Pumpout Unit, Relief Valve Arrangements

FRAME

CONTROL ASSEMBLY

PANEL

VALVE

2	VALVE
	3
VALVE	COMPRESSOR
4
	OIL
	HEATER
VALVE
5
ENTERING	OIL FILL
WATER	FITTING
	FITTING

a23-1546LEAVING CONDENSER WATER

OIL

SEPARATOR

Fig. 42 — Pumpout Unit

INSTALL VENT PIPING TO RELIEF VALVES — The 23XRV chiller is factory equipped with relief valves on the cooler and condenser shells. Refer to Fig. 43 and Table 11 for size and location of relief devices. Vent relief devices to the outdoors in accordance with ANSI/ASHRAE 15 (latest edition) Safety Code for Mechanical Refrigeration and all other applicable codes.

Refrigerant discharged into confined spaces can displace oxygen and cause asphyxiation.

1.Dual pressure relief valves are mounted on the three-way valves in some locations to allow testing and repair with- out transferring the refrigerant charge. Three-way valve shafts should be turned either fully clockwise or fully counterclockwise so only one relief valve is exposed to refrigerant pressure at a time.

The flow area of discharge piping routed from more than one relief valve, or more than one heat exchanger, must be greater than the sum of the outlet areas of all relief valves that are expected to discharge simultaneously. All relief valves within a machinery room that are exposed to refrigerant may discharge simultaneously in the event of a fire. Discharge piping should lead to the point of final release as directly as possible with consideration of pres- sure drop in all sections downstream of the relief valves.

2.Provide a pipe plug near outlet side of each relief device for leak testing. Provide pipe fittings that allow vent piping to be disconnected periodically for inspection of valve mechanism.

3.Piping to relief devices must not apply stress to the device. Adequately support piping. A length of flexible tubing or piping near the relief device is essential on spring-isolated machines.

4.Cover the outdoor vent with a rain cap and place a condensation drain at the low point in the vent piping to prevent water build-up on the atmospheric side of the relief device.

WITH ISOLATION VALVES

a23-1583	WITHOUT ISOLATION VALVES

Fig. 43 — Relief Valve Arrangements

Make Electrical Connections — Field wiring must be installed in accordance with job wiring diagrams and all applicable electrical codes. Refer to Fig. 44 and 45 for typical wiring and component layout.

Only qualified electrical personnel familiar with the con- struction and operation of this equipment and the hazards involved should install, adjust, operate, or service this equipment. Read and understand this manual and other applicable manuals in their entirety before proceeding. Failure to observe this precaution could result in severe bodily injury or loss of life.

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.