According to the report, on page 7[1], it was connected to a WAGO terminal block 280-681 connector. Looking that up on Digikey[2,3] finds that it's a connector suitable for 28 through 12 AWG, up to 800 volts and 24 amps.(UL 20 Amps)

According to "3 - ENGINEERING - DALI - ENGINEERING FACTUAL REPORT"[5], page 20, the circuit was DC, 110 volts, going to a circuit breaker's "under voltage release" terminal. It was 17 AWG, according to page 23.

It apparently goes to a solenoid, and if [6] is in any way typical, it's only 2-6 watts of power in normal operation. This yields a current of 20-50 milliAmps.

Here's a nice animation of the connection failure on that wire.[4]

[1] https://www.ntsb.gov/investigations/Documents/Board%20Summar...

[2] https://www.digikey.com/en/products/detail/wago-corporation/...

[3] https://wago.priintcloud.com/datasheets/280-681/en_GG/d41d8c...

[4] https://www.youtube.com/watch?v=bu7PJoxaMZg

[5] https://data.ntsb.gov/Docket/Document/docBLOB?ID=19228257&Fi...

[6] https://abbsales.com/pdfs/tmax_techspecs.pdf