2007 Lennox Industries Inc.
Litho U.S.A.
Page 1
Corp. 0717−L5
SCA/SCB SERIES
Service Literature
10, 20 & 24 ton
35.2, 70.4 & 84.4 kW
Revised 10−2010
SCA/SCB
The SCA120, 240, 10 and 20 ton and SCB 288 24 ton, (35.2,
70.4 and 84.4 kW) units, are configure to order units (CTO)
with a wide selection of factory installed options. The SCA120
has a cooling capacity of 123,000 Btuh and the SCA240 has
gross a cooling capacity of 242,000 Btuh and the SCB has a
gross cooling capacity of 296,000 Btuh. All models are avai-
labe with factory installed multiple staged air volume (MSAV).
Units are designed for R410A refrigerant. See unit name-
plate. Operating pressures and pressure switch settings
are significantly higher than R22 charged units. Service
equipment must be rated for R410A.
Optional electric heat is factory installed in SCA units. Electric
heat operates in single or multiple stages depending on the
kW input size. 15 kW to 60 kW heat sections are available for
the SCA120 and 30, 60 and 90 kW heat sections are avail-
able for the SCA240/SCB288. SCA120 units utilize two com-
pressors, while SCA240/SCB288 units utilize four.
Information contained in this manual is intended for use by
qualified service technicians only. All specifications are sub-
ject to change. Procedures outlined in this manual are pre-
sented as a recommendation only and do not supersede 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 prop-
er rigging technique.
WARNING
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
agency.
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
Danger of sharp metallic edges. Can cause injury.
Take care when servicing unit to avoid accidental
contact with sharp edges.
SCA120
SCA240/SCB288
Table of Contents
Options / Accessories Page 2. . . . . . . . . . . . . . .
Specifications Page 4. . . . . . . . . . . . . . . . . . . . . .
Blower Data Page 8. . . . . . . . . . . . . . . . . . . . . . .
Electrical / Electric Heat Data Page 12. . . . . . . .
Parts Arrangement Page 15. . . . . . . . . . . . . . . . .
I Unit Components Page 18. . . . . . . . . . . . . . . . . .
II Placement and Installation Page 36. . . . . . . . .
III Charging Page 36. . . . . . . . . . . . . . . . . . . . . . . .
IV System Service Checks Page 38. . . . . . . . . .
V Maintenance Page 38. . . . . . . . . . . . . . . . . . . . .
VI Accessories Page 39. . . . . . . . . . . . . . . . . . .
VII Wiring and Operation Sequence Page 42. . .
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