Thomas & Betts 3880 5 INCH INSL GRND BUSH W/ 14-4 RANGE

The lug takes a 14 through 4 AWG grounding conductor, so it covers typical bonding jumper sizes in that range. If your equipment grounding conductor for a 5 inch feeder is larger than 4 AWG, this lug will not accept it and you need a bushing with a bigger range or a separate ground lug on the enclosure.

The Thomas & Betts 3880 insulated grounding bushing has a malleable iron body. If you want a different material, the American Fittings GB insulated grounding bushing is zinc-plated alloy steel with an aluminum lug, and the ABB A-Series TGC2 equipment grounding bushing is copper and is a box-bonded conduit fitting. All three serve the same role of terminating conduit while providing a lug for the equipment grounding conductor, so the choice comes down to the body and lug metal your spec or your conductor pairing calls for.

A standard insulated grounding bushing like the Thomas & Betts 3880 threads onto the conduit end, so the raceway has to be accessible. Where the conduit is already made up and cannot be broken, the Bridgeport Fittings SGBS-388CL Mighty-Rite is an insulated split grounding bushing in 3 inch, steel with an aluminum lug - the split body lets it go on without pulling the run apart. Match the trade size to your conduit, since the SGBS-388CL is the 3 inch member of that family.

The body is malleable iron with an insulated throat, so you get a metal fitting that still protects conductor insulation as wire passes through. Competing bushings are often built differently: the American Fittings GB is zinc-plated alloy steel with an aluminum lug, and the ABB A-Series TGC2 is copper.

An insulated grounding bushing like the 3880 does two jobs a locknut cannot: it gives a smooth insulated throat so the conductors are not chafed on the conduit end, and it provides a lug to bond the raceway back to the enclosure ground. On a large 5 inch feeder entry where conductors are stiff and heavy, that insulated throat is the reason this fitting exists.

No. The 3880 is a one-piece threaded bushing, so it has to be screwed onto an accessible conduit end. If the conduit is already made up and you cannot get a solid bushing on it, use a split-design bushing instead, such as the Bridgeport Mighty-Rite SGBS-388CL, which is built as a split grounding bushing.

The American Fittings GB insulated grounding bushing is identified as spec-grade, so it is the straightforward answer when a submittal uses that language. The Thomas & Betts 3880 is a malleable iron insulated grounding bushing in 5 inch with a 14-4 AWG lug range, which is the one to carry when the drawing is driven by trade size and conductor range rather than a grade callout.

The ABB A-Series TGC2 is a copper equipment grounding bushing described as a box-bonded conduit fitting, meaning it is built to bond the fitting to the enclosure it lands in. The Thomas & Betts 3880 is a malleable iron insulated grounding bushing, 5 inch, with a 14-4 AWG lug range, intended to protect the conductors at the conduit throat and give you a lug for the grounding conductor. Confirm which bonding method your inspector expects at the enclosure before you choose.

Order Thomas & Betts 3880. That single model covers the 5 inch size with the 14-4 AWG lug range, so there are no handing, finish, or trim options to specify.