255027-YTG-B-0507
side. Aluminum foil faced insulation shall be used in the furnace compartment and be fastened with ridged fasteners to prevent insulation from entering the air stream. Cabinet panels shall be “large” size, easily removable for servicing and maintenance. Full perimeter base rails shall be provided to assure reliable transit of equipment, overhead rigging and proper sealing on roof curb applications. Disposable 1" filters shall be furnished and be accessible through a removable access door, sealed airtight. Units filter track shall be designed to accommodate either 1” or 2” filters. Fan perfor- mance measuring ports shall be provided on the outside of the cabinet to allow accurate air measurements of evaporator fan performance without removing panels or creating air by- pass of the coils. Condensate pan shall be internally sloped and conform to ASHRAE
INDOOR (EVAPORATOR) FAN ASSEMBLY
The indoor fan shall be a factory installed direct drive or belt drive assembly that includes an adjustable pitch motor pulley. Job site selected (B.H.P.) brake horsepower shall not exceed the motors nameplate horsepower rating, plus the service factor. Units shall be designed not to operate above service factor. Fan wheel shall be
OUTDOOR (CONDENSER) FAN ASSEMBLY
The outdoor fan shall be of the
REFRIGERANT COMPONENTS
Compressor:
a.Shall be internally protected with internal
b.Shall have internal spring isolation and sound muf- fling to minimize vibration and noise, and be exter- nally isolated on a dedicated, independent mounting.
Coils:
a.Evaporator and condenser coils shall have alumi- num 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,
Refrigerant Circuit and Refrigerant Safety Components shall include:
a.Independent
b.Filter drier/strainer to eliminate any moisture or for- eign matter.
c.Accessible service gage connections on both suc- tion and liquid lines to charge, evacuate, and mea- sure refrigerant pressure during any necessary servicing or troubleshooting without losing charge.
UNIT CONTROLS
a.Unit shall be complete with
b.Unit shall incorporate a lockout circuit which pro- vides reset capability at the space thermostat or base unit, should any of the following standard safety devices trip and shut off compressor.
c.
d.
e.
f.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.
g.Unit shall incorporate “AUTO RESET” compressor over temperature, over current protection.
h.Unit shall operate with conventional thermostat designs and have a low voltage terminal strip for easy
i.Unit control board shall have
j.Standard controls shall include
k.Control board shall monitor each refrigerant safety switch independently.
l.Control board shall retain last 5 fault codes in non volatile memory, which will not be lost in the event of a power loss.
ELECTRIC HEATING SECTION
An electric heating section, with nickel chromium elements, shall be provided in a range of 5 thru 30 KW, offering two stages of capacity - 16 KW and above on 208/230 volt heaters and 20 KW and above on 460 and 575 volt heaters. The heat- ing section shall have a primary limit control(s) and automatic reset to prevent the heating element system from operating at an excessive temperature. The heating section assembly shall slide out of the unit for easy maintenance and service. Units with Electric Heating shall be wired for a single point power supply with branch circuit fusing (where required).
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