Lennox SCH Series Unit Information

S e r v i c e L i t e r a t u r e
The SCH120 &240 units are configure to order units
(CTO) with a wide selection of factory installed options.
Cooling capacities range from 120,00 to 228,000 Btuh.
SGH120 utilizes two compressors and two condenser
fans. SGH240 utilizes four compressors and six condens-
er fans.
Optional electric heat is factory installed. Electric heat op-
erates in single or multiple stages depending on the kW
input size. 15kW to 60 kW heat sections are available for
the SCH120 units and 20kW to 90kW heat sections are
available for the SCH240.
Both models are equipped with Multi-Stage Air Volume
MSAV blower. The VFD-driven blower will operate at
®
lower speeds when demand is low and increase to higher
speeds when demand is high.
False ceilings or drop ceiling may be used as a return air
plenum only if the unit being installed has a Refrigerant
Detection System installed.
WARNING
Do not use means to accelerate the defrosting
process or to clean, other than those recommended
by the manufacturer.
The appliance shall be stored in a room without
continuously operating
example: open flames, an operating gas appliance,
or an operating electric heater).
Do not pierce or burn.
Be aware that refrigerants may not contain an odor.
WARNING
If this appliance is conditioning a space with an area
smaller than TA min or stored in a space with an area
smaller than A min as defined by this instruction,
then that space must be without continuously
operating open flames (e.g. an operating gas
appliance) or other potential ignition sources (e.g.
an operating electric heater or similar hot surface).
A flame-producing device may be installed in the
same space if the device is provided with an effective
flame arrest system.
WARNING
Auxiliary devices which may be potential ignition
sources shall not be installed in the duct work.
Examples of potential ignition sources are hot
surfaces with a temperature exceeding 700°C and
electric switching components.
UNIT INFORMATION UNIT INFORMATION
SCH120 & 240 With R-454B
ignition sources (for
100115
All maintenance staff and others working in the local area
shall be instructed on the nature of work being carried out
with work in confined spaces being avoided.
Ensure that the area is in the open or that it is adequately
ventilated before breaking into the system or conducting
any hot work. A degree of ventilation shall continue during
the period that the work is carried out. The ventilation
should safely disperse any released refrigerant and pref-
erably expel it externally into the atmosphere.
Options / Accessories . . . . . . . . . . . . . . . . . . .Page 3
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . .Page 5
Blower Data . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 6
Electrical Data . . . . . . . . . . . . . . . . . . . . . . . . . Page 9
Unit Parts Arrangement . . . . . . . . . . . . . . . . . . Page 13
I-Unit Components . . . . . . . . . . . . . . . . . . . . . . Page 14
RDS Sensors. . . . . . . . . . . . . . . . . . . . . . . . Page 24
II-Charging. . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 32
III-Start Up - Operation . . . . . . . . . . . . . . . . . . . Page 42
IV-System Service Checks . . . . . . . . . . . . . . . . .Page 43
V-Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . Page 43
VI-Accessories . . . . . . . . . . . . . . . . . . . . . . . . .Page 46
VII-MSAV Styart Up . . . . . . . . . . . . . . . . . . . . Page 55
VIII -Decommissioning . . . . . . . . . . . . . . . . . . . Page 58
IX-Wiring and Operation Sequence
Page 1
SCH SERIES
10 & 20 Ton

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