fan Operation Defrost Defrost ControlQuiet Shift Horizontal and Downflow Filter Pressure Drop Table IN. W.C Dry Coil Air Delivery Downflow DischargeElectric Heat Pressure Drop Table in. W.C Large Cabinet Electric Heat Pressure Drop Table in. W.C Small CabinetAir Filter MaintenanceIndoor Blower and Motor Personal Injury and Unit Damage HazardCooling Charging Table-Subcooling OF2 Outdoor Coil, Indoor Coil, and Condensate Drain Pan Electrical Controls and WiringOutdoor Fan Refrigerant CircuitLoss of Charge Switch Pressure SwitchesHigh-Pressure Switch Copeland Scroll Compressor Puron RefrigerantSystem Information TroubleshootingSTART-UP Checklist Puronr R-410A Quick Reference Guide Symptom Cause Remedy Troubleshooting ChartRemove and Store in Job Files TemperaturesPreliminary Information Model no III. START-UP Electrical Supply Voltage Compressor AmpsCatalog No 50VT---09SI
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50VT-A specifications

Carrier’s 50VT-A and 50EZ-A series exemplify cutting-edge advancements in heating, ventilation, and air conditioning (HVAC) technology. These products are engineered to meet diverse climate control needs in residential and commercial applications while ensuring operational efficiency and superior indoor air quality.

The Carrier 50VT-A series stands out with its variable-speed technology, which allows for precise temperature control by adjusting the cooling or heating output based on current demand. This capability not only optimizes energy consumption but also enhances comfort by eliminating temperature swings. The 50VT-A units are equipped with hybrid heat technology, which enables seamless integration with alternative heating sources, providing flexibility in energy use.

On the other hand, the Carrier 50EZ-A offers a unique solution for those seeking efficient and reliable climate control in a more compact design. This series incorporates advanced inverter technology, which continuously adjusts the compressor speed, ensuring that the system operates at the utmost efficiency regardless of environmental conditions. The result is significant energy savings and quieter operation compared to traditional units.

Both series feature intelligent refrigerant management, utilizing R-410A refrigerant, which is environmentally friendly and designed to reduce greenhouse gas emissions. The systems are engineered with robust insulation and sound-dampening materials, minimizing noise levels for a peaceful indoor environment.

In addition to their impressive technical specifications, the Carrier 50VT-A and 50EZ-A units come equipped with smart controls, allowing users to monitor and adjust settings remotely through mobile applications. This connectivity feature empowers homeowners and businesses to manage energy consumption, set schedules, and receive maintenance alerts, ensuring optimal performance at all times.

Durability is an important characteristic of both series, as they are designed to withstand various environmental conditions. With corrosion-resistant coatings and high-grade materials, these units promise longevity and reliable performance over their operational lifespan.

In summary, Carrier’s 50VT-A and 50EZ-A series offer an innovative blend of efficiency, advanced technology, and user-friendly features. Whether for residential or commercial applications, these systems provide exceptional comfort, lower energy costs, and an environmentally conscious choice for modern HVAC solutions.