Thomas & Betts ADR21AR ANTI-ROT 1CNDTR 1HL MNT 2/0-14 1/4B

The ADR21AR takes a single conductor from 2/0 AWG down to 14 AWG, so one lug covers a wide span of feeder and branch sizes. It is a one-conductor lug, so each wire needs its own lug. If you need to land several conductors under one connector, a multi-port set-screw lug such as the NSi 220T two-port or the NSi STL250-6 six-port transformer lug is the type to look at instead.

It is a one-hole mount lug with 1/4 inch bolt spacing, so it lands on a single 1/4 inch stud or bolt hole. The anti-rotation design keeps the lug body from spinning on that single fastener as you torque the conductor set screw, which is the usual headache with one-hole terminals. For two-hole NEMA pad spacing you need a different lug entirely.

The ADR21AR body is aluminum with a tin plating. Tin plating is what allows an aluminum connector to be used on copper without direct aluminum to copper contact, but the conductor ratings on a lug are set by its UL listing, and that is the thing to confirm against the marking on the part itself. If you want a lug whose dual CU/AL rating is called out in the catalogue description, the Burndy KA30U Type KA-U aluminum mechanical lug and the NSi 300T are both listed as dual-rated.

The Panduit Pan-Lug LAMA series aluminum mechanical lug is the nearest match in construction: like the ADR21AR it is an aluminum mechanical lug with a tin-plated finish, and the LAMA is a single-barrel design, matching the ADR21AR's single-conductor configuration. The Burndy KA-U series aluminum mechanical lug is the other close analog and is dual-rated for copper or aluminum conductors. Confirm the wire range and stud hole size you need against the specific catalog number in either series before you order.

The ADR21AR is built for one conductor, so for multiple runs on one pad you want a multi-port body. The NSi 220T is a two-port dual-rated aluminum set-screw lug, the NSi 350T-2 is a two-port stacked aluminum alloy lug, and the NSi STL250-6 is a six-port dual-rated aluminum transformer lug for distributing several conductors from one termination. Pick the port count to match the number of conductors landing at that point.

Yes. The ADR21AR carries UL file E9809 as a mechanical connector, which is what an inspector or an institutional spec will usually want cited on a lug termination.

Panduit's Pan-Lug LAMA Series is the comparable item: an aluminum mechanical lug, tin-plated, single-barrel, same basic single-conductor construction as the ADR21AR. On the copper side the Burndy SCRULUG offset tongue copper mechanical lug is a different animal, the offset tongue changes how the pad lines up, so it is not a drop-in for a straight one-hole terminal.

They are not interchangeable. The ADR21AR is an aluminum mechanical lug with a tin-plated finish sized for larger conductors and a 1/4 inch mounting hole. The Burndy CL501 is a Qiklug copper lay-in lug rated for #14 to #4 AWG on a #10 stud, so it is a smaller-conductor, copper-bodied lay-in device on a different stud size. Use the CL501 only where the drawing calls for a small copper lay-in ground lug.

The ADR21AR body is aluminum. Where a copper lug is specified, the Burndy SCRULUG offset tongue copper mechanical lug is the comparable copper-bodied mechanical lug, and its offset tongue lets the pad sit out of plane with the barrel. For smaller copper terminations the Burndy CL501 Qiklug is a copper lay-in lug covering #14 to #4 AWG on a #10 stud.

The ADR21AR is an aluminum-bodied, tin-plated single-conductor mechanical lug. If one part number has to serve both copper and aluminum feeders, the Burndy KA-U series aluminum mechanical lug is dual-rated CU/AL, and the NSi 300T series is a dual-rated aluminum set-screw lug. Both let you stock a single lug across mixed conductor metals; match wire range and mounting hole to the equipment pad.

The ADR21AR terminates a single conductor, so a transformer secondary feeding several taps would need one lug per run. The NSi STL250-6 is a six-port aluminum dual-rated transformer lug designed for that application in one body, and the NSi 220T two-port dual-rated set-screw lug covers lighter tap counts.

It ships as a single lug, sold each, under manufacturer part number ADR21AR. Order one per conductor you are terminating.

Yes. The ADR21AR is a one-hole mount lug with 1/4 inch hole spacing. The Burndy SCRULUG is an offset tongue design, which changes where the tongue sits relative to the barrel and can help clear a crowded gutter. The NSi 350T-2 is a stacked two-port body, so the conductors enter at two levels rather than side by side. Verify pad hole pattern and clearance before substituting.

Thomas & Betts publishes a PDF spec sheet for the ADR21AR, hosted at media.distributordatasolutions.com. That is the document to attach when a job needs submittal data on the lug.