LB vs LL vs LR vs C Conduit Bodies: Which Form Do You Need?

What the Form Letters Actually Mean

Conduit body form codes describe hub orientation relative to the cover opening. The cover is always your access point for pulling wire, so the letter tells you which direction the run continues after you open it up.

The cover location matters for maintenance access. LB bodies mount with the cover facing outward from the wall. LL and LR bodies orient the cover to the left or right side of the bend. C bodies center the cover on a straight run. T bodies place the cover opposite the branch hub.

Selecting by Run Direction and Access

Start with your conduit route. Mark where you need access for pulling and where the run changes direction.

LB bodies work for vertical-to-horizontal transitions. Conduit enters from below or behind, exits perpendicular through the back hub. Common at building entries, panel knockouts, and riser transitions. The back cover faces the accessible side—typically the room interior rather than inside a wall cavity.

LL and LR bodies handle horizontal plane bends. When you face the cover, the run continues left (LL) or right (LR). These matter in exposed runs along walls or ceilings where you need predictable cover orientation. Specifying the wrong one puts your access panel against a beam or another conduit.

C bodies add pull points without bending. Use them for long straight runs where you need to break up pull tension or provide a junction point. The straight-through design keeps wire routing simple.

T bodies serve as branch points. The two inline hubs continue the main run; the third hub takes off to a load. Cover placement opposite the branch lets you access splices without disturbing the through conductors.

Conduit Bodies as Pull Points: NEC 360-Degree Rule

NEC 314.28 limits bends between pull points to 360 degrees total. This is not per fitting—it is the sum of all bends in the run between access points. Exceed 360 degrees and pull tension rises sharply, risking insulation damage and impossible pulls.

Conduit bodies reset this count. Each body with a removable cover qualifies as a pull point, regardless of whether you splice inside. Install an LB at a 90-degree turn and your bend counter restarts. String three 90-degree bends between boxes and you are at the limit; add a C body mid-run and you gain another 360 degrees of capacity.

This is why estimators spec bodies for routing efficiency, not just junction access. A well-placed LL can eliminate a separate junction box and associated support hardware.

Sizing to Conduit Trade Size

Conduit bodies match rigid conduit trade sizes: 1/2-inch through 6-inch. The hub threads match NPT standards for threaded conduit bodies. Select the body size to match your largest entering conduit—stepping down requires reducing washers or bushings, which complicates sealing and fill calculations.

Pulling calculations matter here. A 90-degree turn in an LB creates more friction than a sweep elbow. Upsizing the body one trade size reduces pull tension and leaves room for future circuits. Standard practice for long commercial runs: match body size to conduit size for 2-inch and below; consider upsizing for 2-1/2-inch and larger or runs exceeding 100 feet.

Splicing Inside: NEC 314.16 and Volume

Not every conduit body accepts splices. NEC 314.16(C) requires adequate volume for conductors, devices, and fittings. Conduit bodies marked with cubic-inch capacity meet this requirement. Unmarked bodies are for pulling and tapping only—no splices permitted.

When splices are allowed, calculate fill per 314.16(B). Each conductor counts once. Equipment grounding conductors count as one volume allowance by size. Devices like grounding bushings do not consume volume unless they contain termination points.

Practical note: splices in LB and T bodies are common for branch circuit takeoffs. Main feeder splices usually move to larger junction boxes or wireways where volume is generous and access does not require disturbing multiple conduit runs.

Wet Location Requirements

Outdoor and wet location installations need gasketed covers. Standard stamped steel covers with screw clamps are dry-location only. Wet-location covers use neoprene or EPDM gaskets compressed by a cast cover with sufficient bolt torque.

Check the gasket condition at installation. Pinch it at four points to verify elasticity. Replace gaskets showing compression set or cracking. Torque cover bolts evenly—over-torque distorts the gasket; under-torque leaves gaps.

For submerged or direct-burial applications, verify the body rating. Standard conduit bodies are not rated for burial without supplementary protection. Use concrete encasement or rated enclosures where the application demands it.

Installation Checklist

• Confirm form letter matches your route geometry before ordering
• Verify cubic-inch marking if splices are planned
• Count total bends between pull points; insert bodies to stay under 360 degrees
• Match hub threads to conduit type—NPT for rigid, different for IMC in some sizes
• Specify gasketed covers for damp, wet, or outdoor locations
• Support bodies per NEC 314.23—within 12 inches of conduit terminations unless marked for closer spacing

Form selection seems trivial until you are staring at a cover facing a concrete column. Mark up your drawings with body locations and orientations. Your future self, pulling wire at hour ten, will appreciate the foresight.