York HFC-410A User Manual

JOHNSON CONTROLS

FORM 100.50-EG5 (108)

  2.  Barometric Relief Damper: Building air exhaust shall 

be accomplished through barometric relief damp-
ers installed in the return-air plenum. The dampers 
open relative to the building pressure. The opening 
pressure shall be adjustable.

 2.  On/Off, Fan-Powered Exhaust: A DWDI Class I or  

II forward-curved centrifugal exhaust fan shall be 
provided to exhaust building return air to relieve 
building static pressure. The fans shall be constant 
volume and operate based on either a building static 
pressure, or outside air-damper position.

  2.  Powered Exhaust with Modulating Discharge Damp-

er: A DWDI Class I or II forward-curved centrifugal 
exhaust fan shall be provided to exhaust building 
return air to relieve building static pressure. The 
fans shall operate at a constant volume and operate 
based on building static pressure. Exhaust airfl ow 
shall be modulated via a parallel-acting, control 
damper. The exhaust-air dampers shall be sized 
for 100% of the exhaust airfl ow.

  2.  Powered Exhaust with Variable-Frequency-Drive: A 

twin DWDI Class I or II forward-curved centrifugal 
exhaust fan shall be provided to exhaust building 
return air to relieve building static pressure. Exhaust 
airfl ow shall be modulated via a factory-installed 
and commissioned variable-frequency-drive with 
the same nameplate horsepower as the supply fan 
motor.

  3.  Fan Motor: Fan motors shall be NEMA design ball-

bearing types with electrical characteristics and 
horsepower as specifi ed. Motors shall be 1750 
RPM, ODP [TEFC] open drip-proof type. The mo-
tor shall be located within the unit on an adjustable 
base.

    Mountings: Fan and fan motor shall be internally 

mounted and isolated on a full width isolator sup-
port channel using 1-inch [2-inch] springs. The fan 
discharge shall be connected to the fan cabinet 
using a fl exible connection to insure vibration-free 
operation.

    Bearings and Drives: Fan bearings shall be self-

aligning, pillow block or fl anged type regreaseable 
ball bearings and shall be designed for an average 
life (L50) of at least 200,000 hours. All bearings shall 
be factory lubricated and equipped with standard 
hydraulic grease fi ttings and lube lines extended 
to the motor side of the fan. Fan drives shall be 

selected for a 1.5 service factor and antistatic belts 
shall be furnished. All drives shall be fi xed  pitch. 
Fan shafts shall be selected to operate well below 
the fi rst critical speed and each shaft shall be fac-
tory coated after assembly with an anticorrosion
coating.

  1.  Angled Filter Rack: two-inch throwaway fi lters shall 

be provided in an angled fi lter rack.

 1.  Angled Filter Rack: two-inch carbon media fi lters 

shall be provided in an angled fi lter rack.

 1.  Angled Filter Rack: two-inch cleanable fi lters shall 

be provided in an angled fi lter rack.

 1.  Angled Filter Rack: two-inch high-effi ciency (30%) 

pleated fi lters shall be provided in an angled fi lter 
rack.

 1.  Flat Filter Rack: 60-65% effi cient rigid fi lters with a 

two-inch, high-effi ciency pleated pre-fi lters shall be 
provided in a fl at fi lter rack.

 1.  Flat Filter Rack: 90-95% effi cient rigid fi lters with a 

two-inch, high-effi ciency pleated pre-fi lters shall be 
provided in a fl at fi lter rack.

 2.  Dirty Filter Alarm: A dirty-fi lter switch shall be pro-

vided and wired to the rooftop unit control panel. 
Upon closure of the switch, the controller shall 
display a dirty-fi lter fault. The setting of the switch 
can be changed manually to close at a specifi ed 
pressure drop across the fi lters.

  1.  Cooling Coil: Evaporator coils shall be direct-expan-

sion type with intertwined circuiting to assure com-
plete coil-face activity during part-load operation. 
Coil tubes shall be 3/8” OD copper, with internally 
enhanced tubes. Fins shall be enhanced mechani-
cally expanded to bond with the copper tubes. 
Coil casing shall be fabricated from heavy-gauge 
galvanized steel. All coils shall be pressure tested 
at a minimum of 450 PSIG.

 2.  IAQ Drain Pan: The main coil drain pan shall be 

double-sloped with a condensate connection 
through the base rail of the unit. Clearance between 
the evaporator coil and the drain pan shall allow 
for easy access to the drain pan for cleaning, and 
shall be visible for inspection without the removal 
of components.

 3.  Intermediate Drain Pan: Coils with fi nned  height 

greater than 48” shall have an intermediate drain 
pan extending the entire fi nned length of the coil.