X0609 4 2026-03-19 0 0000080420 POWELL INDUSTRIES INC POWL 0001219199 POWELL THOMAS W false P.O. BOX 300 GIDDINGS TX 78942 0 0 1 0 0 Common Stock 2026-03-19 4 S 0 49778 502.23 D 598694 D Common Stock 6000 I By KRP 2025 Revocable Trust Common Stock 1623328 I Held in TWP Holdings The reporting person contributed 49,778 shares of POWL common stock to an exchange fund in exchange for shares of the exchange fund. The POWL common stock was valued at $502.23 per share for the purpose of determining the number of shares of the exchange fund issuable to the reporting person. These shares are held directly by the KRP 2025 Revocable Trust, a trust established for the benefit of the reporting person's spouse ("Spousal Trust"). The reporting person's spouse is the sole trustee of the Spousal Trust. The reporting person disclaims beneficial ownership of the securities held by the Spousal Trust, and this report shall not be deemed an admission that the reporting person is the beneficial owner of the securities for purposes of Section 16 or for any other purpose. For purposes of Section 16 of the Securities Exchange Act of 1934, as amended, the reporting person disclaims beneficial ownership of any such securities, except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that such reporting person is the beneficial owner of such securities for purposes of Section 16 or otherwise. /s/ Thomas W. Powell 2026-03-23