PACKAGED UNITS
KITS AND ACCESSORIES
506204-03
1/2025
Supersedes 6/2024
DIRTY FILTER
SWITCH KIT
INSTALLATION INSTRUCTIONS FOR DIRTY FILTER SWITCH KIT (603364-03, 04, 05; 53W66, 53W67, 53W68) USED ON LG/LC/KG/KC/KH/KD/LH/LD UNITS
Shipping and Packing List
Package 1 of 1 contains:
1- Filter switch (S27)
1- Plastic tubing
2- Screws
Application
Filter switch kit is used on LG/LC/ KG/KC/KH/KD/LH/LD 024-600 (2 to 50 ton) packaged units. See TABLE 1 for usage.
The normally open filter switch will close with an increase in static pressure.
The Unit Controller will display and store an error code and energize a service output. See Unit Controller manual provided with unit.
TABLE 1
| Unit Tonnage | Kit |
| 024-074 | 603364-03; 53W66 |
| 078-152 | 603364-04; 53W67 |
| 156-600 | 603364-05; 53W68 |
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 all electrical power to unit. Open filter access door.
- Install filter switch in location shown in FIGURE 1 for 024-074 units, FIGURE 2 for 078-152 units, FIGURE 3 for 156-300S units and FIGURE 4 for 420600 units.
- Connect one end of plastic tubing to the filter switch port. See FIGURE 5. On 420-600 units, cut the 30” tubing (provided) to 18-1/2 “.
- Route the other end of plastic tubing as shown in appropriate figure.
- Locate wires marked S27-C and S27-NO hanging near filter switch. Connect wire marked S27-C to the switch common terminal. Connect wire marked S27- NO to the switch NO terminal. See FIGURE 5.
- M3/M4 Unit Controller Setup: Go to SETUP / INSTALL to enable the Dirty Filter Switch (S27). Navigate through the setup questions until Configuration ID 2 appears. Set position two to C if the dirty filter switch is installed on units equipped with an M3/M4 Unit Controller. Set position two to D if the dirty filter switch is installed on units equipped with a DDC controller.
CAUTION
As with any mechanical equipment, contact with sharp sheet metal edges can result in personal in jury. Take care while handling this equipment andwear gloves and protective clothing.
© 2025
Documents / Resources
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LENNOX 53W66 Dirty Filter Switch Kit [pdf] Instruction Manual 603364-03, 603364-04, 603364-05, 53W66, 53W67, 53W68, 53W66 Dirty Filter Switch Kit, 53W66, Dirty Filter Switch Kit, Filter Switch Kit, Switch Kit |