LFMC Installation Tips You Need to Know

Liquidtight Flexible Metal Conduit (LFMC) is a vital component in various electrical installations, offering a versatile and durable solution for protecting wiring systems.

But only when it’s installed correctly, says Derrick Harker, a foreman at Continental Electrical Construction Co.

He has recommendations to make that happen.

Harker offers the following step-by-step guide to help installers, electricians and contractors install a wide range of LFMC from Electri-Flex and ensure safety, compliance and efficiency.

Tools Required for Installation

To install LFMC efficiently, Harker says you need a small set of essential tools, each of which plays a crucial role in the installation process:

• Tape Measure: To determine the exact length of LFMC needed for the installation, so that you have the right amount of conduit without wastage or shortage.
• Sharpie: To mark where precise cuts and proper fitting will be made.
• Electric Band Saw: To make clean and precise cuts on the LFMC at the marked locations. Using an electric band saw ensures that the cuts are smooth and accurate.
• Channel Locks: To tighten the LFMC fittings onto the conduit securely. Channel locks provide the necessary grip and torque to ensure that fittings are properly attached.

Step-by-Step Installation Process

1. Measure the LFMC: Use a tape measure to determine the required length of LFMC. Accurate measurement is crucial to avoid having too much or too little conduit.
2. Mark the Cut: Transfer the measurement to the LFMC and mark it with a Sharpie. Ensuring the mark is visible will help make a precise cut.
3. Cut the LFMC: Use the electric band saw to cut the LFMC at the marked point. After cutting, clean the edge of the cut to remove any roughness from the outer jacket. This step is vital for ensuring the fitting seats properly.

1. Install Fittings: Attach fittings to both ends of the LFMC and secure them onto the pull box or conduit end. Proper fitting installation is critical to protecting electrical wiring.
2. Tighten Fittings: Use channel locks to tighten the fittings to the pull box and the LFMC. Ensure the fittings are securely tightened to prevent any loosening over time.

Always clean the cut ends of the LFMC to ensure the fittings sit correctly. Additionally, gaskets can be used on fittings to maintain water resistance, especially in outdoor applications.

For larger LFMC or when pulling thicker wires, it can be easier to attach one side of the LFMC to the pull box first. Then, pull the wire through the LFMC before installing the second fitting and connecting it to the end device. This method helps avoid difficulties with wire pulling and ensures a smoother installation.

Consider upsizing the LFMC to facilitate easier wire pulling, which can save time and effort. Using high-quality fittings and connectors can also improve the overall durability and performance of the installation.

Safety Tips

Safety is paramount when installing LFMC. Always wear appropriate Personal Protective Equipment (PPE) to avoid injuries during cutting and installation. Other essential safety equipment to wear or use include:

• Safety Glasses: Protect your eyes from debris and particles during cutting.
• Cut-Resistant Gloves: Safeguard your hands from sharp edges and potential cuts.
• Proper Saw: Ensure the saw is suitable for the size of LFMC being cut.
• Sharp Blade: Use a sharp blade for clean cuts to reduce the risk of accidents and ensure smooth cuts.

During installation, secure the LFMC with a chain vise or a similar device while cutting to prevent movement and ensure a straight cut. Always keep both hands on the saw to maintain control and avoid injury.

Additionally, ensure your work area is well-lit and clutter-free to avoid tripping hazards.

Common Mistakes to Avoid

Several common mistakes can occur during the installation of LFMC. They include:

• Not Cleaning the Jacket: Failing to clean the jacket after cutting can prevent fittings from seating properly, leading to potential leaks and compromised integrity.
• Incorrect Length: Cutting the LFMC too short and attempting to stretch it to fit can cause undue stress on the conduit and connections.

To avoid these mistakes, lay the LFMC on the ground slack when measuring to ensure an accurate length. Always clean the cuts before installing fittings. If issues arise, such as the factory end being damaged or a fitting not fitting correctly, cut off the first few inches of a new roll or try another fitting.

Ensuring the longevity and durability of LFMC installations involves tightening all fittings securely and avoiding stretching the LFMC to fit. Regular maintenance checks can also help identify potential issues early on and ensure the system remains in good condition.

Industry Standards and Compliance

LFMC installations must adhere to industry standards, primarily the National Electrical Code (NEC) and the National Fire Protection Association (NFPA). These standards ensure the safety and reliability of electrical installations and must be followed meticulously.

To ensure compliance, regularly reference the code book and consult with local inspectors before installation. Staying updated with changes in regulations and standards is equally crucial. Conduct thorough inspections during and after installation to verify compliance.

Non-compliance can result in failed inspections and necessitating rework, which delays projects and incurs additional costs. It also compromises the safety and reliability of the electrical system, leading to potential hazards.

Installing LFMC is straightforward when you have the right tools and follow best practices. You can have successful and easy installations by understanding the step-by-step installation process, adhering to safety guidelines, avoiding common mistakes, and complying with industry standards.

Whether you’re a seasoned professional or a new installer, these tips and insights will help you achieve efficient and effective LFMC installations in nearly any application.