LENNOX LGH Power Exhaust Fans Instruction Manual
- June 4, 2024
- Lennox
Table of Contents
PACKAGED UNITS KITS AND ACCESSORIES
506745-04 5/2022
Supersedes 12/2020
POWER EXHAUST FANS
INSTALLATION INSTRUCTIONS FOR POWER EXHAUST FANS
USED WITH KG/KC/KH/LG/LC/LH/LD 024-090 PACKAGED UNITS
Shipping and Packing List
Package 1 contains:
- Power exhaust assembly
- GED Seal
- Bag assembly containing:
-
10 Sheet metal screws
- 1-Pink wire (K1-1)
- 1-Gray wire (K1-2)
- 2-Terminal adapters
Check the packaging for shipping damage. Contact the last carrier immediately if any shipping damage is found.
Application
Power exhaust fans are applied to units equipped with an economizer in
downflow air discharge. The power exhaust fan option cannot be used in
horizontal air discharge applications. See table 1.
Locate all other accessories to be installed. Install accessories in the
following order:
- -Economizer Dampers
- -Sensors
- -Power Exhaust Fans
- -Hood assembly
- -Gravity Exhaust Dampers
TABLE 1
Unit| Unit Voltage| Cat No.| Assembly
No.
---|---|---|---
LG/LC/LH/LD
036-074
KG/KC 024-090
KH024-072| 208/230| 21Z13| 607212-09
460| 21Z14| 607212-10
575| 21Z15| 607212-11
380/420| 21Z16| 607212-12
CAUTION
As with any mechanical equipment, contact with sharp sheet metal edges can
result in a personal in jury. Take care while handling this equipment and
wear gloves and protective clothing.
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
Installation
-
– Disconnect electrical power to unit.
-
– Remove or open unit end panel. See figure 1.
-
If the unit does not already contain an economizer, install using the instructions provided with the economizer. Install optional enthalpy sensor(s) if used; refer to instructions provided with sensors.
-
Remove gravity exhaust dampers from the economizer assembly. See figure 2.
-
Refer to instructions provided with the economizer for hood assembly with power exhaust fan.
-
LG/LC/LH/LD Units Remove and discard the power exhaust fan jumper harness. See figure 3. Set fan near the unit opening and connect J18/P18 and J24/P24 plugs. See figure 4 for locations of J18 and J24.
-
KG/KC/KH Units Set fan assembly near the unit opening and connect J132/P132 plugs. See figure 5.
-
KG/KC/KH Units – Field-Installed Economizers OnlyLocate economizer harness wires marked K1-L1 and K1-L2 (already installed and hanging near the economizer control A6). Connect the hanging K1-L1 wire to the pink kit wire marked K1-L1. Connect the hanging K1-L2 wire to the gray kit wire marked K1-L2. Wires hanging in the unit may be pink and gray, red and black, or red and blue. Route the other end of the pink and gray kit wires to the control panel. Connect a pink kit wire to K1 contactor L1 terminal. Connect a gray wire to the K1 contactor L2 terminal using the terminal adapter provided in the kit. See figure 6.
Note – Older economizers may be equipped with longer pink and gray wires coiled in the same area. One end of the pink and gray wires is already connected. Connect the other end according to the previous step. Discard kit wires. -
Install fan assembly and secure with screws provided.
-
Install gravity exhaust in exhaust air hood as shown in the economizer installation instruction.
Set Prodigy M2 Unit Controller
Use the Unit Controller manual provided with each unit to enable the exhaust
fan.
Use the following menu: Settings>Install>New M2>Exhaust Stages> 1 Exhaust
Stage
M3 Unit Controller Setup
The M3 Unit Controller has power exhaust fan control options that include
support for both single‐stage and two‐stage equipment. The power exhaust is
controlled based on the damper position. Refer to the Power Exhaust section
of the 2.0 M3 Unit Controller Application Guide.
Go to SETUP / INSTALL and set Configuration ID 1, position 3 to (S = Single
Stage or D = Dual Stage).
Go to SETUP / INSTALL and set Configuration ID 1, position 4 to A = Damper
Position
M4 Unit Controller Setup
The M4 Unit Controller has power exhaust fan control options that include
support for both single‐stage and two‐stage equipment. The power exhaust is
controlled based on the damper position. Refer to the Power Exhaust section of
the M4 Unit Controller Application Guide.
Go to RTU MENU > SETUP INSTALL and navigate through various setup questions
until Configuration ID
1; set position 3 to (S = Single Stage or D = Dual Stage).
Go to RTU MENU > SETUP INSTALL and navigate through various setup questions
until Configuration ID
1; set position 4 to (A = Damper Position).
Operation
Power exhaust fans are energized when economizer dampers reach 50% (default).
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