York 251934-YTG-J-0910 - Manual (Page 6)

251934-YTG-J-0910
6 Johnson Controls Unitary Products
valve, if applicable, and the temperature limit switch on
gas and electric heat units. The unit control board will
alarm on ignition failures, compressor lockouts and
repeated limit switch trips.
• Nuisance Trip Protection and Strikes - To prevent
nuisance trouble calls, the control board uses a “three
times, you’re out” philosophy. The high and low-
pressure switches and the freezestats must trip three
times within two hours before the unit control board will
lock out the associated compressor.
• On Board Diagnostics - Each alarm will energize a
trouble light on the thermostat, if so equipped, and flash
an alarm code on the control board LED. Each high and
low-pressure switch alarm as well as each freezestat
alarm has its own flash code. The control board saves
the five most recent alarms in memory, and these alarms
can be reviewed at any time. Alarms and programmed
values are retained through the loss of power.
• Reliable - From the beginning - All units undergo
computer automated testing before they leave the factory.
Units are tested for refrigerant charge and pressure, unit
amperage, and 100% functionality. For the long term - All
units are painted with a long lasting, powder paint that
stands up over the life of the unit. The paint used has
been proven by a 1000 hour salt spray test.
• Full Perimeter Base Rails - The permanently attached
base rails provide a solid foundation for the entire unit and
protect the unit during shipment. The rails offer rigging
holes so that an overhead crane can be used to place the
units on a roof.
• Easy Installation - Gas and electric utility knockouts are
supplied in the unit underside as well as the side of the
unit. Utility connections can be made quickly and with a
minimum amount of field labor. All units are shipped with
2" throw-away filters installed.
• Wide Range of Indoor Airflows - All supply air blowers
are equipped with a belt drive that can be adjusted to
meet the exact requirements of the job. A high static drive
option is available for applications with a higher CFM and/
or static pressure requirement.
• Warranty - All models include a 1-year limited warranty
on the complete unit. Compressors and electric heater
elements each carry a 5-year warranty. Aluminized steel
and stainless steel tubular heat exchangers carry a 10-
year warranty.
Factory Installed Options
YORK
®
offers several equipment options factory installed, for
the ZJ/ZR/ZF Series.
• Single Input Electronic Enthalpy Economizers -
Includes a slide-in / plug-in damper assembly with fully
modulating spring-return motor actuator capable of
introducing up to 100% outdoor air with nominal 1%
leakage type dampers.
The enthalpy system contains one sensor that monitors
the outdoor air and determines when the air is cool
enough and dry enough to provide free cooling.
The rainhood is painted to match the basic unit and must
be field-assembled before installing.
• BAS-Ready Economizer - Includes a slide-in / plug-in
damper assembly with fully modulating spring-return
motor actuator with zero to 95-degree rotation capable of
introducing up to 100% outdoor air with nominal 1%
leakage type dampers.
Actuator requires 2-10 VDC input from an external source,
such as a field-installed or factory-installed BAS
controller. BAS-ready actuators have an adjustable
auxiliary end-switch for optional power exhaust control.
For units with optional VAV or Simplicity® Intelli-
Comfort™ control, a factory-installed, dry bulb sensor
determines if outdoor air temperature is low enough to
provide free-cooling operation. (Field-installed humidity
sensors for either outdoor air or outdoor & return air
streams are available for single enthalpy and differential
enthalpy configurations, respectively).
The rainhood is painted to match the basic unit and must
be field-assembled before installing.
• Power Exhaust - Our economizer options are available
with power exhaust. Whenever the outdoor air intake
dampers are opened for free cooling, the exhaust fan will
be energized to prevent the conditioned space from being
over-pressurized during economizer operation.
The exhaust fan, motor and controls are installed and
wired at the factory. The rain hood must be assembled
and installed in the field.
The power exhaust option can only be used on bottom
duct configurations.
• Motorized Outdoor Air Intake Damper - Includes a
slide-in / plug-in damper assembly with a 2- position,
spring return motor actuator which opens to a pre-set
position whenever the supply air blower is operating and
will drive fully closed when the blower unit shuts down.
The rain hood is painted to match the basic unit and must
be field assembled before installing.
• Barometric Relief Damper - This damper option can be
used to relieve internal building air pressure on units with
an economizer without power exhaust. This accessory
includes a rain hood, a bird screen and a fully assembled
damper. With bottom duct connections, the damper
should be mounted over the opening in the return air
panel. With horizontal ductwork, the accessory should be
mounted on the return air duct.
• Phenolic Coated Evaporator And Condenser Coils -
Special coating process that utilizes Technicoat 10-1"
processes. Coating is applied by total immersion of the
complete coil for maximum protection.
• Electric Heaters - wired for single point power supply.
These nickel chromium heater elements are provided with
limit and automatic reset capability to prevent operation at
excessive temperatures.
• Variable Air Volume (VAV) - A factory-installed variable
frequency drive (VFD), mounted in the Blower Access
compartment, is used to control the speed of the indoor
blower motor in order to maintain a constant static