Installation and Maintenance Manual

SCXG-SVX01H-EN 9
General Data
Modular Series Self-Contained
Unit Components
Commercial self contained units are complete HVAC
systems used in floor-by-floor applications. Units are easy
to install because they feature a single point power
connection, factory installed and tested controls, single
water point connection, factory installed options, and an
internally trapped drain connection. Modular self-
contained units can ship as split-apart units for installation
ease. Split-apart units ship with a dry nitrogen charge and
require field refrigerant charging.
Units consist of multiple hermetically sealed 3-D scroll
compressors, water-cooled condensers (water-cooled
units only), an evaporator coil, dual forward curved fans,
and control panel. Air-cooled units require a remote air-
cooled condenser, model CXRC. Unit controls are either
electromechanical thermostat or microprocessor controls
on IntelliPak unit.
Hermetically sealed 3-D scroll compressor motors utilize
internal motor protection and time delays to prevent
excessive cycling.
Water-cooled condensers are shell and tube type with
internal subcooler. Condensers are available as
mechanically or chemically cleanable. Evaporator fan is
double width, double inlet and forward curved with a fixed
pitch belt drive assembly. Variable frequency drives are
optional. EISA efficiency open drip proof (ODP) and totally
enclosed fan cooled (TEFC) motor options are available.
Package water-cooled units ship with full refrigerant and
compressor oil charge. Split apart water cooled, and air
cooled, units ship with dry nitrogen charge and complete
compressor oil charge.
Split apart water cooled units require field connection of
suction and liquid lines. Air-cooled units require field-
piping discharge and liquid lines to remote air cooled
condenser.
All units have two refrigerant circuits that include filter
drier (field installed in air cooled), liquid line service valve,
sight glass/moisture indicator, thermal expansion valve
with a sensing bulb and external equalizing line, suction
and discharge line access ports, and high and low pressure
cutout switches. Water-cooled units also include pressure
relief valve. Air cooled units include liquid line solenoid
valve and discharge line check valve.
Control Options
Units may be ordered with conventional thermostat
interface or IntelliPak™ Direct Digital Control (DDC).
IntelliPak controls include a Human Interface (HI) panel
with two line by forty (40) character clear English display
for easy operator interface to unit setup and control
parameters. All basic setup parameters are preset from
factory.
Human Interface Panel
HI is unit mounted and accessible without opening unit’s
front panel. It allows easy setpoint adjustment using HI
keypad. HI displays all unit operating parameters and
conditions in a clear language display, which can be
configured for either English, French, or Spanish.
Optional remote human interface (RHI) will control up to
four self-contained units, each containing an
interprocessor communications bridge (IPCB). It has the
same features as unit-mounted HI except for service
mode.
For more information on setpoint defaults, ranges and unit
programming, see IntelliPak Self-Contained Programming
Guide, PKG-SVP01*-EN that ships with each unit.
IntelliPak™ DDC Control
IntelliPak™ DDC Control provides “smart” unit control
with safety features and control relays for pumps,
dampers, etc. Modular Series IntelliPak self-contained unit
is controlled by microelectronic control system consisting
of a network of modules.These modules are referred to as
unit control modules (UCM). In this manual, acronym UCM
refers to the entire control system network.
These modules perform specific unit functions using
proportional/integral control algorithms.They are
mounted in the unit control panel and are factory wired to
their respective internal components. Each module
receives and interprets information from other unit
modules, sensors, remote panels, and customer binary
contacts to satisfy the applicable request; i.e.,
economizing, mechanical cooling, heating, ventilation.
See the Operation section of this manual for a detailed
description of each module’s function.
Optional Controls
Optional controls include a disconnect switch, dirty filter
switch, water flow switch (water-cooled only), supply air
temperature reset, or external setpoint inputs. Daytime
heating is available on units with electric, steam, or hot
water heat control options. Morning warmup operation is
available on all units.
The static pressure probe, zone night heat/morning
warmup, supply air temperature reset sensor options ship
separate inside the unit control panel for field installation.
For more detailed information on the unit control options,
see the Owner’s section of this manual.