The invention relates to an electrical connector (1) for connecting an electrical device to an electrical conductor (3) for powering the electrical device with DC voltage. The electrical connector comprises a diagnostic information providing unit for providing diagnostic information about a connection between the electrical device and the electrical conductor and an indicator for indicating the determined diagnostic information. An installer can therefore readily see whether the electrical connection is correct or not. Accordingly, the installer can modify the electrical connections such that the indicated determined diagnostic information indicates a correct electrical connection. This reduces the likelihood of a shutdown of the powering of the electrical device with DC voltage, after the installation has been completed.