York WR 180 User Manual

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262292-YTG-C-0707
8
Unitary Products Group
FACTORY-INSTALLED OPTIONS
• 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% leak-
age 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-cool-
ing 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. 
BAS-ready economizer actuators have an adjustable 
auxiliary end-switch to provide a range of damper positions 
available to energize power exhaust. For units with optional 
VAV, power exhaust is energized by means of a binary 
output signal from the unit's VAV control board.
The exhaust fan, motor and controls are installed and 
wired at the factory. The rain hood must be assembled 
and installed in the field.
• 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, REHEAT, 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 
pressure in the supply duct. A pressure transducer and 
VAV control board are mounted inside the control box. 
The drive comes completely wired and pre-programmed 
from the factory.
An optional, factory-installed manual bypass switch avail-
able with factory-installed VFD can be found in the Blower 
Motor Access compartment. The switch can be used to 
either route power to the VFD for modulating control of the 
blower motor, to bypass the drive and operate the motor 
at full speed, or to power the drive (and not the motor) for 
diagnostic purposes.
Due to space limitations, VAV is not available with any of 
the factory-installed BAS options described below, but is 
available with ‘BAS-ready’ models. Terminal blocks are 
provided in the control box for field wiring of the customer-
installed BAS.
A ‘VFD-ready’ option provides the provisions for a cus-
tomer-installed drive. The unit comes with a mounting 
bracket installed in the Blower Access compartment which 
may accommodate other vendor’s drives depending on 
their size. In order to utilize the unit’s mounting bracket, the 
maximum recommended drive dimensions are as follows:
For 5-hp motor applications ........................13” H x 6” W x 7” D
For 7.5 thru 15-hp motor applications .........13” H x 8” W x 8” D
If the drive will not fit in the allotted space, then it will have to 
be mounted elsewhere; either within the building on a per-
pendicular wall which is not subjected to excessive temper-
ature, vibration, humidity, dust, corrosive gas, explosive gas, 
etc., or within an appropriate enclosure rated for outside 
installation to safeguard against moisture, dust and exces-
sive heat.
A terminal block located in the control box is provided for 
field connection of the VFD controls.
• HOT GAS BYPASS - To allow for low cooling load opera-
tion, a direct-acting pressure-modulating bypass control 
valve installed on the system #1 discharge line is used to 
divert high temperature, high pressure refrigerant around 
the TXV in order to maintain a desired minimum evapora-
tor pressure. HGBP is standard on all units with VAV and 
optional with CV units.