York 251934-YTG-J-0910 Air Conditioner User Manual


 
251934-YTG-J-0910
Johnson Controls Unitary Products 5
Features and Benefits
Standard Features
High Efficiency - High efficiency units reach as high as
12.4 EER. Gas/electric units have electronic spark ignition
and power vented combustion with steady state efficiencies
of 80%. These efficiencies exceed all legislated minimum
levels and provide low operating costs.
Balanced Heating -
Gas Heat - All gas heat units are built with two heating
sections for two equal stages of capacity control. Each
section includes a durable heat exchanger with
aluminized steel or optional stainless steel tubes, a
redundant gas valve, spark ignition, power venting, an
ignition module for 100% shut-off and all of the safety
controls required to meet the latest ANSI standards.
The gas supply piping can be routed into the heating
compartment through a hole in the base pan of the unit
or through a knockout in the piping panel on the front of
the unit.
Electric Heat - All electric heat models (factory installed
only) are wired for a single power source and include a
bank of nickel chromium elements mounted at the
discharge of the supply air blower to provide a high velocity
and uniform distribution of air across the heating elements.
Every element is fully protected against excessive current
and temperature by fuses and two thermal limit switches.
The power supply wiring can be routed into the control
box through a threaded pipe connection in the base pan
of the unit or through a knockout in the wiring panel on
the front of the unit.
BAS Controls - York’s Sunline™ series units offer factory
mounted BAS controls such as Simplicity
®
Intelli-
Comfort
, Novar, Honeywell, Johnson, York Commercial
Comfort System (YCCS) and CPC.
Convertible Airflow Design - All models (including those
with an economizer) are suitable for either bottom or
horizontal duct connections. Models with factory
installed power exhaust are suitable for bottom duct
connections only. For bottom duct, you remove the sheet
metal panels from the supply and return air openings
through the base of the unit. For horizontal duct, you
replace the supply and return air panels on the rear of the
unit with a side duct flange accessory.
Factory Mounted Outdoor Air Dampers - All models are
available with these "factory mounted" outdoor air damper
options:
Single enthalpy economizer with or without power
exhaust
BAS-ready economizer with or without power exhaust
Motorized outdoor air damper
Barometric Relief Damper
A fixed outdoor air intake assembly will be shipped in the
return air compartment of all units ordered without an
economizer or motorized outdoor air damper option. The
assembly includes a rain hood with a damper that can be set
for 10, 15 or 25% outdoor air. With bottom duct connections,
the fixed outdoor air intake assembly should be mounted
over the opening in the return air panel. With horizontal
ductwork, it should be mounted on the return air duct.
System Protection - Suction line freezestats are supplied
on all units to protect against loss of charge and coil frosting
when the economizer operates at low outdoor air
temperatures while the compressors are running. Every unit
has solid-core liquid line filter-driers and high and low-
pressure switches. Internal compressor protection is
standard on all compressors. Crankcase heaters are
standard on reciprocating compressors. Scroll compressors
do not require crankcase heaters. Phase Monitors are
standard on units with scroll compressors. This accessory
monitors the incoming power to the unit and protects the
unit from phase loss and reversed phase rotation.
Advanced Controls - Simplicity™ ZJ/ZR/ZF control
boards have standardized a number of features
previously available only as options or by utilizing
additional controls.
Low Ambient - An integrated low-ambient control
allows all units to operate in the cooling mode down to
0F outdoor ambient without additional assistance.
Optionally, the control board can be programmed to
lockout the compressors when the outdoor air
temperature is low or when free cooling is available.
Anti-Short Cycle Protection - To aid compressor life,
an anti-short cycle delay is incorporated into the
standard controls. Compressor reliability is further
ensured by programmable minimum run times. For
testing, the anti-short cycle delay can be temporarily
overridden with the push of a button.
Lead-Lag - An integrated Lead-Lag option allows equal
run time hours on all compressors, thereby extending
the life of all compressors. This option is selectable on
the unit control board.
Fan Delays - Fan on and fan off delays are fully
programmable. Furthermore, the heating and cooling
fan delay times are independent of one another. All units
are programmed with default values based upon their
configuration of cooling and heat.
Safety Monitoring - The control board monitors the
high and low-pressure switches, the freezestats, the gas
The Simplicity® control board used in this product
will effectively operate the cooling system down to
0°F when this product is applied in a comfort cooling
application for people. An economizer is typically
included in this type of application. When applying
this product for process cooling applications
(computer rooms, switchgear, etc.), please
reference applications bulletin AE-011-07 or call the
applications department for Unitary Products @ 1-
877-UPG-SERV for guidance. Additional
accessories may be needed for stable operation at
temperatures below 30°F.