An electrical connector is configured to couple an electrical conductor to a support surface. The electrical connector includes a terminal block having a connecting aperture, a threaded aperture, and a channel. At least a portion of the threaded aperture is positioned between the channel and the connecting aperture. The connecting aperture is configured to receive the electrical conductor. The electrical connector includes a fastener having threads receivable within the threaded aperture. The fastener is configured to secure the electrical conductor against movement relative to the terminal block. The electrical connector includes a lock receivable within the channel to inhibit unintentional movement of the fastener relative to the terminal block.