LB vs LL Conduit Body: When to Use Which (2026 Guide)

You're standing in front of a junction where your conduit run needs to make a 90-degree turn, and you need to pull wire through it. You know you need a conduit body, but the supply house has both LB and LL types in stock, and choosing wrong means either a failed inspection or a callback when the wire won't pull. The difference between these two conduit body styles isn't just academic—it directly affects your installation method, wire fill calculations, and whether you can legally use the body as a splice point.

Quick Answer

An LB conduit body creates a 90-degree turn with the opening facing the back (away from the mounting surface), while an LL conduit body turns 90 degrees with the opening facing left. Use an LB when you need back access for pulling wire on a wall-mounted run; use an LL when you need side access or when the conduit enters from the right and exits upward or downward. The LB is the most common choice for standard wall-to-ceiling transitions, while the LL solves specific directional access problems in tight installations.

Understanding Conduit Body Designations and Geometry

The letter designation system for conduit bodies tells you exactly how the body is oriented and where the cover opening is located. The first letter indicates the cover position relative to the conduit body's mounting plane, and the second letter (when present) indicates the direction of the outlet opposite the hub.

For LB conduit bodies, the "L" indicates a 90-degree angle, and the "B" means the cover faces back (away from the mounting surface). When you mount an LB to a wall, the removable cover faces outward toward you, making it ideal for wire pulling and inspection. The conduit enters from one direction and exits 90 degrees perpendicular, typically going up a wall and then away from the wall.

For LL conduit bodies, both letters are "L" because the body makes a 90-degree turn and the cover opening faces left when you're looking at the mounting surface. This configuration is less common but critical when your conduit geometry requires side access or when space constraints prevent using an LB.

Both body types must comply with NEC Article 314.16(C) for box fill calculations and Article 314.28 for pull box sizing when conductors are 4 AWG or larger. The internal volume and conductor fill capacity are marked on quality conduit bodies from manufacturers like Appleton and Crouse-Hinds.

LB vs LL Conduit Body: Technical Comparison

The key technical difference is access direction. When you're troubleshooting a wire pull failure or need to add conductors later, the LB's back-facing cover is almost always easier to work with on wall-mounted installations. The LL becomes necessary when the LB's cover would be blocked by adjacent equipment, tight quarters, or architectural features.

When to Use an LB Conduit Body

The LB is your default choice for 90-degree transitions in most installations, particularly when bringing conduit up a wall and then out to equipment, or when transitioning from outdoor to indoor runs. Here are the specific scenarios where an LB is the right call:

• Standard wall-mounted equipment feeds: When your raceway comes up from below and needs to exit horizontally away from the wall to reach a disconnect or panel, the LB provides clean access directly in front of you.
• Outdoor service entrances: Weather-resistant LB bodies (rated Type 3R, Type 4, or Type 4X) are the standard for bringing service conductors from a meter base down to ground or up to a roof-mounted disconnect.
• Rooftop HVAC installations: When conduit runs up a wall and transitions to horizontal runs across a roof, the LB's back-facing cover allows you to stand on the roof and access the body easily.
• Pulling larger conductors: The LB's geometry provides a more gradual bend radius internally compared to an LL in the same trade size, reducing conductor friction during pulls.
• Inspector access requirements: When AHJs require accessible splice or pull points for verification, LB bodies mounted at shoulder height with forward-facing covers are easier to inspect than side-facing LL bodies.

Per NEC 314.28(A)(2), when you're using conductors 4 AWG or larger, the distance from the conduit entry to the opposite wall must be at least eight times the trade size of the largest raceway. For a 2" LB, that's 16 inches minimum internal dimension. Most standard LB bodies don't meet this requirement, which means you cannot use them as pull points for large conductors unless the body is specifically marked and sized as compliant. Check the manufacturer's specifications for UL listing details and marked dimensions.

Need help sizing your installation? Our team can provide technical specifications and volume calculations at our quote page.

When to Use an LL Conduit Body

The LL conduit body solves problems that an LB cannot, specifically when access direction or spatial constraints make a back-facing cover impractical. Here's when you should specify an LL:

• Equipment installed tight to walls: When a panel, motor controller, or disconnect is mounted flush against a wall with minimal clearance, an LL allows the conduit to enter from the right and turn up or down while providing left-side access that doesn't require removing or moving equipment.
• Confined spaces with front access blocked: In mechanical rooms where equipment, pipes, or ductwork blocks direct front access to a wall, an LL can be oriented to provide lateral access from the only available approach angle.
• Parallel conduit runs with staggered access: When running multiple parallel conduits vertically and you need pull points, alternating LB and LL bodies allows access to each without covers interfering with adjacent raceways.
• Left-hand wire pulling setups: Some pulling configurations work better when the pulling grip approaches from a specific angle. An LL accommodates left-approach pulls that would be awkward with an LB.
• Aesthetic or architectural requirements: Occasionally, project specifications require conduit body covers to face specific directions for visual consistency or to hide them from primary viewing angles.

The LL is less common in distributor stock compared to the LB, so plan your material orders accordingly. While ½" through 1" LL bodies are usually available from major manufacturers, larger trade sizes may require special order with longer lead times.

Code Compliance and Conductor Fill Requirements

Both LB and LL conduit bodies must meet the same NEC requirements for conduit bodies, found primarily in Article 314. The critical considerations include:

Conductor Fill (NEC 314.16(C)(2)): Conduit bodies must be marked with their cubic inch capacity if you intend to use them as splice or junction boxes. Count each conductor, clamp, support fitting, and device according to Table 314.16(B). If the conduit body isn't marked with volume, you can only use it as a pull point—no splices allowed.

Conductor Sizing (NEC 314.28(A)): For conductors 4 AWG and larger, the length of the conduit body must be at least eight times the trade diameter of the largest raceway. Most standard LB and LL bodies in sizes 2" and smaller don't meet this requirement. You'll need to use a Type C, T, or X conduit body for larger conductor pulls, or install a proper pull box.

Support Requirements (NEC 314.23): Conduit bodies must be rigidly supported. For most installations, this means the conduit itself provides support through proper mounting within 3 feet of the body per NEC 344.30 (for rigid metallic conduit) or 352.30 (for PVC). Don't rely on the cover screws to support conductor weight.

Grounding (NEC 314.4): Metal conduit bodies must be grounded. The conduit system usually provides this ground, but verify continuity, especially with aluminum bodies or if you're using locknuts and bushings that may not provide reliable bonding. Some electricians install a bonding bushing and ground jumper to ensure code compliance and eliminate future troubleshooting.

Both LB and LL bodies from reputable manufacturers like Appleton (O Series and Unilet), Crouse-Hinds (Condulet), and Eaton (Killark) are UL Listed under UL 514B for conduit bodies and fittings. Verify the UL marking on the body itself before installation—unlisted import bodies may look identical but lack proper testing documentation.

Material Selection: Aluminum, Steel, and PVC Considerations

Beyond the LB vs LL decision, you need to select the right material for your environment and application. The choice affects durability, weight, cost, and code compliance for specific locations.

Aluminum Conduit Bodies: The standard choice for outdoor and wet location installations. Aluminum resists corrosion, weighs significantly less than steel (important for larger trade sizes and overhead work), and costs less than stainless steel. Use Type 4X rated aluminum bodies for coastal or chemical exposure areas. Be aware that aluminum cannot be used in concrete encasement per NEC 344.10(C) unless protected by corrosion protection.

Steel Conduit Bodies: Required for hazardous locations (Class I, Division 1 and 2) and preferred in mechanical damage areas. Malleable iron or ductile iron bodies provide maximum durability. Hot-dip galvanized or zinc electroplated finishes offer corrosion resistance, but not to the same level as aluminum in truly wet environments. Steel weighs 2-3 times more than aluminum in equivalent sizes.

PVC Conduit Bodies: Used exclusively with PVC conduit systems, these bodies are chemically resistant and non-conductive. PVC LB bodies are extremely common in outdoor residential installations and agricultural settings. LL bodies in PVC are less commonly stocked. PVC cannot be used in areas requiring physical protection beyond what Schedule 40 or Schedule 80 provides, and must not be exposed to ambient temperatures exceeding 50°C (122°F) unless specifically rated.

For a detailed technical specification on available materials and environmental ratings, request a quote with your specific application details.

Installation Tips and Common Mistakes to Avoid

Whether you choose an LB or LL, proper installation technique prevents callbacks and code violations. Here are field-tested practices:

• Apply proper thread sealant or tape: Use Teflon tape or pipe dope rated for your system. For rigid metal conduit, 3-4 wraps of tape applied clockwise (when looking at the thread end) prevents galling and ensures weather-tight connections. Don't over-tighten—you'll crack aluminum bodies or strip threads.
• Orient for drainage: Even with gasketed covers, condensation can form inside conduit bodies. Install with a slight tilt so any moisture drains toward a lower point or weep hole. Never trap water at the highest point of the body.
• Use gaskets on all covers: The cover gasket is not optional for wet locations. Replace damaged gaskets—they cost pennies compared to a water intrusion callback. For Type 4X ratings, the gasket must be in place and the cover fully tightened.
• Pull wire correctly: Spray pulling lubricant rated for your conductor insulation type (some lubricants damage THHN). Open the conduit body cover before pulling—trying to pull through a closed body with the cover creating friction is a common mistake that damages conductor insulation.
• Don't overfill: Even if the math works on paper, cramming conductors into a conduit body makes future maintenance impossible. Leave working room. If it's tight going in, it'll be worse when someone needs to add a circuit.
• Verify landing orientation before cementing PVC: With PVC systems, dry-fit the entire assembly before applying cement. An LL body glued facing the wrong direction requires cutting out and replacing the entire section.

A common field error is confusing LL bodies with LR (right-facing) bodies. When ordering, double-check the designation. Most distributors accept returns of unused fittings, but not after you've threaded them onto installed conduit.

Frequently Asked Questions

Can I use an LB conduit body as a junction box for splicing wires?

Yes, but only if the LB conduit body is marked with its cubic inch volume capacity. Per NEC 314.16(C)(2), you must calculate the box fill including all conductors, splices, clamps, and devices, and stay within the marked capacity. If the body has no volume marking, it can only be used as a pull point with no splices. Most modern LB bodies from major manufacturers include volume markings stamped into the body.

What's the difference between Type LB and Type LL in weatherproof ratings?

The LB vs LL designation refers only to the geometric configuration and cover direction, not the weatherproof rating. Both LB and LL conduit bodies are available in various NEMA ratings including Type 3R (weather-resistant), Type 4 (watertight), and Type 4X (corrosion-resistant watertight). Check the body's stamped rating and ensure you use the correct gasket and cover tightening for the required environmental protection.

Why are LL conduit bodies harder to find than LB bodies?

LB conduit bodies solve 90-degree transition needs in the vast majority of installations, making them high-volume products that every distributor stocks in all common sizes. LL bodies serve specialized access situations that occur far less frequently, so distributors typically stock only smaller trade sizes (½" to 1"). Larger LL bodies and less common materials may require special ordering with 2-4 week lead times depending on manufacturer production schedules.

Can I rotate an LB conduit body to function as an LL?

No. The internal geometry and hub positions are different between LB and LL bodies. Rotating an LB 90 degrees does not create an LL—it creates an incorrectly oriented LB with the cover facing the wrong direction and the conduit entries in the wrong positions. The hub threads and internal pathways are manufactured specifically for each body type's intended orientation. Always use the correct body type for your application.

Do I need to bond aluminum LB or LL conduit bodies separately?

The conduit system itself typically provides the ground path per NEC 250.118, but you must ensure continuity. Aluminum conduit bodies with properly tightened rigid or IMC connections generally provide adequate bonding. However, in critical applications or where inspectors require verification, installing a bonding bushing with a ground jumper ensures compliant and reliable equipment grounding. Test continuity with a multimeter if there's any question—poor bonding causes dangerous conditions and code violations.

Get a Quote on LB and LL Conduit Bodies

Conversions Tech stocks LB and LL conduit bodies in aluminum, steel, and PVC across trade sizes from ½" through 4" for most configurations. Whether you need a single specialty LL body for a retrofit or a full project supply of weatherproof LB bodies, our team provides technical specifications, cubic inch capacity data, and competitive pricing. Request your quote today with your project details, trade sizes, material requirements, and quantity, and we'll respond with availability and pricing within one business day.

Shop the full range: Browse our Rigid Conduit Bodies — UL-listed, full AWG range, same-day shipping with Net 30/60 for qualified accounts.