York DM 180 Technical Manual page 6

• ELECTRIC HEATERS wired for single point power sup-
ply. These nickel chromium heater elements are pro-
vided 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
available 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 oper-
ate 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 cus-
tomer-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 depend-
ing 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........................ 10" 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 customer-installed drive will not fit in the allotted
space, then it will have to be mounted within a NEMA-4
enclosure for outside installation or inside the building on
a perpendicular wall not subjected to excessive tempera-
ture, vibration, humidity, dust, corrosive gas, explosive
gas, etc.
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 oper-
ation, 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 evapo-
rator pressure. HGBP is standard on all units with VAV
and optional with CV units.
• FILTER OPTIONS - Standard units are shipped with 2"
throw-away filters installed. 2" pleated and 4" pleated fil-
ters are offered as a factory installed option.
• CONVENIENCE OUTLET - This 110 volt outlet can be
"powered" by the unit with a stepdown transformer or
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you may order the unit with a "non-powered" conve-
nience outlet that can be wired in the field.
• DISCONNECT SWITCH - For gas heat units and cooling
units with electric heat, a HACR breaker sized to the unit
is provided. For cooling only units, a switch sized to the
largest electric heat available for the particular unit is
provided. Factory installed option only.
• BAS - Building Automation System Controls (avail-
able on two-system cooling product only).
Simplicity® INTELLI-Comfort™ CONTROL - The York®
Simplicity® INTELLI-Comfort™ control is factory
installed. It includes a supply air sensor, a return air sen-
sor, and an outside air sensor. There are provisions for a
field installed dirty filter indicator switch, an air-proving
switch, an Outside Air Humidity sensor, a Return Air
Humidity sensor, an Inside IAQ sensor, and an Outside
Air IAQ sensor. Construction mode operation, 365-day
real time clock with 7 day programming plus holiday
scheduling is built-in. Two different modes of demand
ventilation are achieved through the INTELLI-Comfort™
using CO sensors. It uses an inside CO
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form Demand Ventilation. It can also use an Outside CO
sensor to perform Differential Demand Ventilation. It
uses a Patented Comfort Ventilation algorithm to provide
comfortable ventilation air temperature. The patented
economizer-loading algorithm will protect the equipment
when harsh operating conditions exist. Humidity in the
occupied space or return duct can be monitored and
controlled via humidity sensors and the on-board con-
nection for hot gas re-heat system. It uses the INTELLI-
Start™ algorithm to maximize energy savings by recov-
ering the building from the Unoccupied Setpoints to the
Occupied Setpoints just in time for the Occupied Time
Period to begin. The Simplicity® INTELLI-Comfort™ bal-
ances space temperature, ventilation air temperature,
CO and humidity for ultimate comfort.
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Simplicity® INTELLI-Comfort™ with ModLINC CON-
TROL - The York® Simplicity® INTELLI-Comfort™ with
ModLINC control is factory installed. It includes all the
features of the INTELLI-Comfort™ control with an addi-
tional control to translate communications from MOD-
BUS to the BACnet MSTP protocol.
Novar® BAS CONTROL - The Novar® ETC-3 building
automation system controller is factory installed.
Includes supply air sensor, return air sensor, dirty filter
indicator switch, and air proving switch.
JOHNSON CONTROLS BAS CONTROL - The Johnson
Control YK-UNT-1126 building automation system con-
troller is factory installed. Includes supply air sensor,
return air sensor, dirty filter indicator switch, and air prov-
ing switch.
CPC BAS CONTROL - The Computer Process Controls
Model 810-3060 ARTC Advanced Rooftop building auto-
mation system controller is factory installed. Includes
262259-YTG-B-0107
sensor to per-
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Unitary Products Group