100036
LGM SERIES
Service Literature
7.5 to 12.5 ton
38.1 to 70.3 kW
LGM092U through 1502U
The LGM, 092, 102U, 120U and 150U units are configure to
order units (CTO) with a wide selection of factory-installed
options. Units are available in 130,000 to 240,000 Btuh.
heating inputs. Gas heat sections are designed with alu
minized steel tube heat exchangers with stainless steel as
an option.
Cooling capacities range from 7.5 to 12.5 tons. Units come
standard with a fin tube condenser with two single-speed
compressors plumbed in tandem to form a single refriger
ant circuit. Units also offer mechanical cooling down to
40F.
All units are equipped with direct drive blowers. The blower
will operate at lower speeds when demand is low and in
crease to higher speeds when demand is high.
Variable speed VAV system is available as an option which
enables supply duct static measurement to control blower
CFM and discharge air temperature to control cooling
stages. All LGM units are designed to accept any of several
different energy management thermostat control systems
with minimum field wiring. Factory- or field-provided control
options connect to the unit through Smartwire connectors.
When “plugged in” the controls become an integral part of
the unit wiring.
The CORE Control System is designed to accelerate
equipment install and service. Standard with all Model L™
rooftop units, control system integrates key technologies
that lower installation costs, drive system efficiency, and
protect your investments. The CORE Unit Controller is a
microprocessor-based controller that provides flexible con
trol of all unit functions.
Information contained in this manual is intended for use by
qualified service technicians only. All specifications are
subject to change. Procedures outlined in this manual are
presented as a recommendation only and do not super
sede or replace local or state codes.
If the unit must be lifted for service, rig unit by attaching four
cables to the holes located in the unit base rail (two holes at
each corner). Refer to the installation instructions for the
proper rigging technique.
WARNING
Improper installation, adjustment, alteration, service
or maintenance can cause property va, personal in
jury or loss of life. Installation and service must be
performed by a licensed professional HVAC installer
or equivalent, service agency, or the gas supplier
WARNING
To prevent serious injury or death:
1-Lock-out/tag out before performing maintenance.
2- If system power is required (e.g., smoke detector
maintenance, disable power to blower, remove fan
belt where applicable, and ensure all controllers and
thermostats are Set to the “OFF” position before per
forming maintenance.
3- Always keep hands, hair, clothing, jewelery, tools,
etc.,c away from moving parts.
CAUTION
As with any mechanical equipment, contact with
sharp sheet metal edges can result in personal in
jury. Take care while handling this equipment and
wear gloves and protective clothing.
Table of Contents
Options / Accessories Page 2.....................
Specifications Page 5............................
High Altitude Page 6.............................
Blower Data Page 7.............................
Electrical Data Page 10..........................
I-Unit Components Page 13.......................
II-Placement and Installation Page 37...............
III-Charging Page 37..............................
IV-Start Up - Operation Page 38....................
V-System Service Checks Page 40................
VI-Maintenance Page 42..........................
VII-Accessories Page 43..........................
VIII-Direct Drive Supply Air Inverter Page 49.........
XI-Wiring and Operation Sequence Page 51.........
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