Lennox SCH036, Installation Instructions Manual

Page: 1 / 60

©
2019
SGH120 SHOWN
IMPORTANT
Supply air VFD motor rotation is controlled indepen­
dently from scroll compressor rotation. See Cooling
Start-Up section for correct compressor rotation.
Compressor damage due to improper rotation is the
responsibility of the installer.
Table of Contents
Dimensions Page 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts Arrangements Page 5 . . . . . . . . . . . . . . . . . . . . . . . . .
Shipping and Packing List Page 8 . . . . . . . . . . . . . . . . . . . .
General Page 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Safety Page 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Unit Support Page 9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Duct Connection Page 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rigging Unit For Lifting Page 10 . . . . . . . . . . . . . . . . . . . . . . .
Condensate Drains Page 10 . . . . . . . . . . . . . . . . . . . . . . . . . .
Gas Piping Page 11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure Test Gas Piping Page 11 . . . . . . . . . . . . . . . . . . . . .
RETAIN THESE INSTRUCTIONS FOR FUTURE REFERENCE
INSTALLATION
INSTRUCTIONS
SGH/SCH036
(3 TON)
SGH/SCH060
(5 TON)
SGH/SCH120
(10 TON)
SGH/SCH240
(20 TON)
ROOFTOP UNITS
507964-01
9/2019
Supersedes 507364-02
High Altitude Derate Page 12 . . . . . . . . . . . . . . . . . . . . . . . . .
Optional Outdoor Air Hood Page 13 . . . . . . . . . . . . . . . . . . . .
Electrical Connections Page 15 . . . . . . . . . . . . . . . . . . . . . . .
Blower Operation and Adjustments Page 17 . . . . . . . . . . . .
Cooling Start-Up Page 29 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cooling Operation and Adjustments Page 31 . . . . . . . . . . . .
Gas Heat Start-Up Page 41 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electric Heat Start-Up Page 43 . . . . . . . . . . . . . . . . . . . . . . . .
Heating Operation and Adjustments Page 43 . . . . . . . . . . . .
MSAV
t
Unit Start-Up Page 45 . . . . . . . . . . . . . . . . . . . . . . . .
MSAV
t
Operation Page 46 . . . . . . . . . . . . . . . . . . . . . . . . . .
Direct Drive Start-Up Page 47 . . . . . . . . . . . . . . . . . . . . . . . . .
Hot Gas Reheat Startup Page 49 . . . . . . . . . . . . . . . . . . . . . .
Economizer Start-Up Page 53 . . . . . . . . . . . . . . . . . . . . . . . . .
Service Page 55 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Factory Control Parameter Settings Page 58 . . . . . . . . . . . .
Start-Up Report Page 60 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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 licensed professional HVAC in­
staller or equivalent, service agency, or the gas sup­
plier
WHAT TO DO IF YOU SMELL GAS:
If the information in this manual is not
followed exactly, a fire or explosion
may result causing property damage,
personal injury or loss of life.
WARNING
Do not store or use gasoline or
other flammable vapors and liq­
uids in the vicinity of this or any
other appliance.
Installation and service must be
performed by a qualified installer,
service agency or the gas supplier.
S
Do not try to light any appliance.
S
Extinguish any open flame.
S
Do not touch any electrical switch; do not
use any phone in your building.
S
Immediately call your gas supplier from a
neighbor's phone. Follow the gas suppli­
er's instructions.
S
If you cannot reach your gas supplier, call
the fire department.
S
Leave the building immediately.