1. Product Overview
The Lennox 10F73 Contactor is a genuine Lennox OEM part designed for definite purpose applications. This 1-pole contactor operates at 24 VAC 60/50 Hz with a 25 Amp rating and 25 FLA. It is equipped with a shunt and an additional cover, making it suitable for various industrial electrical control systems, particularly in HVAC applications.
This image displays the Lennox 10F73 1 Pole 25 Amp Contactor. It features a black housing with brass terminals on the sides and a visible copper coil at the bottom center. A label with product information and a QR code is affixed to the top surface.
2. Installation and Setup
WARNING: Electrical shock hazard. Installation should only be performed by qualified personnel. Disconnect all power before servicing.
This contactor is designed for direct replacement or new installations in compatible electrical systems. Ensure the power supply matches the contactor's specifications (24 VAC, 60/50 Hz).
- Power Disconnection: Before beginning any work, ensure that the main power supply to the equipment where the contactor will be installed is completely disconnected and locked out. Verify with a voltage tester.
- Identify Mounting Location: Select a secure and appropriate mounting location within the electrical panel or equipment enclosure, ensuring adequate ventilation and clearance.
- Mounting: Secure the contactor firmly using appropriate fasteners through its mounting holes.
- Wiring: Connect the load and control wiring to the appropriate terminals. Refer to the wiring diagram of your specific application or equipment. Ensure all connections are tight and secure to prevent arcing or overheating.
- Verify Connections: Double-check all wiring connections for correctness and tightness.
- Restore Power: Once installation is complete and verified, restore power to the system.
3. Operation
The Lennox 10F73 Contactor functions as an electrically controlled switch. When the 24 VAC control voltage is applied to its coil, an electromagnetic field is generated, which pulls the movable contacts into connection with the stationary contacts. This action closes the circuit, allowing power to flow to the connected load (e.g., a motor or compressor). When the control voltage is removed, the electromagnetic field collapses, and springs return the contacts to their open position, interrupting the power to the load.
4. Maintenance
Regular inspection and maintenance can extend the lifespan of your contactor and ensure reliable operation. Always disconnect power before performing any maintenance.
- Visual Inspection: Periodically inspect the contactor for signs of wear, discoloration, or damage, especially on the contacts and coil. Look for loose connections or burnt insulation.
- Cleanliness: Keep the contactor free from dust, dirt, and debris, which can interfere with proper operation and heat dissipation. Use a dry, non-conductive brush or compressed air.
- Terminal Tightness: Check and re-tighten all terminal screws annually to ensure good electrical contact and prevent overheating.
- Contact Wear: While the contacts are designed for durability, excessive arcing or frequent cycling can cause wear. If contacts appear pitted or severely eroded, replacement may be necessary.
5. Troubleshooting
If the contactor is not functioning as expected, consider the following common issues and their potential solutions:
| Problem | Possible Cause | Solution |
|---|---|---|
| Contactor does not pull in (contacts do not close) | No control voltage to coil Faulty coil Mechanical obstruction | Check control circuit for power (24 VAC) Test coil resistance; replace contactor if coil is open or shorted Inspect for debris or damage preventing movement |
| Contactor hums loudly | Loose shading coil Dirt or foreign material on magnet faces Low control voltage | Replace contactor Clean magnet faces (with power off) Verify control voltage is within specifications |
| Contacts are pitted or burnt | Overload condition Frequent cycling Loose connections | Check load current; address overload Consider a heavier-duty contactor if cycling is excessive Tighten all terminal connections |
| Contactor remains closed (contacts do not open) | Welded contacts Mechanical binding | Replace contactor Inspect for physical damage or debris |
6. Technical Specifications
| Specification | Detail |
|---|---|
| Model Number | 100438-04 |
| Manufacturer | Lennox |
| Poles | 1 Pole |
| Amp Rating | 25 Amp |
| Coil Voltage | 24 VAC 60/50 Hz |
| FLA (Full Load Amps) | 25 FLA |
| Product Dimensions | 3.5 x 2.56 x 2.19 inches |
| Weight | 0.01 ounces |
| First Available | March 26, 2018 |
7. Warranty and Support
For warranty information and technical support regarding your Lennox 10F73 Contactor, please refer to the official Lennox website or contact Lennox customer service directly. Keep your purchase receipt and product model number (100438-04) readily available when seeking support.
You can typically find contact information and detailed warranty terms on the manufacturer's official website: www.lennox.com