Lennox Commercial Sgh-sch036 Rooftop Unit Kits And Accessories Instruction Manual (+ PDF)

Home » Blog » Lennox Commercial Sgh-sch036 Rooftop Unit Kits And Accessories Instruction Manual

Contents hide

1 SGH-SCH036 Rooftop Unit Kits and Accessories

SGH-SCH036 Rooftop Unit Kits and Accessories

Product Information: Product Name: E2022 Rooftop Unit Kits
and Accessories Model: SGH/SCH036 & 060 and LG/LC/LH/LD 024-074
Units Part Number: 508121-01 Supersedes: 2/2022 Application: Blower
Motor & Impeller Replacement Kit Shipping and Packing
List: – Package 1 of 1 contains: – 1 Blower motor and impeller
assembly – 1 Bag assembly containing: – 6 Bolts – 1 Adapter control
harness WARNING: Improper installation, adjustment,
alteration, service, or maintenance can cause property damage,
personal injury, or loss of life. Installation and service must be
performed by a licensed professional HVAC installer or equivalent,
service agency, or the gas supplier. Table 1 – Unit
Compatibility: – SGH/SCH036 & 060 – LG/LC/LH/LD 024-074
Installation Instructions: 1. Disconnect electrical power to
the unit. Wait five minutes before continuing service procedures to
avoid electrical shock. This will allow internal capacitors time to
fully discharge. 2. Open access panels as shown in figure 1 or 2,
depending on the unit type. – For SGH/SCH units, open the blower
access panel (figure 1). – For LG/LC/LH/LD units, open the blower
access panel (figure 2). Control Harness Connection: – For
older model SGH/SCH units: – Use the provided kit harness and make
the 9-pin control harness connection in the blower compartment. –
Discard the kit harness when the control connector (J335 or Modbus
harness) is located in the blower compartment. See figure 3.
Unit-specific Disconnect Instructions: – SGH/SCH Units: –
Disconnect J48 from P48 in the controls area and unscrew the GND
terminal from the control panel. See figure 4. – LG/LC/LH/LD Units:
– Disconnect J48 from P48 in the blower area and unscrew the GND
terminal from the blower deck. Blower Assembly Removal: 1.
Cut wire ties where necessary and pull power and/or control
harnesses from the control area into the blower section. – Note:
The top panel may need to be raised to pull the control harness
through the convoluted tubing between the blower and controls
section. 2. Remove four screws securing the blower assembly to the
unit. See figure 5. Additional Steps for Specific Units: –
Older SGH/SCH Units: – Disconnect J335 from P335 control connectors
located in the control box. – Newer SGH/SCH & LG/LC/LH/LD
Units: – Disconnect the Modbus 9-pin blower control plug located in
the blower area. Optional Removal: – If the unit was
equipped with a blower proving switch, remove the switch from the
blower housing. – For LGM/LCM Units: – Remove PT6 pressure
transducer bracket and silicone tubing from housing. See figure 5.
– If needed, remove the inlet ring to disconnect the tubing from
the inlet ring barb. See figure 7. – Disconnect the pressure
transducer wire connector. CAUTION: As with any mechanical
equipment, contact with sharp sheet metal edges can result in
personal injury. Take care while handling this equipment and wear
gloves and protective clothing. This concludes the installation
instructions for the Blower Motor & Impeller Replacement Kit
used with SGH/SCH036 & 060 and LG/LC/LH/LD 024-074 Units. For
further assistance, please refer to the complete user manual or
contact our customer support.

View Fullscreen

E2022

ROOFTOP UNIT KITS

AND ACCESSORIES

508121-01 BLOWER MOTOR & IMPELLER

5/2022

Supersedes 2/2022

REPLACEMENT KIT

INSTALLATION INSTRUCTIONS FOR BLOWER MOTOR & IMPELLER REPLACEMENT KIT USED WITH SGH/SCH036 & 060 AND LG/LC/LH/LD 024-074 UNITS

Shipping and Packing List
Package 1 of 1 contains: 1- Blower motor and impeller assembly 1- Bag assembly containing:
6-Bolts 1-Adapter control harness

WARNING
Improper installation, adjustment, alteration, ser vice or maintenance can cause property damage, personal injury or loss of life. Installation and ser vice must be performed by a licensed professional HVAC installer or equivalent, service agency, or the gas supplier
Application

See table 1 for usage.
Kit Adapter Control Harness Use the kit harness and make the 9-pin control harness connection in the blower compartment on older model SGH/SCH units. Discard the kit harness when the control connector (J335 or Modbus harness) is located in the blower compartment. See figure 3.
TABLE 1

21P21 621157-03
21P22 621157-04

Unit
SGH/SCH036 & 060 LG/LC/LH/LD 024-074
SGH/SCH036 – 060 LG/LC/LH/LD 024-074

Voltage
Y G, J

Installation
1- Disconnect electrical power to unit. Wait five minutes before continuing service procedures to avoid electrical shock. This will allow internal capacitors time to fully discharge.
2- Open access panels as shown in figure 1 or 2.
SGH/SCH UNITS

BLOWER ACCESS

FIGURE 1

CONTROL ACCESS

LG/LC/LH/LD UNITS

BLOWER ACCESS
FIGURE 2

CONTROL ACCESS

CONTROL HARNESS CONNECTOR LOCATION – SGH/SCH UNITS

BLOWER COMPARTMENT
BLOWER
9-Pin Modbus control connector in newer SGH/SCH units.

POWER HARNESS
9-PIN 2-WIRE

J48/P48
4-PIN 2-WIRE
J335/P335

CONTROL COMPARTMENT TO POWER
TO UNIT CONTROLLER

Adapter control harness (provided in newer SGH/ SCH units and in this kit).
Existing control harness in older SGH/SCH units.

FIGURE 3

Page 1

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.
3- SGH/SCH Units Disconnect J48 from P48 in the controls area and unscrew the GND terminal from the control panel. See figure 4. LG/LC/LH/LD Units Disconnect J48 from P48 in the blower area and unscrew the GND terminal from the blower deck.
4- Older SGH/SCH Units Disconnect J335 from P335 control connectors located in the control box. Newer SGH/SCH & LG/LC/LH/LD Units Disconnect the Modbus 9-pin blower control plug located in the blower area.
5- Cut wire ties where necessary and pull power and/or control harnesses from control area into blower section.
Note – The top panel may need to be raised to pull the control harness through the convoluted tubing in between the blower and controls section.
6- Remove four screws securing blower assembly to unit. See figure 5.
7- If unit was equipped with a blower proving switch, remove switch from blower housing.
8- LGM/LCM Units When present, remove PT6 pressure transducer

bracket and silicone tubing from housing. See figure 5. If needed, remove the inlet ring to disconnect the tubing from the inlet ring barb. See figure 7. Disconnect the pressure transducer wire connector.
9- Use the handle on the blower assembly to slide the assembly out of unit.
10- Turn the blower assembly upside down. See figure 6.
11- Remove the inlet grill, inlet ring, and the side of the housing shown in figure 7.
12- Remove the motor / impeller secured to the housing. See figures 6 and 7.
13- Install replacement motor / impeller on blower housing in the same manner the existing motor / impeller was removed. Secure with 6 bolts provided in this kit. Tighten to 21.7 ft.-lbs.
14- If unit was equipped with a blower proving switch, re-attach the proving switch to the housing in the same manner it was removed.
15- LGM/LCM Units Attach the pressure transducer bracket, wire connector, and silicone tubing to the housing in reverse order of removal.
16- Replace the blower housing side, inlet ring, and inlet grill which was previously disassembled. Tighten inlet ring screws to 10.8 ft.-lbs. Tighten inlet grill screws to 3.7 ft.-lbs.
17- Install blower assembly flanges into rails on the blower deck in the same manner it was removed. Secure into place using four screws shown in figure 5.

TO BLOWER

CONTROL AREA OLDER MODEL SGH/SCH UNITS

J335 P335
CONTROL HARNESS

UNIT CONTROLLER

TO BLOWER
GND

J48 P48 FIGURE 4

POWER HARNESS

Page 2

INLET GRID

SLIDE BLOWER ASSEMBLY OUT OF UNIT
SILICONE TUBING (LGM/LCM ONLY)
BLOWER MOTOR SECURED TO THIS SIDE OF HOUSING
BLOWER HOUSING
PT6 PRESSURE TRANS DUCER ASSEMBLY
(LGM/LCM ONLY)

REMOVE TWO SCREWS ON EACH SIDE TO SLIDE BLOWER OUT OF UNIT

LG/LC/LH/LD & NEWER MODEL SGH/SCH UNITS –
J / P48 POWER AND CONTROL WIRING BUNDLED IN
FRONT OF THE BLOWER

FIGURE 5

18- Uncoil P48 power harness and Modbus control

the unit to the control area in the same manner it was

harnesses secured to replacement blower motor /

removed. Connect J335 to P335.

impeller.

Newer SGH/SCH and LG/LC/LH/LD Units –

19- SGH/SCH Units Route P48 harness through unit to control area in the same manner as they were removed. Connect P48 to J48 and screw GND terminal to control panel as

Discard the kit harness. Connect the Modbus plug in the blower area to the blower motor 9-pin control plug.
21- Bundle harnesses and use wire ties to secure kit

shown in figure 4. LG/LC/LH/LD Units –

harnesses to unit harnesses in the same manner they were removed.

Connect P48 to J48 in blower compartment. Screw GND terminal to blower deck in the same manner it

Warranty Return

was removed.

Package malfunctioned motor / impeller in the same

20- Older SGH/SCH Units –

manner as the replacement was provided. Use the same

Locate harness provided in the kit and connect the packaging. Return malfunctioned motor / impeller along

9-pin plug to the blower Modbus/P335 control with a copy of the warranty claim form to the nearest LPP

harness. Route the J335 end of the harness through store or warehouse.

Page 3