York HFC-410A User Manual

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FORM 100.50-EG5 (108)
41
JOHNSON CONTROLS
The intermediate pans shall have drop tubes to guide 
condensate to the main drain pan.
Supply Fan Section
  1.  Fan: The fan section shall be equipped with a single 
double-width, double-inlet (DWDI), forward-curved 
[airfoil optional] centrifugal type wheel for horizontal 
discharge. An access door shall be provided on both 
sides of the unit for fan/motor access.
  2.  Fan Motor: Fan motors shall be NEMA design ball-
bearing types with electrical characteristics and 
horsepower as specifi ed. Motors shall be 1750 
RPM, open drip-proof type [TEFC optional]. The 
motor shall be located within the unit on an adjust-
able 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 factory 
coated after assembly with an anticorrosion coat-
ing.
 3.  VAV Fan Control: VAV supply fan control shall be 
accomplished by using a variable-frequency drive 
matched to the supply-fan motor HP. The VFD 
shall include an integral DC line reactor to reduce 
harmonic distortion in the incoming and outgoing 
power feeds. If a DC line reactor is not provided, an 
AC line reactor must be provided. Inlet guide vanes 
shall not be acceptable. VFD control keypads shall 
be located in the control cabinet for accessibility and 
servicing while the unit is operating.
 4.  Optional VFD manual bypass: a three-contactor 
manual bypass shall be provided to permit replace-
ment of the VFD in the event of a power failure.
Discharge Plenum
[SELECT ONE OF THE FOLLOWING HEAT/NO 
HEAT CONFIGURATIONS]
 1.  Cooling Only: The discharge-air-temperature sen-
sor shall be located in the discharge plenum and 
be located such that it accurately measures the 
supply-air temperature. Walls shall be lined with a 
solid liner to prevent erosion of the insulation and 
to separate insulation from the air stream.
  1.  Staged Gas Heat: The heating section shall include 
an induced-draft furnace with two stages [four 
stages or six stages] of heating capacity.
 
  Heat Exchanger: The heat exchanger shall be con-
structed of tubular aluminized steel [stainless steel], 
with stainless steel fl ue baffl es and fl ue assembly. 
 
  Burner and Ignition Control: The burner shall include 
a direct-driven induced-draft combustion fan with 
energy effi cient intermittent direct spark ignition, 
redundant main gas valves with pressure regula-
tor. 
 
  Combustion-Air Fan: The inducer fan(s) shall main-
tain a positive fl ow of air through each tube, to expel 
the  fl ue gas and to maintain a negative pressure 
within the heat exchanger relative to the conditioned 
space.
 
  Safety Devices: A high-limit controller with automatic 
reset to prevent the heat exchanger from operat-
ing at an excessive temperature shall be included. 
An air-proving switch shall prevent ignition until 
suffi cient  airfl ow is established through the heat 
exchanger. A rollout switch shall provide secondary 
airfl ow-safety protection. The rollout switch shall 
discontinue furnace operation if the fl ue  becomes 
restricted.
  
Flue: 
The 
furnace 
fl ue shall be shipped loose to pro-
tect it from damage during transit. The fl ue shall be 
fi eld-mounted by the installing contractor. The fl ue 
outlet shall be located above the unit to help prevent 
recycling of combustion gases back through the 
heat exchanger. Agency Certifi cation: Gas heating 
sections are both ETC/CETL approved to both US 
and Canadian safety standards.
  1.  Heat Exchanger(s): The heat exchanger(s) shall be 
constructed of tubular aluminized steel [stainless 
steel], with stainless steel fl ue baffl es and fl ue as-
sembly.
   
Condenser Section
  1.  Condenser Fans: Condenser fans shall be matched 
up with compressors to optimize system control. 
Condenser fans shall be propeller-type, directly 
driven by permanently lubricated TEAO motor.
 2.  Condenser Coil: Condenser coils shall be seam-
less copper tubes, arranged in staggered rows,