Outdoor Condenser Fan Assembly, Unit Controls

251934-YTG-G-0708

equipped with VFD’s shall have factory-installed manual bypass as an option.

Outdoor (Condenser) Fan Assembly

The outdoor fans shall be of the direct-driven propeller type, discharge air vertically, have aluminum blades riveted to corrosion resistant steel spider brackets and shall be dynamically balanced for smooth operation. The 4 outdoor fan motors shall be totally enclosed with permanently lubricated bearings, internally protected against overload conditions and staged independently.

Refrigerant Components

Compressors:

a. Shall be Scroll compressors internally protected with internal high-pressure relief and over temperature protection.

b.Shall have internal spring isolation and sound muffling to minimize vibration and noise, and be externally isolated on a dedicated, independent mounting.

Coils:

a. Evaporator and condenser coils shall have aluminum plate fins mechanically bonded to seamless internally enhanced copper tubes with all joints brazed. Special Phenolic coating shall be available as a factory option.

b. Evaporator and Condenser coils shall be of the direct expansion, draw-thru, design.

Refrigerant Circuit and Refrigerant Safety Components shall include:

a. Balance-port thermostatic expansion valve with independent circuit feed system.

b. Filter drier/strainer to eliminate any moisture or foreign matter.

c. Accessible service gage connections on both suction and discharge lines to charge, evacuate, and measure refrigerant pressure during any necessary servicing or troubleshooting, without losing charge.

d. The refrigeration system shall provide at least 15° F of sub-cooling at design conditions.

e.All models shall have four independent circuits.

f.Hot gas bypass option shall be factory-installed on compressor #1 discharge line to provide cooling in low- load applications. HGBP shall be a standard feature on VAV models and an optional feature on CV models.

Unit Controls

a. Unit shall be complete with self-contained low-voltage control circuit protected by a resettable circuit breaker on the 24-volt transformer side.

b. Unit shall incorporate a lockout circuit which provides reset capability at the space thermostat or base unit,

should any of the following standard safety devices trip and shut off compressor.

c.Loss-of-charge/Low-pressure switch.

1.High-pressure switch.

2.Freeze-protection thermostat, evaporator coil. If any of the above safety devices trip, a LED (light-emitting diode) indicator shall flash a diagnostic code that indicates which safety switch has tripped.

d.Unit shall incorporate "AUTO RESET" compressor over temperature, over current protection.

e.Unit shall operate with conventional thermostat designs and have a low voltage terminal strip for easy hook-up.

f.Unit control board shall have on-board diagnostics and fault code display.

g.Standard controls shall include anti-short cycle and low voltage protection, and permit cooling operation down to

0°F.

h.Control board shall monitor each refrigerant safety switch independently.

i.Control board shall retain last 5 fault codes in non volatile memory, which will not be lost in the event of a power loss.

Gas Heating Section (ZJ/ZR/ZF***N Models)

Shall be designed with induced draft combustion with post purge logic and energy saving direct spark ignition, redundant main gas valve. Ventor wheel shall be constructed of stainless steel for corrosion resistance. The heat exchanger shall be of the tubular type, constructed of T1-40 aluminized steel for corrosion resistance and allowing minimum mixed air entering temperature of 25 °F. Burners shall be of the in-shot type, constructed of aluminum coated steel and contain air mixture adjustments. All gas piping shall enter the unit cabinet at a single location through either the side or curb, without any field modifications. An integrated control board shall provide timed control of evaporator fan functioning and burner ignition. Heating section shall be provided with the following minimum protection:

a.Primary and auxiliary high-temperature limit switches.

b.Induced draft motor speed sensor.

c.Flame roll out switch (automatic reset).

d.Flame proving controls. Unit shall have two independent stages of capacity.

Electric Heating (ZJ/ZR/ZF***C/E Models)

Nickel chromium electric heating elements shall be provided as required by the application with 1 or 2 stage control, as required, from 13.5 KW to 72 KW capacities. The heating section shall have a primary limit control(s) and automatic reset to prevent the heating element system from operating at an excessive temperature. Units with Electric Heating shall be wired for a single point power supply with branch circuit fusing (where required).

10	Johnson Controls Unitary Products

R-410A specifications

York R-410A is a widely recognized and highly efficient refrigerant used in modern air conditioning systems. Developed as an environmentally friendly alternative to R-22, R-410A has gained popularity in the HVAC industry due to its numerous advantageous features and characteristics.

One of the main features of York R-410A is its ability to provide superior cooling performance. This refrigerant operates efficiently at both high and low temperatures, allowing systems using it to maintain optimal indoor climates even during extreme weather conditions. Its high energy efficiency ratio (EER) and seasonal energy efficiency ratio (SEER) ratings make it a preferred choice for energy-conscious consumers, resulting in lower energy bills and a reduced carbon footprint.

Technologically, York R-410A systems feature advanced compressor designs that enhance their overall reliability and performance. These compressors are often equipped with variable-speed technology, enabling them to adjust their output to match the cooling demands of the space. This not only improves comfort levels but also leads to efficient energy consumption, reducing wear and tear on the equipment over time.

Another significant characteristic of York R-410A is its non-ozone-depleting properties. Unlike its predecessor R-22, which is being phased out due to its damaging effects on the ozone layer, R-410A is designed to minimize environmental impact. Its lower global warming potential (GWP) further underscores its role in promoting sustainability within the HVAC sector.

Furthermore, York R-410A systems are engineered with enhanced safety features. The refrigerant is non-toxic and non-flammable, which makes it safer for use in both residential and commercial applications. Additionally, its high thermal stability reduces the risk of breakdown or leakage, contributing to longer system lifespans and lower maintenance costs.

In conclusion, York R-410A stands out as a cutting-edge refrigerant that combines efficiency, safety, and environmental responsibility. With its advanced technologies and remarkable characteristics, it meets the demands of modern air conditioning requirements while paving the way for a sustainable future in HVAC systems. Adopting York R-410A not only benefits individual users through improved comfort and lower energy bills but also plays a vital role in protecting our planet's ozone layer and mitigating climate change.