Lennox LGH Service Manual

Service Literature
The LGH/LCH high and standard efficiency 35, 40, 45 and
50 ton (123, 140.7, 158.3 and 175.9 kW) units, are config­
ure to order units (CTO) with a wide selection of factory in­
stalled options. The LGH/LCH rooftop units are available in
500,000 Btuh or 800,000 Btuh (146.5 kW or 234.4kW)
heating inputs. Gas heat sections are designed with alu­
minized steel tube heat exchangers. LGH and LCH units
are equipped with the same cooling sections and cooling
components. The LGH/LCH units utilize four scroll com­
pressors with each compressor equipped with a crankcase
heater.
LGH/LCH units are designed for R-410A (high efficiency).
Service equipment for R-410A units must be rated for
R-410A refrigerant.
Optional electric heat is factory installed in LCH units. Electric
heat operates in single or multiple stages depending on the
kW input size. 30kW through 90kW heat sections are avail­
able for the LCH units in all voltages G, J and Y while105kW
through 180kW heat sections are available for LCH G and J
voltage units only.
IMPORTANT
Improper installation, adjustment, alteration, service
or maintenance can cause property damage, person­
al injury or loss of life. Installation and service must
be performed by a qualified installer or service agen­
cy.
Corp. 1018-L1
01-2010
LGH/LCH SERIES
The LGH/LCH 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 with jack plugs. When "plugged
in" the controls become an integral part of the unit wiring.
If the unit must be lifted for service, rig unit by attaching eight
cables to the holes located in the unit base rail (two holes at
each corner and center of frame). Refer to the installation in­
structions for the proper rigging technique.
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.
Danger of sharp metallic edges. Can cause injury.
Take care when servicing unit to avoid accidental
contact with sharp edges.
LGH/LCH
35, 40, 45, 50 TON
(123, 140.7, 158.3, 175.9 kW)
WARNING
Electric shock hazard. Can cause injury
or death. Before attempting to perform
any service or maintenance, turn the
electrical power to unit OFF at discon­
nect switch(es). Unit may have multiple
power supplies.
CAUTION