WIRING THE FIELD WIRING TERMINAL STRIPS — This section describes how to wire the field wiring terminal strips shown in Fig. 46 and 47. The control terminal blocks are mounted to the inside of the enclosure, above and below the control panel.

NOTE: Up to 30 v may be measured across open contact terminals on the hazardous voltage terminal strip.

1.Turn off, lock out, and tag the input power to the drive. Wait five minutes.

2.Verify that there is no voltage at the input terminals (L1, L2, and L3) of the power module.

3.Verify that the status LEDs on the Communications Interface Board are not lit. See Fig. 48. The location of the Communications Interface Board is shown in Fig. 6.

4.Use a screwdriver to remove conduit twist outs in the control panel. Do not punch holes or drill into the top surface of the control center enclosure for field wiring. Knockouts are provided in the back of the control center for field wiring connections.

5.Connect the control wiring as shown in Fig. 47. Tighten all connections to 7 to 9 in-lb.

CONNECT CONTROL INPUTS — Wiring may be speci- fied for a spare safety switch, and a remote start/stop contact can be wired to the starter terminal strip. Additional spare sen- sors and Carrier Comfort Network® modules may be specified as well. These are wired to the machine control panel as indicated in Fig. 49.

CONNECT CONTROL OUTPUTS — Connect auxiliary equipment, chilled and condenser water pumps, and spare alarms as required and indicated on job wiring drawings.

CONNECT STARTER — The 23XRV is equipped with a unit-mounted VFD starter (Fig. 50).

IMPORTANT: Be sure to ground the power circuit in accordance with the National Electrical Code (NEC), applicable local codes, and job wiring diagrams. Also, make sure correct phasing is observed for proper rotation.

Do not punch holes or drill into the top surface of the control center. Knockouts are provided in the back of the control center for wiring connections.

Remove the VFD shipping bracket shown in Fig. 16.

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Carrier HFC-134A installation instructions
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HFC-134A specifications

Carrier HFC-134A, also known as tetrafluoroethane, is a hydrofluorocarbon (HFC) refrigerant widely used in a variety of cooling and heating applications. It is recognized for its role in refrigeration and air conditioning systems, making it a crucial component in many modern HVAC units. One of the key features of HFC-134A is its zero ozone depletion potential, which makes it an environmentally friendly alternative to older refrigerants like CFCs and HCFCs.

The characteristics of HFC-134A include its stability, non-corrosiveness, and effectiveness at low temperatures. These properties allow it to perform efficiently in both residential and commercial refrigeration systems. The refrigerant operates within a temperature range that is ideal for many applications, including food preservation and air conditioning. HFC-134A's thermodynamic properties enable it to absorb and release heat effectively, making it suitable for both vapor-compression and absorption refrigeration cycles.

From a technological perspective, the use of HFC-134A aligned with the transition to more sustainable refrigerants. As global environmental regulations have tightened, manufacturers have shifted towards refrigerants with lower global warming potential (GWP). HFC-134A has a GWP of approximately 1,430, which is lower than many of its predecessors but still higher than some newer alternatives. This aspect drives ongoing research and development in the industry, aiming to create even more environmentally sound refrigerants.

Carrier HFC-134A is compatible with various lubricants and can be integrated into systems designed for other refrigerants with minimal modifications. This flexibility allows for a smoother transition within existing installations as businesses and homeowners upgrade their HVAC systems to comply with environmental regulations.

In summary, Carrier HFC-134A plays a significant role in modern refrigeration and air conditioning technology. Its main features, including zero ozone depletion potential, stability, and efficiency, contribute to its widespread use in various applications. As the industry continues to evolve, the focus on reducing the environmental impact of refrigerants will undoubtedly influence the future direction of HFC-134A usage and the development of new alternatives.
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