Introduction
The Carlon FN-23 Vapor-Tight Outlet Box is designed for new work installations, providing a secure and draft-tight enclosure for electrical connections. This 1-gang box features a high-strength polycarbonate construction, making it durable and resistant to temperature extremes. It is specifically engineered to meet energy efficiency requirements for new homes by preventing air flow through the box, thanks to its foam gaskets and 1/2-inch offset flange for flush drywall fit. This manual provides essential information for the safe and proper installation and use of your Carlon FN-23 outlet box.
Safety Information
WARNING: Electrical work can be dangerous. Always consult with a qualified electrician if you are unsure about any part of the installation process. Ensure power is turned off at the circuit breaker before beginning any electrical work. Failure to do so may result in serious injury or death.
- Always disconnect power at the main service panel before installing or servicing electrical boxes.
- Use appropriate personal protective equipment (PPE), such as safety glasses and insulated gloves.
- Ensure all wiring is done in accordance with local and national electrical codes (e.g., NEC in the USA).
- Do not overload the electrical box with excessive wiring or devices beyond its rated capacity.
- This product is intended for use with non-metallic sheathed cable only.
- The product contains chemicals known to the State of California to cause cancer and birth defects or other reproductive harm (Proposition 65 warning). Handle with care and wash hands after use.
Package Contents
Verify that all components are present before beginning installation.
- 1 x Carlon FN-23 Vapor-Tight Outlet Box (Black, Polycarbonate)
- Integrated angled side nails for mounting
- Integrated foam gaskets over cable entry points
Setup and Installation
The Carlon FN-23 outlet box is designed for new work applications, typically installed before drywall. Its angled side nails and 1/2-inch offset flange facilitate a flush and secure installation.
- Prepare the Installation Area: Ensure the wall cavity is clear of obstructions. Identify the desired location for the outlet box.
- Turn Off Power: Locate the appropriate circuit breaker in your electrical panel and turn off the power to the circuit you will be working on. Verify power is off using a voltage tester.
- Position the Box: Place the Carlon FN-23 box into the wall cavity. The angled side nails are designed to attach directly to a wooden stud. The 1/2-inch offset flange should rest against the front edge of the stud, ensuring the box will be flush with 1/2-inch drywall.
- Secure the Box: Drive the integrated angled side nails through the box's mounting tabs and into the wooden stud until the box is firmly secured and flush with the stud.
- Run Non-Metallic Sheathed Cable: Bring the non-metallic sheathed cable (e.g., Romex) into the box through one of the designated cable entry points. The foam gaskets provide a draft-tight seal around the cable. Ensure at least 6 inches of cable extends into the box for proper wiring.
- Wire Connections: Strip the outer jacket and individual wire insulation as required. Make all necessary electrical connections (e.g., connecting to an outlet or switch) inside the box according to electrical codes and device instructions.
- Install Device: Once wiring is complete, carefully fold the wires into the box and secure the electrical device (outlet, switch, etc.) to the box using the provided mounting screws.
- Install Wall Plate: After drywall installation and finishing, attach the appropriate wall plate to cover the device and box opening.
- Restore Power: Once all work is complete and inspected, turn the power back on at the circuit breaker.

Image: Front view of the Carlon FN-23 Outlet Box, showing the main opening, foam gasket, and angled side nails for mounting to a stud.

Image: Side view of the Carlon FN-23 Outlet Box, highlighting the angled side nails and the foam gasket designed for a draft-tight seal.

Image: Back view of the Carlon FN-23 Outlet Box, showing the multiple cable entry points with integrated foam gaskets.
Operating Principles
The Carlon FN-23 outlet box functions as a protective enclosure for electrical wiring connections and devices within a wall cavity. Its vapor-tight design, achieved through integrated foam gaskets and a precise flange, prevents air infiltration and exfiltration, contributing to the energy efficiency of the building envelope. Once installed and wired, the box passively protects the electrical connections from physical damage and environmental factors.
Maintenance
The Carlon FN-23 outlet box is designed for long-term, maintenance-free operation once properly installed. No routine maintenance is required for the box itself. However, it is good practice to periodically inspect electrical outlets and switches for signs of wear, damage, or loose connections. If any issues are observed, disconnect power and consult a qualified electrician.
Troubleshooting
Most issues related to an electrical box are typically associated with the wiring or the device installed within it, rather than the box itself. Always ensure power is off before troubleshooting.
| Problem | Possible Cause | Solution |
|---|---|---|
| Device (outlet/switch) not working after installation. | Power not restored; loose wire connection; faulty device. | Check circuit breaker. Verify all wire connections are secure. Test the device. |
| Drafts or air leakage around the box. | Improper installation; damaged foam gasket; gaps in drywall. | Ensure box is flush with drywall. Inspect foam gaskets for damage. Seal any gaps around the box with appropriate caulk or sealant. |
| Box feels loose in the wall. | Nails not fully secured; stud damage. | Ensure mounting nails are fully driven into the stud. If stud is damaged, consider alternative mounting methods or repair the stud. |
Specifications
| Attribute | Detail |
|---|---|
| Model Number | FN-23 |
| Brand | Carlon |
| Type | New Work, Vapor-tight Outlet Box |
| Gang Configuration | 1 Gang |
| Material | High-strength Polycarbonate |
| Color | Black |
| Capacity | 22.5 Cubic Inches |
| Dimensions (L x W x D) | 3-5/8 inches L x 2-1/4 inches W x 3-5/8 inches D (Product Description) / 3.63"D x 3.63"W x 4"H (Specifications) |
| Mounting Type | Angled Side Nails (Nail-On) |
| Drywall Offset | 1/2-inch offset flange for flush fit in 1/2-inch drywall |
| Cable Compatibility | Non-Metallic Sheathed Cable |
| Certifications | UL Listed, Meets energy efficiency requirements, REACH, RoHS, TSCA |
| Item Weight | 4.8 ounces |
| Manufacturer | Thomas & Betts |
| UPC | 785991020694 |
Warranty Information
Carlon products are manufactured to high standards and are typically covered by a manufacturer's warranty against defects in materials and workmanship. For specific warranty terms and conditions, please refer to the documentation included with your purchase or visit the official Carlon (Thomas & Betts) website. Please retain your proof of purchase for warranty claims.
Customer Support
For technical assistance, product inquiries, or support, please contact Thomas & Betts (the manufacturer of Carlon products) directly. You can typically find contact information on their official website or through the retailer where you purchased the product.
Online Resources: www.tnb.com (Thomas & Betts official website)
When contacting support, please have your product model number (FN-23) and purchase details ready.





