York B1HP024 THRU 048 manual Electric Heating Section, Unit Operating Characteristics

B.Shall have internal isolation and sound muffling to minimize vibration and noise, and be externally iso- lated on a dedicated, independent mounting.

2.Coils:

A.Evaporator and condenser coils shall have alumi- num plate fins mechanically bonded to seamless internally-enhanced copper tubes with all joints brazed.

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

3.Refrigerant Circuit and Refrigerant Safety Compo- nents shall include:

A.Independent thermal expansion devices (TXV).

B.Solid-core filter dryer to eliminate any foreign matter.

C.Accessible service gage connections on both suc- tion and discharge lines to charge, evacuate, and measure refrigerant pressure during any necessary servicing or troubleshooting, without losing charge and without disrupting condenser or evaporator air flow.

D.The refrigeration system shall provide at least 10∞F of liquid sub-cooling at design conditions.

E.Unit shall have a suction line accumulator and auto- matic reversing valve.

4.Unit Controls:

A.Unit shall contain a large, low voltage Terminal Board for easy connection of field low voltage wir- ing.

B.Controls shall be mounted in a large control box with tilt-out, hinged access door, allowing easy access for trouble shooting and maintenance without affect- ing the normal system operation pressures.

C.Unit shall contain a reliable demand defrost control to provide defrost. The defrost control shall also have an ìXî terminal to provide a 24 volt signal for

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room thermostat ìLEDî indication of unit lockout. Plus a built in 5 minute anti-short cycle protection.

D.Unit shall have large, easily removable panels, cov- ering electrical controls and compressor, allowing easy access for any maintenance or servicing.

ELECTRIC HEATING SECTION

1.An electric heating section, with nickel chromium elements, shall be provided in a range of 5 thru 25 KW.

2.The heating section shall have an automatic reset primary limit control to prevent the heating element system from operating at an excessive tempera- ture.

3.The heating section assembly shall slide out of the unit for easy maintenance and service.

4.Units with electric heating sections shall be wired for a single point power supply, with branch circuit fusing (where required).

UNIT OPERATING CHARACTERISTICS

1.Unit shall be capable of starting and running at 125∞F outdoor temperature, exceeding maximum load criteria of ARI Standard 210/240.

2.The compressor, with standard controls, shall be capable of operation down to 45∞F outdoor tem- perature. Accessory low ambient kit shall be avail- able for operation to 0∞F.

ELECTRICAL REQUIREMENTS

All unit power wiring shall enter unit cabinet at a single factory provided location and be capable of side or bot- tom entry. This will minimize roof penetrations and avoid unit field modifications. Separate side and bot- tom openings shall be provided for the control wiring.

26 Unitary Products Group