Comments on: ABYC Ampacity Tables

By: Nigel Calder

Nigel Calder — Thu, 30 Apr 2026 11:43:45 +0000

In reply to Brian Sweeney. Thanks!

By: Brian Sweeney

Brian Sweeney — Wed, 22 Apr 2026 19:02:31 +0000

After viewing several times the clarity of this presentation, Excellent!

By: Nigel Calder

Nigel Calder — Sun, 24 Nov 2024 15:03:38 +0000

In reply to fred tarlic.

Fred,

Yes, conductors running in a loom constitutes a bundle. I don’t think the ABYC has a definition, but essentially it is current-carrying conductors that are run in parallel and held next to each other in some way. The core issue that is being addressed is the potential for heat generated in one conductor, which is running at or close to its rated ampacity, to be transmitted to a neighboring conductor, lowering its ampacity. If we bear this in mind we can look at a specific situation from the perspective of the likelihood of heat transfer, and if it is likely then apply the bundling de-rating.

Nigel

By: fred tarlic

fred tarlic — Wed, 20 Nov 2024 16:38:00 +0000

How do you define a bundle? If I have circuits running in loom is that a bundle?

By: Jan C. Athenstädt

Jan C. Athenstädt — Sun, 18 Jul 2021 07:22:22 +0000

In reply to Robert. Thanks a lot for the comment, there was indeed an error in the title of the table. It's fixed now!

By: Robert

Robert — Sat, 17 Jul 2021 20:08:12 +0000

I believe that the table is mislabeled on page 5